- A Heterobimetallic AuIII-PtII Photocatalyst for Water Reduction to Hydrogen
-
A supramolecular complex, [Au(C^N^C)(C≡CC6H4C≡C)Pt(terpy)]+, has been synthesized as a photocatalyst for water reduction. This compound consists of a cyclometalated alkyne-gold(III) photosensitizer and a platinum(II) terpyridine complex bridged through a central phenylethynyl group.
- Su, Yi-Bing,Yuan, Yong-Jun,Liu, Xiao-Le,Chen, Guang-Hui,Chen, Xin,Yu, Zhen-Tao,Zou, Zhi-Gang
-
-
Read Online
- Synthesis of alkynes under dry reaction conditions
-
An easy synthetic method was developed under dry reaction conditions for the preparation of terminal alkynes from 1,1-dibromoalkenes and in the presence of succinimide which acts as a nucleophile and proton donor. It was demonstrated with the synthesis of a broad spectrum of terminal alkynes and extended to synthesize internal alkynes under tandem reaction conditions.
- Rao, Maddali L.N.,Shamim Islam, Sk
-
supporting information
(2021/04/19)
-
- 2D arrays of organic qubit candidates embedded into a pillared-paddlewheel metal-organic framework
-
The creation of ordered arrays of qubits that can be interfaced from the macroscopic world is an essential challenge for the development of quantum information science (QIS) currently being explored by chemists and physicists. Recently, porous metal?organic frameworks (MOFs) have arisen as a promising solution to this challenge as they allow for atomic-level spatial control of the molecular subunits that comprise their structures. To date, no organic qubit candidates have been installed in MOFs despite their structural variability and promise for creating systems with adjustable properties. With this in mind, we report the development of a pillared-paddlewheel-type MOF structure that contains 4,7-bis(2-(4-pyridyl)-ethynyl) isoindoline N-oxide and 1,4-bis(2-(4-pyridyl)-ethynyl)-benzene pillars that connect 2D sheets of 9,10-dicarboxytriptycene struts and Zn2(CO2)4 secondary binding units. The design allows for the formation of ordered arrays of reorienting isoindoline nitroxide spin centers with variable concentrations through the use of mixed crystals containing the secondary 1,4-phenylene pillar. While solvent removal causes decomposition of the MOF, magnetometry measurements of the MOF containing only N-oxide pillars demonstrated magnetic interactions with changes in magnetic moment as a function of temperature between 150 and 5 K. Variable-temperature electron paramagnetic resonance (EPR) experiments show that the nitroxides couple to one another at distances as long as 2 nm, but act independently at distances of 10 nm or more. We also use a specially designed resonance microwave cavity to measure the face-dependent EPR spectra of the crystal, demonstrating that it has anisotropic interactions with impingent electromagnetic radiation.
- Forbes, Malcolm D. E.,Garcia-Garibay, Miguel A.,Jellen, Marcus J.,Ayodele, Mayokun J.,Cantu, Annabelle
-
supporting information
p. 18513 - 18521
(2020/11/27)
-
- A Triazine-Based Analogue of Graphyne: Scalable Synthesis and Applications in Photocatalytic Dye Degradation and Bacterial Inactivation
-
Graphyne, a theorized carbon allotrope possessing only sp- and sp2-hybridized carbon atoms, holds great potentials in many fields, especially in catalysis and energy-transfer/storage devices. Using a bottom-up strategy, we synthesized a new N-doped graphyne analogue, triazine- and 1,4-diethynylbenzene-based graphyne TA-BGY, in solution in gram-scale. The unique sp/sp2 carbon-conjugated TA-BGY possesses an extended porous network structure with a BET surface area of approximately 300 m2 g?1. Owing to its low optical band gap (1.44 eV), TA-BGY was expected to have many applications, which were exemplified by the photodegradation of methyl orange and photocatalytic bacterial inactivation.
- Chen, Tao,Li, Wen-Qian,Chen, Xiao-Jia,Guo, Yun-Zhe,Hu, Wei-Bo,Hu, Wen-Jing,Liu, Yahu A.,Yang, Hui,Wen, Ke
-
supporting information
p. 2269 - 2275
(2020/02/11)
-
- Study on synthesis, characterization, and nonvolatile memory behavior of ferrocene-containing metallopolymers
-
In this work, two metallopolymers (P1 and P2)were designed and synthesized through coupling of ferrocene-anchored fluorene derivatives with porphyrin and benzene based diethynyl ligand, respectively. The chemical structure and physical properties of these two metallpolymers were fully characterized, which indicate that these two metallopolymers are thermally stable and semiconducting. Then, sandwich-like organic resistive memory based on P1 and P2 for data storage were explored. The memory device testing results manifest that both P1 and P2 are of the stable electric bistability and show write once read many times memory (WORM)characteristics.
- Cheng, Xiaozhe,Md, Asaduzzaman,Lian, Hong,Zhong, Zheng,Guo, Hongen,Dong, Qingchen,Roy
-
-
- Regioselective Gold-Catalyzed Hydration of CF3- and SF5-alkynes
-
The regioselective gold-catalyzed hydration of CF3- and SF5-alkynes is described. The corresponding trifluoromethylated and pentasulfanylated ketones are obtained in up to 91% yield as single regioisomers showcasing the use of CF3 and SF5 as highly efficient directing groups in this reaction. Notably, this transformation represents the first use of CF3- and SF5-alkynes in gold catalysis.
- Cloutier, Mélissa,Roudias, Majdouline,Paquin, Jean-Fran?ois
-
supporting information
p. 3866 - 3870
(2019/05/24)
-
- Synthesis and characterization of propeller-shaped mono- to hexacationic quinolinium-substituted benzenes
-
Diels-Alder reaction of 2-, 3- and 4-(phenylethynyl)quinolines and tetraphenylcyclopentadienone gave three regioisomeric 2,3,4,5,6-pentaphenyl-1-(quinolin-2-yl, -3-yl, and -4-yl)benzenes. Restricted rotation of the 3-yl and 4-yl substituted derivatives is observed between the central core and the substituents, resulting in propeller-shaped molecules. Likewise, 1,2-diquinolinyl-3,4,5,6-tetraphenylbenzenes with 3-yl,3-yl and 3-yl,4-yl connectivity were prepared. As evidenced by NMR spectroscopy, they form two diasteromers due to their restricted rotation. A cobalt-catalyzed [2 + 2 + 2]-cyclotrimerization of 2-(phenylethynyl)quinoline resulted in the formation of triphenyl-2,4,6- and -3,5,6-tri(quinolin-2-yl)benzenes. The same reaction was applied to 3,3′-ethyne-1,2-diyldiquinoline which formed hexa(quinolin-3-yl)benzene. N-Methylation gave the title compounds. Among those, the hexacationic hexa(N-methylquinolinio-3-yl)benzene is described. Stereochemical aspects are predominantly discussed by means of results of NMR experiments. DFT-calculations on the most stable conformations and the frontier orbital profiles of the hexacation as well as of its neutral precursor have been carried out.
- Batsyts, Sviatoslav,Hübner, Eike G.,Namyslo, Jan C.,Gjikaj, Mimoza,Schmidt, Andreas
-
p. 4102 - 4114
(2019/04/30)
-
- The Interconnection of Two Positive Charges by Conjugation and Cross-Conjugation in Bis-Quinolinium Ethynyls
-
1,4-Diethynylbenzene was used as conjugated all-carbon and rigid spacer between the 2-, 3- and 4-positions of two 1-methylquinolinium rings. Thus, for a systematic study, a series of dicationic salts with 2,2-, 3,3-, 4,4-, 3,2-, and 3,4-interconnections of the two positive charges was prepared, in which all even-numbered substitution patterns are conjugated, and all odd-numbered substitution patterns are cross-conjugated. As a consequence, conjugated/conjugated, cross-conjugated/cross-conjugated, and conjugated/cross-conjugated dications have been prepared. The different combinations result in considerably different charge distributions of the positive charges within the π-electron systems according to the rules of resonance which translate into different DFT-calculated frontier orbital profiles and spectroscopic properties such as 13C NMR chemical shifts, IR and Raman absorptions, and the measured as well as calculated UV/Vis spectra.
- Batsyts, Sviatoslav,Hübner, Eike G.,Namyslo, Jan C.,Schmidt, Andreas
-
p. 6168 - 6176
(2019/08/07)
-
- Mixed-Valent Molecular Triple Deckers
-
Two phenothiazine (PTZ) moieties were connected via naphthalene spacers to a central arene to result in stacked PTZ-arene-PTZ structure elements. Benzene and tetramethoxybenzene units served as central arenes mediating electronic communication between the two PTZ units. Based on cyclic voltammetry, UV/Vis-NIR absorption, EPR spectroscopy, and computational studies, the one-electron oxidized forms of the resulting compounds behave as class II organic mixed-valence species in which the unpaired electron is partially delocalized over both PTZ units. The barrier for intramolecular electron transfer depends on the nature of the central arene sandwiched between the two PTZ moieties. These are the first examples of rigid organic mixed-valent triple-decker compounds with possible electron-transfer pathways directly across a stacked structure, and they illustrate the potential of oligo-naphthalene building blocks for long-range electron transfer and a future molecular electronics technology.
- Schmidt, Hauke C.,Guo, Xingwei,Richard, Pascal U.,Neuburger, Markus,Palivan, Cornelia G.,Wenger, Oliver S.
-
supporting information
p. 11688 - 11691
(2018/09/10)
-
- An Additive-Free, Base-Catalyzed Protodesilylation of Organosilanes
-
We report an additive-free, base-catalyzed C-, N-, O-, and S-Si bond cleavage of various organosilanes in mild conditions. The novel catalyst system exhibits high efficiency and good functional group compatibility, providing the corresponding products in good to excellent yields with low catalyst loadings. Overall, this transition-metal-free process may offer a convenient and general alternative to current employing excess bases, strong acids, or metal-catalyzed systems for the protodesilylation of organosilanes.
- Yao, Wubing,Li, Rongrong,Jiang, Huajiang,Han, Deman
-
p. 2250 - 2255
(2018/02/23)
-
- SO2F2-Mediated Oxidative Dehydrogenation and Dehydration of Alcohols to Alkynes
-
Direct synthesis of alkynes from inexpensive, abundant alcohols was achieved in high yields (greater than 40 examples, up to 95% yield) through a SO2F2-promoted dehydration and dehydrogenation process. This straightforward transformation of sp3-sp3 (C-C) bonds to sp-sp (C=C) bonds requires only inexpensive and readily available reagents (no transition metals) under mild conditions. The crude alkynes are sufficiently free of impurities to permit direct use in further transformations, as illustrated by regioselective Huisgen alkyne-azide cycloaddition reactions with PhN3 to give 1,4-substituted 1,2,3-traiazoles (16 examples, up to 92% yield) and Sonogashira couplings (10 examples, up to 77% yield).
- Zha, Gao-Feng,Fang, Wan-Yin,Li, You-Gui,Leng, Jing,Chen, Xing,Qin, Hua-Li
-
supporting information
p. 17666 - 17673
(2019/01/04)
-
- A practical non-metal catalytic silicon of the amino protection of the new method (by machine translation)
-
The invention relates to a high efficiency, mild organic silicon reagent carbon silicon key fracture of the new method. The method of this reaction to the alkali is cheap and easy to obtain metal catalyst, in order to common commercial solvent as a reaction solvent and a hydrogen source, in the air and in the under mild conditions can be successfully catalytic trimethyl aryl silicon reagent or aryl alkyne base silicon reagent selectively generating carbon silicon key cracking hydrogenation reaction, the substrate universality is wide, functional group compatibility outstanding. The first innovative to realize the non-transition metal catalyzed carbon silicon key breaking reaction, also overcome the traditional method requires the use of greatly excessive inorganic alkali or an expensive metal catalyst to the limitation of the silicon of the amino protection, for the laboratory preparation and industry in the production of the organosilicon group deprotection provides a completely new strategy. (by machine translation)
- -
-
Paragraph 0082; 0083
(2018/04/01)
-
- Self-assembling molecular capsules based on α,γ-cyclic peptides
-
A new capsule based on a β-sheet self-assembling cyclic peptide with the ability to recognize and release several guests is described. The host structure is composed of two self-complementary α,γ-cyclic peptides bearing a Zn porphyrin cap that is used for the selective recognition of the guest. The two components are linked through two dynamic covalent bonds. The combination of binding forces, including hydrogen bonding, metal coordination, and dynamic hydrazone bonds, allows the reversible recognition of long bipyridine guests. The affinity for these ligands showed a strong dependence on the guest length. Delivery of the encapsulated ligand can be achieved by hydrolysis of hydrazones to disrupt the sandwich complex structure.
- Ozores, Haxel Lionel,Amorín, Manuel,Granja, Juan R.
-
supporting information
p. 776 - 784
(2017/05/17)
-
- Arene-Inserted Extended Germa[n]pericyclynes: Synthesis, Structure, and Phosphorescence Properties
-
This report describes the synthesis and characterization of arene-inserted extended (ArEx) germa[n]pericyclynes composed of germanium and 1,4-diethynylbenzene units. These novel cyclic germanium-π unit materials were synthesized with diethynylbenzene and germanium dichloride. X-ray crystallographic analysis revealed their structures, and the planar conformation of ArEx germa[4]pericyclyne along with the regular aromatic rings. UV/Vis absorption spectra and fluorescence emission spectra showed considerably unique and highly improved character compared to previously reported germa[n]pericyclynes. Even in the absence of transition metal components, phosphorescence emissions were observed, and the emission lifetimes were dramatically improved. ArEx germa[n]pericyclynes showed high photoluminescence quantum yields, whereas low photoluminescence quantum yields were observed for acyclic compounds. Density functional theory calculations show delocalized orbitals between skipped alkyne units through a germanium tether, and an increase in the HOMO energy level, leading to a small HOMO–LUMO energy gap.
- Tanimoto, Hiroki,Mori, Junta,Ito, Shunichiro,Nishiyama, Yasuhiro,Morimoto, Tsumoru,Tanaka, Kazuo,Chujo, Yoshiki,Kakiuchi, Kiyomi
-
p. 10080 - 10086
(2017/08/01)
-
- Products of the Propargyl Self-Reaction at High Temperatures Investigated by IR/UV Ion Dip Spectroscopy
-
The propargyl radical is considered to be of key importance in the formation of the first aromatic ring in combustion processes. Here we study the bimolecular (self-) reactions of propargyl in a high-temperature pyrolysis flow reactor. The aromatic reaction products are identified by IR/UV ion dip spectroscopy, using the free electron laser FELIX as mid-infrared source. This technique combines mass selectivity with structural sensitivity. We identified several aromatic reaction products based on their infrared spectra, among them benzene, naphthalene, phenanthrene, indene, biphenyl, and surprisingly a number of aromatic compounds with acetylenic (ethynyl) side chains. The observation of benzene confirms that propargyl is involved in the formation of the first aromatic ring. The observation of compounds with acetylenic side chains shows that, in addition to a propargyl- and phenyl-based mechanism, the HACA (hydrogen abstraction C2H2 addition) mechanism of polycyclic aromatic hydrocarbons formation is present, although no acetylene was used as a reactant. On the basis of the experimental results we suggest a mechanism that connects the two pathways.
- Constantinidis,Hirsch,Fischer,Dey,Rijs
-
p. 181 - 191
(2017/06/07)
-
- Functional organic click-materials: application in phosphorescent organic light emitting diodes
-
In the presented work click chemistry is utilized to introduce 1,2,3-triazoles as a functional linker in organic donor-acceptor materials. A systematic series of materials was prepared and characterized to investigate the effect of the linkage mode on the molecular properties. The 1,2,3-triazole linker allowed control of the degree of intramolecular charge transfer over a wide range depending on the substitution pattern of the triazole moiety. The prepared materials were successfully employed as host materials for green and red dopants in phosphorescent organic light emitting diodes. Thus, this work presents the first application of this novel linkage mode in the design and synthesis of functional π-conjugated organic donor-acceptor materials and their application in organic light emitting diodes.
- Kautny, Paul,Zhao, Chenyang,Kader, Thomas,St?ger, Berthold,Horkel, Ernst,Chen, Jiangshan,Ma, Dongge,Fr?hlich, Johannes,Lumpi, Daniel
-
p. 12150 - 12160
(2017/03/08)
-
- Direct Enzymatic Branch-End Extension of Glycocluster-Presented Glycans: An Effective Strategy for Programming Glycan Bioactivity
-
The sequence of a glycan and its topology of presentation team up to determine the specificity and selectivity of recognition by saccharide receptors (lectins). Structure–activity analysis would be furthered if the glycan part of a glycocluster could be efficiently elaborated in situ while keeping all other parameters constant. By using a bacterial α2,6-sialyltransferase and a small library of bi- to tetravalent glycoclusters, we illustrate the complete conversion of scaffold-presented lactoside units into two different sialylated ligands based on N-acetyl/glycolyl-neuraminic acid incorporation. We assess the ensuing effect on their bioactivity for a plant toxin, and present an analysis of the noncovalent substrate binding contacts that the added sialic acid moiety makes to the lectin. Enzymatic diversification of a scaffold-presented glycan can thus be brought to completion in situ, offering a versatile perspective for rational glycocluster engineering.
- Bayón, Carlos,He, Ning,Deir-Kaspar, Mario,Blasco, Pilar,André, Sabine,Gabius, Hans-Joachim,Rumbero, ángel,Jiménez-Barbero, Jesús,Fessner, Wolf-Dieter,Hernáiz, María J.
-
supporting information
p. 1623 - 1633
(2017/02/10)
-
- C-Au Covalently Bonded Molecular Junctions Using Nonprotected Alkynyl Anchoring Groups
-
We report on an approach to realize carbon-gold (C-Au) bonded molecular junctions without the need for an additive to deprotect the alkynyl carbon as endstanding anchor group. Using the mechanically controlled break junction (MCBJ) technique, we determine the most probable conductance value of a family of alkynyl terminated oligophenylenes (OPA(n)) connected to gold electrodes through such an akynyl moiety in ambient conditions. The molecules bind to the gold leads through an sp-hybridized carbon atom at each side. Comparing our results with other families of molecules that present organometallic C-Au bonds, we conclude that the conductance of molecules contacted via an sp-hybridized carbon atom is lower than the ones using sp3 hybridization due to strong differences in the coupling of the conducting orbitals with the gold leads.
- Olavarria-Contreras, Ignacio José,Perrin, Mickael L.,Chen, Zhi,Klyatskaya, Svetlana,Ruben, Mario,Van Der Zant, Herre S. J.
-
supporting information
p. 8465 - 8469
(2016/07/26)
-
- Palladium catalyzed reactions executed on solid-phase peptide synthesis supports for the production of self-assembling peptides embedded with complex organic electronic subunits
-
Methods to synthesize self-assembling peptides embedded with complex organic electronic subunits are provided.
- -
-
-
- Pyrazine-based donor tectons: Synthesis, self-assembly and characterization
-
Two new supramolecular building blocks derived from pyrazine are introduced. These molecules, having pendant pyridine units covalently linked to central pyrazine ring, are structurally rigid with pre-defined bite angles. Therefore they can act as donor tectons in design of supramolecular hexagons using coordination driven self-assembly protocol. Multinuclear NMR (including 1H DOSY) and mass spectrometry have been utilized to confirm the purity and stoichiometry of these self assembled hexagonal ensembles. PM6 molecular modeling studies corroborate their hexagonal shape and nanoscalar dimensions.
- Bhowmick, Sourav,Chakraborty, Sourav,Marri, Subba R.,Behera,Das, Neeladri
-
p. 8992 - 9001
(2016/02/05)
-
- Rapid access to unsymmetrical tolanes and alkynones by sequentially palladium-catalyzed one-pot processes
-
Alkynones as well as unsymmetrically substituted tolanes (diarylalkynes) can be rapidly generated in a one-pot fashion via sequential palladium catalysis. Terminal alkynes, formed in situ by protecting-group free palladium-catalyzed coupling of aryl iodides with ethynyl magnesium bromide, are subsequently transformed by Sonogashira coupling with aryl halides or aroyl chlorides to furnish unsymmetrically substituted alkynes in good to excellent yields.
- G?tzinger, Alissa C.,Müller, Thomas. J. J.
-
supporting information
p. 3498 - 3500
(2016/04/19)
-
- Electrochemically active porous organic polymers based on corannulene
-
For the first time, porous organic polymers (POPs) based on the smallest buckybowl, corannulene (BB-POPs) have been synthesized. Three POPs were synthesised via Sonogashira co-polymerization of 1,2,5,6-tetrabromocorannulene and alkyne linkers. BB-POP-3 exhibits the highest surface area (SABET = 560 m2 g-1) and CO2 adsorption of 11.7 wt%, while they retain the redox properties of corannulene.
- Karunathilake, Arosha A.K.,Thompson, Christina M.,Perananthan, Sahila,Ferraris, John P.,Smaldone, Ronald A.
-
p. 12881 - 12884
(2016/11/06)
-
- Structurally-Defined, Sulfo-Phenylated, Oligophenylenes and Polyphenylenes
-
We report the synthesis and molecular characterization of structurally defined, sulfo-phenylated, oligo- and polyphenylenes that incorporate a novel tetra-sulfonic acid bistetracyclone monomer. The utility of this monomer in the [4 + 2] Diels-Alder cycloaddition to produce well-defined, sulfonated oligophenylenes and pre-functionalized polyphenylene homopolymers is demonstrated. Characterization of the oligophenylenes indicates formation of the meta-meta and para-para adducts in a ~ 1:1 ratio. These functionalized monomers and their subsequent coupling provide a route to prepare novel, sterically encumbered, sulfonated polyphenylenes possessing unprecedented structural control.
- Skalski, Thomas J. G.,Britton, Benjamin,Peckham, Timothy J.,Holdcroft, Steven
-
supporting information
p. 12223 - 12226
(2015/10/12)
-
- Arrays of Molecular Rotors with Triptycene Stoppers: Surface Inclusion in Hexagonal Tris(o -phenylenedioxy)cyclotriphosphazene
-
A new generation of rod-shaped dipolar molecular rotors designed for controlled insertion into channel arrays in the surface of hexagonal tris(o-phenylenedioxy)cyclotriphosphazene (TPP) has been designed and synthesized. Triptycene is used as a stopper intended to prevent complete insertion, forcing the formation of a surface inclusion. Two widely separated 13C NMR markers are present in the shaft for monitoring the degree of insertion. The structure of the two-dimensional rotor arrays contained in these surface inclusions was examined by solid-state NMR and X-ray powder diffraction. The NMR markers and the triptycene stopper functioned as designed, but half of the guest molecules were not inserted as deeply into the TPP channels as the other half. As a result, the dipolar rotators were distributed equally in two planes parallel to the crystal surface instead of being located in a single plane as would be required for ferroelectricity. Dielectric spectroscopy revealed rotational barriers of ~4 kcal/mol but no ferroelectric behavior.
- Kaleta, Ji?í,Dron, Paul I.,Zhao, Ke,Shen, Yongqiang,Císa?ová, Ivana,Rogers, Charles T.,Michl, Josef
-
p. 6173 - 6192
(2015/06/30)
-
- Polytriazole bridged with 2,5-diphenyl-1,3,4-oxadiazole moieties: A highly sensitive and selective fluorescence chemosensor for Ag+
-
Fluorescent conjugated polytriazoles (FCP 1-4) containing both 2,5-diphenyl-1,3,5-oxadiazole (OXD) and 1,2,3-triazole moieties in the main chain were synthesized from aromatic diazide (1) and dialkynes (2-5) via click polymerization, respectively. In the polymers, OXDs (fluorophores) and triazole rings (generated via CuAAC acting as metal ion ligands) comprise a fluorescent system. The polytriazoles displayed relatively strong emission with quantum yields in the range of 0.20-0.28 at room temperature in DMF. The study on their ion-responsive properties showed that, although all four FCPs have good selectivity for Ag+, the integration of alkoxy side groups (methoxy for FCP 2, hexyloxy for FCP 3 and 2-ethylhexyloxy for FCP 4) to the main chains of the polytriazoles decreased their sensitivity for Ag+via alteration of the polymer aggregation status and electron density of the main chains. Thus FCP 1 is highly sensitive for Ag+, where its Ksv is as high as 1.44 × 105 M-1 and its lowest detection limit is in the ppb range (4.22 × 10-7 M). This study provides an efficient click approach to the synthesis of a novel fluorescence sensor for Ag+ detection, which could expand the application of click polymerization in designing fluorescence sensors based on the triazole unit. This journal is
- Cao, Shoupeng,Pei, Zhichao,Xu, Yongqian,Zhang, Ruina,Pei, Yuxin
-
p. 45888 - 45896
(2015/06/08)
-
- Tetramethoxybenzene is a good building block for molecular wires: Insights from photoinduced electron transfer
-
Two donor bridge-acceptor molecules with terminal triarylamine and Ru(bpy)32+ (bpy = 2,2′-bipyridine) redox partners were synthesized and investigated by cyclic voltammetry, optical absorption, luminescence, and transient absorption spectroscopy. The two dyads differ only by the central bridging unit, which was tetramethoxybenzene (tmb) in one case and unsubstituted phenylene (ph) in the other case. Photoirradiation of the Ru(bpy)32+ complex of the two dyads triggers intramolecular electron transfer from the triarylamine to the 3MLCT-excited metal complex, and this process occurs with time constants of 1.5 and 6.8 ns for the tmb- and ph-bridged dyads, respectively. Thermal electron transfer in the reverse direction then leads to disappearance of the photoproduct with a time constant of 10 ns in both dyads. The faster rate of photoinduced charge transfer in the tmb-bridged dyad can be understood in the framework of a hole-tunneling model in which the electron-rich tmb bridge imposes a more shallow barrier than the less electron-rich ph spacer. Until now tmb-based molecular wires have received very little attention, and alkoxy substituents have been mostly used for improving the solubility of oligo-p-phenylene vinylene (OPV) and oligo-p-phenylene ethynylene (OPE) wires. Our study illustrates how four alkoxy-substituents on a phenylene backbone can have a significant influence on the charge-transfer properties of a molecular wire, and this is relevant in the greater context of a future molecular electronics technology.
- Heinz, Luisa G.,Yushchenko, Oleksandr,Neuburger, Markus,Vauthey, Eric,Wenger, Oliver S.
-
p. 5676 - 5684
(2015/06/16)
-
- Tandem Claisen Rearrangement/6-endo Cyclization Approach to Allylated and Prenylated Chromones
-
Allyl, dimethylallyl and prenyl ethers derived from o-acylphenols reacted upon microwave irradiation to form C-allylated or -prenylated chromone derivatives, depending on the substitution pattern of the arene and the allyl substituent. The reaction proceeds through a tandem Claisen rearrangement and 6-endo-trig or 6-endo-dig cyclization sequence. For prenyl ethers, the tandem sequence can be extended by a Cope rearrangement to furnish 6-prenylchromones. The method is potentially useful for the synthesis of natural products and drugs.
- Schmidt, Bernd,Riemer, Martin,Schilde, Uwe
-
supporting information
p. 7602 - 7611
(2016/01/25)
-
- Falling-solid flash vacuum pyrolysis: An efficient preparation of arylacetylenes
-
Automated falling-solid flash vacuum pyrolysis allows the rapid and efficient synthesis of a variety of arylacetylenes from 4-arylmethylidene-5(4H)-isoxazolone derivatives, which were prepared from aldehyde precursors. The acetylenes are readily obtained in multigram quantities. Taking the heat: Unlike in flash vacuum pyrolysis, involatile compounds can be used in falling-solid flash vacuum pyrolysis (FS-FVP). This method is employed for the rapid and efficient synthesis of a variety of arylacetylenes from 4-arylmethylidene-5(4H)-isoxazolones, which were in turn prepared from aldehyde precursors.
- Wentrup, Curt,Becker, Jürgen,Winter, Hans-Wilhelm
-
supporting information
p. 5702 - 5704
(2015/09/21)
-
- Palladium Catalyzed Reactions Executed on Solid-Phase Peptide Synthesis Supports for the Production of Self-Assembling Peptides Embedded with Complex Organic Electronic Subunits
-
Methods to synthesize self-assembling peptides embedded with complex organic electronic subunits are provided.
- -
-
Page/Page column
(2014/05/07)
-
- Self-assembled supramolecular clusters based on phosphines and coinage metals: Tetrahedra, helicates, and mesocates
-
An array of coordination-driven supramolecular metal-ligand clusters has been synthesized using polytopic phosphine ligands and coinage metals (Cu +, Ag+, Au+). Rigid 3-fold or 2-fold symmetric phosphine ligands have been prepared: 1,3,5-tris((4-(diphenylphosphino)ethynyl) phenyl)benzene) (tppepb, L1), 1,4-bis((diphenylphosphino)ethynyl) benzene (1,4-dppeb, L2), 1,3-bis((diphenylphosphino)ethynyl)benzene (1,3-dppeb, L3), 2,6-bis((diphenylphosphino)ethynyl)pyridine (2,6-dppep, L4), and 1,5-bis((diphenylphosphino)ethynyl)naphthalene (1,5-dppen, L5). Self-assembly of these ligands with coinage metals produces four different types of metal-ligand clusters, or in some cases coordination polymers, depending on number and relative geometry of the phosphine donor atoms. Supramolecular tetrahedral clusters of the formula M 4(L1)4I4 (M = Cu+, Ag+, Au+) were obtained with the tppepb ligand, encapsulating solvent molecules (either CH2Cl2 or DMF) as guests within the central cavity of the clusters. The ligands 1,3-dppeb (L 3) and 2,6-dppep (L4) give achiral, triple-stranded, dinuclear mesocates with the formula M2(L)3I2 (M = Cu+ or Au+). In contrast, the ligand 1,4-dppeb (L2) generates a triple-stranded, dinuclear helicate with Cu +, but a coordination polymer with Au+ (both with the empirical formula M2(L2)3I2). Finally, coordination polymers were obtained from 1,5-dppen (L5) with Cu+. The clusters have been fully characterized by single crystal X-ray crystallography, high-resolution mass spectrometry, 1H NMR, and 31P NMR.
- Lim, Sang Ho,Cohen, Seth M.
-
supporting information
p. 7862 - 7872
(2013/08/23)
-
- Encapsulation-induced remarkable stability of a hydrogen-bonded heterocapsule
-
Remarkably enhanced stability of the self-assembled hydrogen-bonded heterocapsule 1×2 by the encapsulation of 1,4-bis(1-propynyl)benzene 3 a was found with Ka=1.14×109 M-1 in CDCl3 and Ka2=1.59×108 M-2 in CD3OD/CDCl3 (10 % v/v) at 298 K. The formation of 3 a(1×2) was enthalpically driven (ΔH°0 and ΔS°0) and there was a unique inflection point in the correlation between ΔH° versus ΔS° as a function of polar solvent content. The ab initio calculations revealed that favorable guest-capsule dispersion and electrostatic interactions between the acetylenic parts (triple bonds) of 3 a and the aromatic inner space of 1×2, as well as less structural deformation of 1×2 upon encapsulation of 3 a, play important roles in the remarkable stability of 3 a(1×2). Copyright
- Ichihara, Keisuke,Kawai, Hidetoshi,Togari, Yuka,Kikuta, Emi,Kitagawa, Hitomi,Tsuzuki, Seiji,Yoza, Kenji,Yamanaka, Masamichi,Kobayashi, Kenji
-
supporting information
p. 3685 - 3692
(2013/04/10)
-
- Synthesis and biological evaluation of new bis-indolone-N-oxides
-
A series of bis-indolone-N-oxides, 1a-f, was prepared from bis(ethynyl)benzenes and o-halonitroaryls and studied for their in vitro antiplasmodial activities against Plasmodium falciparum and representative strains of bacteria and candida as well as for their cytotoxicity against a human tumor cell line (MCF7). They did not cause any haemolysis (300 μg mL-1). Of the synthesized bis-indolones, compound 1a had the most potent antiplasmodial activity (IC50 = 0.763 μmol L-1 on the FcB1 strain) with a selectivity index (CC50 MCF7/IC 50 FcB1) of 35.6. No potency against the tested microbial strains was observed.
- Najahi, Ennaji,Valentin, Alexis,Tene, Nathan,Treilhou, Michel,Nepveu, Francoise
-
-
- A photolabile protection strategy for terminal alkynes
-
We present a strategy for photolabile protection of terminal alkynes. Several photo-caged alcohols were synthesized via mild copper(II)-catalyzed substitution between tertiary propargylic alcohols and 2-nitrobenzyl alcohol to build up robust, base stable o-nitrobenzyl (NB) photo-cleavable compounds. We compare the new photolabile protecting group with the commonly used alkyne protecting group, 2-methyl-3-butyn-2-ol and the results show that NB ethers are stable under the cleaving conditions for the cleavage of methylbutynol protected alkynes. Additionally, we present the synthesis of photo-cleavable NB derivatives containing thiol groups that can serve as agents for photoinduced surface functionalization reactions.
- Gschneidtner, Tina A.,Moth-Poulsen, Kasper
-
p. 5426 - 5429
(2013/09/23)
-
- Conjugated poly(aryleneethynylenesiloles) and their application in detecting explosives
-
Hyperbranched and linear conjugated polysiloles incorporating arylene ethynylene subunits (6 and 7) were synthesized by the Sonogashira reaction. The two polymers possess unusual phenomena of PL, with gradual addition of water in their THF solution, the intensity of PL firstly increased and then decreased, this may be due to the aggregate-enhanced emission (AEE) effect and aggregation-caused quenching (ACQ) effect. The polymers function as sensitive fluorescent chemosensors for the detection of explosives, such as picric acid (PA) and TNT. The quenching constants of 6 for PA and TNT were 4.7 × 10-2 ppm-1 and 4.6 × 10-3 ppm -1, respectively. The quenching constants of 7 for PA and TNT were 8.6 × 10-2 ppm-1 and 6.5 × 10-3 ppm-1 respectively. The polymer 7 has more detective efficiency for PA and TNT than that of polymer 6, this may be due to the less steric hindrance.
- Shu, Weifu,Guan, Changwei,Guo, Wenhao,Wang, Chengyun,Shen, Yongjia
-
experimental part
p. 3075 - 3081
(2012/06/01)
-
- From molecular to macroscopic engineering: Shaping hydrogen-bonded organic nanomaterials
-
The self-assembly and self-organization behavior of chromophoric acetylenic scaffolds bearing 2,6-bis(acetylamino)pyridine (1, 2) or uracyl-type (3-9) terminal groups has been investigated by photophysical and microscopic methods. Systematic absorption and luminescence studies show that 1 and 2, thanks to a combination of solvophilic/solvophobic forces and π-π stacking interactions, undergo self-organization in apolar solvents (i.e., cyclohexane) and form spherical nanoparticles, as evidenced by wide-field optical microscopy, TEM, and AFM analysis. For the longer molecular module, 2, a more uniform size distribution is found (80-200nm) compared to 1 (20-1000nm). Temperature scans in the range 283-353K show that the self-organized nanoparticles are reversibly formed and destroyed, being stable at lower temperatures. Molecular modules 1 and 2 were then thoroughly mixed with the complementary triply hydrogen-bonding units 3-9. Depending on the specific geometrical structure of 3-9, different nanostructures are evidenced by microscopic investigations. Combination of modules 1 or 2 with 3, which bears only one terminal uracyl unit, leads to the formation of vesicular structures; instead, when 1 is combined with bis-uracyl derivative 4 or 5, a structural evolution from nanoparticles to nanowires is observed. The length of the wires obtained by mixing 1 and 4 or 1 and 5 can be controlled by addition of 3, which prompts transformation of the wires into shorter rods. The replacement of linear system 5 with the related angular modules 6 and 7 enables formation of helical nanostructures, unambiguously evidenced by AFM. Finally, thermally induced self-assembly was studied in parallel with modules 8 and 9, in which the uracyl recognition sites are protected with tert-butyloxycarbonyl (BOC) groups. This strategy allows further control of the self-assembly/self-organization process by temperature, since the BOC group is completely removed on heating. Microscopy studies show that the BOC-protected ditopic modules 8 self-assemble and self-organize with 1 into ordered linear nanostructures, whereas BOC-protected tritopic system 9 gives rise to extended domains of circular nano-objects in combination with 1.
- Yoosaf,Llanes-Pallas, Anna,Marangoni, Tomas,Belbakra, Abdelhalim,Marega, Riccardo,Botek, Edith,Champagne, Beno?t,Bonifazi, Davide,Armaroli, Nicola
-
supporting information; scheme or table
p. 3262 - 3273
(2011/04/24)
-
- Calix[4]bis(spirodienone) as a versatile synthon for upper rim alkoxylation of calixarenes and synthesis of novel triazole-based biscalixarene by 'CuAAC' chemistry
-
The spiro rings of calix[4]bis(spirodienone) have been opened up using various bromofunctionalised alcohols employing a novel ipso nucleophilic substitution of tert-butyl groups by alkoxy groups. Additionally, a route has been paved towards the preparation of triazole-linked biscalixarene via the copper(I)-catalysed modern version of classical Huisgen 1,3-dipolar cycloaddition of alkynyl calixarene and azidocalixarene, derived from the above-mentioned bromo-substituted calixarene.
- Thulasi, Sreeja,Savithri, Anupriya,Varma, Ramavarma Luxmi
-
experimental part
p. 501 - 508
(2012/06/18)
-
- Convenient synthesis of terminal alkynes from anti-3-aryl-2,3- dibromopropanoic acids using a K2CO3/DMSO system
-
A convenient, efficient, and generally applicable method was developed for the synthesis of terminal alkynes from anti-3-aryl-2,3-dibromopropanoic acids in the presence of DMSO and K2CO3.
- Cheng, Xuezhi,Jia, Jun,Kuang, Chunxiang
-
p. 2350 - 2354
(2012/02/03)
-
- Cs2CO3-mediated synthesis of terminal alkynes from 1,1-dibromo-1-alkenes
-
An unprecedented route to prepare terminal alkynes from 1,1-dibromo-1-alkenes mediated by Cs2CO3 was proven. 1,1-Dibromo-1-alkenes bearing various functional groups were efficiently converted to corresponding terminal alkynes in moderate to excellent yields.
- Zhao, Ming,Kuang, Chunxiang,Yang, Qing,Cheng, Xuezhi
-
scheme or table
p. 992 - 994
(2011/03/22)
-
- Triazole-pyridine ligands: A novel approach to chromophoric iridium arrays
-
We describe a novel modular approach to a series of luminescent iridium complexes bearing triazole-pyridine-derived ligands that were conveniently prepared by using "click" chemistry. One, two or three triazole-pyridine units were effectively built into the heteroaromatic macromolecule using versatile acetylene- and azide-functionalised precursors. Using this approach, a series of iridium-derived molecules, that differ in the number of iridium centres, the structural characteristics of the cyclometalating ligand and the backbone, were synthesised. The preliminary photophysical properties of the prepared complexes indicate that there is only limited interaction (through space or through the backbone) between the iridium centres within one molecule and that each iridium centre retains its individual properties. The results show that our approach can be generally applied towards covalently linked multichromophoric systems with potential application, for instance, in the design and preparation of tunable light emitters. As a demonstration of this concept, a single molecule white-light emitter, constructed from two iridium centres (yellow emission) and a fluorene unit (blue emission), is presented. The Royal Society of Chemistry.
- Juriek, Michal,Felici, Marco,Contreras-Carballada, Pablo,Lauko, Jan,Bou, Sandra Rodriguez,Kouwer, Paul H. J.,Brouwer, Albert M.,Rowan, Alan E.
-
supporting information; experimental part
p. 2104 - 2111
(2011/10/02)
-
- Selective gas adsorption in the flexible metal-organic frameworks Cu(BDTri)L (L = DMF, DEF)
-
Use of the ditopic ligand 1,4benzenedi(1H-1,2,3-triazole) (H 2BDTri) enabled isolation of two new three-dimensional metal-organic frameworks of formulae Cu(BDTri)L in which L = DMF (1) and diethylformamide (DEF; 2). These compounds have the same primary structure, featuring one-dimensional channels with the bridging DMF or DEF molecules pointing into the cavity. Upon exposure to solvent vapors, both display a reversible flexibility, as characterized by single-crystal to single-crystal phase transitions in 1. The O2 adsorption isotherms for the compounds show a twostep adsorption behavior associated with a permanent microporosity and a pore-opening process. In the case of N2 adsorption, only 1 exhibits a two-step adsorption isotherm, whereas 2 does not present any pore opening, demonstrating that design of a flexible framework cavity can control the pore opening and thereby possibly enhance O2/ N2 separation.
- Demessence, Aude,Long, Jeffrey R.
-
supporting information; experimental part
p. 5902 - 5908
(2010/09/09)
-
- Mixed [2.2]cyclophanes of pyrene and benzene
-
An examination of the literature on [2.2]cyclophanes reveals a loose relationship between the relative sizes of the two 'half-cyclophanes' (as measured by the parameter Δd) and the limitations of the dominant general synthetic approaches. Direct coupling methods tend to be successful only for systems with Δd values below 1.0 A, whereas ring-contraction-based approaches are usually viable for systems with Δd values up to 2.0.A For the very few known systems with Δd values greater than 2.0A, aromatization-based approaches are the only ones that have been successful. The syntheses of two [2.2]cyclophanes with very large Δd values, [2]paracyclo[2](2,7)pyrenophane (17) (Δd = 4.25A) and [2]metacyclo[2](2,7)pyrenophane (18) (d≤5.04A) are presented here. The syntheses hinge on a valence isomerization/dehydrogenation reaction. The crystallographically determined bend angle, θ, for 18 is 96.1°. Cyclophane 18 undergoes a degenerate conformational flip, the energy barrier for which was determined to be 18.9 kcal mol-1 by DNMR. CSIRO 2010.
- Vermeij, Rudolf J.,Miller, David O.,Dawe, Louise N.,Aprahamian, Ivan,Sheradsky, Tuvia,Rabinovitz, Mordecai,Bodwell, Graham J.
-
experimental part
p. 1703 - 1716
(2011/09/16)
-
- New soluble rigid rod copolymers comprising alternating 2-amino-pyrimidine and phenylene repeat units: Syntheses, characterization, optical and electrochemical properties
-
A new type - π-conjugated copolymers of 2-amino-pyrimidine was prepared between 2-amino-4,6-diiodidepyrimidine and 1,4-dibromo-2,5-dialkoxybenzene by Sonogashira polycondensation. The structures of the copolymers were elucidated by FT-IR, 1H NMR and 13C NMR, fluorescence spectroscopy, gel permeation chromatography, thermal analysis and element analysis. The derived polymers were soluble in common organic solvents and trifloroacetic acid and exhibited good thermal stability. They emitted green light under UV irradiation in solid state and blue or green light in solution phase, respectively. Electrochemical behavior of these new polymers depicted facile p-doping and good electron-transporting properties. These polymers displayed bathochromic shift when protonated with CH3SO3H acid in chloroform solutions or m-cresol solutions and the red-shifted peaks were observed from 490 nm to 652 nm. XRD patterns of copolymers showed that the intensity of peaks was enhanced with increasing alkyloxy chain length.
- Mamtimin, Xirali,Matsidik, Rukiya,Nurulla, Ismayil
-
scheme or table
p. 437 - 446
(2011/02/24)
-
- Synthesis of click-chelator via Cu(I)-catalyzed alkyne-azide cycloaddition
-
The click-ligands based on 1,2,3-triazole and pyridine unit has been synthesized via Cu(I)-catalyzed alkyne-azide cycloaddition from corresponding organic azides and terminal alkynes. The ligand structure was characterized by NMR, IR and elemental analysis as well as single crystal diffractions. The single crystal structure of the complexes from two different ligands coordinating to Cu(II) and Co(II) ions indicated that the N(2) atom in 1,2,3-triazole unit can act as an efficient donor to metals through the rational molecular design. Copyright
- Fu, Yang,Liu, Yan,Fu, Xiaoping,Zou, Li,Li, Hua,Li, Ming,Chen, Xingguo,Qin, Jingui
-
body text
p. 2226 - 2232
(2011/09/16)
-
- STRUCTURE, SYNTHESIS, AND APPLICATIONS FOR OLIGO PHENYLENE ETHYNYLENES
-
Novel compounds generally referred to herein as cationic oligomeric phenylene ethynylenes (OPEs), methods of synthesizing OPEs and various uses for the OPEs are described. The compounds can be synthesized in both symmetrical (S-OPE) and non- symmetrical (N-OPE) forms. Suitable uses include sensor and biocidal applications. Reusable structures incorporating the OPEs that are able to capture and release biological species of interest are also described.
- -
-
Page/Page column 10
(2010/01/30)
-
- Unique twisted ribbons generated by self-assembly of oligo(p-phenylene ethylene) bearing dimeric bile acid pendant groups
-
A series of novel oligo(pphenylene ethynylene) (OPE) derivatives bearing dimeric cholic acid (OPE1), deoxycholic acid (OPE2) and lithocholic acid (OPE3) was synthesized. The self-assembly behavior of these derivatives were systematically studied and compared in a THF/water solvent mixture. The addition of water to THF can induce the helical stacking of oligo(p-phenylene ethylene) bearing dimeric deoxycholic acid end groups, which leads to highly interesting twisted assemblies. Variation of the bile acid group led to nanostructures with drastically different morphologies. The application of spectroscopy in combination with X-ray diffraction techniques provided a reasonable view of the final self-assembled structures. The observed distinctive aggregate shapes and the preference in the type of molecular packing of these steroid-OPE conjugates are attributed to the subtle differences in their molecular features.
- Li, Yan,Li, Guangtao,Wang, Xinyan,Li, Weina,Su, Zhixiang,Zhang, Yihe,Ju, Yong
-
scheme or table
p. 6399 - 6407
(2010/02/28)
-
- Cyclopentadienyl ruthenium(II) complexes with bridging alkynylphosphine ligands: Synthesis and electrochemical studies
-
The reaction of [CpRuCl-(PPh3)2] (Cp= cyclopentadienyl) and [CpRuCl(dppe)] (dppe=Ph2PCH2CH 2PPh2) with bis-and trisphosphine ligands 1,4-(Ph 2PC= C)2C6H4 (1) and 1,3,5-(Ph 2PC= C)3C6H3 (2), prepared by Ni-catalysed cross-coupling reactions between terminal alkynes and diphenylchlorophosphine, has been investigated. Using metal-directed self-assembly methodologies, two linear bimetallic complexes,[{CpRuCl(PPh 3)}2(μ-dppab)] (3) and[{CpRu(dppe)}2(μ- dppab)](PF6)2 (4), and the mononuclear complex [CpRuCl(PPh3)(η1-dppab)] (6), which contains a dangling arm ligand, were prepared (dppab=1,4-bis[(diphenylphosphino) ethynyl]benzene). Moreover, by using the triphosphine 1,3,5- tris[(diphenylphosphino)ethynyl]benzene (tppab), the trimetallic [{CpRuCl-(PPh3)}3(μ3-tppab)] (5) species was synthesised, which is the first example of a chiral-at-ruthenium complex containing three different stereogenic centres. Besides these open-chain complexes, the neutral cyclic species [{CpRuCl(μdppab)}2] (7) was also obtained under different experimental conditions. The coordination chemistry of such systems towards supramolecular assemblies was tested by reaction of the bimetallic precursor 3 with additional equivalents of ligand 2. Two rigid macrocycles based on cis coordination of dppab to [CpRu-(PPh 3)] were obtained, that is, the dinuclear complex [{CpRu(PPh 3)(mdppab)}2](PF6)2 (8) and the tetranuclear square [{CpRu(PPh3)(mdppab)}3](PF 3)3 (9). The solid-state structures of 7 and 8 have been determined by X-ray diffraction analysis and show a different arrangement of the two parallel dppab ligands. All compounds were characterised by various methods including ESIMS, electrochemistry and by X-band ESR spectroscopy in the case of the electrogenerated paramagnetic species.
- Di Credico, Barbara,De Biani, Fabrizia Fabrizi,Gonsalvi, Luca,Guerri, Annalisa,Ienco, Andrea,Laschi, Franco,Peruzzini, Maurizio,Reginato, Gianna,Rossin, Andrea,Zanello, Piero
-
scheme or table
p. 11985 - 11998
(2010/04/28)
-
- Rigid rod and tetrahedral hybrid compounds featuring nucleobase and nucleoside End-capped structures
-
Being aimed at a new type of porous solids, a moduled design strategy of molecular tectons, making use of the conjugation between a shape defined artificial backbone and the bioinspired molecular fragments of nucleobases or nucleobase derivatives as functional end-caps, has been developed. This led to the formation of the new hybrid compounds 1-13 of linear and tetrahedral geometry, containing uracil, adenine, adenosine, guanosine and its acylated analogs as the sticky end-cap sites. The compounds were synthesized from a halogen or ethynyl substituted nucleobase component and the corresponding ethynylated spacer unit following a metal assisted coupling process as the key reaction step. X-Ray crystal structure analysis demonstrates that the parent compound 1 is a solvent complex with DMSO (1:2), showing the DMSO molecules incorporated in a hydrogen bonded layer structure. Specific dependencies of the fluorescence properties of the new compounds in solution on the structure of the molecules are reported. A selection of solid compounds has been studied in respect of their ability to adsorb organic vapours. They revealed significant differences both in the sorption capacity and the selectivity towards particular solvent vapours.
- Schindler, Diana,Eissmann, Frank,Weber, Edwin
-
scheme or table
p. 3549 - 3560
(2010/01/06)
-
- Organosilane compound and organosilica obtained therefrom
-
Provided is an organosilane compound expressed by any one of the following general formulae (1) to (7): (wherein: Ar represents a phenylene group or the like; R1 represents a hydrogen atom or the like; R2 to R8 each represent a methyl group or the like; n represents an integer in a range from 0 to 2; m represents an integer of 1 or 2; L represents a single bond or the like; X represents a hydrogen atom or the like; and Y represents a hydrogen atom or the like).
- -
-
Page/Page column 25
(2008/12/07)
-
- Poly(p-phenylene ethynylene)s with facially amphiphilic pendant groups: Solvatochromism and supramolecular assemblies
-
Novel functionalized poly(p-phenylene ethynylene)s (PPEs) bearing facially amphiphilic cholic and deoxycholic acid units are synthesized by a Pd-catalyzed Sonogashira cross-coupling reaction. Some interesting properties, particularly their optical and self-assembly characteristics, are unraveled. The PPEs that carry bile acid substituents exhibit remarkable solvatochromism in a wide range of solvent systems, and judicious choice of the solvents can adjust the size and morphology of the formed nanoscale supramolecular aggregates. The incorporation of these naturally occurring building blocks can also impart bio-compatibility to the conjugated system and stimulate the growth of living cells.
- Li, Yan,Li, Guangtao,Wang, Xinyan,Lin, Changxu,Zhang, Yihe,Ju, Yong
-
scheme or table
p. 10331 - 10339
(2009/10/23)
-
- Removal of water - a factor influencing the synthesis of alkynes in a phase-transfer catalyzed β-elimination reaction
-
Acetylene derivatives 4 were synthesized from the corresponding vicinal bromo compounds 2 in the phase-transfer catalyzed hydrogen bromide β-elimination reaction using solid potassium hydroxide as a base, xylene as a solvent, and a phase-transfer catalyst. The yields of the synthesized acetylene derivatives 4 were substantially improved when water formed in the process had been removed.
- Zakrzewski,Huras,Sas,Zelechowski,Bombinska
-
p. 1051 - 1057
(2008/09/21)
-