- Dinucleating Ligand Platforms Supporting Indium and Zinc Catalysts for Cyclic Ester Polymerization
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The synthesis of the first alkoxide-bridged indium complex supported by a chiral dinucleating ligand platform (1), along with its zinc analogue (2), is reported. Both complexes are synthesized in a one-pot reaction starting from a chiral dinucleating bis(diamino)phenolate ligand platform, sodium ethoxide, and respective metal salts. The dinucleating indium analogue (7) based on an achiral ligand backbone is also reported. Indium complexes bearing either the chiral or achiral ligand catalyze the ring-opening polymerization of racemic lactide (rac-LA) to afford highly heterotactic poly(lactic acid) (PLA; Pr > 0.85). The indium complex bearing an achiral ligand affords essentially atactic PLA from meso-LA. The role of the dinucleating ligand structure in catalyst synthesis and polymerization activity is discussed.
- Kremer, Alexandre B.,Osten, Kimberly M.,Yu, Insun,Ebrahimi, Tannaz,Aluthge, Dinesh C.,Mehrkhodavandi, Parisa
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- Water oxidation catalyzed by molecular di- and nonanuclear Fe complexes: Importance of a proper ligand framework
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The synthesis of two molecular iron complexes, a dinuclear iron(iii,iii) complex and a nonanuclear iron complex, based on the dinucleating ligand 2,2′-(2-hydroxy-5-methyl-1,3-phenylene)bis(1H-benzo[d]imidazole-4-carboxylic acid) is described. The two iron complexes were found to drive the oxidation of water by the one-electron oxidant [Ru(bpy)3]3+.
- Das, Biswanath,Lee, Bao-Lin,Karlsson, Erik A.,?kermark, Torbj?rn,Shatskiy, Andrey,Demeshko, Serhiy,Liao, Rong-Zhen,Laine, Tanja M.,Haukka, Matti,Zeglio, Erica,Abdel-Magied, Ahmed F.,Siegbahn, Per E. M.,Meyer, Franc,K?rk?s, Markus D.,Johnston, Eric V.,Nordlander, Ebbe,?kermark, Bj?rn
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- A carbonothioate-based highly selective fluorescent probe with a large Stokes shift for detection of Hg2+
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Mercury (Hg) is one of the heavy metal pollutants in the environment. Even a very small amount of mercury can cause serious harm to human beings. Herein, we reported a new carbonothioate-based fluorescent probe for the detection of Hg2+ without interference from other metal ions. This probe possessed a very large Stokes shift (192?nm), which could improve the detection sensitivity by minimizing the interferences resulted from self-absorption or auto-fluorescence. With the addition of Hg2+ to the probe solution, considerable fluorescence enhancement was observed. Additionally, the Hg2+ concentration of 0–16?μM and fluorescence intensity showed a good linear relationship (y?=?22106×?+?53108, R2?=?0.9955). Finally, the proposed probe was used to detect Hg2+ in real water samples, and its result was satisfactory. Therefore, our proposed probe would provide a promising method for the determination of Hg2+ in the environment.
- Xu, Jing,Xu, Zhenghe,Wang, Zuokai,Liu, Caiyun,Zhu, Baocun,Wang, Xiuru,Wang, Kun,Wang, Jiangting,Sang, Guoqing
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- Remarkable ESIPT induced NIR emission by a selective colorimetric dibenzimidazolo diimine sensor for acetate
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A new dibenzimidazolo diimine sensor (DDS) has been designed and synthesized for selective detection of acetate ion. Significant naked eye recognized color change of DDS solution from light yellow to pink upon addition of only acetate ion is accompanied with near infra red (NIR) emission exploiting excited state intramolecular proton transfer (ESIPT).
- Goswami, Shyamaprosad,Maity, Sibaprasad,Das, Avijit Kumar,Maity, Annada C.,Mandal, Tarun Kanti,Samanta, Siddhartha
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- A water-soluble metal–organic coordination polymer of Zn(II) Schiff base complex in interaction with DNA: diagnosing the mode of binding by in vitro studies
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In this paper, in vitro DNA binding of a water-soluble metal–organic coordination polymer of Zn(II) Schiff base complex was considered. By focusing on the cooperative effect of multi-Zn(II) centers of the complex, the affinity and mode of binding were investigated by some techniques, e.g., absorption and fluorescence spectroscopy, circular dichroism spectroscopy, viscosity measurement, molecular docking, iodide quenching studies and effect of ionic strength on the complex–DNA binding. The calculated value of Kb = 1.3 × 103?M?1 represented a good affinity of the Zn(II) complex to DNA. From the experimental methods and docking studies, non-classical intercalation (i.e., van der Waals interactions, groove binding or external binding) was proposed as the main mode of binding.
- Asadi, Zahra,Nasrollahi, Neda,Golchin, Maryam
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- A detailed study on the interaction of a novel water-soluble glycine bridged zinc(II) Schiff base coordination polymer with BSA: Synthesis, crystal structure, molecular docking and cytotoxicity effect against A549, Jurkat and Raji cell lines
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A novel water-soluble glycine bridged zinc(II) Schiff base coordination polymer was synthesized by the condensation of 2,6-diformyl-4-methylphenol, glycine, and zinc(II) chloride. The complex was characterized by 1HNMR, FT-IR, elemental analyses and X-ray crystallography. The polymeric complex was built up of two glycine-bridged Zn/L moieties, where L denotes the Schiff base containing 2,6-diformyl-4-methylphenol and glycine in 1:1?M ratio. The carboxylic group of L was coordinated to the Zn atoms of the neighboring moieties; thus each Zn center was five-coordinated. The interaction between polymeric Zn(II) complex and bovine serum albumin (BSA) was studied by UV–Vis, fluorescence, and synchronous fluorescence spectroscopic techniques. By considering the sign and values of the thermodynamic parameters (ΔH and ΔS), it is clear that the binding between BSA and complex was exothermic and entropy-driven and electrostatic interactions between the complex and BSA was supposed. Site-selective binding studies revealed that the complex were mainly located in the region of site II (subdomain IIIA) in BSA. From the synchronous fluorescence spectroscopic studies, it is concluded that complex could bind to tyrosine and tryptophan residues simultaneously. The Kb values indicated a high binding affinity of the complex to BSA. In vitro anticancer activity of the polymeric Zn(II) complex was evaluated against A549, Jurkat, and Raji cell lines by MTT assay. The complex was remarkably active against the cell lines and can be a good candidate for an anticancer therapy. Theoretical docking studies were performed to further investigate the BSA binding interactions.
- Asadi, Zahra,Golchin, Maryam,Eigner, Vaclav,Dusek, Michal,Amirghofran, Zahra
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- A NIR-emitting cyanine with large Stokes shifts for live cell imaging: Large impact of the phenol group on emission
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There are a limited number of near-infrared (NIR) emitting (λem = 700-900 nm) molecular probes for imaging applications. A NIR-emitting probe that exhibits emission at ~800 nm with a large Stokes shift was synthesized and found to exhibit excellent selectivity towards mitochondria for live-cell imaging. The photophysical properties were attributed to an excited cyanine structure via intramolecular charge transfer (ICT) involving a phenol group.
- Dahal, Dipendra,McDonald, Lucas,Pokhrel, Sabita,Paruchuri, Sailaja,Konopka, Michael,Pang, Yi
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- Investigation of the complex structure, comparative DNA-binding and DNA cleavage of two water-soluble mono-nuclear lanthanum(III) complexes and cytotoxic activity of chitosan-coated magnetic nanoparticles as drug delivery for the complexes
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Two water-soluble mono-nuclear macrocyclic lanthanum(III) complexes of 2,6-diformyl-4-methylphenol with 1,3-diamino-2-propanol (C1) or 1,3-propylenediamine (C2) were synthesized and characterized by UV–Vis, FT-IR, 13C and 1H NMR spectroscopy and elemental analysis. C1 complex was structurally characterized by single-crystal X-ray diffraction, which revealed that the complex was mononuclear and ten-coordinated. The coordination sites around lanthanum(III) were occupied with a five-dentate ligand, two bidentate nitrates, and one water molecule. The interaction of complexes with DNA was studied in buffered aqueous solution at pH 7.4. UV–Vis absorption spectroscopy, emission spectroscopy, circular dichroism (CD) and viscometric measurements provided clear evidence of the intercalation mechanism of binding. The obtained intrinsic binding constants (Kb) 9.3 × 103 and 1.2 × 103 M? 1 for C1 and C2, respectively confirmed that C1 is better intercalator than C2. The DNA docking studies suggested that the complexes bind with DNA in a groove binding mode with the binding affinity of C1 > C2. Moreover, agarose gel electrophoresis study of the DNA-complex for both compounds revealed that the C1 intercalation cause ethidium bromide replacement in a competitive manner which confirms the suggested mechanism of binding. Finally, the anticancer experiments for the treated cancerous cell lines with both synthesized compounds show that these hydrophilic molecules need a suitable carrier to pass through the hydrophobic nature of cell membrane efficiently.
- Asadi, Zahra,Nasrollahi, Neda,Karbalaei-Heidari, Hamidreza,Eigner, Vaclav,Dusek, Michal,Mobaraki, Nabiallah,Pournejati, Roya
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- Lanthanide cryptate monometallic coordination complexes
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We report the synthesis, characterisation and magnetic properties of six novel neutral lanthanide cryptate coordination complexes. Reaction of 2,6-diformyl-4-methylphenol, tris(2-aminoethyl)amine and Ln(OTf)3·9H2O in the ratio 3?:?2?:?1, respectively, and in the presence of base affords the isolation of the six complexes LnL·4H2O (Ln = Tb (1), Dy (2), Ho (3), Er (4), Tm (5) and Yb (6)), with H3L being the cryptand N[(CH2)2NCH-R-CHN-(CH2)2]3N (R = m-C6H2OH-2-Me-5). Powder X-ray diffraction confirms that the six complexes are isostructural. The crystal structure of 6 reveals that the Ln(iii) centre is heptacoordinated, in a geometry close to a monocapped distorted octahedron and lies on a pseudo (non-crystallographically imposed) C3 axis. This coordination sphere is similar to the one found in the previously studied Ln(trensal) complexes (H3trensal = 2,2′,2′′-tris(salicylideneimino)triethylamine). The static and dynamic magnetic properties of these complexes were investigated by SQUID magnetometry. Crystal field parameters were determined for all complexes by modelling of the direct current magnetic susceptibility and variable-temperature-variable-field magnetisation data. As for Ln(trensal), only complexes containing the Kramers ions Dy, Er and Yb displayed out-of-phase susceptibility signals in SQUID measurements in an applied magnetic field. Investigation of the dynamic susceptibility of the Yb complex revealed that the magnetic relaxation is governed by a direct process at low temperatures and a Raman process at higher temperatures, similar to Yb(trensal). This journal is
- Buch, Christian D.,Mitcov, Dmitri,Piligkos, Stergios
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- Transition metal complexes of 2, 6-di ((phenazonyl-4-imino) methyl)-4-methylphenol: Structure and biological evaluation
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A symmetric ligand 2, 6-di ((phenazonyl-4-imino)methyl)-4-methylphenol (Dpmp) and its cobalt dinuclear complex (Co2(Dpmp) 2(NO3)2(H2O)2·NO3· EtOH, (1) and zinc mononuclear complex Zn(Dpmp)(NO3)2, (2) have been prepared. The crystal structures were determined by single-crystal X-ray diffraction. The biological activity has been evaluated by examining their anti-oxidative activity and ability to bind to bovine serum albumin (BSA) and calf-thymus DNA (CT DNA) with UV-vis absorption, fluorescence, viscosity measurements and circular dichroism (CD) spectroscopies. The complexes exhibit good binding propensity to BSA and CT DNA. Both 1 and 2 have been found to promote cleavage of pUC19 DNA in the absence of any reducing agent. Antioxidant tests in vitro show the compounds possess significant antioxidant activity against superoxide and hydroxyl radicals.
- Liu, Hongyan,Shi, Xiaoyan,Xu, Min,Li, Zhengpeng,Huang, Liang,Bai, Decheng,Zeng, Zhengzhi
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- Exchange coupling in a bis(heterodinuclear) [CuIINiII]2 and a linear heterotrinuclear complex CoIIICuIINiII. Synthesis, structures and properties
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Two heterometallic complexes [{CuII(HLOX)NiII(N3)}2] and [(tmtacn)CoIII(μ-OH)CuII(LOX)NiII(OH 2)2]-[ClO4]2 (tmtacn = 1,4,7-trimethyl-1,4,7-triazacyclononane) containing the same [CuIINiII] core embedded in an unsymmetrical dicompartmental imine-oxime ligand H4LOX have been synthesized and characterized. Their crystal structures show that the CuII resides at the N(oxime)2O(phenolate)2 site and assumes a planar geometry. The NiII is six-co-ordinated and bound to an N2O4 donor array comprising two iminonitrogens, two phenolate oxygens and two axially co-ordinated H2O molecules. The cobalt(III) is low spin and six-co-ordinated. In DMF solution at 10 K the EPR spectra of the complexes exhibit a spin-doublet ground state with inverted g values which demonstrate the delocalization of the unpaired electron over the CuNi core. Magnetic susceptibility measurements over the range 2-290 K confirm that the paramagnetic nickel(II) and copper(II) centres are antiferromagnetically coupled, with values for the exchange coupling constant J through the phenolate oxygens of -115 cm-1 and -130 cm-1 respectively. Considering the dimer as a single tetranuclear unit, the coupling constant J′ through the path Cu-N-O-Ni is very small (≈1 cm-1) but positive (ferromagnetic coupling). The Royal Society of Chemistry 2000.
- Verani, Claudio Nazari,Rentschler, Eva,Weyhermueller, Thomas,Bill, Eckhard,Chaudhuri, Phalguni
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- Examination of structure-activity relationship of new n-acylhydrazones
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In this study we describe synthesis and characterization of new substituted hydroxy-bis-N-acylhydrazones in order to investigate influence of their switching emission properties, according to the nature of the substituent. The fluorescence of the compounds depended on the solvent used (organic or aqueous). The different emission colors observed could be explained by conformation modifications.
- Coman, Anca G.,Paun, Anca,Popescu, Codru?a C.,Hadade, Niculina D.,Hanganu, Anamaria,M?d?lan, Augustin M.,Matache, Mihaela
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p. 109 - 114
(2021/02/05)
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- Examination of structure-activity relationship of new n-acylhydrazones
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In this study we describe synthesis and characterization of new substituted hydroxy-bis-N-acylhydrazones in order to investigate influence of their switching emission properties, according to the nature of the substituent. The fluorescence of the compounds depended on the solvent used (organic or aqueous). The different emission colors observed could be explained by conformation modifications.
- Coman, Anca G.,Hadade, Niculina D.,Hanganu, Anamaria,Mǎdǎlan, Augustin M.,Matache, Mihaela,Paun, Anca,Popescu, Codru?a C.
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p. 109 - 114
(2020/07/23)
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- Synthesis and study of new photochromic spiropyrans modified with carboxylic and aldehyde substituents
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Three new photochromic spiropyrans containing a carboxylic group in the indoline fragment and an aldehyde substituent in the [2H]-chromene moiety were synthesized. The structure of the compounds obtained was studied using 1H and 13C NMR, IR and elemental analysis. Single crystal X-ray analysis was used to refine the molecular structure of 8′-formyl-1,3,3,6′-tetramethyl-spiro[indoline-2,2′-2H-chromene]-5-carboxylic acid. It was found out that in the solid state the molecules of that compound are arranged in dimeric associates due to the formation of intermolecular hydrogen bonds between carboxylic groups of two adjacent molecules. All the spiropyrans were shown to be photochromic with the lifetimes of the open forms in the range of 1.5–46.0 s.
- Ozhogin, Ilya V.,Chernyavina, Valentina V.,Lukyanov, Boris S.,Malay, Vasily I.,Rostovtseva, Irina A.,Makarova, Nadezhda I.,Tkachev, Valery V.,Lukyanova, Maria B.,Metelitsa, Anatoly V.,Aldoshin, Sergey M.
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p. 409 - 416
(2019/07/04)
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- A small break chemical sterically hindered [...] and its preparation method and application (by machine translation)
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The invention discloses a chemical sterically hindered small breakable [...] and its preparation method and application. This can be cut off the molecular formula of the [...] C13 H16 O3 , Its structural formula such as formula (I) as shown: , Its phenol hydroxyl can be connected with the model response group, hydroxy can [...] drug or fluorophore is connected, when the model response under the action of the group in response to the species after the departure, drug or fluorophore will through the 1, 6 - elimination reaction is released. The [...] can be cut off with the advantage of small chemical sterically hindered, solved the model in response to the group of drug or fluorophore of sterically hindered problem; in addition, the can be cut off [...] can quickly and effectively release the drug or fluorophore, and has good biocompatibility, can be widely used for prodrug and the design of the fluorescent probe material, have good application prospect and broad development space. (by machine translation)
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Paragraph 0020; 0079; 0080; 0081
(2019/01/23)
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- 1,6-Elimination reaction induced detection of fluoride ions in vitro and in vivo based on a NIR fluorescent probe
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Near-Infrared “turn on” type fluorescent probes are attractive and promising in the fields of chemical sensing and bioimaging. Here, a new dicyanomethylene-4H-pyran derivative (DCM-Si) NIR fluorescent probe was designed and synthesized for specific lighting up F? in living cells and bodies. Si–O bond was used as F? trigger, and the release of fluorophore (DCM-NH2) occurred after substituent reaction and subsequent 1,6-elimination. This NIR probe displayed high sensitivity and selectivity for the sensing of F?, and the detection limit was calculated to be as low as 157 nM. Moreover, the “off-on” fluorescent signal changes can be realized by adding F? in living cells and zebrafish embryos.
- Feng, Aiqing,Jia, Yongmei,Huang, Liping,Wang, Lin,Zhou, Guohua,Wang, Sheng,Liu, Peilian
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- A fluorogenic probe based on chelation-hydrolysis-enhancement mechanism for visualizing Zn2+ in Parkinson's disease models
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Developing efficient methods for the real-time detection of Zn2+ levels in biological systems is highly relevant to improving our understanding of the role of Zn2+ in the progression of Parkinson's disease (PD). In this work, a novel Schiff base based Zn2+ fluorescent probe (ZP) was designed, synthesized and systematically investigated. A significant turn-on effect on ZP upon the addition of Zn2+ was observed, accompanied by a blue-shift of the fluorescence spectra. ZP is sensitive to Zn2+ and has excellent selectivity against various biologically relevant cations, anions and amino acids. The sensing mechanism of ZP was studied by 1H NMR, MS, single crystal X-ray diffraction and theoretical calculations. The results showed that the response of ZP to Zn2+ was based on the chelation-hydrolysis-enhancement process. Upon bonding, Zn2+ hydrolyzes the Schiff base to an aldehyde precursor, the resulting aldehyde further coordinates to Zn2+ to form a more stable heterobimetallic complex leading to the emission enhancement and blue-shift. ZP was applied to imaging exogenous/endogenous Zn2+ in live HeLa cells. Furthermore, we successfully measured the Zn2+ levels using in vitro PD models, which provided a visualization method to better understand the relationship between Zn2+ levels and PD development.
- Zhang, Gaobin,Zhao, Yanfei,Peng, Bo,Li, Zheng,Xu, Chenchen,Liu, Yi,Zhang, Chengwu,Voelcker, Nicolas H.,Li, Lin,Huang, Wei
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p. 2252 - 2260
(2019/04/10)
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- BINUCLEATING LIGAND OR BINUCLEAR METAL COMPLEX
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PROBLEM TO BE SOLVED: To provide a binuclear metal complex that can be easily synthesized and has a proper anticancer action. SOLUTION: The present invention provides a binuclear metal complex represented by the following chemical formula (IV). SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2018,JPOandINPIT
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Paragraph 0043; 0044
(2018/09/25)
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- Zinc catalyst, preparation method and application thereof in ring-opening polymerization of lactone
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The invention discloses a preparation method of a zinc complex and application of the zinc complex as a catalyst in ring-opening polymerization reaction of a lactone monomer. The catalyst system adopts zinc metal as the center of a coordination catalyst, and the ligand is a tridentate ligand composed of NNO. Specifically, the zinc catalyst and a certain amount of alkyl lithium are firstly mixed with in a solvent for reaction to generate an alkyl zinc complex, and then a lactone monomer is added for polymerization reaction. The zinc complex provided by the invention shows excellent catalytic activity in the ring-opening polymerization reaction of epsilon-caprolactone, and as an inherent trace element in the human body, zinc metal is non-toxic and harmless to the human body, therefore the polyester material prepared from the system as a catalyst has wide application prospects in the medical field.
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Paragraph 0024; 0026
(2018/11/03)
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- Mimicking multivalent protein-carbohydrate interactions for monitoring the glucosamine level in biological fluids and pharmaceutical tablets
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An easily synthesizable probe has been employed for dual mode sensing of glucosamine in pure water. The method was also applied for glucosamine estimation in blood serum samples and pharmaceutical tablets. Further, selective detection of glucosamine was also achieved using portable color strips.
- Dey, Nilanjan,Bhattacharya, Santanu
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supporting information
p. 5392 - 5395
(2017/07/06)
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- A New Triazine-Based Covalent Organic Framework for High-Performance Capacitive Energy Storage
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The new covalent organic framework material TDFP-1 was prepared through a solvothermal Schiff base condensation reaction of the monomers 1,3,5-tris-(4-aminophenyl)triazine and 2,6-diformyl-4-methylphenol. Owing to its high specific surface area of 651 m2 g?1, extended π conjugation, and inherent microporosity, TDFP-1 exhibited an excellent energy-storage capacity with a maximum specific capacitance of 354 F g?1 at a scan rate of 2 mV s?1 and good cyclic stability with 95 % retention of its initial specific capacitance after 1000 cycles at 10 A g?1. The π-conjugated polymeric framework as well as ionic conductivity owing to the possibility of ion conduction inside the micropores of approximately 1.5 nm make polymeric TDFP-1 a favorable candidate as a supercapacitor electrode material. The electrochemical properties of this electrode material were measured through cyclic voltammetry, galvanic charge–discharge, and electrochemical impedance spectroscopy, and the results indicate its potential for application in energy-storage devices.
- Bhanja, Piyali,Bhunia, Kousik,Das, Sabuj K.,Pradhan, Debabrata,Kimura, Ryuto,Hijikata, Yuh,Irle, Stephan,Bhaumik, Asim
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p. 921 - 929
(2017/03/17)
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- A highly sensitive turn-on fluorescent chemosensor for recognition of Zn2?+ and Hg2?+ and applications
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A fluorescence probe has been designed and synthesized, and applied with a combined theoretical and experimental study. Research suggests that the probe can be used to sense Zn2?+ and Hg2?+ through selective turn-on fluorescence responses in the aqueous HEPES buffer (0.05M, pH?=?7.4). The limit of detection (LOD) were determined as 1.46?×?10??7?M (Zn2?+) and 2.50?×?10??7?M (Hg2?+). Moreover, based on DFT, the geometry optimizations of probe 1, [1-Hg2?+] complex and [1-Zn2?+] complex were carried out using the Gaussian 09 program, in which the B3LYP function was used. The electronic properties of free probe 1 and the metal complexes were studied based on the Natural Bond Orbital (NBO) analyses. The probe 1 has also been successfully applied to detection of Zn2?+ and Hg2?+ in living cells.
- Tang, Xu,Han, Juan,Wang, Yun,Bao, Xu,Ni, Liang,Wang, Lei,Li, Longhua
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p. 177 - 183
(2017/05/12)
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- Preparation method and application of bis-schiff base based fluorescent sensing material
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The invention relates to a preparation method and application of a bis-schiff base based fluorescent sensing material and belongs to the technical field of chemical fluorescent sensing materials. 2,6-dihydroxymethyl phenol p-methyl phenol and thiosemicarbazide are adopted as basic raw materials, active manganese dioxide firstly serves as an oxidizing agent to oxidize the 2,6-dihydroxymethyl phenol p-methyl phenol into aldehyde, then glacial acetic acid is adopted as a catalyst to prepare the fluorescent sensing material through nucleophilic reaction and the thiosemicarbazide. The prepared material is based on symmetrical bis-schiff base, is stable in structure, and the water-soluble thiosemicarbazide is introduced to make the water solubility of the sensing material greatly enhanced. The prepared fluorescent sensing material has dual response, respectively has the sensitive selective recognition properties on Hg and Zn, shows different fluorescence emissions, is short in response time, is macroscopic under change of fluorescence signals of an ultraviolet lamp, and other common metal ion interferences are small.
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Paragraph 0031; 0033; 0035
(2017/08/29)
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- Hydrogenolysis of glycerol using Fe-Fe/Al2O3 complex catalyst
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Macrocyclic complex catalyst Fe-FeL1 complex of L1 (L1 = C24H26O2N4.) was synthesized and studied in the hydrogenolysis reaction of glycerol reaction in a high pressure batch reactor. The catalyst was well characterized i.e. FTIR, XRD, TGA and BET surface area. The study of hydrogenolysis was found that the selectivity of 1,2-propane diol 80 % at 220°C temperature and 0.35 MPa pressure in presence of hydrogen gas and Fe-Fe/Al2O3 and 30 % glycerol concentration in water gives 1,2-propane diol as the only product and conversion was 36 % at 220°C. It is further seen that if the concentration of glycerol in water is increased beyond 40 % there is a decrease in the total conversion and carbon is produced as coke during the reaction.
- Lal, Sunder,Thakur, Ramswaroop Singh
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p. 2596 - 2600
(2016/10/17)
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- Solvent dependent photophysical properties and near-infrared solid-state excited state intramolecular proton transfer (ESIPT) fluorescence of 2,4,6-trisbenzothiazolylphenol
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A new excited-state intramolecular proton transfer (ESIPT) fluorophore, 2,4,6-trisbenzothiazolylphenol (4), was synthesized and its photophysical properties were studied with steady state absorption and emission spectroscopy as well as time-dependent density functional theory calculation. It was found that 4 showed solvent dependent absorption and fluorescence emission. In the nonpolar solvents, ESIPT occurred and only keto tautomer emission at 570 nm was observed, whereas an emission at 510 nm from the deprotonated anion species was observed in polar solvents. With addition of fluoride, the keto emission was quenched, whereas the anion emission was drastically enhanced, making a ratiometric fluorescence sensing of fluoride achievable. In solid state, 4 showed a fluorescence emission at 605 nm, which is longer than those of 2,4-dibenzothiazolylphenol (575 nm) and 4-methyl-2,6-dibenzothiazolylphenol (592 nm) respectively. Thus, the color tuning of solid state ESIPT emission were achieved from green to yellow and near-infrared by extending of the π-conjugation.
- Zhang, Xuan,Liu, Jing-Yun
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- Facile synthesis of bis-thiosemicarbazone derivatives as key precursors for the preparation of functionalised bis-thiazoles
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A new class of bis-thiosemicarbazones was designed and synthesised by the condensation of 2,6-diformylphenol derivatives and thiosemicarbazide using either ultrasound or conventional methods. Both thiosemicarbazone groups of these derivatives underwent a heterocyclisation process to give a series of novel bis-thiazole derivatives as major products. The structures of all the synthesised compounds were characterised by multinuclear NMR (1H and 13C), IR, HRMS and elemental analyses.
- Arafa, Wael A.A.,Badry, Mohamed G.
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p. 385 - 392
(2016/07/21)
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- Water oxidation catalyzed by molecular Di- and nonanuclear Fe complexes: Importance of a proper ligand framework
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The synthesis of two molecular iron complexes, a dinuclear iron(III,III) complex and a nonanuclear iron complex, based on the dinucleating ligand 2,2'-(2-hydroxy-5-methyl-1,3-phenylene)bis(1H-benzo[d]imidazole-4-carboxylic acid) is described. The two iron complexes were found to drive the oxidation of water by the oneelectron oxidant [Ru(bpy)3]3+.
- Das, Biswanath,Lee, Bao-Lin,Karlsson, Erik A.,?kermark, Torbj?rn,Shatskiy, Andrey,Demeshko, Serhiy,Liao, Rong-Zhen,Laine, Tanja M.,Haukka, Matti,Zeglio, Erica,Abdel-Magied, Ahmed F.,Siegbahn, Per E. M.,Meyer, Franc,K?rk?s, Markus D.,Johnston, Eric V.,Nordlander, Ebbe,?kermark, Bj?rn
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supporting information
p. 13289 - 13293
(2016/09/04)
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- Triply phenoxo bridged Eu(III) and Sm(III) complexes with 2,6-diformyl-4-methylphenol-di(benzoylhydrazone): Structure, spectra and biological study in human cell lines
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Two dinuclear lanthanide(III) complexes, [M2(HL)3] (M = Sm(III) (1), Eu(III) (2); H3L, 2,6-diformyl-4-methylphenol-di(benzoylhydrazone)) were generated with good yield and characterised systematically. The single crystal X-ray structure determination of [Eu2(HL)3] (2) confirmed the tricapped trigonal prismatic geometry of the N3O6 coordination environment around europium. Indeed, Eu(1) and Eu(2) are bridged by phenolato-O belonging to the p-cresol ring, by deprotonated 'enol' groups from the benzoyl hydrazide part and by the imine-N centres. A temperature dependent magnetic study suggested that anti-ferromagnetic coupling occurs between the two Eu(III) ions and the magnetic moment was found to vary from 0.48 B.M. at 5 K to 3.03 B.M. at 300 K. Electron paramagnetic resonance spectroscopy confirmed that anti-ferromagnetic coupling occurs between the atoms of Eu(III) and Sm(III). Both the complexes show emission in the visible range. The ligand, H3L and the complexes exhibit anti-mycobacterial activity against M. tuberculosis H37Rv (ATCC 27294) and M. tuberculosis H37Ra (ATCC 25177) strains. The molecular docking of H3L with the enoyl acyl carrier protein reductase of M. tuberculosis H37Rv (PDB ID: 4U0K) was examined and the best docked pose of H3L was shown to have one hydrogen bond with Thr196 (2.03 A).
- Das, Kuheli,Nandi, Soumendra,Mondal, Sudipa,Askun, Tulin,Cantürk, Zerrin,Celikboyun, Pinar,Massera, Chiara,Garribba, Eugenio,Datta, Amitabha,Sinha, Chittaranjan,Akitsu, Takashiro
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supporting information
p. 1101 - 1114
(2015/02/19)
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- Ratiometric detection of adenosine-5'-triphosphate (ATP) and cytidine-5'-triphosphate (CTP) with a fluorescent spider-like receptor in water
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A series of water-soluble spider-like receptor molecules has been developed by the Schiff-base condensation of tris-(hydroxymethyl)aminomethane (TRIS) with various 2,6-diformylphenol (dfp) derivatives. The products were assessed for their anion sensing properties. Among these, the receptor with a methoxy substituent showed selective fluorescent sensing towards adenosine-5'-triphosphate (ATP) and cytidine-5'-triphosphate (CTP) in contrasting modes in 100% aqueous media at pH 7.2.
- Gupta, Abhishek Kumar,Dhir, Abhimanew,Pradeep, Chullikkattil P.
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p. 122 - 129
(2015/02/19)
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- Visual and near IR (NIR) fluorescence detection of Cr3+ in aqueous media via spirobenzopyran ring opening with application in logic gate and bio-imaging
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A new spirobenzopyran derivative (SPNH) was designed and synthesized which was applied in simultaneous colorimetric and NIR fluorescence detections for Cr3+. This spirobenzopyran receptor is normally colorless in aqueous organic media but the formation of merocyanine occurs by Cr3+ showing a yellow color. Here the formation of yellow color in UV-vis spectra and strong NIR fluorescence emission at 675 nm makes SPNH a good sensor for Cr 3+ ion. It is also found to be useful in cell imaging and in construction of logic gate. It shows INHIBIT gate in fluorescence and OR gate in absorption. To the best of our knowledge, this is the first report of NIR fluorescence emission of a spirobenzopyran derivative by Cr3+ and its application to cell-biology and also in the logic gate.
- Goswami, Shyamaprosad,Das, Avijit Kumar,Maity, Anup Kumar,Manna, Abhishek,Aich, Krishnendu,Maity, Sibaprasad,Saha, Partha,Mandal, Tarun Kanti
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p. 231 - 239
(2014/01/06)
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- Phenoxo bridged tetranuclear copper(II) and dinuclear zinc(II) complexes of 2,6-diformyl-4-methylphenol-di(benzoylhydrazone): Synthesis, structure, spectra and magnetism
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Phenoxo bridged tetranuclear Cu(II) and dinuclear Zn(II) complexes are synhesized namely, Cu4[(L)2(OCH3)2] (1) and Zn2(HL)2 (2) (H3L = [(HOC 6H2CH3){2,6-(CHN-NC(OH)(C6H 5))(CHN-NC(OH)(C6H5))}]) and characterized by FTIR, UV-Vis, 1H NMR, fluorescence and mass spectrometry. Single crystal X-ray diffraction analysis of 1 shows that the Cu atom possesses a square pyramid environment via bridging of 'phenolato'-O and 'enolato'-O of the ligand, additional bridging of 'methanolato'-O of coordinated CH3OH and monodentate coordination of imine-N. The EPR spectrum of 1 are characterized by g∥ = 2.286, A∥ = 169 × 10-4 cm-1, gτ = 2.068, Aτ = 17 × 10-4 cm-1 (298 K) and g∥ = 2.283, A ∥ = 178 × 10-4 cm-1, g τ = 2.072, Aτ = 15 × 10-4 cm -1 (77 K). The study of the variable temperature magnetic properties agrees with a predominant intramolecular antiferromagnetic coupling (2J = -186.5 cm-1), rendering a ground state of S = 0.
- Das, Kuheli,Mondal, Tapan Kumar,Garribba, Eugenio,Fondo, Matilde,Sinha, Chittaranjan,Datta, Amitabha
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p. 194 - 202
(2014/03/21)
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- Macrocyclic ZnII and CuII complexes as guests of the hybrid composites based on the layered MnPS3 phase. Comparison of spectroscopic properties
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A family of macrocyclic complexes [M2LnCl2] have been synthesized and characterized (M: CuII or ZnII; Ln: macrocyclic ligand derived from 2-hydroxy-5-methyl-1,3-benzenedicarbaldehyde and different aliphatic diamines and o-phenylenediamine). The influence of the aromaticity of the ligand and the metal center on the spectroscopic properties of the complexes (absorption and emission) has been studied. Making use of the weak interactions between hydrated potassium ions and the layers of the K0.4Mn0.8PS3 precursor, the obtained macrocyclic complexes have been intercalated in the interlamellar space by a microwave assisted cationic exchange reaction. The optical properties of the obtained hybrid materials are reported. The absorption edge, recorded by solid state reflectance spectroscopy for CuII and the ZnII macrocycle-based composites, is 1.67-1.76 eV, both shifted to lower energy compared with that of the pristine MnPS3.
- Fuentealba, Pablo,Serón, Lorenzo,Sánchez, Camila,Manzur, Jorge,Paredes-Garcia, Verónica,Pizarro, Nancy,Cepeda, Marjorie,Venegas-Yazigi, Diego,Spodine, Evgenia
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p. 3894 - 3908
(2015/04/14)
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- Solid-state photochromism of 5-tert-butyl-2-hydroxyisophthalaldehyde
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Colorless crystals of 5-tert-butyl-2-hydroxyisophthalaldehyde change to an orange-red color upon brief exposure to UV-vis radiation (λ> 300 nm). The colored crystals revert to colorless in the dark. X-ray diffraction revealed different packing patterns for the crystals of nonphotochromic and photochromic compounds.
- Tanaka, Koichi,Watanabe, Yuta,Kalicki, Przemyslaw,Urbanczyk-Lipkowska, Zofia
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experimental part
p. 727 - 729
(2012/08/08)
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- A general and convenient route to oxazolyl ligands
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A diverse range of chiral and achiral oxazolyl ligands, which have many applications including catalysis and luminescent devices, are synthesized simply in three steps from readily available and inexpensive phenol and amino alcohol starting materials. The method can be applied to ligands with electron-donating/-withdrawing and sterically demanding/undemanding substituents, and can conveniently be scaled up to >25 g of product.
- Aspinall, Helen C.,Beckingham, Oliver,Farrar, Michael D.,Greeves, Nicholas,Thomas, Christopher D.
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supporting information; experimental part
p. 5120 - 5123
(2011/10/19)
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- New efficient ruthenium metathesis catalyst containing chromenyl ligand
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A synthesis of new Hoveyda-Grubbs-type catalyst with chromenyl ligand was described herein. The new catalyst was tested in model RCM and CM reactions. The catalyst proved to be quite efficient. It showed activity comparable or superior to that of commercially available Grubbs second-generation complexes.
- Hryniewicka, Agnieszka,Morzycki, Jacek W.,Witkowski, Stanis?aw
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experimental part
p. 1265 - 1270
(2010/06/13)
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- Microwave-assisted Vilsmeier-Haack formylation of aromatic substrates
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A microwave-assisted Vilsmeier-Haack formylation reaction has been studied on various amines, phenols and polynuclear hydrocarbons under solvent free condition that rapidly affords higher yield of products compared to traditional thermal condition.
- Ghosh, Kumaresh,Adhikari, Suman
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experimental part
p. 959 - 961
(2009/12/24)
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- Efficient enhancement of DNA cleavage activity by introducing guanidinium groups into diiron(III) complex
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Inspired by the structures of natural nucleases, guanidinium groups were introduced into binuclear iron(III) systems. Compared with the corresponding analogue without guanidinium groups, the new diiron(III) system led to considerable rate enhancement on DNA cleavage. The cooperativity between metal ions and guanidine groups was evidenced by the fact that no significant cleavage was observed after incubating pBR322 plasmid DNA with non-metalated ligands or free Fe3+ ion. DNA binding experiments indicated that introduction of positively charged guanidinium groups can obtain more than one order of magnitude enhancement in the affinity of complex with DNA.
- Chen, Xiaoqiang,Wang, Jingyun,Sun, Shiguo,Fan, Jiangli,Wu, Song,Liu, Jianfeng,Ma, Saijian,Zhang, Lizhu,Peng, Xiaojun
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p. 109 - 113
(2008/09/18)
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- An improved oxidation approach for preparing 4-substituted-2,6- diformylphenol by manganese(IV) dioxide
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The method for the oxidation of 4-alkyl-2,6-di(hydroxymethyl)phenol to 4-alkyl-2,6-diformylphenol (alkyl = Me or t-Bu) by activated manganese(IV) dioxide was improved, and also expanded to the oxidation of 4-chloro-2,6- di(hydroxymethyl)phenol. The resulting three dialdehydes were obtained in good yields.
- Huang, Wei,Gou, Shaohua,Hu, Dahua,Meng, Qingjing
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p. 1555 - 1561
(2007/10/03)
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- Prodrugs: Part 3. 2-Formylphenyl esters of indomethacin, ketoprofen and ibuprofen and 6-substituted 2-formyl and 2-acylphenyl esters of aspirin
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The synthesis and study of a novel series of potential prodrugs of indomethacin, ketoprofen, ibuprofen and aspirin are reported. 2-Formylphenyl esters of the NSAIDs, together with two 6-substituted 2-formyl and two 2-acylphenyl aspirins and 4-formylphenyl indomethacin, have been prepared. A study of their alkaline and neutral hydrolysis shows that these compounds, with the exception of 2-acetylphenyl aspirin, act as true prodrugs of the NSAIDs, giving the NSAID and acylphenol. The rates of hydrolysis and activation parameters indicate that the 2-acylphenyl esters employ an intramolecular catalytic route. The 2-formylphenyl esters were more potent as anti-inflammatory agents than the parent compounds in the carragheenan-induced paw oedema test.
- Abordo, Evelyn A.,Bowden, Keith,Huntington, Anthony P.,Powell, Sarah L.
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- Mono- and diformylation of 4-substituted phenols: A new application of the duff reaction
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Careful control of the reaction conditions in a modified Duff reaction using anhydrous trifluoroacetic acid as the solvent enables the selective synthesis of either 4-substituted 2-formylphenols (5-substituted salicylaldehydes) or 4-substituted 2,6-diformylphenols in one step starting from commercially available 4-substituted phenols in moderate to good yield.
- Lindoy, Leonard F.,Meehan, George V.,Svenstrup, Niels
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p. 1029 - 1032
(2007/10/03)
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- Controlled synthesis and reversible oxidation of a thiolate-bridged macrocyclic dinickel(II) complex
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The synthesis of S-(2,6-Diformyl-4-methylphenyl) dimethylthiocarbamate, a valuable thiolate-containing ligand precursor, is reported in detail for the first time. This precursor has considerable potential in biosite modelling studies. A macrocycle L and a related acyclic ligand L′ have been prepared, as complexes, from the precursor and 1,3-diaminopropane. The macrocycle was successfully templated by both zinc(II) and nickel(II) ions yielding [Zn2L(H2O)2][O3SCF3] 2·H2O 1 and the diamagnetic complex [Ni2L][ClO4]2 2, respectively. A single-crystal X-ray analysis of 1 showed the zinc ions to have trigonal-bipyramidal environments and the macrocycle to have a stepped conformation. In contrast, the structure determination of 2 revealed square-planar N2S2 co-ordination for NiII and a bowed macrocycle conformation which results in much shorter metal-metal and sulfur-sulfur separations than the stepped conformation adopted in the case of ZnII [average Zn ... Zn 3.351(1), S ... S 3.363(3) for 1 vs. Ni ... Ni 3.146(2), S ... S 2.839(5) A for 2]. Two one-electron oxidations, the first reversible and the second quasi-reversible, were observed for the dinickel(II) complex, whereas one irreversible two-electron oxidation was observed for the dizinc(II) complex. An acetal forms in the presence of ethanol and leads to the isolation of the acyclic trinickel(II) complex [Ni2L′2Ni][ClO4]2 3.
- Brooker, Sally,Croucher, Paul D.,Roxburgh, Fiona M.
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p. 3031 - 3037
(2007/10/03)
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- Selective mono- and bis-oxidation of 2,6-bis(hydroxy methyl) phenols with active manganese dioxide
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Selective mono- and bis-oxidations of 2, 6-bis (hydroxy methyl) phenols with active M(n)O2 were realized, giving 2-hydroxy-3- hydroxymethyl benzaldehydes and 2-hydroxyisophthalaldehydes in good yields. The influence of oxidant activity, reaction solvent and temperature on the selectivity were investigated, and favorable conditions developed.
- Xie,Zhang,Yan,Yuan
-
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- Solvent effects on the ground and excited states proton transfer in 4-methyl-2,6-diformylphenol: Aprotic solvents
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The interaction of 4-methyl-2,6-diformylphenol (MFOH) with tributylamine and trioctylamine in different aprotic solvents has been studied quantitatively by means of electronic absorption and fluorescence spectroscopy with special attention to proton transfer at different temperatures.The acid-base interaction leads to different types of complexes, depending upon the dielectric constant of the solvents.In cyclohexane, dioxane or tetrahydrofuran hydrogen-bonded ion pair is formed, whereas a solvent-separated ion pair is formed in acetonitrile by the addition of amine inthe ground state.The large Stokes-shifted band in the fluorescence specrum of this compound in the 530 nm region is attributed to the tautomer generated by intramolecular proton transfer in the excited state.In the presence of an amine the sharp band at 445 nm region in cyclohexane, dioxane and tetrahydrofuran has been assigned to the schiff base and the band at 520 nm in acetonitrile to the hydrogen-bonded ion pair.Some thermodynamic data have been evaluated and discussed.
- Roy, R.,Mukherjee, S.
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- A novel selective oxidation of 5-substituted 2-hydroxy-3-hydroxymethylbenzaldehydes
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5-Substituted 2-hydroxy-1,3-benzenedicarbaldehydes 3 and 5-substituted 3-formyl-2-hydroxbenzoic acids 4 were prepared by selective oxidation of 5-substituted 2-hydroxy-3-(hydroxymethyl)-benzaldehydes 1 in a one-pot reaction. Compounds 1 were reacted with ethylenediamine and copper acetate to produce the complexes 2 as intermediates, in which formyl and phenolic hydroxy groups were protected in the subsequent oxidation step.
- Hu,Hu
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p. 325 - 326
(2007/10/02)
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- The Synthesis, Redox Properties, and Ligand Binding of Heterobinuclear Transition-Metal Macrocyclic Ligand Complexes. Measurement of an Apparent Delocalization Energy in a Mixed-Valent CuICuII Complex
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A series of binuclear complexes MAIIMBIIL2+ have been synthesized and characterized.The binuleating macrocyclic ligand L2+ is a symmetric Schiff base derived by condensing 2 equiv. of 2,6-diformyl-4-methylphenol with 2 equiv of 1,3-diaminopropane, resulting in two identical N2O2 coordination sites.In all cases, MA(II) = Cu(II) while MB was varied across the series MB(II) = Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II).The electrochemical properties of these species were examined by cyclic voltammetry, differential pulse polarography, sampled DC polarography, and coulometry.In each case reversible to quasi-reversible Cu(II)C(I) electrochemistry was observed.The Cu(II)Cu(I) reduction potential was, within experimental error, invariant with respect to the remote metal MB; Ef(Cu(II)Cu(I)) = -1.068 V vs. ferrocene/ferrocinium(1+).The one exception is the homonuclear complex MA(II) = MB(II) = Cu(II); the homobinuclear complex was more readily reduced, Ef = -0.925 V vs.Fc/Fc+, than the heteronuclear species.After a correction due to magnetic stabilization the difference between the heteronuclear and homonuclear reduction potantials, 143 mV = 3.3 kcal/mol, has been ascribed to a special stability associated with the mixed-valent CuIICuIL+ species, where some electronic delocalization has been previously demonstrated.In addition, the electrochemical properties of homonuclear complexes (MA = MB) are reported.The ligand-binding properties of the species CuIMBIIL+, MB(II) = Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II), have been examined.Cu(I) shows an affinity for the axial bases carbon monoxide, ethylene, tris(o-methoxyphenyl)phosphine, and 4-ethylpyridine.In contrast to the Cu(II)/Cu(I) reduction potentials, the binding of axial bases to Cu(I) does seem to depend on the nature of the remote metal, Mb.
- Gagne, R. R.,Spiro, C. L.,Smith, T. J.,Hamann, C. A.,Thies, W. R.,Shiemke, A. K.
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p. 4073 - 4081
(2007/10/02)
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