- Hydrogen bond networks in five- and eight-membered palladium and platinum complexes derived from bis(2-aminophenyl)ether and bis(2-aminophenyl)thioether ligands
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The reaction of [MII(MeCN)2Cl2] (M = Pd, Pt) with the diamino ligands either bis(2-aminophenyl)ether or bis(2-aminophenyl)thioether {(NH2-C6H4)2D} [D = O (L1); D = S (L2)] yielded neutral coordination complexes of general formulae [M(Ln)Cl2] [M = Pd, n = 1 (1); Pt, n = 1 (2); Pd, n = 2 (3); Pd, n = 2 (4); Pt, n = 2 (5). The reaction of L2 with K2[PtCl6] promoted the mono-deprotonation of the diamino ligand to yield the neutral complex [PtIV{(NH2-C6H4)S(NH-C6H4)}Cl3] (6); when the H2[PtCl6] acid was used an ionic complex [PtIV(L2)Cl3]Cl (7) was obtained. All complexes were characterized by NMR in solution, vibrational spectroscopy, and by X-ray diffraction studies. The molecular structures of the complexes revealed different coordination patterns of the diamino ligands; L1 just displayed a κ2N mode meanwhile L2 exhibited a wide variety of patterns (κ2N, κNκS, and κ2NκS) forming chelate rings of five- or eight-members. The presence of N-H functions in the ligand moieties enhanced the formation of extended hydrogen-bond networks; these supramolecular arrangements were mainly discussed at unitary and binary levels and sorted according to the molecular coordination patterns observed.
- Hernández-Balderas, Uvaldo,Andrade-López, Noemí,Alvarado-Rodríguez, José G.,Moreno-Esparza, Rafael,Paneque, Margarita
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- Solid-state valence tautomeric octahedral {CoII[(BQ-N-Cat)]2}0 complex formation via ligand-centered phenolic C-O bond breaking and Co-O bond making
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Ligand H4LO(AP/AP) underwent ligand-centered C-O bond cleavage during a complexation reaction with Co(ii)-salt. The thus formed octahedral {CoII[(BQ-N-Cat)]2}0 complex showed valence tautomerization in the solid state. While the process was triggered by the presence of lattice solvent, the nature of the solvent molecule has less effect on the process.
- Mondal, Manas Kumar,Tiwari, Archana,Mukherjee, Chandan
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- A Comprehensive Study of the Ca2+ Ion Binding of Fluorescently Labelled BAPTA Analogues
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Since its development, the ionophore BAPTA (1,2-bis(2-aminophenoxy)-ethane-N,N,N’,N’-tetraacetic acid) has been used unchanged in calcium sensing applications. In this work we present a comprehensive experimental and theoretical study of novel alterations in the structure of BAPTA, with a focus on the systematic modification of the chain connecting the two aromatic rings of the molecule (denoted as “linker”). A bis-(diethylamino)xantene fluorophore was also attached to the structures in a fixed position and the structure-fluorescence response relationship of these molecules was investigated in addition. The effect of the linker's length, the number of oxygen atoms in this chain and even the removal of one of the rings was tested; these all proved to significantly alter the characteristics of the compounds. For example, it was found that the second aromatic ring of BAPTA is not essential for the turn-on of the fluorescence. We also demonstrated that successful sensing can be realized even by replacing the chain with a single oxygen atom, which suggests the availability of a new calcium binding mode of the chelator. The reliable turn-on characteristic, the steep Ca2+ fluorescence titration curve and the intense fluorescence emission combine to make this compound a prospective candidate as a calcium sensing molecular probe in diagnostic neurobiological applications.
- Csomos, Attila,Kontra, Bence,Jancsó, Attila,Galbács, Gábor,Deme, Ruth,Kele, Zoltán,Rózsa, Balázs József,Kovács, Ervin,Mucsi, Zoltán
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p. 5248 - 5261
(2021/10/19)
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- A silicon-containing compound and comprising the silicon-containing compound of the organic electroluminescent device (by machine translation)
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Provides improved emission efficiency silicon-containing compound and comprising the silicon-containing compound of the organic electroluminescent device. According to the present invention contemplates silicon-containing compound by the following formula 1 expressed. Type 1 . (by machine translation)
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- Metal- and Phenol-Free Synthesis of Biaryl Ethers: Access to Dibenzobistriazolo-1,4,7-oxadiazonines and Vancomycin-Like Glyco-Macrocycles as Antibacterial Agents
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An efficient synthesis of biaryl ethers, from electron-deficient aryl halides using NaH/DMSO under metal- and phenol-free conditions, has been achieved to access dibenzo-bistriazolo-1,4,7-oxadiazonines and vancomycin-like glyco-macrocycles. A 44-membered glyco-macrocycle showed promising activity against vancomycin-resistant Staphylococcus aureus (VRSA).
- Singh, Kartikey,Sharma, Gaurav,Shukla, Manjulika,Kant, Ruchir,Chopra, Sidharth,Shukla, Sanjeev K.,Tripathi, Rama P.
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p. 14882 - 14893
(2018/12/14)
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- Method for the preparation of diphenyl ether compounds
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The invention relates to a method for preparing a diphenyl ether compound. The method is characterized by comprising the following technical steps of: (1) adding a halogenated benzene derivative and a bis(pinacolato)diboron into a reaction vessel, adding copper chloride or aluminum chloride and 1,2-bi(diphenylphosphine) ethane as a catalyst, then adding alkaline and an organic solvent, and reacting at 25-160 DEG C for 6-24 hours; and (2) after extracting a reaction solution obtained from the step (1) by using ethyl acetate, purifying by a 200-300 meshes silica gel column, pre-eluting the silica gel column by using 20-50 mL of normal hexane, eluting by adopting an eluent at a flow speed of 1-2 mL/min for 3-6 hours, and removing the solvent to obtain the diphenyl ether compound. The method for preparing the diphenyl ether compound, disclosed by the invention, no only overcomes the disadvantage of the use of phenolic substances in a reaction process, but also has the advantages of mild reaction condition and high yield.
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Paragraph 0050-0052
(2016/12/01)
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- Tethered bis(amidate) and bis(ureate) supported zirconium precatalysts for the intramolecular hydroamination of aminoalkenes
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Tethered bis(amide) and bis(urea) proligands featuring a neutral chalcogen donor (O or S) in the backbone were synthesized and installed on zirconium via protonolysis. The bis(amidate) zirconium complexes adopt a κ4(N,N,O,O) binding motif and were characterized in the solid state with a pyridine donor. Likewise, the bis(ureate)-supported complexes are also found to have a κ4(N,N,O,O) binding motif in the solid state however no additional donor ligand is required for discrete complex formation. No evidence for interaction between the neutral chalcogen donor and the zirconium atom is found for any of the transition metal species. All complexes were screened as precatalysts for the intramolecular hydroamination reaction with both primary and secondary aminoalkene substrates. Interestingly, the bis(ureate) species show similar reactivity to the bis(amidate) species, in contrast to a recently reported alkyl-bridged bis(ureate) complex, which readily cyclizes secondary aminoalkenes.
- Lauzon, Jean Michel P.,Schafer, Laurel L.
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p. 128 - 135
(2015/01/30)
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- Oxygen bridged nitroanilines for quadratic nonlinear optics
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Several nitro aromatic compounds bridged by an oxygen atom have been synthesized and their linear and nonlinear optical properties have been investigated. In one of the compounds (1), a powder SHG efficiency of 6.2 times of urea was observed while its absorption lies in the UV region. The highest molecular hyperpolarizability β, measured was 230 x 10-30 for a compound (8f) with increased conjugation. Thermal stability of these compounds has been checked using differential scanning calorimetry and the decomposition temperature (Td) was found to be high and lying between 266-298 °C. These molecules have potential importance as thermally stable, visible-transparent second order NLO materials.
- Sudharsanam, Ramanathan,Chandrasekaran, Srinivasan,Das, PuspenduKumar
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- Syntheses of ligands containing two and three 2,2'-(bisamino)diphenyl ether units designed for molecular self-assembly on lithiation
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The syntheses of polyamines containing two or three 2,2'-(bisamino)diphenyl ether units linked together, designed for self-assembly following lithiation, are reported. The X-ray crystal structures of two of the bis[2,2'-(bisamido)diphenyl ethers] are described. The ligand, which is linked by an ethylene glycol spacer, exhibits a coiled conformation constrained by intramolecular hydrogen bonds and supplemented by [CH-π] interactions. The ligand, which is linked by a more rigid bridge, containing a paraphenylene unit, displays a stretched conformation stabilised by intramolecular hydrogen bonds and intramolecular T-type aromatic-aromatic edge-to-face interactions.
- Ashton, Peter R.,H?rner, Bernd,Kocian, Oldrich,Menzer, Stephan,White, Andrew J. P.,Stoddart, J. Fraser,Williams, David J.
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p. 930 - 940
(2007/10/03)
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- Self-Assembly in the Metallation of Bis(aminoaryl) Ethers
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The dilithiation of 2,2'-bis(2-methoxyethylamino)diphenyl ether (4) and 2,2'-bis(N,N-dimethylethylenediamino)diphenyl ether (7) in the absence of any Lewis base donor resulted in the formation of dimeric complexes 8 and 9, respectively, containing the unprecedented Li4O2N4 "adamantanoid" metal core as a consequence of the self-recognition and self-assembly involving the two metallated subunits.In contrast, on monometallation using particular conditions, e.g. sodium hydride in the presence of Lewis base donor, the same ligands undergo a Smiles-type rearrangement, providing the first example of such a reaction involving an amine and a deactivated aromatic system.The conditions needed to promote this rearrangement have been invstigated.
- Kocian, Oldrich,Spencer, Neil,Stoddart, J. Fraser,Cragg-Hine, Ian,Davidson, Matthew,et al.
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p. 579 - 590
(2007/10/02)
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- A New and Efficient Preparation of Cyclic Carbodiimides from Bis(iminophosphoranes) and the System Boc2O/DMAP
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A one-pot synthesis of cyclic carbodiimides which involves reaction of C,C-bis(aryliminophosphoranes) connected by aliphatic bridges with Boc2O in the presence of DMAP is described.The method is also applicable when a heteroatom such as oxygen or nitrogen is incorporated into the tether connecting the two aromatic rings.A conformation study has been carried out on carbodiimide 23a, which possess a central nine-membered ring, using 1H NMR spectroscopy and semiempirical as well as molecular mechanics calculations.
- Molina, Pedro,Alajarin, Mateo,Sanchez-Andrada, Pilar,Elguero, Jose,Jimeno, Maria Luisa
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p. 7306 - 7315
(2007/10/02)
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- Preparation of P,P'-oxybis(aniline)
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Oxybisaniline is prepared in high yield by reacting a hydroxylamine with a polycarboxylic diphenyl ether in the presence of an inorganic acid. The acid groups are directly converted to amine groups. By-products of the reaction are negligible.
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