Search

A tetrathiafulvalene (TTF) derivative 4-pyridyltetrathiafulvalene (Py-TTF) is synthesized. Molecules stack in a face-to-face mode along the b axis, and there are intermolecular interactions between columns.

A 3-D chiral cadmium coordination polymer [Cd2(OH)(1,2,4-BTC)] is prepared under hydrothermal conditions using an unsymmetrical 1,2,4-benzenetricarboxylate (1,2,4-BTC) and characterized by single crystal X-ray diffraction and the 1,2,4-BTC ligand is found to show an unprecedented coordination mode. The compound exhibits intense photoluminescence at room temperature and shows distinct NLO properties.

Two molecular assemblies with one Ru(II)-polypyridine photosensitizer covalently linked to one Ru(II)(bda)L2 catalyst (1) (bda = 2,2'-bipyridine-6,6'-dicarboxylate) and two photosensitizers covalently linked to one catalyst (2) have been prepared using a simple C-C bond as the linkage. In the presence of sodium persulfate as a sacrificial electron acceptor, both of them show high activity for catalytic water oxidation driven by visible light, with a turnover number up to 200 for 2. The linked photocatalysts show a lower initial yield for light driven oxygen evolution but a much better photostability compared to the three component system with separate sensitizer, catalyst and acceptor, leading to a much greater turnover number. Photocatalytic experiments and time-resolved spectroscopy were carried out to probe the mechanism of this catalysis. The linked catalyst in its Ru(II) state rapidly quenches the sensitizer, predominantly by energy transfer. However, a higher stability under photocatalytic condition is shown for the linked sensitizer compared to the three component system, which is attributed to kinetic stabilization by rapid photosensitizer regeneration. Strategies for employment of the sensitizer-catalyst molecules in more efficient photocatalytic systems are discussed. [ABSTRACT FROM AUTHOR]

Reaction of multidentate 5-(4-imidazol-1-yl-phenyl)-2H-tetrazole (L) ligand with Ag(I) ions in the existence of H3PW12O40 as anionic template under hydrothermal conditions results in tridecanuclear silver cluster-polyoxometalates hybrid: {Ag13L12}{PW12O40}4·30H2O (1). X-ray single crystal diffraction analysis indicates that the main structural feature of 1 is a nanosized molecular windmill-shaped polynuclear Ag cluster with intriguing {M@M12}-type cuboctahedral topology. The as-synthesized compound exhibits effective photocatalytic activity in the photodegradation of Rhodamine-B (RhB) and antibacterial activity against Escherichia coli, respectively. [ABSTRACT FROM AUTHOR]

A series of isostructural 2-fold interpenetrating 2D Cd(II)-MOFs, namely G⊂CdL2(OTs)2 (G = THF (1), PhF (2), PhCl (3), PhBr (4), PhI (5), L = 1,2-bis[(3-(pyridin-4-yl)phenoxy]ethane, and OTs- = p-toluenesulfonate anion), have been successfully synthesized from the flexible ethylene glycol ether-bridging ligand L and Cd(OTs)2 in solution. The CdL2(OTs)2 framework contains squarelike nonpolar channels, and the encapsulated guest molecules can be removed by heating (150 °C) to generate a guest-free host framework which is able to reversibly adsorb monohalobenzenes PhX (X = F, Cl, Br, I) in the liquid phase under ambient conditions without loss of framework integrity. Furthermore, it can effectively separate these monohalobenzenes and exhibits a clear affinity for monohalobenzenes according to the following order: PhI > PhBr > PhCl > PhF. In addition, PhX⊂CdL2(OTs)2 exhibits guest-dependent luminescence properties. [ABSTRACT FROM AUTHOR]

A series of Ru-bda water oxidation catalysts [Ru(bda)L2] (H2bda = 2,2'-bipyridine-6,6'-dicarboxylic acid; L = [HNEt3][3-SO3-pyridine], 1; 4-(EtOOC)-pyridine, 2; 4-bromopyridine, 3; pyridine, 4; 4-methoxypyridine, 5; 4-(Me2N)-pyridine, 6; 4-[Ph(CH2)3]-pyridine, 7) were synthesized with electron-donating/-withdrawing groups and hydrophilic/hydrophobic groups in the axial ligands. These complexes were characterized by ¹H NMR spectroscopy, high-resolution mass spectrometry, elemental analysis, and electrochemistry. In addition, complexes 1 and 6 were further identified by single crystal X-ray crystallography, revealing a highly distorted octahedral configuration of the Ru coordination sphere. All of these complexes are highly active toward CeIV-driven (CeIV = Ce(NH4)2(NO3)6) water oxidation with oxygen evolution rates up to 119 mols of O2 per mole of catalyst per second. Their structure--activity relationship was investigated. Electron-withdrawing and noncovalent interactions (attraction) exhibit positive effect on the catalytic activity of Ru-bda catalysts. [ABSTRACT FROM AUTHOR]

A new bridging ligand 1,3,6,8-tetrakis(1-butyl-1H-1,2,3-triazol-4-yl)pyrene (ttapyr) was designed and synthesized by "click" chemistry. This ligand was used to construct a linear dimetallic biscyclometalated Ru(II) complex [(tpy)Ru(ttapyr)Ru(tpy)]2+ and a monometallic complex [(tpy)Ru(ttapyr)]+, where tpy is 2,2′:62′,22″-terpyridine. The electronic properties of these complexes were studied and compared by electrochemical and spectroscopic methods with the aid of DFT calculations. One-electron oxidation of [(tpy)Ru(ttapyr)Ru(tpy)]2+ with cerium ammonium nitrate produced a mixed-valent complex [(tpy)Ru(ttapyr)Ru(tpy)]3+. The intramolecular electronic coupling between individual metal centers was quantified by the intervalence charge transfer transition analysis. Mixed-valent complex [(tpy)Ru(ttapyr)Ru(tpy)]3+ exhibits a metal-centered rhombic EPR signal at 77 K with an average g factor of 2.203. [ABSTRACT FROM AUTHOR]

We report a facile mechanochemical preparation method for nanocrystalline BaFCl doped with samarium in the 2+ oxidation state by ball milling BaCl2 BaF2, and SmI2 under a nitrogen atmosphere. The resulting phosphors were characterized by powder X-ray diffraction; electron microscopy, X-ray photoelectron spectroscopy; and photoluminescence, photoexcitation, cathodoluminescence, and diffuse reflectance spectroscopy. This is the first report of a direct preparation method of Sm2+ doped alkaline earth fluorohalides at room temperature and points to a significant potential for the preparation of a wide range of related X-ray storage phosphors containing rare earth ions in divalent and trivalent cationic states by mechanochemical methods. [ABSTRACT FROM AUTHOR]