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A neutral nickel complex with the extended tetrathiafulvalene-4,5-dithiolate ligand benzotetrathiafulvalenedithiolate (btdt2-) is synthesized and characterized. From the structural analysis, the neighboring molecules in this complex are stacked in a different way compared to the previously reported single-component metal [Ni(tmdt)2]. The computational studies confirm that the difference in molecular packing results in the variance of conductivity. [ABSTRACT FROM AUTHOR]

A new series of mononuclear copper(l) complexes (l-- 9) with functionalized 3-(2'-pyridyl)-l,2,4-triazole chelating ligands, as well as the halide and/or phosphine ancillary ligands, have been synthesized. Complexes 1--9 were fully characterized by elemental analysis, NMR spectroscopy, mass spectroscopy, electronic absorption spectroscopy, fluorescence spectroscopy, cyclic voltammetry, and X-ray crystallography (1--8). They adopt a distorted tetrahedral configuration, and are considerably air-stable in solid state and in solution. All these Cu(l) complexes display a comparatively weak low-energy absorption in CH2C12 solution, assigned to charge-transfer transitions with appreciable MLCT character, as supported by TD-DFT studies. Cu(l) halide complexes 1--4 each shows bright solid-state emission at room temperature, although they are nonemissive in fluid solutions, in which the emission markedly depends on the halide and the substituent on the 2-pyridyl ring. Complexes 5--9 bearing 2-pyridyl functionalized 1,2,4-triazole and phosphine exhibit good photoluminescence properties in solution and solid states at ambient temperature, which are well-modulated via the alteration of the auxiliary phosphine ligand and the structural modification of 3-(2'-pyridyl)-l,2,4-triazole. Interestingly, cationic complex 6 and neutral derivative 7 can readily be interconverted through die ring inversion of the 1,2,4-triazolyl regulated by the NH N~ transformation. [ABSTRACT FROM AUTHOR]

A novel family of iridium(III) bis-tridentate complexes are reported that contain the deprotonated, N∧N∧N-coordinated 6-(5-trifluoromethylpyrazol-3-yl)-2,2′-bipyridine (fpbpyH) ligand. The monocationic homoleptic iridium(III) complex [Ir(fpbpy)2](PF6) (1) was first prepared by treatment of IrCl3·3H2O with 2.2 equiv of fpbpyH in degassed ethylene glycol at 196 °C and structurally characterized by single-crystal X-ray crystallography. The reaction of Ir(tpy)Cl3with an equimolar amount of fpbpyH under comparable conditions generated a dicationic heteroleptic iridium(III) complex, [Ir(fpbpy)(tpy)](PF6)2(2), featuring one 2,2′:6′2′′-terpyridine (tpy) in place of one fpbpy. The charge-neutral heteroleptic complex [Ir(fpbpy)(dppy)] (3) (dppyH2= 2,6-diphenylpyridine) was also afforded successfully via a solvent-free method, giving a complex with one dppy bound to the Ir(III) ion through two carbon atoms for the cyclometalation reaction. Complexes 1−3are emissive in acetonitrile solution at ambient temperature, perhaps best assigned to the MLCT character, mixed with intraligand charge transfer (ILCT) transition inside fpbpy and ligand-to-ligand charge transfer (LLCT) π(fpbpy) → π*(tpy) or π(dppy) → π*(fpbpy) transition, respectively, which are supported by DFT calculations. It is noteworthy that the photoluminescence of 3displays a significant red-shifting compared to those of 1and 2due to the large reduction of the HOMO−LUMO energy gap as a consequence of the introduction of the more electron-donating and strong ligand-field cyclometalate dppy chelate. [ABSTRACT FROM AUTHOR]