摘要:
Two new luminescent mononuclear Pt(II) chloride complexes possessing C-linked 2,2'-bipyridyl tetrazole terdentate chelating ligands, namely, Pt(tbpy)Cl (1) and Pt(tmbpy)Cl (2) (tbpyH = 6-(1H-tetrazol-5-yl)-2,2'-bipyridine; tmbpyH = 6-(1H-tetrazol-5-yl)-4,4'-dimethyl-2,2'-bipyridine), have been synthesized. and characterized. Complex 2 adopts a distorted square-planar geometry with a mono-anionic terdentate chelate tmbpy, and it presents a zigzag head-to-tail stacking array along the a axis with alternating Pt center dot center dot center dot Pt separations of 3.415 and 5.469 angstrom. For 2, a moderately intensive broad absorption band appears at 350-425 nm in dilute DMF solution, most likely assigned as the metal-to-ligand charge transfer (MLCT)-M-1 (Pt(5d) -> tmbpy) transition, mixed with some halide-to-ligand charge transfer (XLCT)-X-1 (Cl -> tmbpy) and intraligand (IL) (1)pi pi* transitions inside tmbpy. It is demonstrated that the solubilities and luininescence properties of 1 and 2 are markedly influenced by the substituents in the 4 and 4'-positions of the 2,2'-bipyridyl ring. The solid-state emissions of 1 and 2 are perhaps best attributable to the (MMLCT)-M-3/(XLCT)-X-3/(IL)-I-3.. states, as supported by TD-DFT calculation of 2. (C) 2013 Elsevier B.V. All rights reserved.