1211510-03-0Relevant articles and documents
Spectroscopic and luminescence studies on square-planar platinum(ll) complexes with anionic tridentate 3-bis(2-pyridylimino)isoindoline derivatives
Wen, Hui-Min,Wu, Yu-Hui,Fan, Yang,Zhang, Li-Yi,Chen, Chang-Neng,Chen, Zhong-Ning
, p. 2210 - 2221 (2010/05/15)
Reactions of 1,3-bis(2-pyridylimino)isoindoline (HL1 ), 1,3-bis(2-pyridylimino)benz(f)isoindoline (HL2), or 5,6-dihydro2,3-diphenyl-5- (pyridin-2-ylimino)pyrrolo[3,4-b]pyrazin-7-ylidene)pyridin-2-amine (HL3) with Pt(tht)2Cl2 (tht = tetrahydrothiophene) afforded the corresponding Pt(L)Cl complexes. A series of neutral platinum(II) alkynyl complexes Pt(L)(C≡CR) were prepared by reactions of the precursors Pt(L)CI with alkynyl ligands through Cul-catalyzed platinum acetylide σ coordination. Crystal structural determination of Pt(L3)Cl (3), Pt(L1)(C≡CPh) (4), and Pt(L1)(C≡CC6H4Bu t-4) (6) by X-ray crystallography revealed that the neutral platinum(II) complexes with monoanionic tridentate L ligands display more perfect square-planar geometry than that in platinum(II) complexes with neutral tridentate 2,2':6',2"-terpyridyl ligands. Both the Pt(L)Cl and Pt(L)(C≡CC6H4R-4) complexes exhibit lowenergy absorption at 400-550 nm, arising primarily from π → π*(L) intraligand (IL) and 5d(Pt) →π *(L) metal-toligand charge-transfer (MLCT) transitions as suggested from density functional theory calculations. They display bright-orange to red room-temperature luminescence in fluid dichloromethane solutions with microsecond to submicrosecond ranges of emissive lifetimes and 0.03-3.79% quantum yields, originating mainly from 3IL and 3MLCT excited states. Compared with the emissive state in Pt(L)Cl complexes, substitution of the coordinated Cl with C≡CC6H 4R-4 in Pt(L)(C≡CC6H4R-4) complexes induces an obviously enhanced contribution from the 3[π(C≡ CC6H4R-4) → π*(L))] ligand-to-ligand charge-transfer (LLCT) triplet state. The photophysical properties can be finely tuned by modifying both the L and alkynyl ligands. The calculated absorption and emission spectra in dichloromethane coincide well with those measured in a fluid dichloromethane solution at ambient temperature. 2010 American Chemical Society.