π...π interaction assembled silver(I) complexes with the ligand 4′,5′-diaza-9′-(4,5-disubstituted-1,3-dithiol-2-ylidene)fluorene

Six silver(I) complexes with a new type of ligand, 4',5'-diaza-9'-(4,5-disubstituted-1,3-dithiol-2-ylidene)fluorene (L-n, n = 1, Me; 2, Et; 3, Bu substituted) have been obtained. Two of the complexes [Ag(L-1)(2)]ClO4 (1) and [Ag(L-1)(2)]SO3CF3 (4) have been structurally characterized by single-crystal X-ray diffraction. All of the Ag(I) ions are coordinated linearly by two ligands and the cations take planar structures. These planes are further assembled into one dimensional columns by Ag-Ag weak bonds, pi-pi stacking and (AgN)-N-... interactions. The UV-Vis and fluorescence spectra of the complexes were studied and the ligand-centered energy levels are not changed dramatically when the complexes are formed. (C) 2004 Elsevier Ltd. All rights reserved.