Synthesis, structure and spectral properties of dithiocarbamato bridged dirhenium(III,II) complexes: A combined experimental and theoretical study

摘要

Sodium salts of dimethyldithiocarbamate, diethyldithiocarbamate and pyrrolidinedithiocarbamate react with the multiply bonded paramagnetic dirhenium(III,II) complex Re-2(mu-O2CCH3) Cl-4(mu-dppm)(2), 1 (dppm = Ph2PCH2PPh2) in refluxing ethanol to afford the paramagnetic substitution products of the type Re-2(eta(2)- S,S)(2)(mu-S,S)(mu-Cl)(2)(mu-dppm), where S,S represents the dithiocarbamato ligands [S,S = S2CNMe2, 4(L-Me); S2CNEt2, 4(L-Et) and S2CN(CH2)(4), 4(L-Pyr)]. These are the first examples of dirhenium complexes that contain bridging dithiocarbamato ligand along with the dppm ligand. These complexes have very similar spectral (UV-Vis, IR, EPR) and electrochemical properties which are also reported. The identity of 4(L-Et) has been established by single-crystal X-ray structure determination (Re-Re distance 2.6385 (9) angstrom) and is shown to have edge-shared bioctahedral structure. The electronic structure and the absorption spectra of the complexes are scrutinized by the density functional theory (DFT) and time-dependent density functional theory (TD-DFT) analyses. (C) 2014 Elsevier B.V. All rights reserved.