Dirhenium paddlewheel complexes bearing para-substituted triphenylguanidinate ligands : Synthesis, spectroscopic and computational studies

The quadruply bonded dirlignium(III) complexes, [Re-2(mu-TPG(R))(4)Cl]Cl, bridged by four para-substituted triphenylguanidinate ligands (TPG(R), R = H, Me, OMe) have been synthesized by the reaction of molten HTPG(R) and [Bu4N](2)Re2Cl8 (Bu = n-butyl). Conductivity measurements of the complexes in acetone solution confirmed their electrolytic nature. These complexes have very similar spectral and electrochemical properties, which are also reported. The identities of the complexes have been established by ESI-mass spectrometry. The electronic structures of the complexes are also scrutinized by density functional theory (DFT) calculations.