Preferred Abstract (Original):
Five
trans-[Ru(P-P)
2Cl
2] complexes were prepared by reacting RuCl
2(PPh
3)
3 with P-P ligands {PāP = 3-hexyl-1,3-bis(diphenylphosphino) propane (hdppp) (
1); = 1,3-bis(diphenylphosphino)propane (dppp)
(2); = 1,2-bis(diphenylphosphino)ethane (dppe) (
3); 1.1ā-bis(diphenylphosphino)methane (dppm) (
4); 1,2-bis(diphenylphosphino)ethylene (depe) (
5}. The complexes were characterized by an elemental analysis, IR,
1H,
13C and
31P{1H}NMR,
FAB-MS and TG/DTA. These Ru(II) complexes showed Ru(III)/Ru(II)
quasireversible redox couple. The molecular structures of the complexes
1 and
3 were determined by X-ray crystallography, and their spectroscopic properties were studied. Another polymorph of
3 was reported in literature, the reported polymorph of
3 in this work crystallizes in p
-1 space group, whereas, the previously reported polymorph crystallizes in C2/c space group. The two complexes adopt a distorted
trans
octahedral coordination and ruthenium (II) ions are located on a
crystallographic centre of symmetry. Based on the optimized structures,
computational investigations were carried out in order to determine the
electronic structures of the complexes. The electronic spectra of
1 and
1+
in dichloromethane were calculated with the use of time-dependent DFT
methods, and the electronic spectra of the transitions were correlated
with the molecular orbitals of the complexes.