Phosphine oxide-based tricarbonylrhenium(i) complexes from phosphine/phosphine oxide and dihydroxybenzoquinones

Abstract

Neutral phosphine oxide (PO) donor-based organometallic complexes [{Re(CO)3OPCy3}{μ-DHBQ}{Re(CO)3OPCy3}] (1), [{Re(CO)3OPPh3}{μ-DHBQ}{Re(CO)3OPPh3}] (2), [{Re(CO)3OPCy3}{μ-THQ}{Re(CO)3OPCy3}] (3), [{Re(CO)3OPPh3}{μ-THQ}{Re(CO)3OPPh3}] (4), [{Re(CO)3OPCy3}{μ-CA}{Re(CO)3OPCy3}] (5), and [{Re(CO)3OPPh3}{μ-CA}{Re(CO)3OPPh3}] (6) were assembled from phosphine/phosphine oxide, a dihydroxybenzoquinone donor and Re2(CO)10via a one-pot solvothermal approach. The soft phosphine donor was transformed into a hard phosphine oxide donor during the formation of 1, 3, 4, 5, and 6. The complexes 1-6 were air and moisture stable and were soluble in polar organic solvents. The complexes were characterized by elemental analysis, FT-IR, and NMR spectroscopic methods. The molecular structures of 1, 2, 4, and 6 were analyzed by single-crystal X-ray diffraction analysis. The UV-Visible absorption studies indicated that 1-6 in THF display strong visible light absorption in the range of ∼350-700 nm.