Azidotetrakis(diarylformamidinate)diruthenium(II,III) compounds: Synthesis, molecular structures and voltammetric properties; Linear free energy relationships in dinuclear compounds VII

摘要

A series of Ru-2(DArF)(4)(N-3) compounds have been prepared from the metathesis reaction between Ru-2(DArF)(4)Cl and NaN3, where DArF is diarylformamidinate, and aryl is X-Ph with X as 4-MeO (1), 4-Me (2), H (3), 3-MeO (4), 4-Cl (5), 3-Cl (6), 3-CF3 (7), 4-CF3 (8), 3,4-Cl-2 (9) and 3,5-Cl-2 (10). Single crystal X-ray diffraction studies of 3 and 10 revealed the expected paddlewheel motif for the first coordination sphere of Ru-2 and axial ligation of azide. Voltammetric studies revealed a (quasi)reversible oxidation (A) and a irreversible reduction (B) for all compounds, and a second (quasi)reduction (C) for compounds 6-10. The half-wave potentials of couple A span a remarkable range of 640 mV, and they correlate linearly with the Hammett constant (sigma) of the aryl substituent.