Synthesis and X-ray crystal structure of an oxorhenium(V) complex with a double Schiff base

Abstract

The reaction of the double Schiff bases, RL, formed from 2,6-diformyl-4-methyl-phenol and p-RC 6H 4NH 2 (R=H, Me, OMe, Cl) with ReOCl 3(PPh 3) 2 afforded red coloured complexes of the type Re vOCl 3(RL). The X-ray structure of the R = Me complex (crystal data: ReOCl 3(MeL)·CH 2Cl 2, triclinic, space group P I , a = 8.736(2), b=10.632(3), c=10.575(5)Å, a=104.64(2)°, β=93.22(2)°, γ = 110.57(2)°, V = 1376.6(7) A ̊ , Z =2, R = 3.06%, R w = 3.51% ) revealed meridional chloro coordination in an ReOCl 3(ON) coordination sphere. The RL ligand binds in the bidentate ON mode, the second imine function occurring in the protonated from (NH…O hydrogen bonding). IR and 1H NMR data indicate that the solid-state structure is substantially retained in solution. The complexes display a quasi-reversible Re VIO/Re VO couple whole potential depends on the R substituent.