Synthesis, characterization and structures of the novel rhenium(IV) complexes trans-[ReCl_4{PPh_2(OMe)}_2], trans-[ReCl_4{PPh_2(OEt)}_2] and trans-[ReCl_4(OPPh_3)_2]

摘要

trans-Tetrachlorobis(methyl-diphenylphosphinite)rhenium(IV) and trans-tetrachlorobis(ethyl-diphenylphosphinite)rhenium(IV) were obtained by recrystallization of the corresponding rhenium(III) phosphinite complexes, [ReCl_3L_3], in chlorinated solvents. The structures of the compounds consist of discrete molecules with trans-octahedral coordination geometry around the rhenium atom, having Re-P distances between 2.534(1) and 2.555(2) A and Re-Cl distances in the range 2.321(1)-2.336(1) A, trans-[ReCl_4(OPPh_3)_2] is formed during the reaction of triphenyloxonium tetrafluoroborate with [ReNCl_2(PPh_3)_2]. P-O bond lengths of 2.033(4) A have been found, while the Re-Cl bonds are 2.336(2) and 2.344(2) A. respectively.