Synthesis, characterization and structures of the novel rhenium(IV) complexes trans-[ReCl4{PPh2(OMe)}(2)], trans-[ReCl4{PPh2(OEt)}(2)] and trans-[ReCl4(OPPh3)(2)]

trans-Terrachlorobis(methyl-diphenylphosphinite)rhenium(IV) and trans-tetra chlorobis(ethyl-diphenylphosphinite)rhenium(IV) were obtained by recrystall ization of the corresponding rhenium(III) phosphinite complexes, [ReCl3L3], in chlorinated solvents. The structures of the compounds consist of discre te molecules with trans-octahedral coordination geometry around the rhenium atom, having Re-P distances between 2.534(1) and 2.555(2) Angstrom and Re- CI distances in the range 2.321(1)-2.336(1) Angstrom, trans-[ReCl4(OPPh3)(2 )] is formed during the reaction of triphenyloxonium tetrafluoroborate with [ReNCl2(PPh3)(2)]. P-O bond lengths of 2.033(4) Angstrom have been found, while the Re-Cl bonds are 2.336(2) and 2.344(2) Angstrom, respectively. (C) 1999 Elsevier Science Ltd. All rights reserved.