Synthesis and characterization of six-coordinate "3+2" mixed-ligand oxorhenium complexes with the o-diphenylphosphinophenolato ligand and tridentate coligands of different N and S donor atom combinations

A series of octahedral six-coordinate oxorhenium(V) mixed ligand complexes containing the common [ReO(L)](2+) fragment (L = o-OC6H4P(C6H5)(2)] have be en synthesized and characterized. Hence, it was shown that the [ReO(L)](2+) moiety can accommodate a variety of tridentate ligands containing a centra l amine group amenable to deprotonation and different combinations of later al groups, such as ethylamine, substituted ethylamine, ethylthiol, and ethy lthioether arms. In particular, by reaction of equimolar amounts of the per tinent HLn ligands with the [(n-C4H9)(4)N][ReOCl3(L)] precursor in refluxin g acetonitrile/methanol or dichloromethane/methanol mixtures, the following series of [ReO(L-n)(L)](+/0) oxorhenium(V) complexes has been generated: R eO{[N(CH2CH2NH2)(2)][o-OC6H4P(C6H5)(2)]}Cl (1); ReO{[(C2H5)(2)NCH2CH2NCH2CH 2S][o-OC6H4P(C6H5)(2)]} (2); ReO{[(CH2)(4)NCH2CH2-NCH2CH2S][o-OC6H4P(C6H5)( 2)]) (3); and ReO{[C2H5SCH2CH2NCH2CH2S][o-OC6H4P(C6H5)(2)]} (4). The comple xes are closed-shell 18-electron oxorhenium species, which adopt octahedral geometries both in solution and in the solid state, as established by conv entional physicochemical techniques including multinuclear NMR and single-c rystal X-ray diffraction fanalyses.