The evaluation of singlet-triplet separations for [W2(μ-H)(μ-CL)CL4(μ-dppm)2] and [W2(μ-H)2 (μ-O2CC6H5)2CL 2(P(C6H5)3)2] based on 31P NMR and crystallographic data

Article abstract of DOI:10.1016/0277-5387(96)00207-0

The singlet-triplet separations for the edge-sharing bioctahedral (ESBO) complex W₂(μ-H)(μ-Cl)(Cl₄(μ-dppm)₂ · (THF)₃ (II) has been studied by ³¹P NMR spectroscopy. The structural characterization of [W₂(μ-H)₂(μ-O₂CC₆H ₅)₂Cl₂(P(C₆H₅) ₃)₂] (I) by single-crystal X-ray crystallography has allowed the comparison of the energy of the HOMO-LUMO separation determined using the Fenske-Hall method for a series of ESBO complexes with two hydride bridging atoms, two chloride bridging atoms and the mixed case with a chloride and hydride bridging atom. The complex representing the mixed case, [W₂(μ-H)(μ-Cl)Cl₄(μ-dppm)₂ · (THF)₃] (II), has been synthesized and the value of -2J determined from variable-temperature ³¹P NMR spectroscopy.