3,6-Di-tert-butyl-o-benzosemiquinone complexes of copper(I) with bidentatebis(diphenylphosphine) ligands. Synthesis, structures, and properties

New mononuclear 3,6-di-tert-butyl-o-benzosemiquinone complexes of copper(I) with bis(diphenylphosphine) ligands were synthesized: (DBSQ)Cu(dppe) (1) ( DBSQ = 3,6-di-tert-butyl-o-benzosemiquinone and dppe = 1,2-bis(diphenylphos phino)ethane), (DBSQ)Cu(dppp) (2) (dppp = 1,3-bis(diphenylphosphino)propane ), (DBSQ)Cu(dppn) (3) (dppn = 2,2 '-bis(diphenylphosphino)-1,1'-binaphthyl) , and (DBSQ)Cu(dppfc) (4) (dppfc = 1,1'-bis(diphenylphosphino)ferrocene). T he compositions and structures of complexes 1-4 were characterized by eleme ntal analysis and electronic absorption, IR, and ESR spectroscopy. The mole cular structures of complexes 3 and 4 were established by X-ray diffraction analysis. The reactions of elimination and replacement of neutral ligands in the coordination sphere of the complexes were studied by ESR spectroscop y.