Oxidative decarbonylation of m-terphenyl isocyanide complexes of molybdenum and tungsten: precursors to low-coordinate isocyanide complexes.

摘要: Synthetic studies are presented addressing the oxidative decarbonylation of molybdenum and tungsten complexes supported by encumbering m-terphenyl isocyanide ligand CNAr(Dipp2) (Ar(Dipp2) = 2,6-(2,6-(i-Pr)(2)C(6)H(3))(2)C(6)H(3)). These represent an effort to access halide or pseudohalide M/CNAr(Dipp2) species (M Mo, W) for use as precursors low-coordinate, low-valent group 6 complexes. The synthesis structural chemistry tetra- tricarbonyl trans-W(CO)(4)(CNAr(Dipp2))(2) trans-W(NCMe)(CO)(3)(CNAr(Dipp2))(2) reported. acetonitrile adducts trans-M(NCMe)(CO)(3)(CNAr(Dipp2))(2) react with I(2) form divalent, diiodide in which extent differs between Mo W. In example, diiodide, dicarbonyl complex MoI(2)(CO)(2)(CNAr(Dipp2))(2) is generated, has S 1 ground state solution. Paramagnetic MX(2)L(4) rare, structure discussed relation other diamagnetic C(2v)-distorted Diiodide reacts further effect complete decarbonylation, producing paramagnetic tetraiodide trans-MoI(4)(CNAr(Dipp2))(2). reactivity toward benzoyl peroxide also surveyed, it shown that dicarboxylate can be obtained salt-elimination routes. reduction behavior trans-MoI(4)(CNAr(Dipp2))(2) Mg metal sodium amalgam studied. benzene solution under N(2), reduced Na/Hg η(6)-arene-dinitrogen complex, (η(6)-C(6)H(6))Mo(N(2))(CNAr(Dipp2))(2). diiodide-η(6)-benzene (η(6)-C(6)H(6))MoI(2)(CNAr(Dipp2))(2) isolable intermediate this reaction, its formation context putative