93110-44-2Relevant articles and documents
Insertion reactions of hexaalkoxydimolybdenum and -ditungsten compounds with organic isocyanates. Syntheses and structures of W2(OCMe3)4[N(C6H 5)C(O)OCMe3]2 and Mo2(O-i-Pr)4[N(C6H5)C(O)O-i-Pr]
Chisholm, Malcolm H.,Cotton, F. Albert,Folting, Kirsten,Huffman, John C.,Ratermann,Shamshoum, Edwar S.
, p. 4423 - 4427 (2008/10/08)
Dimolybdenum and ditungsten hexaalkoxides react with phenyl isocyanates (2 equiv) in nonpolar solvents to form products involving insertion of the isocyanate into the metal alkoxide bond. The new products Mo2(O-i-Pr)4[N(C6H5)C(O)O-i-Pr] 2 (1) and W2(OCMe3)4[N(C6H 5)C(O)OCMe3]2 (2) have both been characterized by X-ray crystallography. Compound 1 crystallizes in space group Pnab with a = 18.652 (22) ?, b = 10.808 (11) ?, c = 18.912 (24) ?, and Z = 4 (at -55 °C). The molecule has a twofold axis of symmetry perpendicularly bisecting the Mo-Mo bond, and it consists of two cis bridging bidentate ligands and four isopropoxy groups. Each molybdenum atom is in the +3 oxidation state, and the Mo-Mo bond length is 2.221 (5) ?. Compound 2 crystallizes in space group P1 with a = 10.48 (1) ?, b = 11.38 (1) ?, c = 11.80 (1) A, α = 96.96 (3)°, β = 110.02(3)°, γ = 106.93(3)°, V = 1226 (2) ?3, and Z = 1. The molecule is centrosymmetric and consists of two trans bridging bidentate ligands and four tert-butoxy ligands. Each tungsten atom is in the +3 oxidation state, and the W-W bond length is 2.290 (1) ?. The bond distance in each compound is consistent with a bond order of 3, and the magnitude of the difference, 0.069 (5) ?, is as expected.
