WELL-CHARACTERIZED COMPOUND CONTAINING A HETERONUCLEAR (MOLYBDENUM-TUNGSTEN) QUADRUPLE BOND

The compound MoW(mhp)4 (Hmhp = 2-hydroxy-6-methylpyridine), which contains a heteronuclear quadruple bond, has been isolated in pure form and structurally characterized. MoW(mhp)4 is formed in good yield from a reaction of Mo(CO)6, W(CO)6, and Hmhp in a molar ratio of 1.5:1:5. Purification was accomplished by oxidation with iodine followed by reduction with zinc amalgam to eliminate Mo2(mhp)2 which is the major contaminant. The dichloromethane solvate of MoW(mhp)4 is isomorphous with M2(mhp)4•CH2Cl2, where M = Cr, Mo, W. The space group is P21/n with cell parameters a = 12.909 (2) Å, b = 16.910 (3) Å, c = 13.014 (2) Å, β = 104.85 (1)°, and Z = 4. The compound contains a very short Mo-W bond length, 2.091 (1) A, and has a Mo-W stretching frequency of 384 (3) cm-1. © 1978, American Chemical Society. All rights reserved.