Poly(methimazolyl)borato Nitrosyl Complexes of Molybdenum and Tungsten

The syntheses of a range of poly(methimazolyl)borate -ligated nitrosyl complexes of tungsten and molybdenum are reported, the characterization of which includes the crystal structure determinations of the compounds [W(NO)(CO)2{κ3-S,S′,S′′-HB(mt)3}], [W(NO)(CO)2(PPh3){κ2-S,S′-H2B(mt)2}], and [Mo(NO)(CO)2{κ3-H,S,S′-H2B(mt)2}] (mt = methimazoyl). The reaction of [W(NO)(CO)3(PPh3)2]PF6 with Na[HB(mt)3] and Na[H2B(mt)2] provides respectively [W(NO)(CO)2{HB(mt)3}] and [W(NO)(CO)2(PPh3){κ2-S,S′-H2B(mt)2}]. The complexes [M(NO)(CO)2{HB(mt)3}] and [M(NO)(CO)2{κ3-H,S,S′-H2B(mt)2}] (M = W, Mo) arise from the reactions of Na[M(CO)3{H2B(mt)2}] with N-methyl-N-nitrosotoluenesulfonamide. The molybdenum complex [Mo(NO)(CO)2{HB(mt)3}] is also obtained unexpectedly from the reaction of [Mo(η3-C3H5)(CO)2{HB(mt)3}] with [NO]BF4.