HOMOLEPTIC OPTICALLY-ACTIVE DITUNGSTEN AND DIMOLYBDENUM ALKOXIDES - THE CRYSTAL-STRUCTURE OF (+)[W2(OC10H19)6]

Reaction of optically resolved menthol (1R,2S,5R or 1S,2R,5S) with [M2(NMe2)6] or [M2(OBut)6] (M = Mo or W) in hexane produces (+)- or (-)-[M2(OC10H19)6] respectively in high yield (86-98%).The [M2(OC10H19)6] compounds are air sensitive, extremely soluble in hydrocarbon solutions and have decomposition points of 174-177-degrees-C. Characterization was achieved by H-1, C-13, (C-{H})-C-13-H-1 NMR, IR, CD, ORD, UV and mass spectrometry. For (+)[W2(OC10H19)6] X-ray crystallography revealed two independent molecules in the unit cell, both d3-d3 ethane-like dimers: space group P1, a = 1 5.439(3), b = 15.883(3), c = 13.684(3) angstrom, alpha = 104.4(1), beta = 99.10(1), gamma = 94.27(1)-degrees, Z = 2; W=W 2.338 (average), W-0 1.88 angstrom (average). Reaction of [W2(NMe2)6] with neomenthol produces [W2(NMe2)(OC10H19)5] in high yield. Reaction of [W2(OC10H19)6] with MeCN produces [{WN(OC10H19)3}x] and [W(CMe)(OC10H19)3] and with hex-3-yne produces [W(CEt)(OC10H19)3] and polyhexyne. Reaction of (+)[W2(OC10H19)6] with 6 equivalents of L-HOC10H19 produces racemic [W2(OC10H19)6] in less than 5 min. Treatment of [{MoN(OBut)3}x] with menthol produces the optically active polymer [{MoN(OC10H19)3}x].