The use of the bulky diols, H2L1 = 2,5-dimethylhexane-2,5-diol and H3L2 = 2,2'-methylenebis(6-tert-butyl-p-cresol) in reactions with M2(NMe2)6 (M = M) compounds leads to dinuclear diolates M2(L1)3(HNMe2)2 1, M2(L1)3 2, Mo2(NMe2)2-(HL2) 3 having seven-, eight- and nine-membered rings and W2(mu-H)(mu-NMe2)(NMe2)(HNMe2)(HL2)(L2), 4, where L2 is the anionic ligand derived from cyclometallation at the methylene carbon atom; the compounds 1 and 2 where M = W, 3, and 4 have been structurally characterized.