TRIDENTATE COORDINATION MODE OF N,N'-DIMETHYL-2,11-DIAZA[3.2](2,6)PYRIDINOPHANE IN A TRICARBONYLMOLYBDENUM(0) COMPLEX

Tridentate coordination of the potentially tetradentate ligand N,N'-di methyl-2,11-diaza[3.3](2,6)pyridinophane (L-N4Me2) has been structural ly established in the tricarbonylmoly(0) complex [Mo(L-N4Me2)(CO)(3)]. The fluxional behavior of the coordinated tetraazamacrocyclic ligand is demonstrated by a variable-temperature H-1-NMR study. The relevance of the tridentate coordination mode of the ligand is discussed with r espect to its intermediacy in the reaction mechanism for the formation of cis octahedral metal complexes containing tetradentate 2,11-diaza[ 3.3](2,6)pyridinophane derivatives as ligands.