Coordination of LiH Molecules to MoMo Bonds: Experimental and Computational Studies on Mo2LiH2, Mo2Li2H4, and Mo6Li9H18 Clusters

The reactions of LiAlH4 as the source of LiH with complexes that contain (H)Mo Mo and (H)Mo Mo(H) cores stabilized by the coordination of bulky Ad(Dipp2) ligands result in the respective coordination of one and two molecules of (thf)LiH, with the generation of complexes exhibiting one and two HLi(thf)H ligands extending across the Mo.Mo bond (Ad(Dipp2) = HC(NDipp)(2); Dipp = 2,6-(Pr2C6H3)-Pr-i; thf = tetrahydrofuran, C4H8O). A theoretical study reveals the formation of Mo-H-Li three-center-two-electron bonds, supplemented by the coordination of the Mo Mo bond to the Li ion. Attempts to construct a [Mo-2{HLi(thf)H}(3)(Ad(Dipp2))] molecular architecture led to spontaneous trimerization and the formation of a chiral, hydride-rich Mo6Li9H18 supramolecular organization that is robust enough to withstand the substitution of lithium-solvating molecules of tetrahydrofuran by pyridine or 4-dimethylaminopyridine.

Automated summary

The reaction between LiAlH4 and complexes containing (H)Mo Mo cores results in the coordination of LiH molecules and the formation of Mo-H-Li three-center-two-electron bonds. The complexes exhibit a hydride-rich Mo6Li9H18 supramolecular organization that is stable and can withstand substitution of solvating molecules.