Molybdenum Carbonyl Complexes with Citrate and Its Relevant Carboxylates

Reactions of ammonium salts of citrate and
its relevant carboxylates with a molybdenum(0) carbonyl
complex (C7H8)Mo(CO)3 resulted in the formation of
(Et4N)3[(Hcit)Mo(CO)3] (1), (Et4N)2[(Hcmal)Mo(CO)3] (2),
(Et4N)2[(Hmal)Mo(CO)3] (3), and (Me4N)2[(Meida)Mo(CO)3] (4), which are the first examples of organo-molybdenum complexes having a tri- or dicarboxylate.
Complexes 1−4 were characterized by means of IR and
UV−vis spectra and elemental analyses. Molecular
structures of all complexes were determined by an X-ray
diffraction study. The molybdenum center adopts an
octahedral coordination geometry with three carbonyl
ligands and a tridentate ligand which displays a unique
coordination to molybdenum with its carboxylates and
hydroxyl group or nitrogen atom.