Abstract: Carbonylmolybdenum(Ⅰ) compounds with bridge carboxyl group ligand [(CO)₃Mo(SPh)₂LMo(CO)₃](L=CF₃COO,HCOO,CH₃COO,C₂H_-5COO,OOCCH₂CH₂COO,Me₃COO), are synthesized by the reaction of Compound [(CO)₄Mo(SPh)₂Mo(CO)₄] and carboxyl acids L the ¹H, ¹³C, ⁹⁵Mo NMR spectra of 7 carbonylmolybdenum compounds have been determined in room tempurate. The diffence between the spectra of reactant and product is obvious because of the chonge of the structral charge of the ligands, symmetrization, bond distances. Especially, the influence of carboxyl goup on chemical shifts and linewidth for ⁹⁵Mo NMR is sensitive. The shielding and widening order is Me₃COO^-1 > C₂H_-5COO^-1 > CH₃COO^-1 > HCOO^-1 > F₃COO^-1.

Key words: Bridge carboxyl group ligand, Carbonylmolybdenum (Ⅰ) compounds, NMR