Formation and Cleavage of N-H Bonds on Nitrido Metal Carbonyl Clusters

Article abstract of DOI:10.1021/ja00269a028

A study of the protonation of three tetranuclear nitrido clusters having the butterfly geometry is reported.While the final product of each of these reactions is a hydrido-nitrido cluster, the intermediates contain the imido (NH) ligand which can be trapped by CO.For ^1-, the products of protonation in a CO atmosphere are FeRu2(NH)(CO)10, ^1-, and small amounts of HFeRu3N(CO)12 and Ru3(CO)12.With ^1-, this reaction generates Ru3(NH)(CO)10, ^1-, HRu4N(CO)12,and small quantities of Ru3(CO)12.The new NH-containing clusters FeRu2(NH)(CO)10 and Ru3(NH)(CO)10 contain a triply bridging N-H ligand and a triply bridging carbon monoxide.The substituted cluster 2>^1- was shown by X-ray crystallography a = 11.603 (3) Angstroem, b = 18.521 (6) Angstroem, c = 8.908 (4) Angstroem, Z = 2> to contain the two Ru(CO)2 fragments in the wing-tip positions.Protonation leads to a green intermediate that reacts with CO to give FeRu2(NH)(CO)9, which was structurally characterized 1/m, a = 8.596 (2) Angstroem, b = 15.576 (3) Angstroem, c = 7.870 (4) Angstroem, β = 100.37 (3) deg, Z= 2>.The structure contains both a triply bridging CO and NH ligand, and the phosphite is bound to a ruthenium and oriented trans to the NH group. 1H and 15N NMR spectroscopies were used to identify the intermediate imido cluster FeRu3(NH)(CO)102.