INTRA-MOLECULAR HYDROGEN-BONDING IMPLICATIONS ON THE LABILITY OF THE MOLYBDENUM-PIPERIDINE BOND - KINETIC AND MECHANISTIC STUDIES OF THE REACTION OF CIS-MO(CO)4[P(OCH3)3]NHC5H10 WITH CARBON-MONOXIDE

13C NMR and infrared spectral properties in the CO region are provided for the cis-Mo(CO)4[P(OMe)3]NHC5H10 derivative. The effects of intramolecular hydrogen-bonding interactions between the -P-O.H-N- groupings in cis-Mo(CO)4[P-(OMe)3]NHC5H10 on the solution dynamics of this species toward amine-displacement reactions are reported. This hydrogen-bonding interaction results in an enhanced stabilization of the piperidine ligand toward dissociative loss as compared with the analogous process in the Mo(CO)5NHC5H10 derivative, ΔH* for NHC5H10 dissociation being 3.5 kcal mol-1 higher for the former process. The reaction of cis-Mo(CO)4[P(OMe)3]NHC5H10 with 13CO was found to afford stereospecifically the equatorially 13CO-substituted derivative Mo(CO)4(13CO)P(OMe)3. Additionally, facMo(CO)3(13CO)[P(OMe)3]NHC5H10 was synthesized and observed to react with 13CO to yield exclusively the equatorially 13CO substituted Mo(CO)3-(13CO)2P(OMe)3 species. © 1979, American Chemical Society. All rights reserved.