%0 Journal Article %1 Kaim.1984c %A Kaim, Wolfgang. %D 1984 %J Journal of Organometallic Chemistry %K ESR ESR;ESR ESR;phosphine arsine carbonyl dinuclear molybdenum pyrazine pyrazine;molybdenum tungsten tungsten;bipyridine tungsten;phosphite tungsten;tungsten %N 2 %P 171--178 %R 10.1016/S0022-328X(00)99140-X %T Binuclear radical complexes of molybdenum and tungsten tetracarbonyls with bridging N-heterocycles and Group VA ligands. ESR evidence for a cis configuration %V 262 %X The reactions of Mo(CO)6 or W(CO)6 and of bridging N-heterocyclic ligands (L) such as pyrazine or 4,4'-bipyridine with K were studied by ESR spectroscopy in the presence of excess phosphine, phosphite or arsine ligands. In many cases, double substitution at the metals could be obsd., yielding [(XR3)(CO)4M-L-M(CO)4(XR3)]-. (X = P, As; R = alkyl, aryl, alkoxy; M = Mo, W). ESR study of the complexes in THF soln. revealed extensive coupling of the unpaired electron with the nuclei 1H, 13C(CO), 14N, 31P, 75As, 95.97Mo and 183W. Evidence for a cis configuration at the metals is presented, and a p*/smx* hyperconjugation model is used to account for the facile substitution of CO and for the spin transfer to the peripheral nuclei. [on SciFinder(R)]

@article{Kaim.1984c, abstract = {The reactions of Mo(CO)6 or W(CO)6 and of bridging N-heterocyclic ligands (L) such as pyrazine or 4,4'-bipyridine with K were studied by ESR spectroscopy in the presence of excess phosphine, phosphite or arsine ligands. In many cases, double substitution at the metals could be obsd., yielding [(XR3)(CO)4M-L-M(CO)4(XR3)]-. (X = P, As; R = alkyl, aryl, alkoxy; M = Mo, W). ESR study of the complexes in THF soln. revealed extensive coupling of the unpaired electron with the nuclei 1H, 13C(CO), 14N, 31P, 75As, 95.97Mo and 183W. Evidence for a cis configuration at the metals is presented, and a \textgreek{p}*/\textgreek{s}mx* hyperconjugation model is used to account for the facile substitution of CO and for the spin transfer to the peripheral nuclei. [on SciFinder(R)]}, added-at = {2022-06-15T11:26:56.000+0200}, author = {Kaim, Wolfgang.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/23ece4502651ad5ed0aa3d02cb65b467b/huebleriac}, doi = {10.1016/S0022-328X(00)99140-X}, interhash = {83e7f7d111b4aebab2c4fafdb5c08054}, intrahash = {3ece4502651ad5ed0aa3d02cb65b467b}, journal = {Journal of Organometallic Chemistry}, keywords = {ESR ESR;ESR ESR;phosphine arsine carbonyl dinuclear molybdenum pyrazine pyrazine;molybdenum tungsten tungsten;bipyridine tungsten;phosphite tungsten;tungsten}, number = 2, pages = {171--178}, timestamp = {2022-06-15T09:26:56.000+0200}, title = {Binuclear radical complexes of molybdenum and tungsten tetracarbonyls with bridging N-heterocycles and Group VA ligands. ESR evidence for a cis configuration}, volume = 262, year = 1984 }