D. J. Berg, and James M. Boncella, R. Andersen
Oct 3, 2002
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0
Influential Citations
67
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Journal
Organometallics
Abstract
Several adducts are isolated between heterocyclic nitrogen bases and Cp*2Yb. The adducts fall into several general classes. The membership within the class is related to the reduction potential of the given heterocyclic base relative to that of Cp*2Yb. Analytically pure 1:1 adducts of the type Cp*2Yb(L) are formed with pyrazine, quinoxaline, 1,5- and 1,8-naphthyridine, and 4,4‘-bipyridine as toluene-insoluble solids. The 1:1 adducts with phthalazine and azobenzene and the 1:2 adduct with pyridazine are soluble in toluene, from which they may be isolated by crystallization. All of the adducts in this class are paramagnetic, and their effective magnetic moments are consistent with the formulation Cp*2YbIII(L•-) (L•- = radical anion), in which spins on the individual units are uncoupled to 5 K. Adducts between Cp*2Yb and phenazine, 2,2‘-azopyridine, 2,2‘-bipyrimidine, 2,2‘-azobenzene, and 2,3-bis(2-pyridino)quinoxaline are of 2:1 stoichiometry: (Cp*2Yb)2(μ-L). The crystal structure of (Cp*2Yb)2(μ-bipyrimidi...