Inorganic Chemistry, Vol.46, No.17, 7040-7049, 2007
Dinitrogen activation, partial reduction, and formation of coordinated imide promoted by a chromium diiminepyridine complex
Reduction of 12,6-[2,6-(i-Pr)2PhN=C(CH3)12(C5H3N)ICrCI (3) with NaH afforded the dinuclear dinitrogen complex 1[12,6-[2,6-(i-Pr)2PhN=C(CH3)12(C5H3N)ICr(THF)12(u-N2)1-THF (5). Reaction carried in exclusion of dinitrogen afforded instead deprotonation of the ligand with the formation of t2-[2,6-(i-Pr)2PhN C(CH3)]-6-[2,6-(i-Pr)2PhNC= CH21(C5H3N)JCr(THF) (4). Further reduction of 5 with NaH yielded a curious dinuclear compound formulated as [12,6-[2,6-(i-Pr)2PhN C(CH3)12(C5H3N)ICr(THF)][12-[2,6-(i-Pr)2PhN=C(CH3)]-6-[2,6-(i-Pr)2PhNC=C H2](C5H3N)ICr- (THF)](u-N2 H)(u-Na)2 (6) containing two sodium atoms only bound to the dinitrogen unit and the -/r systems of the two diiminepyridine ligands. Subsequent reduction with NaH triggered a complex series of events, leading to the formation of a species formulated as 12-[2,6-(i-Pr)2PhN=C(CH3)]-6-[2,6-(i-Pr)2PhNC=CH2](c5H3N)ICr(u-NH)][Na(T HF)l (7) on the basis of crystallographic, spectroscopic, isotopic labeling, and chemical degradation experiments.