1025505-73-0Relevant articles and documents
Reactivity of low-valent iridium, rhodium, and platinum complexes with Di- and tetrasubstituted hydrazines
Hoover, Jessica M.,Freudenthal, John,Michael, Forrest E.,Mayer, James M.
, p. 2238 - 2245 (2009/02/02)
Three complexes, IrCl(PEt3)3, Rh(NNN)Cl (NNN = 2,6-(CyN=CH)2C5H3N), and (NN)PtMe2 [NN = 1,10-phenanthroline (phen) or 2,2′-bipyridine (bpy)], have been investigated for N-N oxidative addition reactivity with di- and tetrasubstituted hydrazines. The reaction of IrCl(PEt3)3with 1,2-diphenylhydrazine (PhNHNHPh) forms the cyclometalated azobenzene complex (Et3P)2Cl(H)Ir(C6H4N=NPh) (1) and the 2:1 complex [(Et3P)2Cl(H)Ir]2(μ-C 6H4N=NC6H4) (2). The Rh(NNN)Cl pincer complex catalyzes the disproportionation of PhNHNHPh to azobenzene and aniline with no change in the Rh complex. The reaction of (bpy)PtMe2 with the hydrazine AcNHNHC(O)CH2CH2CH=CH2 (3) yields the platinum metallacycle (bpy)Pt(η2-AcN-NC(O)(CH 2)2CHCH2 (4). Although IrCl(PEt 3)3, Rh(NNN)Cl, and (NN)PtMe2 all undergo facile oxidative addition of other X-Y bonds, such reactivity is not observed for hydrazines; in the Ir and Pt systems there is a clear preference for cleavage of the stronger N-H bond over the N-N bond. The tetrasubstituted hydrazines tetraphenylhydrazine, 1,2-diphenyl-1,2-dimethylhydrazine, bisuccinimide, biphthalimide, and N-dimethylamino phthalimide do not react with IrCl(PEt3)3, Rh(NNN)Cl, and (NN)PtMe2. This lack of reactivity appears to be due to kinetic rather than thermochemical factors.
