INSERTION OF A COPPER NITRENE INTO A C-H BOND TO FORM BIS(2-(PHENYLAMINO)-1,10-PHENANTHROLINATO)DICOPPER(I) - A SHORT CU-CU DISTANCE WITH NO BOND

The complex Cu(phen)Cl2 (phen = 1,10-phenanthroline) reacts with [Li(THF)x]2[PhNN=NNPh] (I) to yield the copper(I) dimer [Cu(2-NPh-phen)]2(II), formed by insertion of NPh into the ortho C-H bond of phenanthroline. Complex II crystallizes in the monoclinic crystal system at 294 K with space group P21/n and lattice constants a = 5.551 (2) Å, b = 13.700 (5) Å, c = 17.865 (6) Å, β = 97.85 (3)°, and Z = 2. Refinement of the structure led to an R factor of 0.055 for 1399 reflections with I >3σ(I) and 82 least-squares parameters. In the structure of II, the coordination sphere of Cu approximates a square plane with a Cu-Cu separation of 2.600 (2) Å. Each square plane shares a common vertex. Complex II is inert to unsaturated (PhN=NPh, PhC?CPh, CH2=CHCH2Cl) and amine (CH3NH2) ligands. Electrochemical studies show that II undergoes one chemically reversible oxidation, forming the mixed-valence complex, and a second chemically irreversible oxidation. SCF-Xα-DV calculations of model complexes for II and for a monomeric fragment suggest a repulsive interaction between the d10Cu(I) centers. The dinuclear configuration appears to be dictated by the 2-(phenylamino)-1,10-phenanthroline(1-) ligand. © 1990, American Chemical Society. All rights reserved.