Lewis-Base Adducts of Group 11 Metal(I) Complexes. XXXV. Complexes of the Asymmetric Bidentate Ligands (L) 2-Aminomethylpyridine and 2-Hydrazinopyridine With Copper(I) Halides: Syntheses and Structural Characterization of [CuL₂]⁺X^-, X = Cl, Br, I

Abstract

The 1:2 adducts of the copper(I) halides (CuX ; X = Cl, Br, I) with the aliphatic/aromatic bidentate nitrogen bases 2-aminomethylpyridine, H₂NCH₂.C₅H₄N, and 2-hydrazinopyridine, H₂N.NH.C₅H₄N, L, have been synthesized by recrystallization of stoichiometric copper(I) halide/base solutions from acetonitrile . In all cases, ionic complexes [CuL₂]⁺ X^- are obtained, copper being four-coordinated by a pair of bidentate ligands, and with widely varying distortions from ideal 2 symmetry. Cu-N (aromatic) in the 2-aminomethylpyridine adducts range from 1.979(8) to 2.037(5)Ǻ; while Cu-N(H₂) are 2.102(9)-2.172(10)Ǻ, N( Ar )-Cu-N( Ar ) angles [130.7(2)-143.2(4)°] are larger than N(H₂)-Cu-N(H₂)[114.8(2)-116.3(4)°]. Comparable values for the 2-hydrazinopyridine complexes are 1.95(1)-2.036(5), 2.085(4)-2.214(7)Ǻ; 124.1(2)-140.8(4), 94.5(3)-128.0(3)°. In no case does the halide anion coordinate to the copper, displacing the aliphatic nitrogen donor group; rather it is stabilized in the crystal lattice by strong NH₂…X hydrogen bonding.