Pavlyuk O. The peculiarities of formation and structure of crystalline Cu(I) halide complexes with onium salts of mononitrogen aromatic heterocycles.

By means of the alternatingcurrent electrochemical technique and, partially, by direct interaction of components, using the onium salts of N-allyl derivatives of mononitrogen heterocycles, 23 copper(I) (and some Cu(II)) halide complexes have been obtained and X-ray structurally investigated by single crystal method. It has been displayed a peculiar behavior of allyl C=C bond regarding to Cu(I) halides: an ability of Cu(I)–(C=C) interaction in the compounds is connected with the basicity of an initial heterocycle (pKa). At pKa < 5.20 any pi-interaction has not been detected (complexes with N-allylquinolinium cation). At pKa > 5.20 (complexes with N-allylpyridinium or N-allylisoquinolinium cations) effective Cu(I)–(C=C) interactionappeared. N-allylquinolinium halides (Cl–, Br–, I–) in apresence of CuCN, Cu and methanol as a solvent undergo cyclic dimerization which produces unknown earlier pentacyclic [C24H21N2]+ cation. Contrary to these, N-allylisoquinolinium halides appeared to be unable for such transformation. A complication degree of inorganic fragment inthe complexes under consideration is a consequence of competition among relatively strong Cu(I)–Hal, Cu(I)–(C=C) interactions and weaker H-bonds and pi-pi-stacking.