Investigation of the Composition Space Diagram CuCl–Allylamine–dabco. A New Mixed Ligand Compound of (H2dabco)2[Cu4Cl9(allNH3)] Composition with Unique Cu4Cl9 5– Cupro(I)-chloride Fragment

The ternary system CuCl-allylamine-dabco (dabco = 1,4-diazabicyclo[2.2.2]octane) with an excess of HCl was explored. Starting from an ethanol solution of CuCl2·2H2O, allylamine and dabco titrated with HCl, copper(I) salts were generated by means of electrochemical alternating current synthesis. In addition to the already known (H2dabco)[CuCl3], two modifications of the (allNH3)2[Cu2Cl4] compound and some Cu(II) by-products, a new mixed ligand compound of the composition (H2dabco)2[Cu4Cl9(allNH3)] was synthesized and structurally investigated. Its structure contains unique Cu4Cl95- inorganic moiety bound via a h2-interaction allylammonium moiety and discrete (H2dabco)2+ cations. The structure is stabilized by the system of N-H···Cl hydrogen bonds.