Self-Assembled Cyclophane-Type Copper(I) Complexes of 2,4,6-Tris(diphenylphosphino)-1,3,5-triazine and Their Catalytic Application

The
triazine-based trisphosphine, 2,4,6-tris­(diphenyl­phosphino)-1,3,5-triazine
(1) was prepared in improved yield by reacting cyanuric
chloride with 3 equiv of trimethylsilyldiphenylphosphine. The solid-state
structure of 1 showed short intermolecular P···P
contacts of 3.362 Å, which is significantly shorter than the
sum of the van der Waals radii of phosphorus atoms (3.6 Å). The
reaction of 2,4,6-tris­(diphenyl­phosphino)-1,3,5-triazine (1) with copper­(I) salts in a 2:3 molar ratio yielded various
cyclophane-type complexes in quantitative yield. The solid-state structures
of these clusters have been found to depend on the size of the halide
ions, the solvent employed, and the reaction conditions. Copper­(I)
chloride formed a monomeric metallocyclophane, whereas copper­(I) bromide
and copper­(I) iodide derivatives preferred dimeric and 1D-polymeric
structures, respectively. The tricationic complexes derived from CuI ion and 2,4,6-tris­(diphenyl­phosphino)-1,3,5-triazine
also adopted monomeric metallocyclophane structures. These complexes
have been employed in the A3 coupling reaction under microwave
irradiation. The copper­(I) iodide derivative showed excellent catalytic
efficiency.