Reversible carbon monoxide binding at copper(I) P–S–X (X = N, O) coordination polymers

Reaction of Ph2PCH2CH2S(2-C6H4NH2) (1) or Ph2PCH2CH2S(2-C6H4OMe) (2) with CuCl and AgSbF6 in the presence of THF affords {[Cu(1)THF](SbF6)}n (3) and {[Cu(2)THF](SbF6)}n (4). In the solid state, THF-inclusive 3 exists as a one dimensional zigzag coordination polymer in which each P–S–N ligand is connected to two copper(I)-centres. Both 3 and 4 are able to bind CO reversibly in solution or can be desolvated at 110 °C in vacuo to give {[Cu(1)](SbF6)}n (7) and {[Cu(2)](SbF6)}n (8). These solvent-free compounds have been found to bind carbon monoxide reversibly over multiple cycles in solution and in the solid state, under mild conditions.