Structures, spectroscopic studies and solid-state thermal transformations of coordination polymers from P4Se3 and CuX (X=Cl, Br, I)

The formation of coordination polymers (CuCl)P 4 Se 3 ( 1 ), (CuBr) 3 (P 4 Se 3 ) 2 ( 2 ), (CuI) 3 (P 4 Se 3 ) 2 ( 3 ) and (CuI)P 4 Se 3 ( 4 ), from solutions of copper(I) halides and P 4 Se 3 by diffusion methods has been studied. The new compounds were characterized by X-ray crystallography, solid-state 31 P MAS NMR and Raman spectroscopy. Theoretical studies on the DFT level in the crystalline phase allowed the unequivocal assignment of the recorded Raman shifts between 200 and 480 cm −1 . The structure of 1 consists of a 2D network of castellated [CuCl] n chains and bidentate P 4 Se 3 molecules. The 3D network of 2 comprises [CuBr] n chains, which are linked by tridentate P 4 Se 3 molecules. Compound 3 is a three-dimensional polymer composed of four-membered (CuI) 2 rings and castellated [CuI] n chains, which are linked by tridentate P 4 Se 3 molecules involving two basal and the apical P atoms. Thermal conversion of 1 at 230 °C gives (CuCl) 3 (P 4 Se 3 ) 2 ( 5 ), which is isostructural with 2 . The thermal conversion of (CuI) 3 P 4 S 3 , which was studied for comparison gave at 371 °C (CuI) 3 P 4 S 4 , Cu 3 PS 4 and small amounts of Cu 6 PS 5 I.