Verdampfung von Kupfer(II)chlorid und Struktur des Dampfes untersucht mit UV./VIS.‐ und Raman‐Spektroskopie

The vapour pressure of CuCl2 and the dimerization of CuCl2(g) have been investigated by optical spectroscopy in the range 420–650°C, p = 0.5‐5 atm. The enthalpy of dimerization of CuCl2(g) was determined by visible and by Raman spectroscopy and good agreement was found (−154 kJmol−1 and −143 kJmol−1). CuCl2(g) shows two totally symmetric Raman modes (373 and 127 cm−1) indicating that, at least at elevated temperatures, CuCl2(g) is not a linear molecule. The optical spectra of Cu2Cl4(g) and CuLCl5(g) (L  Ga, In) are very similar supporting a CuCl3‐chromophor in both cases. The formerly proposed structure of CuL2Cl8(g) (L  Al, Ga) contains bridging and terminal chlorides, structural elements also present in Cu2Cl4(g). In agreement with the proposed structure v is identical in Cu2Cl4(g) and CuL2Cl8(g), while V is at lower energies (20–30 cm−1) in CuL2Cl8(g) than in Cu2Cl4(g).