One-electron energy levels in Cu(H2O)4TiF6,NH4F

Abstract

The polarized single-crystal electronic spectra, measured at ambient, liquid-nitrogen, and liquid-helium temperatures, and single-crystal e.p.r. spectra, measured at ambient temperature and 96 K, of Cu(H₂O)₄TiF₆,NH₄F are reported. The data indicate C_4h effective symmetry with hydrogen-bonding playing an important role in determining the electronic structure. Because the vibronic selection rules for C_4h are not definitive with respect to the order of the orbitals, band assignments are made by the extrapolation of data from previously reported complexes to the present case. The suggested one-electron orbital sequence is d_x²–y² > d_z² > d_xy > d_xz,d_yz.