(TeCl)4(TiCl4) with isolated Te4Cl16 and TiCl4 molecules and second-harmonic-generation

(TeCl4)(4)(TiCl4) is obtained by reaction of TeCl4 and TiCl4 at 50 degrees C with quantitative yield. The compound is composed of isolated, molecular (TeCl4)(4) heterocubane-type units as well as isolated, molecular TiCl4 tetrahedra. The (TeCl4)(4) heterocubane is arranged like a body-centred cubic cell with TiCl4 tetrahedra occupying 4 of 6 octahedral sites. (TeCl4)(4)(TiCl4) crystallizes in the space group I with an unidirectional alignment of the tetrahedral building units. The structure of the compound is obtained from single crystal X-ray diffraction and confirmed by Rietveld refinement of powder diffraction data. Thermogravimetry, optical spectroscopy, infrared and Raman spectroscopy are employed to further characterize the title compound. Second harmonic generation (SHG) is observed with a strong intensity (1.6-times higher than potassium dihydrogen phosphate/KDP). The SHG effect is observed in the visible spectral regime as the band gap, derived from a Tauc plot, is 2.8 eV.