Crystal structure and infrared spectrum of thallium holmium polyphosphate, TlHo(PO 3) 4

Abstract

Crystals of thallium-holmium polyphosphate TlHo(PO 3) 4 were grown by flux method technique and characterized by single crystal X-ray diffraction. Structure of TlHo(PO 3) 4 was solved for the first time, and it crystallized in the monoclinic P2 1/ n space group with the following unit-cell dimensions: a=1.02225(3) nm, b=0.88536(2) nm, c=1.09541(4) nm, β=105.888(1)®, V=0.95354(5) nm 3 and Z=4. The crystal structure was solved from 2174 independent reflections with final R 1( F 2)=0.0442 and R w( F 2)=0.0861 refined with 164 parameters. The atomic arrangement could be described as a long chain polyphosphate organization. Holmium atoms had eightfold coordination. The structure of TlHo(PO 3) 4 consisted of HoO 8 polyhedra sharing oxygen atoms with phosphoric group PO 4. Infrared spectrum was investigated at room temperature in the frequencies range, 350–4000 cm −1, showing some characteristic vibration bands of infinite chain structure of PO 4 tetrahedra linked by bridging oxygen.