The structure and luminescent properties of TlZn(PO3)(3)

The crystal structure and the luminescent properties of TIZn(PO3)(3) are st udied with respect to Tl+ stereochemistry, In this polyphosphate the Tl+ io ns are located in tunnels created by the zinc polyphosphate network [Zn(PO3 )(3)]. Actually the thallium atoms are found in a disymmetric configuration and bond calculation allows the determination of the coordination number b y oxygen: 6. Nevertheless a large Tl-O distance induces a low stereochemica l activity of the 6s(2) lone pair. The luminescent properties are analyzed in the context of Fukuda's model. Thermal variations of excitation and emis sion spectra can be explained by the small influence of the electron-lattic e interaction in agreement with the thallium environment. (C) 2000 Academic Press.