Novel organically templated mixed-valent titanium phosphates with open framework structures: hydrothermal synthesis and characterization

摘要

We have hydrothermally synthesized the first reduced titanium phosphates with openframework structures. The synthetic approach is quite unusual since elemental titanium is used. The full structural, thermal, magnetic, and spectroscopic characterization of a 1,3-diaminopropane-templated compound, Ti~(III)Ti~(IV)(PO_4)(HPO_4)_2(H_2O)_2centre dot(NH_2CH_2CH_2CH_2NH_2)_(0.5), is presented. The frame of the compound is of the octahedral/tetrahedral type with octahedrally coordinated Ti~(III) and Ti~(IV) atoms. The template of 1,3-diaminopropane occupies channels with dimensions that are comparable to those of many zeolites. Magnetic measurements are consistent with one d-electron per formula unit. TGA/DTA and IR data will be reported as well. This compound is most likely the first member of a larger class of reduced titanium phosphates. Some preliminary data suggests that similar reduced titanium phosphates with different templates and structures exist as well. All compounds are blue-purple due to Ti(III).