Synthesis and characterization of mixed alkali borophosphate with a new 1D chain: Li3Cs2BP4O14

A new anhydrous mixed alkali metals borophosphate, Li 3 Cs 2 BP 4 O 14 , has been synthesized by the solid-state reaction. Single crystal X-ray diffraction analysis reveals that the title compound crystallized in a tetragonal geometry with space group of P 4 2 / mbc (No. 135) and cell parameters of a   =   10.3413(5)   Å, b   =   10.3413(5)   Å, c   =   12.042(2)   Å. Its one-dimensional (1D) chain structure is constructed by fundamental building unit (FBU) of [B(P 2 O 7 ) 2 ] 5− which contains P–O–P connections with B:P   =   1:4. Thermal analysis, UV–Vis-near-IR diffuse reflectance spectroscopy, IR spectroscopy and theoretical calculations have been well performed on this new borophosphate compound.