Two molybdenum (VI) monophosphates with a tunnel structure: AMoO2PO4 (A=Cs, Tl) and structural relationships in the series

Two new molybdenum (VI) monophosphates CsMoO2PO4 and TlMoO2PO4 have been synthesized by solid state chemistry. Their structure were determined from single crystal X-ray diffraction studies. The frameworks MoO2PO4 delimit tunnels in which are located the univalent cations. Structural relationships between the different monophosphates of the AMoO2PO4 series with A = Ag, Na, K, Tl, Cs, are presented in which two kinds of frameworks appear owing to the size of the univalent cations.