Linear-to-λ-Shape P-O-P Bond Transmutation in Polyphosphates with Infinite (PO 3 ) ∞ Chain.

A new metal polyphosphate, α-CsBa2 (PO3 )5 , exhibiting the first example of a linear P-O-P bond angle in a one-dimensional (PO3 )∞ chain has been reported. Interestingly, α → β phase transition occurs in CsBa2 (PO3 )5 along with the P-O-P bonds varying from linear to λ-shape, suggesting that α-CsBa2 (PO3 )5 with unfavorable linear P-O-P bonds is more stable at ambient temperature.