Unprecedented 5,5-connected (47 · 63) (48 · 62) structural topology: A lead biphosphonate with double layered structure

Hydrothermal reaction of lead(II) acetate with diphosphonate Hedp (Hedp = l-hydroxyethylidene diphosphonate) yield a new lead(II) phosphonate, Pb[(PO3)2C(OH)CH3] · H2O (1). Complex 1 has a two-dimensional double layered hybrid structure containing interconnected 4- and 12-membered rings and shows an unusual (5,5)-connected (47 · 63) (48 · 62) topology.