Poly[sesqui(μ4‐biphenyl‐4,4′‐dicarboxyl­ato‐κ4O:O′:O′′:O′′′)(diethyl­formamide‐κO)gadolinium]

The crystal structure of the title compound, [Gd(C14H8O4)1.5(C5H11NO)]n, comprises chains of Gd atoms intra­connected by the carboxyl­ate groups of the biphenyl‐4,4′‐dicarboxyl­ate (BPDC) linkers, one of which is disposed about a twofold axis. The Gd atom chains are aligned along the b axis and are inter­connected by BPDC linkers, creating a three‐dimensional framework. A single diethyl­formamide (DEF) mol­ecule is bonded to each Gd atom. This mol­ecule is positioned in the cavities formed by the inter­connection of the Gd atom chains via the BPDC linkers. Due to the steric constraints of the carboxyl­ate groups, the square antiprismatic coordination geometry of eight O atoms (one from the DEF mol­ecule and seven from carboxyl­ate groups) around Gd is distorted.