Crystal structure of dilithium biphenyl-4,4'-di-sulfonate dihydrate.

The asymmetric unit of the title compound, μ-biphenyl-4,4'-di-sulfonato-bis-(aqua-lithium), [Li 2 (C 12 H 8 O 6 S 2 )(H 2 O) 2 ] or Li 2 [Bph(SO 3 ) 2 ](H 2 O) 2 , consists of an Li ion, half of the diphenyl-4,4'-di-sulfonate [Bph(SO 3 - ) 2 ] ligand, and a water mol-ecule. The Li ion exhibits a four-coordinate tetra-hedral geometry with three oxygen atoms of the Bph(SO 3 - ) 2 ligands and a water mol-ecule. The tetra-hedral LiO 4 units, which are inter-connected by biphenyl moieties, form a layer structure parallel to (100). These layers are further connected by hydrogen-bonding inter-actions to yield a three-dimensional network.