Crystal structure of zwitterionic 2-[bis(2-methoxyphenyl)phosphaniumyl]-4-methylbenzenesulfonate monohydrate dichloromethane monosolvate

In the title compound, C21H21O5PS·H2O·CH2Cl2, the phosphonium–sulfonate zwitterion has the acidic H atom located on the P atom rather than the sulfonate group. The S—O bond lengths [1.4453 (15)–1.4521 (14) Å] are essentially equal. In the crystal, the water molecules bridge two zwitterions via Owater—H...Osulfonate hydrogen bonds into a centrosymmetric dimer. The dimers are further linked by weak CAryl—H...Osulfonate hydrogen bonds into chains extending along [100]. The PH+ group is not involved in intermolecular interactions