Structures and properties of ion pair charge-transfer salts: [DMBPE]2Ge4S10 (DMBPE = N,N′-dimethyl-1,2-bis(4-pyridinium)-ethylene)

Crystal structures and properties of two new ion pair charge-transfer (IPCT) compounds, [DMBPE]2Ge4S10·8H2O (1) and [DMBPE]2Ge4S10·5H2O (2), (DMBPE = N,N′-dimethyl-1,2-bis(4-pyridinium)-ethylene) are characterized. The IPCT property was confirmed by their charge-transfer absorption bands. Fluorescence emission for 1 in water was observed, that is affected by the cation–anion interaction. The photocurrent measurement showed that compounds 1 and 2 are also photoelectric responsive materials.