Multi-arm ionic liquid crystals formed by pyridine-mesophase and copper phthalocyanine

Abstract Phthalocyanine emerged as a promising molecular component for photoreceptors because of their high extinction coefficients, stability, and energy band gaps well-matched to the incident solar spectrum. The cavity in the center can be occupied by dozens of cation types to form metallo-phthalocyanines which show a number of special properties such as electrical, optical, non-linear optical and opto-electronic. A kind of novel multi-arm ionic liquid crystalline materials combined the characteristics of liquid crystals with phthalocyanine were prepared using copper phthalocyanine as a matrix, [1,1′-biphenyl]-4,4′-diyl diisonicotinate or cyclohexane-1,4-diyl diisonicotinate as a mesogen, and different ions (B-SO 3 − , C-SO 3 − , H 2 PO 4 − and BF 4 − ) as counterions. The mesomorphic properties of these ionic liquid crystals were investigated by differential scanning calorimetry, polarizing optical microscopy, and X-ray diffraction measurements. The copper phthalocyanine-based multi-arm ionic liquid crystals showed excellent electrical conductivity (the optimum value of conductivity can reach 0.0248 S/cm) because of their ionic channels and π-π stacking structure. This materials might provide a promising application prospect for electronic or optoelectronic applications.