Synthesis and characterization of some manganese complexes of 5,10,15,20-tetrakis (4-n-dodecylphenyl)porphyrin

The mesomorphic properties of 5,10,15,20-tetrakis(4-n-dodecylphenyl) porphy rin and its divalent metal complexes are well documented. Also, some trival ent metal complexes have been considered. In this work, the chloromanganese (III) complex of tetrakis(4-n-dodecylphenyl)porphyrin was synthesized and i ts thermotropic behaviour was observed. The telracyanoquinodimethane(TCNQ) complex was also prepared by metathesis between chloro manganese porphyrin and Li+(TCNQ(-)). Magnetic susceptibility measurements were performed on th is complex. The chloromanganese(III) complex showed a substantial depressio n of clearing point over the equivalent divalent complexes. However, althou gh both crystalline and mesomorphic phases could be observed a reproducible phase transition was not seen. Furthermore, the clearing transition was ir reversible under a healing/cooling rate of 5 deg/min. X-ray diffraction mea surements showed an increase in the ordering of the mesophase upon heating.