X-ray investigations on the cyclopalladated mesogen bis-{5-(1-nonyl)-2{[4'(1-nonyloxy)phenyl-2’-ato]}pyrimidine-N’,C2’]-μ-iodo}dipalladium(II)

The cyclopalladated complex [Pd(L3)(μ-I)]2 ([Pd(L3)(μ -I)]2 = bis-{5-(1-nonyl)-2{[4′(1-nonyloxy)phenyl-2′-ato]}pyrimidine-N′, C2′]-μ-iodo}dipaladium (II); C→105·1°C (C1)→128·1°C (SA)→202·5°C (I)) has been investigated by X-ray diffraction and the electron density profile along the director, in the smectic phase, determined. [Pd(L3(μ -I)]2 is a mesogenic species with a lateral-lateral fused molecular shape whose main features are: (i) the solid C1 phase when observed with a polarizing microscope gives a polygonal texture like a smectic A phase, and (ii) to describe properly the electron density profile along the director a model which takes into account a high electron density area (i.e. the four aromatic rings and the Pd2I2 fragment) extending perpendicular to the director is required.