X-RAY-INVESTIGATIONS ON THE CYCLOPALLADATED MESOGEN BIS-(5-(1-NONYL)-2([4'(1-NONYLOXY)PHENYL-2'-ATO])PYRIMIDINE-N',C2']-MU-IODO)DIPALLADIUM(II)

The cyclopalladated complex [Pd(L3)(muunderbar-I)]2 ([Pd(L3)(mu-I)]2 = bis-{5-(1-nonyl)-2{[4'(1-nonyloxy)phenyl-2'-ato]}pyrimidine-N',C2']-mu-iodo}dipalladium (II); C-->105.1-degrees-C (C1)-->128.1-degrees-C (S(A))-->202.5-degrees-C (1)) has been investigated by X-ray diffraction and the electron density profile along the director, in the smectic phase, determined. [Pd(L3)(muunderbar-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.