Synthesis and mesomorphic properties of γ-substituted β-diketones and their dicarbonylrhodium(I) complexes

Five series of 3-(C10H21OPhXPhY) substituted pentane-2,4-diones and their dicarbonylrhodium(I) complexes, namely, series 1: X=CHCHCOO and Y=COO, series 2: X=CHCHCOO and Y=CHCHCOO, series 3: X=COO and Y=CHCHCOO, series 4: X=CH2O and Y=COO, series 5: X=NN and Y=COO, have been synthesized, their mesogenic properties have been investigated using a Nikon polarizing microscope and DSC. It is found the β-diketones 1a–3a, 5a and the complexes 1b–3b exhibit liquid crystal behaviors. The effect of the bridging groups of X and Y on the mesogenic properties of the ligands and the complexes has been explored.