Discotic Liquid Crystals of Transition Metal Complexes. XVI. Discotic Mesomorphism and Unique Chromism of Bis[1,2-bis(3,4-dialkoxyphenyl)ethanedione dioximato]palladium(II) Complexes

Bis[1,2-bis(3,4-dialkoxyphenyl)ethanedione dioximato]palladium(II) complexes, (abbreviated [Pd{(CnO)4dpg}2]; n = 1—12)have been synthesized and characterized. It was found that each of the [Pd{(CnO)4dpg}2] (n = 2—12) complexes has an enantiotropic discophase (Dhd). The clearing points of the [Pd{(CnO)4dpg}2] (n = 4, 8, 12) complexes are higher than those of the corresponding [Ni{(CnO)4dpg}2] (n = 4, 8, 12) complexes. Interestingly, the [Pd{(CnO)4dpg}2] complexes exhibit thermochromism and solvatochromism similar to that of [Ni{(CnO)4dpg}2] complexes.