Discotic liquid crystals of transition metal complexes 39 double dagger: columnar mesomorphism and homeotropic alignment speed of sandwich-type of double-deckers and triple-deckers based on phthalocyaninato lutetium metal complexes

作者：Mukai Hidetomo; Hatsusaka Kazuaki; Ohta Kazuchika^*

来源：Journal of Porphyrins and Phthalocyanines, 2007, 11(11-12): 846-856.

• discotic liquid crystal
• homeotropic alignment
• sandwich type
• lanthanoid
• phthalocyanine

A series of sandwich-type metal complexes, bis[2,3,9,10,16,17,23,24-octakis(3,4-dialkoxyphenoxy)phthatocyaninato]lutetium(III) ({[(CnO)(2)PhO](8)Pc}(2)Lu (n = 8-16): double-deckers (2)), were synthesized. As the by-product, tris[2,3,9,10,16,17,23,24-octakis(3,4-diakoxyphenoxy)phthalocyaninato]dilutetium(III) ({[(CnO)(2)PhO](8)PC}(3)Lu-2 (n = 8, 9, 11, 12, 14, 16): triple-deckers (3)) were successfully separated. The mesomorphic properties of these double-deckers (2) and triple-deckers (3) were investigated using a polarization microscope, differential scanning calorimetry and temperature-dependent X-ray diffraction techniques. The double-deckers (2) showed Col(h), Cub and Col(tet) mesophases for n >= 10. On the other hand, the triple-deckers (3) showed only a Col(r) mesophase for n = 8, only a Col(tet) mesophase for n = 14, and both Col(r) and Col(tet) mesophases for n = 9, 11, 12 and 16. For the Col(tet) mesophase, both the double-deckers (2) and the triple-deckers (3) exhibited spontaneous homeotropic alignment in a large area. In comparison with the homeotropic alignment of these present lutetium complexes 2, 3 and the previous copper complexes, 2,3,9,10,16,17,23,24-octakis(3,4-dialkoxyphenoxy)phthalocyaninato copper(II) ([(CnO)(2)PhO](8)PcCU (n = 9-14): single-decker (1)), the alignment was fast, slow and fast, respectively, in the order of the single-deckers (1), double-deckers (2) and triple-deckers (3). Very interestingly, the complexes I and 3 which have flat PC macrocycles gave fast alignment, whereas the complexes, 2, which have non-flat Pc macrocycles, gave slow alignment. Thus, it was revealed for the first time that the flatness of discotic liquid crystalline molecules influences the speed of homeotropic alignment.

• 出版日期2007