Dr. Long-Li Lai
National Chi Nan University, Chinese Taipei
Title: Study of triazine-based dendrimers with C3 symmetry or breaking their C2 symmetry as Mesogenes
Abstract:
Dendrimers, generally consisting of central and linking moieties as well as peripheral groups in spheroid or globular packings are noteworthy because these molecules with well-defined chemical structures, often show interesting and predictable properties and thus have attracted a lot of intention in recent decades. Due to their varied architectures and multiple functions in one single molecule, these molecules in the fields of catalysts, drug-carriers, photoelectric materials, and porous materials have been extensively investigated.
Dendrimers that exhibit columnar liquid crystalline (LC) phases have also been found useful in photovoltaics and field transistors7 because of their non-grained boundary and uniform alignment in the solid state. However, the molecular conformations of dendrimers are versatile and it is not easy to control molecular shapes due to their various combinations of cores, linking units, and peripheral functionalities. The LC phases of traditional dendrimers, containing flexible spacers and mesogenic units, are generally induced by the mesogenic moieties. Instead of traditional LC dendrimers, we are devoted in the study of unconventional triazine-based LC dendrimers that contain rigid cores, rigid linkages, and flexible peripheral chains. Such dendriemrs with C2 symmetry may exhibit mesogenic phases on thermal treatment only in high molecular weight. On the application point of view, dendrimers with lower molecular weight that can exhibit mesogenic phases on thermal treatment is necessary. Therefore, preparing dendrimers with C3 symmetry or breaking their C2 symmetry is worthwhile to study further.
Biography:
Long-Li Lai received his Ph. D. degree in Se chemistry in 1992 from the Department of Chemistry, the University of Witwatersrand under professor D. H. Reid. After several research stints as postdoctoral scholars, he currently is a professor in Department of Applied Chemistry, National Chi Nan University Taiwan. His research interests include the synthesis and physical study of LC dichroic azo-dyes and triazine-based dendrimers. In dendritic areas, he is particularly interested in preparing dendrimers containing various pore sizes in the dendritic framework for their potential in catalytic reaction. He has published over 70 scientific papers including patents and articles.