Dantlgraber Gert, Baumeister Ute, Diele Siegmar, Kresse Horst, Lühmann Bettina, Lang Heinrich, Tschierske Carsten
Department of Chemistry, Martin-Luther University Halle-Wittenberg, Institute of Organic Chemistry, Kurt-Mothes Strasse 2, D-06120 Halle, Germany.
J Am Chem Soc. 2002 Dec 18;124(50):14852-3. doi: 10.1021/ja028508k.
The first carbosilane dendrimer with peripheral bent-core mesogenic units is reported. This material forms a liquid crystalline phase which is stable over a wide temperature range and forms an LC glass on cooling. Polarizing microscopy, X-ray diffraction, and dielectric and electrooptic investigations reveal the presence of a novel liquid crystalline phase, in which the molecules are tilted and adapt a polar order within the layers, but without long-range correlation between the layers. By applying external electric fields, switching into a ferroelectric organization can be achieved. Once formed the ferroelectric states are stable and can be switched between the different polarization states.
报道了首例带有外围弯曲核介晶单元的碳硅烷树枝状大分子。这种材料形成了一种液晶相，该相在很宽的温度范围内稳定，冷却时会形成液晶玻璃。偏光显微镜、X射线衍射以及介电和电光研究表明存在一种新型液晶相，其中分子倾斜并在层内呈现极性有序，但层间没有长程相关性。通过施加外部电场，可以实现向铁电组织的转变。一旦形成，铁电态是稳定的，并且可以在不同的极化状态之间切换。
