Connector type‐controlled mesophase structures in poly(propyl ether imine) dendritic liquid crystals of identical dendrimer generations

Abstract

Poly(propyl ether imine) (PETIM) dendrimers of one to three generations are used as dendritic cores to identify the influence of varying connector types that connect the dendritic core with peripheral mesogens on the emerging liquid crystalline (LC) properties. The LC properties vary in these dendritic liquid crystals, even when the dendrimer generations and thus the number of peripheral mesogenic moieties remain identical. PETIM dendrimer generations one to three, ester and amide connectors varying with succinates, phthalates, and succinamides, are studied herein. Cholesteryl moieties are installed at the peripheries through the above connectors to induce mesogenic properties. These modified dendritic liquid crystals reveal a layered mesophase structure in most ester and amide connector‐derivatives, whereas a third‐generation phthalate ester dendrimer favors a rectangular columnar mesophase structure. A transition from layered to a rectangular columnar structure results by a mere change in the connector varying between a succinate or succinamide or phthalate, within one particular dendrimer generation and without altering the underlying dendrimer core or the number of mesogenic moieties. The study demonstrates that in dendritic liquid crystals with essentially identical chemical constitutions, a change in the connector type connecting the mesogen with the dendrimer core is sufficient to change the mesophase structures. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3665–3678

Synthetic Methodologies for Chelating Polymer Ligands: Recent Advances and Future Development

“…Poly(propyl ether imine) (PETIM) G1‐G3 dendrimers were used as dendritic cores to identify the effect of various types of connectors (succinates, phthalates, and succinamides) (Figure ) . Cholesteryl fragments are installed at the periphery through connectors to induce mesogenic properties.…”

Chiral plasmonic liquid crystal gold nanoparticles: self-assembly into a circular dichroism responsive helical lamellar superstructure

“…With very few exceptions, diffraction from smectic phases gives a single wide-angle diffuse peak that is associated with the intermolecular separation within the layer. However, in the case of molecules having widely different terminal groups such as fluorocarbon/hydrocarbon, 64,65 hydrocarbon/siloxane 66 or hydrocarbon/cholesteryl 67 moieties, twin reflections are observed. In the latter case, we proposed that the need for efficient packing as well as the mutual interaction of the two moieties results in diffraction on two length scales.…”