Converting non-Mesogenic to Mesogenic Stacking of Amino-s-Triazine-Based Dendrons with p-CN Phenyl Unit by Eliminating Peripheral Dipole.

ABSTRACT: Three new amino-s-triazine-based dendrons, 1a, 1b, and 1c, containing an aryl-CN moiety in the dendritic skeleton were prepared in 72-81% yields (1a: R1 = - N(n-C8H17)2, R2 = n-OC8H17, 1b: R1 = R2 = - N(n-C8H17)2, 1c: R1 = - N(n-C8H17)2, R2 = - N(n-C4H9)2). Dendrons 1a with N(n-C8H17)2 and n-OC8H17 peripheral substituents, surprisingly, did not show any mesogenic phase during the thermal process. However, non-mesogenic 1a can be converted to mesogenic 1b or 1c by eliminating the peripheral dipole arising from the alkoxy substituent; dendron 1b only comprising the same N(n-C8H17)2 peripheral groups showed a ~25 °C mesogenic range on heating and ~108 °C mesogenic range on cooling. In contrast, dendron 1c possessing different N(n-CmH2m+1)2 (m = 8 versus m = 4) peripheral units, having similar

SUBMITTER: Lu YC 

PROVIDER: S-EPMC8782037 | biostudies-literature | 2022 Jan

REPOSITORIES: biostudies-literature