# Tuning the Crystal Structure of Amphiphilic 3,4,5-Tris(alkyloxy)benzenesulfonates with Bulky Tetrabutylammonium Cations by Variation in the Aliphatic Chain

## TL;DR

This paper explores how changing the chain length of a specific compound affects its crystal structure and self-assembly into ordered lattices.

## Contribution

The study reveals a distinct structural transition in compounds with longer aliphatic chains, offering new insights into self-assembly mechanisms.

## Key findings

- Giant octupoles self-assemble into ordered lattices across various chain lengths.
- A unique crystalline lattice forms in compounds with hexadecyloxy and octadecyloxy chains.
- Phase behavior is governed by aliphatic chain length and ionic interactions.

## Abstract

3,4,5-Tris(alkyloxy)benzenesulfonates constitute a class of wedge-shaped dendrons exhibiting liquid crystalline properties, characterized by a diverse and intricate phase behavior that is predominantly governed by the length of the terminal aliphatic chains and the size and nature of the dendrons’ focal group, which collectively influence their self-organization. In systems comprising both two large counterions—wedge-shaped 3,4,5-tris(alkyloxy)benzenesulfonate anions and tetrabutylammonium (N(C4H9)4+) cations—a delicate balance between ionic interactions and microphase segregation drives the formation of giant octupoles that self-assemble subsequently into a remarkably ordered lattice. Such phase behavior is consistently observed across a broad range of compounds, with terminal aliphatic chain lengths varying from six to eighteen methylene units. While the structural configuration of the octupoles and the resulting crystalline lattice remains consistent across most compounds, a distinct transition from quantitative to qualitative changes is observed in tetrabutylammonium 3,4,5-tris(hexadecyloxy)benzenesulfonates and 3,4,5-tris(octadecyloxy)benzenesulfonates that exhibit a unique crystalline lattice structure.