Synthesis and Crystal Structure Determination of a Dimeric Complex of Dimethylammoniumbis(p-tert-butylcatecholato) borate

Abstract

For decades, there has been growing interest in borates mainly due to the fact that B atoms are capable of forming both the BO3 triangles or the BO4 tetrahedra. Through polymerization these B–O groups can result in constructing one dimensional (1D) chains, 2D layers, and 3D networks.1 The wide range of applications of borates virtually stems from the structureproperty relationship that render possible their huge structural varieties and the functionality of the BO units.2 Such structure diversities make the structure chemistry of borates extraordinary. Thus far, a series of borate materials have been reported for a number of utilizations, including, birefringence, piezoelectric, pyroelectric, and nonlinear optics.3–6 Boron compounds formed by a non-metallic support unit can be displayed in a binary fashion composed of an anionic borate structural unit and a cationic interstitial complex.7 The role of non-metal cations differs from metal cations, since they generally do not coordinate to oxygen in the same way, and may act instead as hydrogen bond donors to the structural unit. Continuation persistently our progressing work on borates,8–11 the process of the self-assembly of organic and inorganic moieties has been performed under DMF solution conditions, and yielded original borate with organic amine, namely dimethyl ammonium bis(p-tertbutylcatecholato) borate. The aforesaid compound (Fig. 1) was prepared by employing a DMF solution (10 mL) of 4-tert-butylcatechole (4.65 mmol), onto which was afterwards added solid boric acid (2.15 mmol) with strong stirring. The reaction mixture was allowed to be stirred at 120°C for 3 h, resulting in the formation of a colorless material. The crude product was crystallized from a water/ acetone mixture. Crystals of the title compound were obtained by slow evaporation. X-ray crystallography was performed at 223.15 K on a RIGAKU AFC73 diffractometer employing graphitemonochromated fine focussed sealed-tube Mo-Kα radiation. Crystal data and details related to the data collection are given in Table 1. The structure was solved by an intrinsic phasing 2020 © The Japan Society for Analytical Chemistry