TRIMETHYL ORTHOBORATE – AMINE INCLUSION COMPOUNDS

Abstract

A new class of non-stoichiometric crystalline inclusion compounds has been discovered, having the general formula[Formula: see text]where 0.5 < n < 1.0 and 0 < x < 3 depending on the method of preparation and on the nature of the amine and solvent. Such compounds have been prepared with ammonia and a variety of primary and secondary amines. Among the solvents which can be incorporated into the crystals are alcohols, ketones, ethers, esters, nitriles, nitroparaffins, and hydrocarbons. Such compounds are also formed by triphenyl orthoborate, with 1.7 < n < 2.4 and 1.2 < x < 1.6.The incorporated solvent has been shown to exert a definite vapor pressure. Furthermore, many of the compounds sublime at room temperature to form large transparent crystals which also contain incorporated solvent. The mechanism probably involves dissociation, followed by reassociation on the walls of the vessel. Preliminary X-ray diffraction measurements suggest that the trimethyl orthoborate – ammonia inclusion compounds have essentially the same crystal lattice as pure trimethyl orthoborate – ammonia.