Synthesis and plant growth modulation of tris (2-hydroxyethyl)ammonium boron-containing compounds

To develop boron deficiency treatment composite preparations for significant agricultural crops tris(2-hydroxyethyl)ammonium complexes containing boron and lower dicarboxylic acid (C2-C4) anions were synthesized and characterized. It was shown, that formation and stabilization of complexes containing a greater number of carbon atoms or intermolecular ?- conjugation (e.g. maleic acid) is related to space and electrostatical hurdles, respectively. According to NMR spectroscopy, in case of tartaric acid complex vicinal hydroxyl bounding with boron was found. The preexisted boratrane azeotropic water distillation synthetic method was modernized (videlicet optimal solvent mixture and raw materials ratio were chosen). Various triethanolamine and boric acid reaction mediums, i.e. nonpolar (toluene), polar aprotic (dimethylsulphoxide), protic (isopropanol, 2-butanol) solvents and their mixtures, were tested. In the issue optimal synthetic method, utilizing isopropanol/2-butanol mixture in ratio 3 to 1, was elaborated. In comparison to standard azeotropic water-isopropanol distillation the yield of the process was exceeded to 12.08% (from 82.70% to 94.78%) and low impurity concentrations in product was committed. Besides alternative laboratory solvent-free boratrane synthetic method was developed and optimal rinsing fluid composition was found. During agricultural experiments substance effectiveness in germination power and germinability of beet seeds and productivity of sugar beet was studied. Boratrane was found to be slightly effective for seed germinability stimulation. Boratrane-containing composition (i.e. boratrane + tris(2-hydroxyethyl)ammonium o-cresoxyacetate + 1-chloromethylsilatrane) was shown to have the best results in apical root length, average root-crop and average plant weigth increasing in comparison with the control.