Department of Chemistry, Hitit University, Ulukavak, 19030 Çorum, Turkey.
Department of Chemical Engineering, Gazi University, Maltepe, 06570 Ankara, Turkey.
Molecules. 2019 Jul 31;24(15):2790. doi: 10.3390/molecules24152790.
Non-metal cation (NMC) pentaborate structures, in which some amino acids (valine, leucine, isoleucine, and threonine) were used as cations, were synthesized. The structural characterization of molecules was carried out by elemental analysis, FT-IR, mass, B-NMR, and thermal analysis (TGA/DTA) methods. The hydrogen storage capacity of molecules was also calculated by taking experimental results into consideration. The FT-IR spectra support the similarity of structures. The characteristic peaks attributable to pentaborate rings and amino acids were observed. When thermal analysis data were examined, it was observed that pentaborate salts gave similar degradation steps and degradation products. As a final degradation product of all thermal analysis experiments, a glassy form of BO was observed. The valine pentaborate is the most thermally stable. Also, the amounts of hydrate water outside the coordination sphere of the compounds were determined by thermal analysis curves. The peaks of boric acid, triborate, and pentaborate structures were obtained in ppm with the B-NMR results of synthesized pentaborate compounds. With powder X-ray spectroscopy, all structures were found to be crystalline but not suitable for single-crystal X-ray analysis. The molecular cavities of the compounds detected by BET were found to be 3.286, 1.873, 2.309, and 1.860 g/cm, respectively. A low number of molecular cavities can be interpreted in several existing hydrogen bonds in structures. The hydrogen storage capacities of the molecules were found to be in the range of 0.04 to 0.07% by mass.
非金属阳离子（NMC）五硼酸盐结构，其中一些氨基酸（缬氨酸、亮氨酸、异亮氨酸和苏氨酸）被用作阳离子，被合成。通过元素分析、FT-IR、质谱、B-NMR 和热分析（TGA/DTA）方法对分子的结构特征进行了表征。还考虑实验结果计算了分子的储氢容量。FT-IR 光谱支持结构的相似性。观察到归因于五硼酸盐环和氨基酸的特征峰。当检查热分析数据时，观察到五硼酸盐盐给出了类似的降解步骤和降解产物。作为所有热分析实验的最终降解产物，观察到了玻璃状的 BO。戊硼酸盐是最热稳定的。此外，还通过热分析曲线确定了化合物配位球外水合水的量。通过 B-NMR 结果获得了合成的五硼酸盐化合物的硼酸、三硼酸盐和五硼酸盐结构的 ppm 峰。通过粉末 X 射线光谱，发现所有结构均为结晶态，但不适合单晶 X 射线分析。通过 BET 检测到的化合物分子腔分别为 3.286、1.873、2.309 和 1.860 g/cm。结构中存在大量的氢键可以解释分子腔数量较少的情况。通过质量发现，分子的储氢容量在 0.04%至 0.07%之间。
