Dell'Amico Daniela Belli, Calderazzo Fausto, Labella Luca, Marchetti Fabio
Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Pisa, Italy.
Inorg Chem. 2008 Jun 16;47(12):5372-6. doi: 10.1021/ic7024523. Epub 2008 May 20.
N,N-di- iso-propylcarbamato derivatives of boron(III) have been synthesized from di-iso-propylamine and boron trichloride in the presence of carbon dioxide. With a large excess of amine, a single boron product was obtained, [NH2i)Pr2][B(O2CNiPr2)4], 1, while with a lower excess a mixture of 1 and of the dinuclear derivative [B2(O2CNiPr2)6], 2, was produced. By heating in vacuo at 60 degrees C, solid 1 slowly converted to 2. The transformation was reversible, 2 giving 1 back with di- iso-propylamine under carbon dioxide at atmospheric pressure. The molecular structure of both compounds was established by X-ray diffraction methods. Compound 1 is constituted by ion-pairs where the ammonium cation is hydrogen-bonded to the mononuclear anion. Compound 2 is a dinuclear species with two bridging carbamato ligands. In both derivatives, boron shows tetrahedral coordination. As IR- and 1H NMR spectra of the two species are well differentiated, it is possible to monitor the interconversion of 1 and 2 by both spectroscopic methods.
在二氧化碳存在下，由二异丙胺和三氯化硼合成了硼（III）的N，N - 二异丙基氨基甲酸酯衍生物。当胺大量过量时，得到单一的硼产物[NH2i)Pr2][B(O2CNiPr2)4]，即化合物1；而当胺的过量较少时，则生成化合物1与双核衍生物[B2(O2CNiPr2)6]，即化合物2的混合物。通过在60℃真空加热，固体1缓慢转化为2。该转化是可逆的，在大气压下，二氧化碳存在时，化合物2与二异丙胺反应又生成1。通过X射线衍射方法确定了两种化合物的分子结构。化合物1由离子对构成，其中铵阳离子通过氢键与单核阴离子相连。化合物2是具有两个桥连氨基甲酸酯配体的双核物种。在这两种衍生物中，硼均呈现四面体配位。由于这两种物质的红外光谱和1H NMR光谱有明显差异，因此可以通过这两种光谱方法监测化合物1和2的相互转化。
