Department of Chemistry, University of New Brunswick, P.O. Box 4400, Fredericton, NB E3B 5A3, Canada.
Dalton Trans. 2013 May 21;42(19):6953-64. doi: 10.1039/c3dt00046j.
The AlH3 adducts of TMEDA (Me2NCH2CH2NMe2), DIOX (O(CH2CH2)2O), TEA (Et3N), BDMA (PhNMe2), and TMPDA (Me2NCH2CH2CH2NMe2) have each been characterised by single-crystal X-ray diffraction at low temperature, by (1)H, (14)N and (27)Al NMR and FT-Raman and FT-IR spectroscopy, and by DFT calculations and elemental analysis. Hence, AlH3·TMEDA and AlH3·DIOX are both shown to adopt a polymeric structure, with the bidentate ligand bridging two Al centres, each of which adopts a trigonal bipyramidal (TBP) arrangement with equatorial hydride moieties. The 1 : 2 adduct AlH3·2BDMA is monomeric but the geometry at the Al centre resembles closely that of the polymeric TMEDA and DIOX complexes. AlH3·TEA alone adopts a monomeric structure in which the Al centre is tetrahedrally coordinated by three hydride and one amine ligand. The Al-L bond distance of 2.0240(17) Å for AlH3·TEA is the shortest of all the complexes in this study, and AlH3·TEA also possesses the shortest Al-H bonds. AlH3·DIOX has the shortest Al-L bond distance of the polymeric species (2.107(14) Å) on account of the higher electronegativity of the oxygen donor. The structure of AlH3·TMEDA was determined at low temperature (monoclinic space group P2(1)/c), and salient features are compared to the previous room temperature study, for which a highly disordered orthorhombic space group (P2(1)2(1)2(1)) was reported. The polymeric structures appear to be stabilised by a number of intermolecular interactions and unconventional hydrogen bonds; these are most pronounced for AlH3·DIOX, whose chains are connected by highly directional C-H···H-Al bonding with an H···H distance of 2.32(6) Å.
TMEDA（Me2NCH2CH2NMe2）、DIOX（O（CH2CH2）2O）、TEA（Et3N）、BDMA（PhNMe2）和 TMPDA（Me2NCH2CH2CH2NMe2）的 AlH3 加合物均通过低温单晶 X 射线衍射、（1）H、（14）N 和（27）Al NMR 及 FT-Raman 和 FT-IR 光谱、DFT 计算和元素分析进行了表征。因此，AlH3·TMEDA 和 AlH3·DIOX 均被证明采用聚合结构，双齿配体桥接两个 Al 中心，每个 Al 中心均采用三角双锥（TBP）排列，具有赤道氢化物部分。1:2 加合物 AlH3·2BDMA 是单体，但 Al 中心的几何形状与聚合 TMEDA 和 DIOX 配合物非常相似。AlH3·TEA 单独采用单体结构，其中 Al 中心由三个氢化物和一个胺配体四面配位。AlH3·TEA 的 Al-L 键距离为 2.0240(17)Å，是本研究中所有配合物中最短的，并且 AlH3·TEA 还具有最短的 Al-H 键。由于供电子体的电负性较高，AlH3·DIOX 具有聚合物种中最短的 Al-L 键距离（2.107(14)Å）。AlH3·TMEDA 的结构在低温下确定（单斜空间群 P2(1)/c），并与之前的室温研究进行了比较，其中报道了高度无序的正交空间群（P2(1)2(1)2(1)）。聚合结构似乎通过许多分子间相互作用和非常规氢键稳定；这些对于 AlH3·DIOX 最为明显，其链通过高度定向的 C-H···H-Al 键连接，H···H 距离为 2.32(6)Å。
