Nguyen Vinh T, Lai Qingheng, Witayapaisitsan Naphol, Bhuvanesh Nattamai, Surawatanawong Panida, Ozerov Oleg V
Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77842, United States.
Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.
Organometallics. 2023 Oct 24;42(21):3120-3129. doi: 10.1021/acs.organomet.3c00359. eCollection 2023 Nov 13.
Protolysis of AlMe or AlBu with 2-diisopropylphosphinopyrrole (1) yields molecules containing two flanking phosphines and a central Al-Me (2-Me), Al-Bu (2-Bu), or Al-H (2-H) unit. The reactions of 2-Me with [LMCl] (L = cyclooctene or 1/2 1,5-cyclooctadiene and M = Rh or Ir) in the presence of pyridine produces PAlP pincer complexes (3-Rh and 3-Ir) with Al-Cl and M-Me bonds. The analogous reaction of a mixture of 2-Bu and 2-H with [LMCl] and pyridine resulted in the formation of analogous Rh-H (4-Rh) and Ir-H (4-Ir) complexes. Treatment of 3-Rh with NaBEtH produced compound 5-Rh with an Al-Me and a Rh-H bond; the analogous reaction of 3-Ir did not result in a clean product. 4-Ir accepted an equivalent of H to produce 6-Ir with two terminal Ir-H bonds and one bridging Al-H-Ir moiety, whereas 4-Rh did not react with H. The density functional theoretical treatment is in accord with this finding, highlights the likely mechanism for the H addition, and supports the bonding picture in 6-Ir arising from NMR and X-ray diffraction (XRD) observations. Spectroscopic data and XRD studies are consistent with distorted square-pyramidal structures (about Rh or Ir) for compounds 3-5, with an alane occupying the apical position. Complexes 3 and 4 possess some of the shortest known Rh-Al or Ir-Al distances.
用2-二异丙基膦基吡咯（1）对AlMe或AlBu进行质子分解，得到含有两个侧翼膦和一个中心Al-Me（2-Me）、Al-Bu（2-Bu）或Al-H（2-H）单元的分子。在吡啶存在下，2-Me与[LMCl]（L = 环辛烯或1/2 1,5-环辛二烯，M = Rh或Ir）反应生成具有Al-Cl和M-Me键的PAlP钳形配合物（3-Rh和3-Ir）。2-Bu和2-H的混合物与[LMCl]和吡啶的类似反应导致形成类似的Rh-H（4-Rh）和Ir-H（4-Ir）配合物。用NaBEtH处理3-Rh得到具有Al-Me和Rh-H键的化合物5-Rh；3-Ir的类似反应没有得到纯净产物。4-Ir接受一当量的H生成具有两个末端Ir-H键和一个桥连Al-H-Ir部分的6-Ir，而4-Rh不与H反应。密度泛函理论处理与这一发现一致，突出了H加成的可能机制，并支持了由NMR和X射线衍射（XRD）观察得出的6-Ir中的键合情况。光谱数据和XRD研究与化合物3-5（关于Rh或Ir）的扭曲四方锥结构一致，其中一个铝烷占据顶端位置。配合物3和4具有一些已知最短的Rh-Al或Ir-Al距离。
