Preparation and properties of a series of structurally diverse aluminium hydrides supported by β-diketiminate and bis(amide) ligands
Preparation and properties of a series of structurally diverse aluminium hydrides supported by β-diketiminate and bis(amide) ligands
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DOI：
10.1039/c3dt52148f
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发表时间：
2013-01-01
影响因子：
4
通讯作者：
Crimmin, Mark R.
中科院分区：
文献类型：
--
作者：
Nako, Adi E.;Gates, Sarah J.;Crimmin, Mark R.
报道了一系列N，N‘-螯合配体配位的铝氢化物配合物的合成。[{2，6-(Pr2C6H3)-Pr-i}NC(Me)CHC(Me)N(H)CH2CH2NMe2]与LiAlH4或Me3N中心点AlH3反应，分离出相应的五配位二氢铝[kappa(3)-{(2，6-(Pr2C6H3)-Pr-i)-NC(Me)CHC(Me)NCH2CH2NMe2}AlH2](2)。后者在固体中表现为三方双锥几何构型。固体和正己烷溶液的红外光谱数据关联表明，这种配位被保留在溶液中。为了评价观察到的配位几何构型，用密度泛函方法M06-2X和杂化6，31G+(d，p)/Lanl2DZ基组研究了2的侧链配体的解离。Me3N中心点AlH3与N，N‘-二(二异丙基苯基)乙二胺和N，N’-二(均三甲基)乙二胺反应生成[{kappa(2)-(ArNCH2)(2)}AlH(NMe3)](Ar=MES，3a；Ar=2，6-二异丙基苯基，3b)。通过在动态真空下加热从3b中除去NMe3，使得顺式-[AlH-[MU-N(Ar)CH2CH2N(Ar)}](Ar=2，6-二异丙基苯基，顺-4b(2))在结晶后分离为单一的非对映异构体。结合红外和核磁共振光谱以及单晶X射线衍射数据进行的DFT研究提供了大量证据，证明顺式-4b(2)在溶液中保持完整的强健二聚体结构。还报道了二氢化铝[kappa(2)-{(2，6-Me2C6H3NHCH2)(2)CH}AlH2]促进Ph3PCH2的P-C键断裂的不寻常反应。
The synthesis of a diverse series of hydride complexes of aluminium coordinated by N,N'-chelating ligands is reported. Reaction of [{2,6-(Pr2C6H3)-Pr-i}NC(Me)CHC(Me)N(H)CH2CH2NMe2] with either LiAlH4 or Me3N center dot AlH3 allows isolation of the corresponding five-coordinate aluminium dihydride [kappa(3)-{(2,6-(Pr2C6H3)-Pr-i)-NC(Me)CHC(Me)NCH2CH2NMe2}AlH2] (2). The latter complex demonstrates trigonal bipyramidal geometry in the solid-state. Correlation of solid and n-hexane solution infrared spectroscopy data reveals that this coordination is retained in solution. To evaluate the observed coordination geometry, the dissociation of the pendant ligand of 2 was investigated by DFT methods conducted with the M06-2X functional and a hybrid 6,31G+(d, p)/Lanl2DZ basis-set. Reaction of Me3N center dot AlH3 with both N,N'-bis(di-isopropylphenyl) ethylenediamine and N,N'-bis(mesityl)ethylenediamine gave [{kappa(2)-(ArNCH2)(2)}AlH(NMe3)] (Ar = Mes, 3a; Ar = 2,6-di-iso-propylphenyl, 3b)in moderate yields. Removal of NMe3 from 3b by heating under dynamic vacuum allowed the isolation of cis-[AlH{mu-N(Ar)CH2CH2N(Ar)}] (Ar = 2,6-di-iso-propylphenyl, cis-4b(2))as a single diastereomer following crystallization. DFT studies in combination with infrared and NMR spectroscopy and single crystal X-ray diffraction data provide a weight of evidence consistent with the robust dimeric structure of cis-4b(2) remaining intact in solution. An unusual reaction in which the aluminium dihydride, [kappa(2)-{(2,6-Me2C6H3NHCH2)(2)CH}AlH2], promotes the P-C bond cleavage of Ph3PCH2 is also reported.