Fraser Duncan A X, Turner Zoë R, Cooper Robert T, Buffet Jean-Charles, Green Jennifer C, O'Hare Dermot
Department of Chemistry, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, U.K.
Inorg Chem. 2022 Aug 8;61(31):12207-12218. doi: 10.1021/acs.inorgchem.2c01267. Epub 2022 Jul 25.
The synthesis and characterization of group 4 permethylpentalene (Pn* = CMe) hydride complexes are explored; in all cases, multimetallic hydride clusters were obtained. Group 4 lithium metal hydride clusters were obtained when reacting the metal dihalides with hydride transfer reagents such as LiAlH, and these species featured an unusual hexagonal bipyramidal structural motif. Only the zirconium analogue was found to undergo hydride exchange in the presence of deuterium. In contrast, a trimetallic titanium hydride cluster was isolated on reaction of the titanium dialkyl with hydrogen. This diamagnetic, mixed valence species was characterized in the solid state, as well as by solution electron paramagnetic resonance and nuclear magnetic resonance spectroscopy. The structure was further probed and corroborated by density functional theory calculations, which illustrated the formation of a metal-cluster bonding orbital responsible for the diamagnetism of the complex. These permethylpentalene hydride complexes have divergent structural motifs and reactivity in comparison with related classical cyclopentadienyl analogues.
对第4族全甲基戊搭烯（Pn* = CMe）氢化物配合物的合成与表征进行了探索；在所有情况下，均得到了多金属氢化物簇。当金属二卤化物与诸如LiAlH之类的氢化物转移试剂反应时，得到了第4族锂金属氢化物簇，这些物种具有不寻常的六角双锥结构 motif。仅发现锆类似物在氘存在下会发生氢化物交换。相比之下，钛二烷基与氢气反应分离出了三金属钛氢化物簇。通过固态以及溶液电子顺磁共振和核磁共振光谱对这种抗磁性的混合价态物种进行了表征。通过密度泛函理论计算进一步探究并证实了其结构，该计算说明了形成负责配合物抗磁性的金属 - 簇键合轨道。与相关的经典环戊二烯基类似物相比，这些全甲基戊搭烯氢化物配合物具有不同的结构 motif 和反应活性。
