A Synthetic, X-ray, NMR Spectroscopy and DFT Study of β-Naphthil Dihydrazone, Di(β-naphthyl)acetylene, Tetra(β-naphthyl)cyclopentadienone, and Hexa(β-naphthyl)-benzene: C<sub>6</sub>
(C<sub>10</sub>
H<sub>7</sub>
)<sub>6</sub>
Is a Disordered Molecular Propeller
作者:Laura E. Harrington、James F. Britten、Kirill Nikitin、Michael J. McGlinchey
DOI:10.1002/cplu.201600512
日期:2017.3
characterised by X-ray crystallography, but hexa(β-naphthyl)benzene exhibits rotational disorder of the peripheral substituents. Nevertheless, calculations at the density functional level reveal the favoured structure of 5 to be a molecular propeller, in which the eight possible rotamers are essentially iso-energetic. Variable-temperature NMR spectroscopy studies yield a naphthyl rotational barrier of approximately
用氧化银处理β-萘乙二hydr 1,得到二(β-萘基)乙炔2,将其与四(β-萘基)环戊二烯酮4进行Diels-Alder环加成反应,得到六(β-萘基)苯, 5,脱羰后。分子1、2和4已经通过X射线晶体学表征,但是六(β-萘基)苯表现出外围取代基的旋转无序。然而,在密度泛函水平上的计算显示5是分子推进器的有利结构,其中八个可能的旋转异构体基本上是等能量的。可变温度NMR光谱研究得出的萘基旋转势垒约为17 kcal mol-1,与先前发现的间位取代苯基相似。