School of Chemistry, University of St Andrews, St Andrews, Fife, KY16 9ST UK.
Chemistry. 2010 Jul 5;16(25):7605-16. doi: 10.1002/chem.201000435.
A series of eight 1-halo-8-(alkylchalcogeno)naphthalene derivatives (1-8; halogen=Br, I; alkylchalcogen=SEt, SPh, SePh, TePh) containing a halogen and a chalcogen atom occupying the peri positions have been prepared and fully characterised by using X-ray crystallography, multinuclear NMR spectroscopy, IR spectroscopy and MS. Naphthalene distortion due to non-covalent substituent interactions was studied as a function of the bulk of the interacting chalcogen atoms and the size and nature of the alkyl group attached to them. X-ray data for 1, 2, 4 and 5-8 were compared. Molecular structures were analysed in terms of naphthalene ring torsions, peri-atom displacement, splay angle magnitude, X...E interactions, aromatic ring orientations and quasi-linear X...E-C arrangements. A general increase in the X...E distance was observed for molecules that contain bulkier atoms at the peri positions. The I...S distance of 4 is comparable with the I...Te distance of 8, and is ascribed to a stronger lone pair-lone pair repulsion due to the presence of an axial S(naphthyl) ring conformation. Density functional theory (B3LYP) calculations performed on 5-8 revealed Wiberg bond index values of 0.05-0.08, which indicate minor interactions taking place between the non-bonded atoms in these compounds.
已制备并通过 X 射线晶体学、多核 NMR 光谱学、IR 光谱学和 MS 对一系列八个 1-卤代-8-（烷基亚硒/碲基）萘衍生物（1-8；卤素=Br、I；烷基亚硒/碲基=SEt、SPh、SePh、TePh）进行了充分的表征。研究了非共价取代基相互作用引起的萘变形与相互作用的硒/碲原子的体积以及与之相连的烷基的大小和性质的关系。比较了 1、2、4 和 5-8 的 X 射线数据。根据萘环扭转、周向原子位移、错位角大小、X…E 相互作用、芳环取向和准线性 X…E-C 排列来分析分子结构。对于含有周位较大原子的分子，观察到 X…E 距离普遍增加。4 中的 I…S 距离可与 8 中的 I…Te 距离相媲美，这归因于轴向 S（萘基）环构象中存在更强的孤对-孤对排斥。对 5-8 进行的密度泛函理论（B3LYP）计算得到了 0.05-0.08 的 Wiberg 键指数值，这表明这些化合物中非键原子之间存在轻微的相互作用。
