Supramolecular Chromotropism of the Crystalline Phases of 4,5,6,7-Tetrafluorobenzo-2,1,3-telluradiazole
作者:Anthony F. Cozzolino、Pamela S. Whitfield、Ignacio Vargas-Baca
DOI:10.1021/ja107252f
日期:2010.12.8
The remarkable effect that secondary bonding interactions can have on the macroscopic properties of a material is illustrated by two polymorphs of the title compound. The phase which is most stable under ambient pressure and temperature consists of puckered supramolecular ribbon polymers assembled by Te-N secondary bonding interactions and displays a characteristic red-orange color. A second yellow phase consists of ribbons with alternating short and long intermolecular Te-N secondary bonding distances and is metastable; at 127 degrees C the material undergoes an exothermic irreversible transition to the red polymorph. A third phase consists of pyridine-solvated supramolecular dimers; it is also yellow and transforms into the red phase after the crystals effloresce. Computational DFT studies indicate that the observed changes in optical properties are related to intermolecular mixing pi orbitals enabled by the supramolecular interactions and the symmetry of the supramolecular synthon.
A polyfluoroaromatic tellurium–nitrogen compound: synthesis and properties of 4,5,6,7-tetrafluoro-2λ<sup>4</sup>δ<sup>2</sup>,1,3-benzotelluradiazole
作者:Vladimir N. Kovtonyuk、Alexander Yu. Makarov、Makhmut M. Shakirov、Andrey V. Zibarev
DOI:10.1039/cc9960001991
日期:——
4,5,6,7-Tetrafluoro-2 lambda(4) delta(2),1,3-benzotelluradiazole compound 2 (and a N-15-enriched sample) is synthesized by treating TeCl4 with the corresponding diamine 4 in the absence of HCl accepters, Some of its properties, e.g. high volatility, facile hydrolysis and vibrational frequencies, are experimentally determined.
Chalcogen Bonding in Solution: Interactions of Benzotelluradiazoles with Anionic and Uncharged Lewis Bases
作者:Graham E. Garrett、Gregory L. Gibson、Rita N. Straus、Dwight S. Seferos、Mark S. Taylor
DOI:10.1021/ja512183e
日期:2015.4.1
Chalcogen bonding is the noncovalent interaction between an electron-deficient, covalently bonded chalcogen (Te, Se, S) and a Lewis base. Although substantial evidence supports the existence of chalcogen bonding in the solid state, quantitative data regarding the strengths of the interactions in the solution phase are lacking. Herein, determinations of the associationconstants of benzotelluradiazoles with
硫属元素键合是缺电子、共价键合的硫属元素(Te、Se、S)和路易斯碱之间的非共价相互作用。尽管大量证据支持固态硫属元素键的存在,但缺乏关于溶液相中相互作用强度的定量数据。本文描述了苯并碲拉唑与各种路易斯碱(Cl(-)、Br(-)、I(-)、NO3(-) 和奎宁环,在有机溶剂中)的缔合常数的测定。通过紫外-可见光、(1)H 和 (19)F NMR 光谱以及纳米 ESI 质谱法探测了苯并碲二唑在硫属元素键合相互作用中的参与。从这些数据中可以明显看出供体、受体和溶剂变化时硫属元素键的自由能趋势,包括硫属元素键供体能力与碲中心处计算的静电势之间的线性自由能关系。发现使用色散校正的 B97-D3 泛函的计算与硫属元素键合的实验自由能非常吻合。