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首页> 外文期刊>The journal of physical chemistry, A. Molecules, spectroscopy, kinetics, environment, & general theory >C _Ar-H?O hydrogen bonds in substituted isobenzofuranone derivatives: Geometric, topological, and nmr characterization
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C _Ar-H?O hydrogen bonds in substituted isobenzofuranone derivatives: Geometric, topological, and nmr characterization

机译：取代的异苯并呋喃酮衍生物中的C _Ar-H2O氢键：几何，拓扑和核磁共振表征

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摘要

Substituted isobenzofuranone derivatives 1a-3a and bindone 4 are characterized by the presence of an intramolecular C _(Ar)-H?O hydrogen bond in the crystal (X-ray), solution (~1H NMR and specific and nonspecific IEF-PCM solvation model combined with MP2 and B3LYP methods), and gas (MP2 and B3LYP) phases. According to geometric and AIM criteria, the C _(Ar)-H?O interaction weakens in 1a-3a (independent of substituent nature) and in 4 with the change in media in the following order: gas phase > CHCl _3 solution > DMSO solution > crystal. The maximum value of hydrogen bond energy is 4.6 kcal/mol for 1a-3a and 5.6 kcal/mol for 4. Both in crystals and in solutions, hydrogen bond strength increases in the order 1a < 2a < 3a with the rising electronegativity of the ring substituents (H < OMe < Cl). The best method for calculating ~1H NMR chemical shifts (δ ~(calcd) - δ ~(expl) < 0.7 ppm) of hydrogen bonded and nonbonded protons in 1a-3a and 1b-3b (isomers without hydrogen bonds) is the GIAO method at the B3LYP level with the 6-31G * and 6-311G * basis sets. For the C-H moiety involved in the hydrogen bond, the increase of the spin-spin coupling constant ~1J(~(13)C- ~1H) by about 7.5 Hz is in good agreement with calculations for C-H bond shortening and for blue shifts of C-H stretching vibrations (by 55-75 cm ~(-1)).
机译：取代的异苯并呋喃酮衍生物1a-3a和键合酮4的特征是晶体中存在分子内C_（Ar）-H2O氢键（X射线），溶液（〜1H NMR和特异IEF-PCM溶剂化结合MP2和B3LYP方法的模型）和气相（MP2和B3LYP）相。根据几何和AIM标准，随着介质的变化，C _（Ar）-H 2 O相互作用在1a-3a（与取代基性质无关）和4中减弱，依次为：气相> CHCl _3溶液> DMSO解决方案>晶体。 1a-3a的氢键能最大值为4.6 kcal / mol，4的氢键能最大值为5.6 kcal / mol。在晶体和溶液中，氢键强度随环的电负性的升高而按1a <2a <3a的顺序增加。取代基（H ＜OMe ＜Cl）。 GIAO方法是计算1a-3a和1b-3b中氢键和非键质子的〜1H NMR化学位移（δ〜（计算）-δ〜（expl）<0.7 ppm）的最佳方法在B3LYP级别上具有6-31G *和6-311G *基集。对于参与氢键的CH部分，自旋-自旋偶合常数〜1J（〜（13）C-〜1H）的增加约7.5 Hz与CH键缩短和C的蓝移的计算非常吻合CH拉伸振动（55-75 cm〜（-1））。

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