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首页> 外文期刊>The journal of physical chemistry, A. Molecules, spectroscopy, kinetics, environment, & general theory >Selenoxides Are Better Hydrogen-Bond Acceptors than Sulfoxides: a Crystallographic Database and Theoretical Investigation
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Selenoxides Are Better Hydrogen-Bond Acceptors than Sulfoxides: a Crystallographic Database and Theoretical Investigation

机译：亚硒酸盐比亚砜是更好的氢键受体：晶体学数据库和理论研究

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摘要

The relative hydrogen-bond (HB) properties of sulfoxides and selenoxides have been investigated experimentally using data retrieved from the Cambridge Structural database and theoretically through density functional calculations at the B3LYP/6-311++G(3df,3pd)//B3LYP/6-311++G(3df,3pd) level. The HB are significantly shorter (stronger) in selenoxides (d(O···H) = 1.78 (3) A) than in sulfoxides (d(O···H) = 1.85 (2) A). The HB directionalities and linearities observed in the solid state for the two functionalities are very similar. The spatial and molecular surface minima of the electrostatic potential are, respectively, 43.9 and 23.4 kJ/mol more negative in dimethyl selenoxide (DMSeO) in comparison with that in dimethyl sulfoxide (DMSO). The investigation of the S(Se)O bond's electronic structure using the Natural Bond Orbital (NBO) approach shows that negative hyperconjugation of the type n_O→σ~*S(Se)-C is much more important in DMSO than that in DMSeO. In the HB complexes, the NBO analysis shows competition between n_O→σ~S(Se)-C delocalizations associated to hyperconjugation and n_O→σ~*HF delocalizations related to hydrogen-bonding. The NBO energetic analysis of the HB complexes demonstrates that the H···O interaction is significantly greater in DMSeO compared to that in DMSO. The computed thermodynamic parameters of HB complexation support the better HB ability of selenoxides since the δΔ°_(298) and δΔ°_(298) are, for the three HB donors used (HF, H_2O, and p-fluorophenol) always significantly in favor of DMSeO. The theoretical δΔ°_(298) and δΔ°_(298) calculated for DMS(Se)O HB interactions with p-fluorophenol, respectively, of 8.5 and 6.0 kJ/mol, compares reasonably well with the corresponding experimental data in solution of 2.8 and 5.0 kJ/mol. The theoretical δΔ°v(XH) clearly confirm the various observations, the δΔv(OH) value of 111 cm~(-1) calculated from the HB complexes with H_2O being close to the experimental δΔ°v(OH) of about 110(±20) cm~(-1).
机译：亚砜和亚硒酸盐的相对氢键（HB）性能已使用从Cambridge结构数据库中检索到的数据进行了实验研究，并通过B3LYP / 6-311 ++ G（3df，3pd）// B3LYP /的密度泛函计算从理论上进行了研究6-311 ++ G（3df，3pd）级别。亚硒酸盐（d（O···H）= 1.78（3）A）中的HB明显短于（强）HB（d（O···H）= 1.78（3）A）。固态观察到的两种功能的HB方向性和线性非常相似。与二甲基亚砜（DMSO）相比，二氧化亚硒酸酯（DMSeO）中的静电势空间和分子表面最小值分别分别为43.9和23.4 kJ / mol。使用自然键轨道（NBO）方法对S（Se）O键的电子结构进行的研究表明，nDM_n→σ〜* S（Se）-C型负超共轭在DMSO中比在DMSeO中更重要。在HB络合物中，NBO分析显示与超共轭相关的n_O→σ〜S（Se）-C脱域与与氢键相关的n_O→σ〜* HF脱域之间存在竞争。 NBO对HB配合物的能量分析表明，DMSeO中的H··O相互作用比DMSO中的H···O相互作用大得多。 HB络合物的热力学参数支持了亚硒酸盐更好的HB能力，因为对于所用的三个HB供体（HF，H_2O和对氟苯酚），δΔ°_（298）和δΔ°_（298）始终显着。 DMSeO的青睐。 DMS（Se）O HB与对氟苯酚相互作用的理论δΔ°_（298）和δΔ°_（298）分别为8.5和6.0 kJ / mol，与溶液中的相应实验数据相比较合理。 2.8和5.0 kJ / mol。理论δΔv（XH）清楚地证实了各种观察结果，由H_2O与HB配合物计算得到的δΔv（OH）值为111 cm〜（-1），接近于约110（〜）的实验δΔv（OH）。 ±20）厘米〜（-1）。

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