苯甲醛 - 一氧化碳中的竞争性碳族元素键和氢键：转动光谱表征

Competitive tetrel bond and hydrogen bond in benzaldehyde-CO: characterization rotational spectroscopy.

作者信息

Wang Hao, Wang Xiujuan, Tian Xiao, Cheng Wanying, Zheng Yang, Obenchain Daniel A, Xu Xuefang, Gou Qian

机构信息

School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331, Chongqing, China.

Institut für Physikalische Chemie, Universität Göttingen, Tammannstr. 6, 37077 Göttingen, Germany.

出版信息

Phys Chem Chem Phys. 2021 Nov 24;23(45):25784-25788. doi: 10.1039/d1cp03608d.

DOI:10.1039/d1cp03608d

PMID:34757355

Abstract

The rotational spectrum of the 1 : 1 benzaldehyde-CO complex has been investigated using pulsed-jet Fourier transform microwave spectroscopy complemented with quantum chemical calculations. Two isomers, both characterized by one C⋯O tetrel bond (n → π* interaction) and one C-H⋯O hydrogen bond (n → σ* interaction), have been observed in the pulsed jet. Competition between the tetrel bond and the hydrogen bond has been disclosed by natural bond orbital analysis: isomer I is characterized by one dominating OC⋯O tetrel bond (12.6 kJ mol) and a secondary (C-H)⋯O hydrogen bond (2.2 kJ mol); by contrast, in isomer II the (C-H)⋯O hydrogen bond (7.6 kJ mol) becomes the dominant bond, while the OC⋯O tetrel bond (5.8 kJ mol) becomes much weaker with respect to that of isomer I. Using intensity measurements the relative population ratio of the two isomers was estimated to be / ≈ 2/1.

摘要

利用脉冲喷射傅里叶变换微波光谱并结合量子化学计算，对1:1苯甲醛 - CO络合物的转动光谱进行了研究。在脉冲喷射中观察到了两种异构体，它们都具有一个C⋯O四元键（n → π相互作用）和一个C - H⋯O氢键（n → σ相互作用）。自然键轨道分析揭示了四元键和氢键之间的竞争：异构体I的特征是一个占主导地位的OC⋯O四元键（12.6 kJ/mol）和一个次级（C - H）⋯O氢键（2.2 kJ/mol）；相比之下，在异构体II中，（C - H）⋯O氢键（7.6 kJ/mol）成为主导键，而OC⋯O四元键（5.8 kJ/mol）相对于异构体I变得弱得多。通过强度测量，估计两种异构体的相对丰度比为/ ≈ 2/1。