Competitive tetrel bond and hydrogen bond in benzaldehyde–CO2: characterization via rotational spectroscopy. Issue 45 (10th November 2021)

• Record Type: Journal Article
• Authors: Wang, Hao; Wang, Xiujuan; Tian, Xiao; Cheng, Wanying; Zheng, Yang; Obenchain, Daniel A.; Xu, Xuefang; Gou, Qian
• Is Part Of: Physical chemistry chemical physics. Volume 23:Issue 45(2021)
• Page Start: 25784
• Page End: 25788
• Publication Date: 2021-11-10
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/d1cp03608d
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : The rotational spectrum of the 1 : 1 benzaldehyde–CO2 complex has been investigated using pulsed-jet Fourier transform microwave spectroscopy complemented with quantum chemical calculations. Abstract : The rotational spectrum of the 1 : 1 benzaldehyde–CO2 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CCO2 ⋯O tetrel bond (12.6 kJ mol −1 ) and a secondary (C–H)formyl ⋯O hydrogen bond (2.2 kJ mol −1 ); by contrast, in isomer II the (C–H)phenyl ⋯O hydrogen bond (7.6 kJ mol −1 ) becomes the dominant bond, while the OCCO2 ⋯O tetrel bond (5.8 kJ mol −1 ) 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 N I / N II ≈ 2/1.