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Decrypting the critical point of internal rotation of formaldehyde: A rotational study of the acrolein-formaldehyde
Meiyue Li1, Xiao Tian1, Weiping Du1
1School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331 Chongqing, China.
Abstract:
The rotational spectrum of an acrolein-formaldehyde complex has been characterized using pulsed jet Fourier transform microwave spectroscopy complemented with quantum chemical calculations. One isomer has been observed in pulsed jets, which is stabilized by a dominant O=C⋯O tetrel bond (n → π* interaction) and a secondary C-H⋯O hydrogen bond. Splittings arising from the internal rotation of formaldehyde around its C2v axis were also observed, from which its V2 barrier was evaluated. It seems that when V2 equals or exceeds 4.61 kJ mol-1, no splitting of the spectral lines of the rotational spectrum was observed. The nature of the non-covalent interactions of the target complex is elucidated through natural bond orbital analysis. These findings contribute to a deeper understanding on the non-covalent interactions within the dimeric complex formed by two aldehydes.
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