Jochnowitz Evan B, Zhang Xu, Nimlos Mark R, Varner Mychel E, Stanton John F, Ellison G Barney
Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, USA.
J Phys Chem A. 2005 May 5;109(17):3812-21. doi: 10.1021/jp040719j.
The propargyl radical has twelve fundamental vibrational modes, gamma(vib)(HCCCH2) = 5a1 [symbol: see text] 3b1 [symbol: see text] 4b2, and nine have been detected in a cryogenic matrix. Ab initio coupled-cluster anharmonic force field calculations were used to help guide some of the assignments. The experimental HC=:C-:CH2 matrix frequencies (cm(-1)) and polarizations are a1 modes--3308.5 +/- 0.5, 3028.3 +/- 0.6, 1935.4 +/- 0.4, 1440.4 +/- 0.5, 1061.6 +/- 0.8; b1 modes--686.6 +/- 0.4, 483.6 +/- 0.5; b2 modes--1016.7 +/- 0.4, 620 +/- 2. We recommend a complete set of gas-phase vibrational frequencies for the propargyl radical, HC=:C-:CH2 2 X (2)B1. From an analysis of the vibrational spectra, the small electric dipole moment, mu(D)(HCCCH2) = 0.150 D, and the large resonance energy (HCCCH2), roughly 11 kcal mol(-1), we conclude that propargyl is a completely delocalized hydrocarbon radical and is best written as HC=:C-:CH2.
炔丙基有12种基本振动模式，γ(vib)(HCCCH2) = 5a1 [符号：见原文] 3b1 [符号：见原文] 4b2，其中9种已在低温基质中检测到。采用从头算耦合簇非谐力场计算来辅助一些归属。实验测得的HC=:C-:CH2基质频率（cm(-1)）和偏振情况为：a1模式——3308.5±0.5、3028.3±0.6、1935.4±0.4、1440.4±0.5、1061.6±0.8；b1模式——686.6±0.4、483.6±0.5；b2模式——1016.7±0.4、620±2。我们推荐了炔丙基HC=:C-:CH2 2 X (2)B1完整的气相振动频率集。通过对振动光谱的分析、小电偶极矩μ(D)(HCCCH2) = 0.150 D以及大约11 kcal mol(-1)的大共振能（HCCCH2），我们得出结论，炔丙基是一个完全离域的烃基自由基，最好写成HC=:C-:CH2。
