Ge Maofa, Ma Chunping, Xue Wei
State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
J Phys Chem A. 2009 Apr 2;113(13):3108-15. doi: 10.1021/jp8110277.
Acryloyl isocyanate CH(2)=CHC(O)NCO is quantitatively prepared by the metathesis reaction between CH(2)=CHC(O)Cl and AgNCO. Also, jointly with acryloyl chloride, their molecular and electronic structures have been investigated by photoionization mass spectroscopy (PIMS), HeI photoelectron spectroscopy (PES), and theoretical calculations. CH(2)=CHC(O)NCO was theoretically predicted to prefer the trans-cis (tc) conformation as the most stable conformer, with the C=O bond trans to the C=C bond and cis to the NCO moiety. IR and Raman spectra also suggest the presence of the trans-cis (tc) conformation only. Calculations of the cationic-radical form were carried out in order to compare their properties with those of the neutral molecules. It is worthwhile mentioning that both compounds retain planar structures after ionization. After structural optimizations, a theoretical study involving the calculation of the ionization energies using orbital valence Green's functional (OVGF) was performed. The ionization energies of different bands in the photoelectron spectrum are in good agreement with the calculated values from the OVGF method. The first vertical ionization energies of CH(2)=CHC(O)Cl and CH(2)=CHC(O)NCO are determined to be 10.97 and 10.68 eV, respectively. The HOMOs correspond to the ionization of electrons mainly localized on the pi(C=C) or the pi(NCO) orbitals: {4a''(pi(C=C))}(-1) and {5a''(pi(NCO))}(-1), respectively.
异氰酸丙烯酯CH(2)=CHC(O)NCO通过CH(2)=CHC(O)Cl与AgNCO之间的复分解反应定量制备。此外，与丙烯酰氯一起，通过光电离质谱（PIMS）、HeI光电子能谱（PES）和理论计算研究了它们的分子和电子结构。理论预测CH(2)=CHC(O)NCO最稳定的构象为反式-顺式（tc）构象，其中C=O键与C=C键呈反式，与NCO部分呈顺式。红外光谱和拉曼光谱也仅表明存在反式-顺式（tc）构象。进行了阳离子自由基形式的计算，以便将它们的性质与中性分子的性质进行比较。值得一提的是，两种化合物在电离后都保持平面结构。在结构优化之后，进行了一项理论研究，涉及使用轨道价格林函数（OVGF）计算电离能。光电子能谱中不同谱带的电离能与OVGF方法的计算值吻合良好。CH(2)=CHC(O)Cl和CH(2)=CHC(O)NCO的第一垂直电离能分别确定为10.97和10.68 eV。最高占据分子轨道（HOMOs）分别对应于主要定域在π(C=C)或π(NCO)轨道上的电子电离：{4a''(π(C=C))}(-1)和{5a''(π(NCO))}(-1)。
