Horný L'ubos, Petraco Nicholas D K, Schaefer III Henry F
Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA.
J Am Chem Soc. 2002 Dec 11;124(49):14716-20. doi: 10.1021/ja0210190.
The optimized geometries, adiabatic electron affinities, vertical electron affinities, vertical electron detachment energies (for the anions), and IR-active vibrational frequencies have been predicted for the long linear carbon chains HC(2)(n)()(+1)H (n = 4-11). The B3LYP density functional combined with DZP and TZ2P basis sets was used in this theoretical study. These methods have been extensively calibrated versus experiment for the prediction of electron affinities (Chem. Rev. 2002, 102, 231). The computed physical properties are discussed and compared with the even carbon chains HC(2)(n)()H. The predicted electron affinities form a remarkably regular sequence: 2.12 eV (HC(9)H), 2.42 eV (HC(11)H), 2.66 eV (HC(13)H), 2.85 eV (HC(15)H), 3.01 eV (HC(17)H), 3.14 eV (HC(19)H), 3.25 eV (HC(21)H), and 3.35 eV (HC(23)H). These electron affinities are as much as 0.4 eV higher than those for analogous even carbon chains. The predicted structures display an intermediate cumulene-polyacetylene type of bonding, with the inner carbons appearing cumulenic and the outer carbons polyacetylenic.
已预测了长直链碳氢化合物HC(2)(n)()(+1)H（n = 4 - 11）的优化几何结构、绝热电子亲和能、垂直电子亲和能、垂直电子脱离能（针对阴离子）以及红外活性振动频率。本理论研究采用了结合DZP和TZ2P基组的B3LYP密度泛函。这些方法在预测电子亲和能方面已通过与实验进行广泛校准（《化学评论》2002年，102卷，231页）。讨论了计算得到的物理性质，并与偶数碳链HC(2)(n)()H进行了比较。预测的电子亲和能形成了一个非常规则的序列：2.12电子伏特（HC(9)H）、2.42电子伏特（HC(11)H）、2.66电子伏特（HC(13)H）、2.85电子伏特（HC(15)H）、3.01电子伏特（HC(17)H）、3.14电子伏特（HC(19)H）、3.25电子伏特（HC(21)H）和3.35电子伏特（HC(23)H）。这些电子亲和能比类似的偶数碳链高出多达0.4电子伏特。预测的结构显示出一种介于累积烯 - 聚乙炔类型的键合，内部碳原子呈现累积烯型，外部碳原子呈现聚乙炔型。
