Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan.
Org Lett. 2010 May 21;12(10):2262-5. doi: 10.1021/ol1006168.
The structures and strain energies of cycloparaphenylenes (CPPs) have been determined by DFT calculation at the B3LYP/6-31G(d) level of theory. Fifteen stable conformations of [12]CPP were found as local minimum structures. It was also found that benzene rings of [12]CPP can rotate rather freely at room temperature. The strain energies of [n]CPP (n = 6-20) were estimated on the basis of the homodesmotic reaction using CPP, biphenyl, and p-terphenyl. It was also found that CPPs have higher strain energy in comparison to cycloparaphenyleneacetylenes (CPPAs).
通过密度泛函理论（DFT）在 B3LYP/6-31G(d)水平上计算，确定了环并苯（CPP）的结构和应变能。发现了 15 种[12]CPP 的稳定构象，它们是局部最小结构。还发现，[12]CPP 的苯环在室温下可以自由旋转。基于 CPP、联苯和对三联苯的同系物反应，估算了[n]CPP（n=6-20）的应变能。还发现 CPP 比环并苯乙炔（CPPA）具有更高的应变能。
