Department of Physics and Astronomy, Texas Christian University, Fort Worth, Texas 76129, USA.
J Phys Chem A. 2011 Mar 31;115(12):2533-9. doi: 10.1021/jp111974d. Epub 2011 Mar 8.
A high yield of carbon chains has been produced by the laser ablation of carbon rods having (13)C enrichment. FTIR spectroscopy of these molecules trapped in solid Ar has resulted in the identification of two new combination bands for linear C(5) and C(9). The (ν(1) + ν(4)) combination band of linear C(5) has been observed at 3388.8 cm(-1), and comparison of (13)C isotopic shift measurements with the predictions of density functional theory calculations (DFT) at the B3LYP/cc-pVDZ level makes possible the assignment of the ν(1)(σ(g)(+)) stretching fundamental at 1946 cm(-1). Similarly, the observation of the (ν(2) + ν(7)) combination band of linear C(9) at 3471.8 cm(-1) enables the assignment of the ν(2)(σ(g)(+)) stretching fundamental at 1871 cm(-1). The third and weakest of the infrared stretching fundamentals of linear C(7), the ν(6)(σ(u)(+)) fundamental at 1100.1 cm(-1), has also been assigned.
通过激光烧蚀（13）C 富集的碳棒，产生了高产率的碳链。这些分子在固态 Ar 中被捕获的 FTIR 光谱学研究结果表明，线性 C(5)和 C(9)有两个新的组合带。线性 C(5)的（ν(1) + ν(4))组合带在 3388.8 cm(-1)处被观察到，（13）C 同位素位移测量与密度泛函理论（DFT）在 B3LYP/cc-pVDZ 水平上的预测的比较，使得 1946 cm(-1)处的 ν(1)(σ(g)(+))伸缩基频的分配成为可能。同样，线性 C(9)的（ν(2) + ν(7))组合带在 3471.8 cm(-1)处的观察使得 1871 cm(-1)处的 ν(2)(σ(g)(+))伸缩基频的分配成为可能。线性 C(7)的第三个也是最微弱的红外伸缩基频，即 1100.1 cm(-1)处的 ν(6)(σ(u)(+))基频，也被分配了。
