Stepanian Stepan G, Karachevtsev Maksym V, Glamazda Alexander Yu, Karachevtsev Victor A, Adamowicz L
B. Verkin Institute for Low Temperature Physics and Engineering, NAS of Ukraine, 47, Lenin Avenue, 61103 Kharkov, Ukraine.
J Phys Chem A. 2009 Apr 16;113(15):3621-9. doi: 10.1021/jp810205a.
In this work, we have used Raman spectroscopy and quantum chemical methods (MP2 and DFT) to study the interactions between nucleic acid bases (NABs) and single-walled carbon nanotubes (SWCNT). We found that the appearance of the interaction between the nanotubes and the NABs is accompanied by a spectral shift of the high-frequency component of the SWCNT G band in the Raman spectrum to a lower frequency region. The value of this shift varies from 0.7 to 1.3 cm(-1) for the metallic nanotubes and from 2.1 to 3.2 cm(-1) for the semiconducting nanotubes. Calculations of the interaction energies between the NABs and a fragment of the zigzag(10,0) carbon nanotube performed at the MP2/6-31++G(d,p)[NABs atoms]|6-31G(d)[nanotube atoms] level of theory while accounting for the basis set superposition error during geometry optimization allowed us to order the NABs according to the increasing interaction energy value. The order is: guanine (-67.1 kJ mol(-1)) > adenine (-59.0 kJ mol(-1)) > cytosine (-50.3 kJ mol(-1)) approximately = thymine (-50.2 kJ mol(-1)) > uracil (-44.2 kJ mol(-1)). The MP2 equilibrium structures and the interaction energies were used as reference points in the evaluation of the ability of various functionals in the DFT method to predict those structures and energies. We showed that the M05, MPWB1K, and MPW1B95 density functionals are capable of correctly predicting the SWCNT-NAB geometries but not the interaction energies, while the M05-2X functional is capable of correctly predicting both the geometries and the interaction energies.
在这项工作中，我们使用拉曼光谱和量子化学方法（MP2和DFT）研究了核酸碱基（NABs）与单壁碳纳米管（SWCNT）之间的相互作用。我们发现，纳米管与NABs之间相互作用的出现伴随着拉曼光谱中SWCNT G带高频成分的光谱位移至较低频率区域。对于金属纳米管，该位移值在0.7至1.3 cm⁻¹之间变化，对于半导体纳米管，该位移值在2.1至3.2 cm⁻¹之间变化。在MP2/6 - 31++G(d,p)[NABs原子]|6 - 31G(d)[纳米管原子]理论水平下，对NABs与锯齿形(10,0)碳纳米管片段之间的相互作用能进行计算，并在几何优化过程中考虑基组叠加误差，这使我们能够根据相互作用能值的增加对NABs进行排序。排序结果为：鸟嘌呤（-67.1 kJ mol⁻¹）>腺嘌呤（-59.0 kJ mol⁻¹）>胞嘧啶（-50.3 kJ mol⁻¹）≈胸腺嘧啶（-50.2 kJ mol⁻¹）>尿嘧啶（-44.2 kJ mol⁻¹）。MP2平衡结构和相互作用能被用作评估DFT方法中各种泛函预测这些结构和能量能力的参考点。我们表明，M05、MPWB1K和MPW1B95密度泛函能够正确预测SWCNT - NAB的几何结构，但不能正确预测相互作用能，而M05 - 2X泛函能够正确预测几何结构和相互作用能。
