Della Therese Davis, Suresh Cherumuttathu H
Chemical Sciences and Technology Division, Academy of Scientific & Innovative Research, CSIR - National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram, 695 019, India.
Phys Chem Chem Phys. 2017 Feb 22;19(8):5830-5838. doi: 10.1039/c6cp07722f.
Acetylene and polyyne carbon chains show a negligible ability to bind even a single dihydrogen molecule. M06L/6-311++G(d,p) DFT and CCSD(T)/aug-cc-pVTZ//CCSD/aug-cc-pVDZ calculations corroborate that these carbon chains in the first deprotonated anionic and second deprotonated dianionic forms display massive dihydrogen uptake capabilities (45.3 to 62.8 wt%). The coordinatively saturated complexes of these anions and dianions with chain lengths of up to six carbons hold 20-32 H molecules. The interaction energy (E) values of the saturated state of the monoanions (44.5-50.0 kcal mol) and dianions (79.8-87.4 kcal mol) indicate substantial energetic stabilization per H molecule adsorbed. The binding of H to the carbon chain is established by the observation of bond critical points in the electron density analysis. The noncovalently bonded interconnections of the adsorbed H molecules indicated by HH bond critical points, provide additional stability to the complex keeping the system a fully noncovalently allied entity. Further, molecular electrostatic potential analysis (MESP) is conducted to study the delocalization of the extra electron(s) over the entire complex.
乙炔和多炔碳链表现出即使结合单个双氢分子的能力也可忽略不计。M06L/6 - 311++G(d,p)密度泛函理论（DFT）和CCSD(T)/aug - cc - pVTZ//CCSD/aug - cc - pVDZ计算证实，这些处于首次去质子化阴离子形式和第二次去质子化双阴离子形式的碳链具有大量吸收双氢的能力（45.3至62.8重量%）。这些链长可达六个碳的阴离子和双阴离子的配位饱和配合物容纳20 - 32个氢分子。单阴离子（44.5 - 50.0千卡/摩尔）和双阴离子（79.8 - 87.4千卡/摩尔）饱和态的相互作用能（E）值表明，每吸附一个氢分子有显著的能量稳定作用。通过电子密度分析中键临界点的观测确定了氢与碳链的结合。由氢 - 氢键临界点表明的吸附氢分子的非共价键互连为配合物提供了额外稳定性，使系统保持为完全非共价结合的实体。此外，进行了分子静电势分析（MESP）以研究额外电子在整个配合物上的离域情况。
