Begum Samiyara, Subramanian Ranga
Department of Chemistry, Indian Institute of Technology, Patna, 800013, India.
Phys Chem Chem Phys. 2014 Sep 7;16(33):17658-69. doi: 10.1039/c4cp01084a.
van der Waals complexes of sulfur dioxide (SO2) with oxygen (O2) and nitrogen (N2) have been investigated by using MP2 and aug-cc-pVXZ (X = D, T) basis set. Two minimum structures with symmetry C1 and Cs have been located at the intermolecular potential energy surface (IPES) of the complex of SO2-O2. Stacked Cs structure of SO2-O2 is found to have greater stability than C1 structure. In the case of SO2-N2, one minimum structure with Cs symmetry has been characterized. In this study, CCSD(T)/aug-cc-pVTZ//MP2/aug-cc-pVTZ and interaction energy calculation at complete basis set (CBS) limit has been employed for better energetic description. The natural bond orbital (NBO) calculation demonstrates the bonding in terms of charge transfer from X-atom lone pair of X2 (X = O or N) to the antibonding SO orbital of SO2. The strength of various intra and inter bonds in the complexes were calculated in terms of electron density at bond critical points (BCP) using quantum theory of atoms in molecules (QTAIM). Frequency calculations for these complexes show a number of interactions induced by low frequency modes in the far IR region. Symmetry adapted calculation were also computed for the complexes and is established that the ratio of dispersion to induction effect is large for the most stable conformers. The atmospheric implications are also discussed for these complexes.
已使用MP2和aug-cc-pVXZ（X = D，T）基组研究了二氧化硫（SO₂）与氧气（O₂）和氮气（N₂）的范德华复合物。在SO₂ - O₂复合物的分子间势能面（IPES）上找到了具有C₁和Cs对称性的两个最低结构。发现SO₂ - O₂的堆叠Cs结构比C₁结构具有更高的稳定性。对于SO₂ - N₂，已表征了一个具有Cs对称性的最低结构。在本研究中，采用了CCSD(T)/aug-cc-pVTZ//MP2/aug-cc-pVTZ以及在完全基组（CBS）极限下的相互作用能计算，以获得更好的能量描述。自然键轨道（NBO）计算表明，从X₂（X = O或N）的X原子孤对向SO₂的反键SO轨道的电荷转移形成了键。使用分子中的原子量子理论（QTAIM），根据键临界点（BCP）处的电子密度计算了复合物中各种内键和间键的强度。这些复合物的频率计算显示了远红外区域低频模式引起的一些相互作用。还对复合物进行了对称适配计算，并确定对于最稳定的构象异构体，色散与诱导效应的比率很大。还讨论了这些复合物对大气的影响。
