Saha Bapan
Department of Chemistry, Handique Girls' College, Guwahati , 781001, Assam, India.
J Mol Model. 2025 Jan 21;31(2):57. doi: 10.1007/s00894-025-06279-x.
Cation-π and cation-lone pair interactions between 3d-metal (II) ions [Fe(II), Co(II), Ni(II) and Cu(II)] and furan are explored in the formation of 1:1 and 1:2 type complexes. Both cation-π (IE = -192.27 to -312.65 kcal mol) and cation-lone pair (IE = -163.13 to -271.76 kcal mol) interactions are reasonably strong and lead to the formation of stable 1:1 and 1:2 type complexes in gas phase. The complexes are also stable in solvent phase, but their stability is reduced significantly in presence of solvent dielectrics, especially in ethanol, DMSO and water. Formation of the complexes is thermodynamically favourable (exothermic and spontaneous). Charge transfer (Δq = 0.62 to 1.92 e), Laplacian of electron density (∇ρ = 0.1435 to 0.6628 au) and total electron energy density (H(r) = -0.0019 to -0.0436 au) analysis have argued in favour of partial ionic and partial covalent character of the interactions.
Density functional theory (DFT) is exclusively used for the study. Polarizable continuum model (PCM) is used to perform solvent phase study. Natural bond orbital (NBO), quantum theory of atoms in molecules (QTAIM) and non-covalent interaction (NCI) analyses are performed for understanding other aspects of complex formation.
在1:1和1:2型配合物的形成过程中，研究了3d金属（II）离子[Fe（II）、Co（II）、Ni（II）和Cu（II）]与呋喃之间的阳离子-π和阳离子-孤对相互作用。阳离子-π相互作用（相互作用能IE = -192.27至-312.65 kcal/mol）和阳离子-孤对相互作用（IE = -163.13至-271.76 kcal/mol）都相当强，导致在气相中形成稳定的1:1和1:2型配合物。这些配合物在溶剂相中也很稳定，但在溶剂电介质存在下，其稳定性会显著降低，尤其是在乙醇、二甲基亚砜和水中。配合物的形成在热力学上是有利的（放热且自发）。电荷转移（Δq = 0.62至1.92 e）、电子密度拉普拉斯量（∇ρ = 0.1435至0.6628 au）和总电子能量密度（H(r) = -0.0019至-0.0436 au）分析表明这些相互作用具有部分离子和部分共价的性质。
本研究专门使用密度泛函理论（DFT）。采用极化连续介质模型（PCM）进行溶剂相研究。进行自然键轨道（NBO）、分子中的原子量子理论（QTAIM）和非共价相互作用（NCI）分析以了解配合物形成的其他方面。
