Saha Soumen, Sastry G Narahari
Centre for Molecular Modeling, CSIR-Indian Institute of Chemical Technology , Tarnaka, Hyderabad 500007, Andhra Pradesh, India.
J Phys Chem B. 2015 Aug 27;119(34):11121-35. doi: 10.1021/acs.jpcb.5b03005. Epub 2015 May 18.
This computational study examines the key factors that control the structures and energetics of the coexistence of multiple noncovalent interactions. 4-Amino-2-iodophenol is taken as a model that exhibits nine different kinds of noncovalent interactions, viz., cation-π (CP), hydrogen bond (HB) through O (OHB), HB through N (NHB), halogen bond (XB), π-π (PP), metal ion-lone pair (ML) through O (OML), ML through N (NML), charge assisted hydrogen bond (CHB) through O (OCHB), and CHB through N (NCHB). Through all possible combinations of these noncovalent interactions, based on energy, geometry, charge, and atoms in molecules (AIM) analysis, we have systematically analyzed the cooperativity among 40 ternary systems and 105 quaternary systems. We have observed that CP-HB, CP-XB, CP-PP, HB-HB, HB-XB, HB-PP, HB-ML, HB-CHB, XB-PP, XB-ML, XB-CHB, PP-ML, and PP-OCHB can form cooperative ternary systems. While studying the quaternary systems, we have observed that HB, XB, and PP work together by enhancing each other's strength. The study highlights that the positively charged species enhances HB-HB and HB-PP interactions and forms cooperative HB-HB-CHB, HB-HB-ML, HB-PP-ML, and HB-PP-CHB systems. Surprisingly, OHB-OML-NML, OHB-OML-OCHB, OHB-OML-NCHB, OHB-NML-OCHB, NHB-OML-NML, NHB-OML-NCHB, and NHB-NML-OCHB are also cooperative in nature despite the electrostatic repulsion between two positive charge species. The current study shows the widespread presence of cooperativity as well as anticooperativity in supramolecular assembles.
这项计算研究考察了控制多种非共价相互作用共存时的结构和能量的关键因素。以4-氨基-2-碘苯酚作为一个模型，它展现出九种不同类型的非共价相互作用，即阳离子-π（CP）、通过O的氢键（HB，OHB）、通过N的氢键（NHB）、卤键（XB）、π-π（PP）、通过O的金属离子-孤对（ML，OML）、通过N的金属离子-孤对（NML）、通过O的电荷辅助氢键（CHB，OCHB）以及通过N的电荷辅助氢键（NCHB）。通过这些非共价相互作用的所有可能组合，基于能量、几何结构、电荷以及分子中的原子（AIM）分析，我们系统地分析了40个三元体系和105个四元体系中的协同性。我们观察到CP-HB、CP-XB、CP-PP、HB-HB、HB-XB、HB-PP、HB-ML、HB-CHB、XB-PP、XB-ML、XB-CHB、PP-ML和PP-OCHB能够形成协同三元体系。在研究四元体系时，我们观察到HB、XB和PP通过增强彼此强度而协同作用。该研究强调带正电的物种增强了HB-HB和HB-PP相互作用，并形成了协同的HB-HB-CHB、HB-HB-ML、HB-PP-ML和HB-PP-CHB体系。令人惊讶的是，尽管两个带正电物种之间存在静电排斥，但OHB-OML-NML、OHB-OML-OCHB、OHB-OML-NCHB、OHB-NML-OCHB、NHB-OML-NML、NHB-OML-NCHB和NHB-NML-OCHB本质上也是协同的。当前研究表明协同性以及反协同性在超分子组装体中广泛存在。
