Wolters Lando P, Smits Nicole W G, Guerra Célia Fonseca
Department of Theoretical Chemistry and Amsterdam Center for Multiscale Modeling, VU University Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands.
Phys Chem Chem Phys. 2015 Jan 21;17(3):1585-92. doi: 10.1039/c4cp03740e. Epub 2014 Dec 1.
Halogen bonds are shown to possess the same characteristics as hydrogen bonds: charge transfer, resonance assistance and cooperativity. This follows from the computational analyses of the structure and bonding in N-halo-base pairs and quartets. The objective was to achieve an understanding of the nature of resonance-assisted halogen bonds (RAXB): how they resemble or differ from the better understood resonance-assisted hydrogen bonds (RAHB) in DNA. We present an accurate physical model of the RAXB based on the molecular orbital theory, which is derived from the corresponding energy decomposition analyses and study of the charge distribution. We show that the RAXB arise from classical electrostatic interaction and also receive strengthening from donor-acceptor interactions within the σ-electron system. Similar to RAHB, there is also a small stabilization by π-electron delocalization. This resemblance leads to prove cooperativity in N-halo-guanine quartets, which originates from the charge separation that occurs with donor-acceptor orbital interactions in the σ-electron system.
电荷转移、共振辅助和协同性。这是通过对N-卤碱基对和四重体的结构与键合进行计算分析得出的。目的是了解共振辅助卤键（RAXB）的本质：它们与DNA中理解得更好的共振辅助氢键（RAHB）有何相似或不同之处。我们基于分子轨道理论提出了一个精确的RAXB物理模型，该模型源自相应的能量分解分析和电荷分布研究。我们表明，RAXB源于经典静电相互作用，同时也受到σ电子系统内供体-受体相互作用的增强。与RAHB类似，π电子离域也有小程度的稳定作用。这种相似性导致在N-卤鸟嘌呤四重体中证明了协同性，其源于σ电子系统中供体-受体轨道相互作用时发生的电荷分离。
