期刊
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
卷 25, 期 24, 页码 16597-16612出版社
ROYAL SOC CHEMISTRY
DOI: 10.1039/d3cp00781b
关键词
-
Protonated complexes composed of a basket-like host molecule and glycine were studied in the gas phase. Experimental and computational methods were used to analyze their properties, and the existence of two isomeric complexes was confirmed. The relative stability of the complexes followed a certain trend, and the polarization component was found to play an important role.
Protonated complexes composed of a basket-like host molecule 1,1,n,n-tetramethyl[n](2,11)teropyrenophanes (TMnTP) (n = 7, 8, 9) and glycine as a guest were studied in the gas phase by experimental and computational methods. Blackbody infrared radiative dissociation (BIRD) experiments of [(TMnTP)(Gly)]H+ not only provided the observed Arrhenius parameters (activation energies, Eobs a, and frequency factors, A) but also suggested the existence of two populations of isomeric complexes of [(TMnTP)(Gly)]H+, termed fast dissociating (FD) and slow dissociating (SD), due to their relative BIRD rate constants. Master equation modeling was conducted to obtain the threshold dissociation energies E0 of the host-guest complexes. The relative stabilities of the most stable of the n = 7, 8, or 9 [(TMnTP)(Gly)]H+ complexes followed the trend SD-[(TM7TP)(Gly)]H+ 4 SD-[(TM8TP)(Gly)]H+ 4 SD[(TM9TP)(Gly)]H+ by both BIRD and energy resolved sustained off-resonance irradiation collisioninduced dissociation experiments (ER-SORI-CID). Computed structures and energies of [(TMnTP)(Gly)]H+ were obtained using B3LYP-D3/6-31+G(d,p) and for all TMnTP molecules, the lowest-energy structures were ones where protonated glycine was within the cavity of the TMnTP, despite the TMnTP molecules having a proton affinity 100 kJ mol-1 higher than glycine. An independent gradient model based on the Hirshfeld partition (IGMH) and natural energy decomposition analysis (NEDA) were applied to visualize and reveal the nature of interactions between hosts and guest. The NEDA analysis suggested that the polarization (POL) component which described interactions between induced multipoles contributed the most to the [(TMnTP)(Gly)]H+ (n = 7, 8, 9) complexes.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据