Isonitrile as an Ultrasensitive Infrared Reporter of Hydrogen-Bonding Structure and Dynamics

Cited 11 time in webofscience Cited 0 time in scopus
165 Viewed 4 Downloaded
Title
Isonitrile as an Ultrasensitive Infrared Reporter of Hydrogen-Bonding Structure and Dynamics
Author(s)
Michal Maj; Changwoo Ahn; Bartosz Blasiak; Kyungwon Kwak; Hogyu Han; Minhaeng Cho
Publication Date
2016-10
Journal
JOURNAL OF PHYSICAL CHEMISTRY B, v.120, no.39, pp.10167 - 10180
Publisher
AMER CHEMICAL SOC
Abstract
Infrared (IR) probes based on terminally blocked beta-isocyanoalanine (AlaNC) and p-isocyanophenylalanine (PheNC) amino acids were synthesized. These isonitrile (NC)-derivatized compounds were extensively characterized by FTIR and femtosecond IR pump-probe spectroscopies, and a direct comparison was made with popularly used nitrile (CN)- and azide (N-3)-derivatized analogs. It is shown that the isonitrile stretch frequency exhibits extremely high sensitivity to hydrogen-bonding interactions. In addition, the IR intensity of the isonitrile group is much higher than that of the nitrile group and almost as intense as that of the azido group. Furthermore, its vibrational lifetime is much longer than that of the nitrile and azido groups. To elucidate the origin of such a high H-bond sensitivity and IR intensity observed for isonitrile, extensive quantum chemical calculations were performed. It is shown that the Coulombic contributions to the vibrational frequency shifts of the isonitrile and nitrile stretch modes have opposite signs but similar magnitudes, whereas the contributions of exchange repulsion and charge delocalization to their frequency shifts are comparable. Therefore, the isonitrile stretch frequency is much more sensitive to H-bonding interactions because the blue-shifting exchange-repulsion effects additionally enforced by such electrostatic effects. It is also shown that the much higher IR intensity of the isonitrile group compared to that of the nitrile group is due to the configuration reversal of the atomic electronegativity between the NC and CN groups. Owing to these features, we believe that isonitrile is a much better IR reporter of H-bonding structure and dynamics than the widely used nitrile and azide. © 2016 American Chemical Society
URI
https://pr.ibs.re.kr/handle/8788114/3161
ISSN
1520-6106
Appears in Collections:
Center for Molecular Spectroscopy and Dynamics(분자 분광학 및 동력학 연구단) > Journal Papers (저널논문)
Files in This Item:
Isonitrile as an Ultrasensitive Infrared Reporter_Prof. Kwak.pdfDownload

qrcode

  • facebook

    twitter

  • Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.
해당 아이템을 이메일로 공유하기 원하시면 인증을 거치시기 바랍니다.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

Browse