O鈥揌路路路S Hydrogen Bonds Conform to the Acid鈥揃ase Formalism

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• 作者：Surjendu Bhattacharyya ; Aditi Bhattacherjee ; Pranav R. Shirhatti ; Sanjay Wategaonkar
• 刊名：Journal of Physical Chemistry A
• 出版年：2013
• 出版时间：August 29, 2013
• 年：2013
• 卷：117
• 期：34
• 页码：8238-8250
• 全文大小：470K
• 年卷期：v.117,no.34(August 29, 2013)
• ISSN：1520-5215

文摘

Hydrogen bonding interaction between the ROH hydrogen bond donor and sulfur atom as an acceptor has not been as well characterized as the O鈥揌路路路O interaction. The strength of O鈥揌路路路O interactions for a given donor has been well documented to scale linearly with the proton affinity (PA) of the H-bond acceptor. In this regard, O鈥揌路路路O interactions conform to the acid鈥揵ase formalism. The importance of such correlation is to be able to estimate molecular property of the complex from the known thermodynamic data of its constituents. In this work, we investigate the properties of O鈥揌路路路S interaction in the complexes of the H-bond donor and sulfur containing acceptors of varying proton affinity. The hydrogen bonded complexes of p-Fluorophenol (FP) with four different sulfur containing acceptors and their oxygen analogues, namely H₂O/H₂S, MeOH/MeSH, Me₂O/Me₂S and tetrahydrofuran (THF)/tetrahydrothiophene (THT) were characterized in regard to its S₁鈥揝₀ excitation spectra and the IR spectra. Two-color resonantly enhanced multiphoton ionization (2c-R2PI), resonant ion-dip infrared (RIDIR) spectroscopy, and IR-UV hole burning spectroscopic techniques were used to probe the hydrogen bonds in the aforementioned complexes. The spectroscopic data along with the ab initio calculations were used to deduce the strength of the O鈥揌路路路S hydrogen bonding interactions in these system relative to that in the O鈥揌路路路O interactions. It was found that, despite being dominated by the dispersion interaction, the O鈥揌路路路S interactions conform to the acid鈥揵ase formalism as in the case of more conventional O鈥揌路路路O interactions. The dissociation energies and the red shifts in the O鈥揌 stretching frequencies correlated very well with the proton affinity of the acceptors. However, the O鈥揌路路路S interaction did not follow the same correlation as that in the O鈥揌路路路O H-bond. The energy decomposition analysis showed that the dissociation energies and the red shifts in the O鈥揌 stretching frequencies follow a unified correlation if these two parameters were correlated with the sum of the charge transfer and the exchange component of the total binding energy.