Spectroscopic and Ab Initio Investigation of C−H⋅⋅⋅N Hydrogen‐Bonded Complexes of Fluorophenylacetylenes: Frequency Shifts and Correlations. Issue 16 (7th June 2016)

• Record Type: Journal Article
• Authors: Dey, Arghya; Mondal, Sohidul Islam; Sen, Saumik; Patwari, G. Naresh
• Is Part Of: Chemphyschem. Volume 17:Issue 16(2016)
• Page Start: 2509
• Page End: 2515
• Publication Date: 2016-06-07
• Subjects: density functional calculations -- donor–acceptor systems -- hydrogen bonds -- vibrational spectroscopy -- Stark tuning rates; Chemistry, Physical and theoretical -- Periodicals; 541.05
• DOI: 10.1002/cphc.201600343
• Languages: English
• ISSNs: 1439-4235

Abstract

Abstract: The C−H⋅⋅⋅N hydrogen‐bonded complexes of several fluorophenyacetylenes with ammonia and methylamine were characterized by a redshift in the acetylenic C−H stretching vibration of the phenylacetylene moiety. These redshifts were linearly correlated with the stabilization energies calculated at the CCSD(T)/CBS//MP2‐aug‐cc‐pVDZ level. Analysis of various components of the interaction energy indicated that the observed redshifts were weakly correlated with the electrostatic component. The weaker linear correlation between the frequency shifts and the electrostatic component between two data sets can perhaps be attributed to the marginal differences in the Stark tuning rate and zero‐field shifts. The induction and exchange‐repulsion components were linearly correlated. However, the dispersion component depends on the nature of the hydrogen‐bond acceptor and shows a quantum jump when the hydrogen‐bond acceptor is changed from ammonia to methylamine. The observed linear correlation between the redshifts in the C−H stretching frequencies and the total stabilization energies is due to mutual cancellation of deviations from linearity between various components. Abstract : Linear relationships : The redshifts in the donor stretching frequency are linearly correlated with the total stabilization energy, whereas the correlation for various energy components varies from linear to quantum jumps.