Correlating Photoacidity to Hydrogen-Bond Structure by Using the Local O–H Stretching Probe in Hydrogen-Bonded Complexes of Aromatic Alcohols

2015 ◽  
Vol 119 (20) ◽  
pp. 4800-4812 ◽  
Author(s):  
Brian T. Psciuk ◽  
Mirabelle Prémont-Schwarz ◽  
Benjamin Koeppe ◽  
Sharon Keinan ◽  
Dequan Xiao ◽  
...  
2021 ◽  
Vol 23 (12) ◽  
pp. 7271-7279
Author(s):  
Anthony C. Legon

Radial P.E. functions of hydrogen-bonded complexes B⋯HF (B = N2, CO, PH3, HCN and NH3) have been calculated ab initio at the CCSD(T)(F12C)/cc-pVTZ-F12 level as a function of the hydrogen-bond length r(Z⋯H), where Z is the H-bond acceptor atom of B.


2013 ◽  
Vol 91 (12) ◽  
pp. 1292-1302 ◽  
Author(s):  
Osama Y. Ali ◽  
Elyse Jewer ◽  
Travis D. Fridgen

The infrared absorption spectra of hydrogen-bonded complexes of propylene oxide with either ethanol or 2-fluoroethanol have been recorded in neon matrices. Mixtures of propylene oxide and ethanol or propylene oxide and 2-fluoroethanol vapors were mixed with an excess of neon gas and deposited onto a KBr substrate at 4.2 K. The results indicate that hydrogen-bonded complexes were formed with propylene oxide as the hydrogen bond acceptor and either ethanol or 2-fluoroethanol as the hydrogen bond donors. The features assigned to the O−H stretch were red-shifted by 175 and 193 cm−1 for the ethanol- and 2-fluoroethanol-containing complexes, respectively. The difference in red shifts can be accounted for due to the greater acidity of 2-fluroethanol. Deuterium isotope experiments were conducted to help confirm the assignment of the O–H stretch for the complexes. As well, structures and infrared spectra were calculated using B3LYP/6-311++G(2d,2p) calculations and were used to compare with the experimental spectra. A “scaling equation” rather than a scaling factor was used and is shown to greatly increase the utility of the calculations when comparing with experimental spectra. An examination of the O–H stretching red shifts for many hydrogen-bound complexes reveals a relationship between the shift and the difference between the acidity of the hydrogen bond donor and the basicity of the hydrogen bond acceptor (the enthalpy of proton transfer). Both hydrogen-bonded complexes and proton-bound complexes appear to have a maximum in the reduced frequency value that corresponds to complexes where the hydrogen/proton are equally shared between the two bases.


RSC Advances ◽  
2015 ◽  
Vol 5 (9) ◽  
pp. 6452-6461 ◽  
Author(s):  
Jiao-Jiao Hao ◽  
Chang-Sheng Wang

The polarizable dipole–dipole interaction model has been developed to rapidly and accurately estimate the hydrogen bond distances and interaction energies for carbohydrate-containing hydrogen-bonded complexes.


2018 ◽  
Vol 20 (33) ◽  
pp. 21557-21566 ◽  
Author(s):  
Saurabh Mishra ◽  
Jer-Lai Kuo ◽  
G. Naresh Patwari

Enhancement of Fermi resonance intensities due to the formation of N–H⋯N hydrogen bonding of anilines with alkyl amines is analyzed using a two-state deperturbation model.


2012 ◽  
Vol 90 (4) ◽  
pp. 368-375 ◽  
Author(s):  
Boaz G. Oliveira ◽  
Regiane C. M. U. Araújo

This work presents a theoretical study about the interaction strength of the hydrogen-bonded complexes C2H4O···HF, C3H6O···HF, C2H4O···HCF3, and C3H6O···HCF3 at the B3LYP/6–311++G(d,p) level. The structures, hydrogen bond energies, charge transfers, and dipole moments of these complexes were analyzed in accordance with routine spectroscopy events, such as the red- and blue-shifts on the stretch frequencies of the proton donors (HF and HCF3). The ChelpG atomic charges were used to quantify the charge-transfer fluxes from electron donor (O) towards to acceptors (HF or HCF3). Moreover, the topological calculations on the basis of the quantum theory of atoms in molecules (QTAIM) approach were also used to unveil the hydrogen bond strength (O···H), mainly in the determination of their electronic densities and Laplacian shapes.


1986 ◽  
Vol 41 (1-2) ◽  
pp. 225-229 ◽  
Author(s):  
Mariusz Maćkowiak ◽  
Piotr Kozioł ◽  
Jan Stankowski

35Cl NQR measurements were carried out on complexes of pentachlorophenol with nitrogen bases as a function of pressure (up to 300 MPa) and of temperature. It is shown that the sign and magnitude of the pressure coefficient of the 35Cl NQR frequency is related to the degree of proton transfer. An anomaly in the pressure coefficient of ν (35Cl) has been observed near 50% of the proton transfer in the hydrogen bond. This anomaly is discussed assuming that the proton transfer equilibrium is pressure dependent. The fact that the transition from the double-well potential of the hydrogen bond to the single-well potential occurs in the critical manner is also taken into account.


2010 ◽  
Vol 88 (8) ◽  
pp. 716-724 ◽  
Author(s):  
Ponnadurai Ramasami ◽  
Thomas A. Ford

Ab initio molecular orbital theory has been used to compute the properties of a number of hydrogen-bonded complexes between fluoroacetylene as proton donor and ammonia, water, hydrogen fluoride, phosphine, hydrogen sulfide, and hydrogen chloride as proton acceptors. The properties considered were the vibrational spectra, the molecular structures, the hydrogen-bond energies, and the electron densities, and one of the aims of the study was to ascertain whether there was any evidence of blue-shifting hydrogen-bond character in the complexes formed. The adducts with NH3, H2O, PH3, and H2S were of the conventional CH···X kind (X = N, O, P, S), with hydrogen-bond energies decreasing in the order NH3 > H2O > PH3 ≈ H2S. Those formed with HF and HCl showed the presence of three alternative structures; in addition to the CH···F(Cl) complexes, adducts of the F(Cl)H···F and F(Cl)H···π type were also found to be stationary points on the potential energy surfaces, with stabilities in the order F(Cl)H···π > CH···F(Cl) > F(Cl)H···F. The hydrogen-bond energies of the CH···X series correlated with the gas-phase basicities of the proton acceptors; moreover, the CH bond-length changes, the wavenumber shifts, the complex–monomer infrared intensity ratios of the CH stretching modes, and the amounts of charge transferred on complex formation were all found to track with the hydrogen-bond energies. All those properties considered here are consistent with the formation of red-shifting hydrogen bonds, to the exclusion of the blue-shifting alternatives.


2012 ◽  
Vol 11 (03) ◽  
pp. 493-504 ◽  
Author(s):  
YU-HUI LIU ◽  
PAN-WANG ZHOU

Time-dependent density functional theory (TDDFT) and second-order coupled cluster method with resolution-of-the-identity approximation (RICC2) were used to investigate the photolysis dynamics of 9-fluorenol (FOH) in alcohols. In this work, a novel mechanism for the accelerated photolysis dynamics of FOH in alcohols is proposed for the first time. The two hydrogen bonds present different effects in the dissociation process of C9–O bond in MeOH⋯FOH⋯MeOH trimer: formation of hydrogen bond MeOH⋯FOH could weaken the C9–O bond, while, hydrogen bond FOH⋯MeOH fastens the bond. Moreover, the thermodynamic equilibrium can be accomplished in both ground and excited states between hydrogen-bonded complexes, since the hydrogen bond reorganization occurs in hundreds of femtosecond upon the excitation. The excited-state potential energy (PE) curves along C9–O bond have been optimized in S1 state. The cleavage of C9–O bond upon the photoexcitation would be facilitated effectively in MeOH⋯FOH dimer. This leads the thermodynamic equilibrium between hydrogen-bonded complexes leaning to the side of MeOH⋯FOH dimer to quench the fluorescence. Therefore, the photolysis of 9-fluorenol in alcohols can be facilitated effectively by MeOH⋯FOH hydrogen bond via excited-state hydrogen bond reorganization. Additionally, the excited-state hydrogen bond reorganization is also the rate-controlling step in photolysis of FOH in alcohols, since there is no barrier in the PE curve of MeOH⋯FOH dimer.


1999 ◽  
Vol 19 (1-4) ◽  
pp. 1-10 ◽  
Author(s):  
S. M. Arrivo ◽  
V. D. Kleiman ◽  
W. T. Grubbs ◽  
T. P. Dougherty ◽  
E. J. Heilweil

Transient picosecond infrared (IR) spectra of the OH and NH-stretch (v=0–1) absorption bands of several hydrogen-bonded complexes have been investigated. Solutions of 1:1 complexes of weak acids (methanol, triethylsilanol and pyrrole, < 0.1 mol/dm3) and bases (acetonitrile, pyridine and tetrahydrofuran, < 2 mol/dm3) in CCl4 at 295 K were interrogated with IR excitation and broadband probing. Lorentzian-shaped absorption bands are uniformly bleached while those with near-Gaussian bandshapes produce transient spectral holes. These results indicate a base functionality and hydrogen-bond strength dependence for determining the broadening mechanisms of these absorptions.


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