Time-dependent density functional theory study on the electronic excited-state hydrogen bonding dynamics of BHC-nicotinamide in MeOH solution

2013 ◽  
Vol 91 (4) ◽  
pp. 248-254 ◽  
Author(s):  
Jinling Cheng ◽  
Di Liu
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Excited State ◽  
Ground State ◽  
Density Functional ◽  
Time Dependent ◽  
Functional Theory ◽  
Hydrogen Bonding Dynamics ◽  
Hydrogen Bond Strengthening

The density functional theory (DFT) and time-dependent density functional theory (TDDFT) methods were performed to investigate the electronic excited-state hydrogen bonding dynamics of the hydrogenbonded complex formed by BHC-nicotinamide (BHCN) and methanol (MeOH). The ground-state geometry optimizations, electronic transition energies, corresponding oscillation strengths of the low-lying electronically excited states, and the optimized S1 excited-state geometry for the isolated BHCN and MeOH monomers, the hydrogen-bonded BHCN–MeOH dimers, and BHCN–2MeOH trimer complexes have been calculated by using the DFT and TDDFT methods, respectively. We have demonstrated that the intermolecular hydrogen bond C10=O14···H40−O39−Me is weaker than C16=O17···H46−O45−Me in the hydrogen-bonded dimers and trimer no matter whether in the ground state or the excited state. In addition, our results are consistent with the relationship between the electronic spectral shifts and excited-state hydrogen bonding dynamics: hydrogen bond strengthening can induce the relative electronic spectra redshift, whereas a blueshift will be induced. In addition, we focused our attention on the frontier molecular orbital and the results could reasonably explain the hydrogen bond strengthening or weakening mechanism.

Exploring excited state properties of 7-hydroxy and 7-methoxy 4-methycoumarin: a combined time-dependent density functional theory/effective fragment potential study

2016 ◽  
Vol 40 (3) ◽  
pp. 2211-2219 ◽  
Author(s):  
Mariyappa Ramegowda ◽  
Keremegaladoddi N. Ranjitha ◽  
Thalashasana N. Deepika
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Excited State ◽  
Density Functional ◽  
Time Dependent ◽  
Functional Theory ◽  
Effective Fragment Potential ◽  
Bond Stretching ◽  
Hydrogen Bond Dynamics ◽  
Dependent Density

Hydrogen bond dynamics, C–OH bond contracting, O–H bond stretching and O–H⋯O HB strengthening reveal the ESHT in 4MU at the S1state.

A theoretical study of hydration effects on structural stability and hydrogen-bonding dynamics of 2′-deoxyguanosine 5′-monophosphate with different negative charges

2013 ◽  
Vol 91 (2) ◽  
pp. 169-175
Author(s):  
Weiping Zhang ◽  
Xiaoyu Zhang
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Density Functional ◽  
Negative Charge ◽  
Solvation Shell ◽  
Excitation Energies ◽  
Functional Theory ◽  
Hydrogen Bonding Dynamics

The effects of hydration on the ground-state structural stability and excited-state hydrogen-bonding dynamics of 2′-deoxyguanosine 5′-monophosphate (dGMP) carrying different negative charges were investigated with B3LYP/6–31+G(d,p) using density functional theory (DFT) and time-dependent density functional theory (TDDFT) methods, respectively. Particularly, we not only considered the solvent effects by the polarizible continuum model (PCM), but also the first solvation shell was included explicitly. We demonstrated that the intramolecular hydrogen bond O2–H1···O3 will be weakened with the strengthening of the hydration. From the view of bond length, we can make a valid presumption that the site of negative charge will be the more preferable site of the hydration, and the preferable site may be changed because of the presence of other hydrogen bonds. Furthermore, we found that the first solvation shell had very little effect on the geometric structures except for the hydrogen bond P–O5···H5. By comparing the excitation energies, one important finding is that the changes in different electronic states are not obvious with the increase in n value when considering the PCM. Another finding is that the average interactions of hydrogen bonds may be strengthened with an increase of negative charge because of a decrease in excitation energies.

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