Ab initio calculation of atomic axial tensors and vibrational rotational strengths using density functional theory

Stephens, Philip J.; Ashvar, C. S.; Devlin, F. J.; Cheeseman, James R.; Frisch, Michael J.

doi:10.1080/00268979609482495

Cited by 53 publications

(54 citation statements)

References 26 publications

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“…In this case, the continual increase in rotational. Strength of the two transitions with increasing |R kk | is compensated by a simultaneous decrease-in-splitting [78][79][80].…”

Section: Vcd Analysismentioning

confidence: 97%

Molecular first order hyperpolarizability and vibrational spectral investigation of Warfarin sodium

Kostova¹,

Joe²

2010

Chemical Physics

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“…In this case, the continual increase in rotational. Strength of the two transitions with increasing |R kk | is compensated by a simultaneous decrease-in-splitting [78][79][80].…”

Section: Vcd Analysismentioning

confidence: 97%

Molecular first order hyperpolarizability and vibrational spectral investigation of Warfarin sodium

Kostova¹,

Joe²

2010

Chemical Physics

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“…Smaller fragments were used for evaluation of VCD parameters, Ac-A 6 -NH-CH 3 for the ␣-helix and Ac-A 4 -NH-CH 3 for the 3 1 helix, each fragment constrained to the appropriate torsional values and reoptimized at the density functional-BPW91͞6-31G* level with GAUSSIAN 98 (21). Analytical harmonic FF, APT, and AAT values all were calculated for the fragment molecule at the same density functional level by using gauge invariant atomic orbitals within the magnetic field perturbation theory for the AAT (19).…”

Section: Methodsmentioning

confidence: 99%

“…For the simulation of IR and VCD spectra, the molecular force field (FF), atomic polar tensors (APTs), and axial tensors (AATs) were computed ab initio by using the magnetic field perturbation and density functional theories (19) on smaller model peptides. These FF, APT and AAT parameters were transferred in Cartesian coordinates onto a larger oligopeptide as described in earlier work (13,20).…”

Section: Methodsmentioning

confidence: 99%

Site-specific conformational determination in thermal unfolding studies of helical peptides using vibrational circular dichroism with isotopic substitution

Silva

Kubelka

Bouř

et al. 2000

Proc. Natl. Acad. Sci. U.S.A.

186

275

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Understanding the detailed mechanism of protein folding requires dynamic, site-specific stereochemical information. The short time response of vibrational spectroscopies allows evaluation of the distribution of populations in rapid equilibrium as the peptide unfolds. Spectral shifts associated with isotopic labels along with local stereochemical sensitivity of vibrational circular dichroism (VCD) allow determination of the segment sequence of unfolding. For a series of alanine-rich peptides that form ␣-helices in aqueous solution, we used isotopic labeling and VCD to demonstrate that the ␣-helix noncooperatively unwinds from the ends with increasing temperature. For these blocked peptides, the C-terminal is frayed at 5°C. Ab initio level theoretical simulations of the IR and VCD band shapes are used to analyze the spectra and to confirm the conformation of the labeled components. The VCD signals associated with the labeled residues are amplified by coupling to the nonlabeled parts of the molecule. Thus small labeled segments are detectable and stereochemically defined in moderately large peptides in this report of site-specific peptide VCD conformational analysis.

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“…26,27 Excellent agreement between experimental and calculated VCD spectra 27,28 has confirmed the reliability of calculations on metal complexes of moderate size and hydrogen stretching motions, which have been carried out at the DFT level with gauge invariant atomic orbital (GIAO). [28][29][30][31] Meantime, some DFT and ab initio studies concentrated on the molecular properties of cisplatin and its analogues were reported.…”

Section: Introductionmentioning

confidence: 99%

How can the Cross‐Link Adducts Formed by Novel Trans Platinum Drug be Influenced by Hydrogen Bond

Chang¹,

Zhou²,

Chen³

2006

Chin. J. Chem.

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A systematic quantum chemical characterization of intrinsic structure, energies and spectral properties of all the studied cross-link adducts formed by the novel trans platinum with thiazole ligand has been carried out at B3LYP/6-31G* level of theory with the Lanl2dz pseudo potential basis set for the Pt atom. Special attention has been paid to the relative stability of these complexes and the factors that probably alter the order of the relative stability. The important influence of hydrogen bond on the structures, the energies and the spectral property was revealed. Other factors that contribute to relative stability including solvation effect, entropy and electronic delocalization energy were taken into account. The stability energy of the whole complex, and the interaction energy between two purine bases and the )thiazole] 2＋ group were adopted to study the interplay among subsystems and their contribution to relative stability of all the studied cross-link model. Finally, basic spectral properties of these complexes including H(8) chemical shifts of all the studied complexes and the VCD (vibrational circular dichroism) spectra of two pairs of GG chelate enantiomers, were provided in order to define the structure of the most possible duplex bearing novel trans platinum drug lesions.

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Ab initio calculation of atomic axial tensors and vibrational rotational strengths using density functional theory

Cited by 53 publications

References 26 publications

Molecular first order hyperpolarizability and vibrational spectral investigation of Warfarin sodium

Molecular first order hyperpolarizability and vibrational spectral investigation of Warfarin sodium

Site-specific conformational determination in thermal unfolding studies of helical peptides using vibrational circular dichroism with isotopic substitution

How can the Cross‐Link Adducts Formed by Novel Trans Platinum Drug be Influenced by Hydrogen Bond

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