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Dyshin AA, Eliseeva OV, Bondarenko GV, Kolker AM, Kiselev MG. Dispersion of single-walled carbon nanotubes in dimethylacetamide and a dimethylacetamide–cholic acid mixture. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2016. [DOI: 10.1134/s0036024416120086] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Liu F, Tian W, Yang X, Jia G. Hydrogen-bonding and dielectric response of N,N-dimethylacetamide aqueous solutions under E/M fields using molecular dynamics. J Mol Liq 2014. [DOI: 10.1016/j.molliq.2014.04.038] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Lin B, Lopes PEM, Roux B, MacKerell AD. Kirkwood-Buff analysis of aqueous N-methylacetamide and acetamide solutions modeled by the CHARMM additive and Drude polarizable force fields. J Chem Phys 2013; 139:084509. [PMID: 24007020 PMCID: PMC3772949 DOI: 10.1063/1.4818731] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 08/04/2013] [Indexed: 11/14/2022] Open
Abstract
Kirkwood-Buff analysis was performed on aqueous solutions of N-methylacetamide and acetamide using the Chemistry at HARvard Molecular Mechanics additive and Drude polarizable all-atom force fields. Comparison of a range of properties with experimental results, including Kirkwood-Buff integrals, excess coordination numbers, solution densities, partial molar values, molar enthalpy of mixing, showed both models to be well behaved at higher solute concentrations with the Drude model showing systematic improvement at lower solution concentrations. However, both models showed difficulties reproducing experimental activity derivatives and the excess Gibbs energy, with the Drude model performing slightly better. At the molecular level, the improved agreement of the Drude model at low solute concentrations is due to increased structure in the solute-solute and solute-solvent interactions. The present results indicate that the explicit inclusion of electronic polarization leads to improved modeling of dilute solutions even when those properties are not included as target data during force field optimization.
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Affiliation(s)
- Bin Lin
- Department of Pharmaceutical Sciences, University of Maryland, School of Pharmacy, 20 Penn Street HSFII, Baltimore, Maryland 21201, USA
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Sensato FR, Cass QB, Lopes BR, Lourenço TC, Zukerman-Schpector J, Tiekink ER, Longo E, Andrés J. A joint computational and experimental study of a novel dioxomolybdenum(VI) complex bearing chiral N,N-dimethyllactamide ligand. Inorganica Chim Acta 2011. [DOI: 10.1016/j.ica.2011.04.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Samchenko AA, Kabanov AV, Komarov VM. On the possible influence of different pathways of binding of amides with water on “Pyramidalization” of valence bonds of peptide group nitrogen. Biophysics (Nagoya-shi) 2010. [DOI: 10.1134/s0006350910020016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Wilkins C, Turnbull M, Wikaira J. A comparison of the molecular and crystal structures of the dimethylacetamide complexes from zinc chloride, bromide, and iodide. Z KRIST-CRYST MATER 2009. [DOI: 10.1524/zkri.2000.215.11.702] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The dimethylacetamide complexes ZnCl2(dma)2 and ZnI2(dma)2 crystallise according to the respective space groups P212121 and P21/c. The molecules of the two compounds are conformationally different through differing ligand rotations about the Zn-O bonds. These are such as to enable a molecular packing in which there is a balance of the predominant CH3--X attractions and CH3--CH3 repulsions. The bromide is P¯1 triclinic, now with two conformationally different molecules in the asymmetric unit, but its molecular packing is similar to that of the iodide, again to balance the same attractions and repulsions. Approach distances to the amide carbon atoms are discussed.
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Samchenko AA, Kabanov AV, Komarov VM. Conformational mobility of the O=C−N−H fragments in isolated dipeptides of L-amino acids. Biophysics (Nagoya-shi) 2007. [DOI: 10.1134/s0006350907020029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Fabian J, Gloe K, WÜSt M, Krüger-rambusch T, Rademacher O, Graubaum H. THE STRUCTURE OF 3,4-DIAZA-1,6,6aλ4−TRITHIAPENTALENES-A COMBINED EXPERIMENTAL AND THEORETICAL STUDY. PHOSPHORUS SULFUR 2006. [DOI: 10.1080/10426509808035730] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- J. Fabian
- a Technische Universität Dresden Institut für Organische Chemie , 0–01062, Dresden, Mommsenstr 13, Germany
| | - K. Gloe
- b Technische Universität Dresden lnstitut für Anorganische Chemie , 0–01062, Dresden, Mommsenst. 13, Germany
| | - M. WÜSt
- b Technische Universität Dresden lnstitut für Anorganische Chemie , 0–01062, Dresden, Mommsenst. 13, Germany
| | - T. Krüger-rambusch
- b Technische Universität Dresden lnstitut für Anorganische Chemie , 0–01062, Dresden, Mommsenst. 13, Germany
| | - O. Rademacher
- b Technische Universität Dresden lnstitut für Anorganische Chemie , 0–01062, Dresden, Mommsenst. 13, Germany
| | - H. Graubaum
- c Institute für Angewandte Chemie Adlershof , Rudower Chaussee, D-12484, Berlin, Germany
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Substituent and solvent effects on the rotational barriers in selenoamides: A theoretical study. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.theochem.2005.10.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Troganis AN, Sicilia E, Barbarossou K, Gerothanassis IP, Russo N. Solvation Properties of N-Substituted Cis and Trans Amides Are Not Identical: Significant Enthalpy and Entropy Changes Are Revealed by the Use of Variable Temperature 1H NMR in Aqueous and Chloroform Solutions and ab Initio Calculations. J Phys Chem A 2005; 109:11878-84. [PMID: 16366639 DOI: 10.1021/jp0537557] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The cis/trans conformational equilibrium of N-methyl formamide (NMF) and the sterically hindered tert-butylformamide (TBF) was investigated by the use of variable temperature gradient 1H NMR in aqueous solution and in the low dielectric constant and solvation ability solvent CDCl3 and various levels of first principles calculations. The trans isomer of NMF in aqueous solution is enthalpically favored relative to the cis (deltaH(o) = -5.79 +/- 0.18 kJ mol(-1)) with entropy differences at 298 K (298 x deltaS(o) = -0.23 +/- 0.17 kJ mol(-1)) playing a minor role. The experimental value of the enthalpy difference strongly decreases (deltaH(o) = -1.72 +/- 0.06 kJ mol(-1)), and the contribution of entropy at 298 K (298 x deltaS(o) = -1.87 +/- 0.06 kJ mol(-1)) increases in the case of the sterically hindered tert-butylformamide. The trans isomer of NMF in CDCl3 solution is enthalpically favored relative to the cis (deltaH(o) = -3.71 +/- 0.17 kJ mol(-1)) with entropy differences at 298 K (298 x deltaS(o) = 1.02 +/- 0.19 kJ mol(-1)) playing a minor role. In the sterically hindered tert-butylformamide, the trans isomer is enthalpically disfavored (deltaH(o) = 1.60 +/- 0.09 kJ mol(-1)) but is entropically favored (298 x deltaS(o) = 1.71 +/- 0.10 kJ mol(-1)). The results are compared with literature data of model peptides. It is concluded that, in amide bonds at 298 K and in the absence of strongly stabilizing sequence-specific inter-residue interactions involving side chains, the free energy difference of the cis/trans isomers and both the enthalpy and entropy contributions are strongly dependent on the N-alkyl substitution and the solvent. The significant decreasing enthalpic benefit of the trans isomer in CDCl3 compared to that in H2O, in the case of NMF and TBF, is partially offset by an adverse entropy contribution. This is in agreement with the general phenomenon of enthalpy versus entropy compensation. B3LY/6-311++G** and MP2/6-311++G** quantum chemical calculations confirm the stability orders of isomers and the deltaG decrease in going from water to CHCl3 as solvent. However, the absolute calculated values, especially for TBF, deviate significantly from the experimental values. Consideration of the solvent effects via the PCM approach on NMF x H2O and TBF x H2O supermolecules improves the agreement with the experimental results for TBF isomers, but not for NMF.
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Affiliation(s)
- Anastassios N Troganis
- Department of Biological Applications & Technologies, University of Ioannina, Ioannina GR-45110, Greece
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Landi BJ, Ruf HJ, Worman JJ, Raffaelle RP. Effects of Alkyl Amide Solvents on the Dispersion of Single-Wall Carbon Nanotubes. J Phys Chem B 2004. [DOI: 10.1021/jp047521j] [Citation(s) in RCA: 166] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Brian J. Landi
- NanoPower Research Laboratories (NPRL) and Department of Chemistry, Rochester Institute of Technology, Rochester, New York, 14623
| | - Herbert J. Ruf
- NanoPower Research Laboratories (NPRL) and Department of Chemistry, Rochester Institute of Technology, Rochester, New York, 14623
| | - James J. Worman
- NanoPower Research Laboratories (NPRL) and Department of Chemistry, Rochester Institute of Technology, Rochester, New York, 14623
| | - Ryne P. Raffaelle
- NanoPower Research Laboratories (NPRL) and Department of Chemistry, Rochester Institute of Technology, Rochester, New York, 14623
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Jean Y, Demachy I, Lledos A, Maseras F. Electronic against steric effects in distorted amides. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s0166-1280(03)00294-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Takamuku T, Matsuo D, Tabata M, Yamaguchi T, Nishi N. Structure of Aqueous Mixtures of N,N-Dimethylacetamide Studied by Infrared Spectroscopy, X-ray Diffraction, and Mass Spectrometry. J Phys Chem B 2003. [DOI: 10.1021/jp0226578] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Toshiyuki Takamuku
- Department of Chemistry, Faculty of Science and Engineering, Saga University, Honjo-machi, Saga 840-8502, Japan, Advanced Materials Institute and Department of Chemistry, Faculty of Science, Fukuoka University, Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan, and Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan
| | - Daisuke Matsuo
- Department of Chemistry, Faculty of Science and Engineering, Saga University, Honjo-machi, Saga 840-8502, Japan, Advanced Materials Institute and Department of Chemistry, Faculty of Science, Fukuoka University, Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan, and Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan
| | - Masaaki Tabata
- Department of Chemistry, Faculty of Science and Engineering, Saga University, Honjo-machi, Saga 840-8502, Japan, Advanced Materials Institute and Department of Chemistry, Faculty of Science, Fukuoka University, Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan, and Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan
| | - Toshio Yamaguchi
- Department of Chemistry, Faculty of Science and Engineering, Saga University, Honjo-machi, Saga 840-8502, Japan, Advanced Materials Institute and Department of Chemistry, Faculty of Science, Fukuoka University, Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan, and Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan
| | - Nobuyuki Nishi
- Department of Chemistry, Faculty of Science and Engineering, Saga University, Honjo-machi, Saga 840-8502, Japan, Advanced Materials Institute and Department of Chemistry, Faculty of Science, Fukuoka University, Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan, and Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan
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Bürgi HB. What we can learn about fast chemical processes from slow diffraction experiments. Faraday Discuss 2003; 122:41-63; discussion 79-88. [PMID: 12555849 DOI: 10.1039/b201630c] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The potential energy surface is an important determinant of a chemical reaction. Three ways of deducing non-trivial properties of such surfaces from the results of crystal structure analyses are discussed and illustrated with examples. (1) The mapping approach brings together structures of the same molecular fragment from different environments to outline reaction coordinates and vibrations. (2) Correlations between molecular structures and activation energies for a given reaction type reveal general and quantitative relations between seemingly independent entities such as ground state structure, force constants, reaction path length, activation energy and catalysis. (3) The evolution of atomic mean square amplitudes (displacement parameters) with temperature uncovers frequencies and atomic displacement patterns of large-amplitude vibrations in molecular crystals. Examples include the vibrations of molecular zeolite building blocks, the crankshaft motion of stilbenes, the dynamic coupling between pyramidal deformation of the amide NH2 group and hydrogen bonding, the bowl inversion of corannulenes and nucleophilic addition/elimination reactions.
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Affiliation(s)
- Hans-Beat Bürgi
- Laboratory of Crystallography, University of Berne, Freiestr. 3, CH-3012, Berne, Switzerland.
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Niu S, Li GM, Zingaro RA, Reibenspies JH, Ichiye T. Planarity of acetamides, thioacetamides, and selenoacetamides: Crystal structure ofN,N-dimethylselenoacetamide. HETEROATOM CHEMISTRY 2002. [DOI: 10.1002/hc.10056] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Trautner F, Abe T, Oberhammer H. Effect of fluorination: gas-phase structures of N,N-dimethylvinylamine and perfluoro-N,N-dimethylvinylamine. J Am Chem Soc 2001; 123:2865-9. [PMID: 11456974 DOI: 10.1021/ja003942c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The gas-phase structures of N,N-dimethylvinylamine, (CH(3))(2)NC(H)=CH(2) (1), and perfluoro-N,N-dimethylvinylamine, (CF(3))(2)NC(F)=CF(2) (2), were determined by gas electron diffraction and quantum chemical methods (B3LYP and MP2 with 6-31G basis sets). The configuration around nitrogen is slightly pyramidal in both compounds, with the sum of the nitrogen bond angles 351.2(12) degrees and 354.8(6) degrees in 1 and 2, respectively. In the parent compound 1, the (CH(3))(2)N group lies nearly in the plane of the vinyl group, and the nitrogen lone pair (lp) is almost perpendicular to this plane (Phi(C=C-N-lp) = 98(6) degrees). In the perfluorinated species 2, however, the (CF(3))(2)N group is oriented perpendicular to the vinyl plane, and the lone pair is parallel to the C=C bond (Phi(C=C-N-lp) = 2(5) degrees). A natural bond orbital analysis provides a qualitative explanation for this conformational change upon fluorination. The sterically unfavorable in-plane orientation of the dimethylamino group in 1 is stabilized by conjugation between the nitrogen lone pair and the C=C pi-bond. The anomeric effect between the lone pair and the C(alpha)-F sigma-bond in addition to steric effects favors the perpendicular orientation of the (CF(3))(2)N group in 2. Both quantum chemical methods reproduce the experimental structures satisfactorily.
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Affiliation(s)
- F Trautner
- Institut für Physikalische und Theoretische Chemie, Universität Tübingen, 72076 Tübingen, Germany
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Kahn K, Bruice TC. Alpha-ketoamides and alpha-ketocarbonyls: conformational analysis and development of all-atom OPLS force field. Bioorg Med Chem 2000; 8:1881-91. [PMID: 11003132 DOI: 10.1016/s0968-0896(00)00122-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The molecular structures and barriers for the internal rotation around the OC-CO single bond in four alpha-ketoamides and eight alpha-ketocarbonyls have been determined from the MP3/aug-cc-pVDZ and MP2/aug-cc-pVDZ calculations. Alpha-ketocarbonyls with non-bulky substituents adopt planar conformations with two carbonyl oxygens in s-trans arrangement. The s-cis conformation is significantly less stable due to the electrostatic repulsion between the two carbonyl groups. Primary and secondary alpha-ketoamides are planar when the substituent at the carbonyl carbon is hydrogen or methyl group but tertiary alpha-ketoamides adopt a conformation where the OC-CO unit is significantly bent. Based on current ab initio structural data, a set of OPLS-AA force field parameters has been derived. These parameters can be used for the modeling of a variety of alpha-ketoamide or alpha-ketocarbonyl containing drugs such as novel protease inhibitors or neuroregenerative polyketides.
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Affiliation(s)
- K Kahn
- Department of Chemistry and Biochemistry, University of California-Santa Barbara, 93106, USA
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Trautner F, Reinemann S, Minkwitz R, Oberhammer H. Fluorination and Conjugation. The Structure of Perfluoro-N,N-dimethylformamide. J Am Chem Soc 2000. [DOI: 10.1021/ja994024l] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Frank Trautner
- Contribution from the Institut für Physikalische und Theoretische Chemie, Universität Tübingen, 72076 Tübingen, Germany, and Lehrstuhl für Anorganische Chemie, Universität Dortmund, 44221 Dortmund, Germany
| | - Stefan Reinemann
- Contribution from the Institut für Physikalische und Theoretische Chemie, Universität Tübingen, 72076 Tübingen, Germany, and Lehrstuhl für Anorganische Chemie, Universität Dortmund, 44221 Dortmund, Germany
| | - Rolf Minkwitz
- Contribution from the Institut für Physikalische und Theoretische Chemie, Universität Tübingen, 72076 Tübingen, Germany, and Lehrstuhl für Anorganische Chemie, Universität Dortmund, 44221 Dortmund, Germany
| | - Heinz Oberhammer
- Contribution from the Institut für Physikalische und Theoretische Chemie, Universität Tübingen, 72076 Tübingen, Germany, and Lehrstuhl für Anorganische Chemie, Universität Dortmund, 44221 Dortmund, Germany
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Density functional studies of molecular structures of N-methyl formamide, N,N-dimethyl formamide, and N,N-dimethyl acetamide. J CHEM SCI 2000. [DOI: 10.1007/bf02704298] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Fabian WM, Semones MA, Kappe C. Ring conformation and ester orientation in dihydropyrimidinecarboxylates: a combined theoretical (ab initio, density functional) and X-ray crystallographic study. ACTA ACUST UNITED AC 1998. [DOI: 10.1016/s0166-1280(98)00061-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Maple JR, Hwang MJ, Jalkanen KJ, Stockfisch TP, Hagler AT. Derivation of class II force fields: V. Quantum force field for amides, peptides, and related compounds. J Comput Chem 1998. [DOI: 10.1002/(sici)1096-987x(199803)19:4<430::aid-jcc5>3.0.co;2-t] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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