Parameters of average molecular polarizability in the MNDO, AM1 and PM3 methods

Bond dissociation energies (BDEs) for complexes of ground state Mg+ (2S) with several small oxygen- and nitrogen-containing ligands (H2O, CO, CO2, H2CO, CH3OH, HCOOH, H2CCO, CH3CHO, c-C2H4O, H2CCHOH, CH3CH2OH, CH3OCH3, NH3, HCN, H2CNH, CH3NH2, CH3CN, CH3CH2NH2, (CH3)2NH, H2NCN, and HCONH2) have been calculated at the CP-dG2thaw level of theory. These BDE values, as well as counterpoise-corrected MP2(thaw)/6-311+G(2df,p) calculations on the Mg+ complexes of several larger ligands, augment and complement existing experimental or theoretical determinations of gas-phase Mg+/ligand bond strengths. The reaction kinetics of complex formation are also investigated via variational transition state theory (VTST) calculations using the computed ligand and molecular ion parameters. Radiative association rate coefficients for most of these systems increase by approximately 1 order of magnitude with every 3-fold reduction in temperature from 300 to 10 K. Several of the largest molecules surveyed-notably, CH3COOH, (CH3)2CO, and CH3CH2CN-exhibit comparatively efficient radiative association with Mg+ (k(RA) > or = 1.0 x 10(-10) cm3 molecule(-1) s(-1)) at temperatures as high as 100 K, implying that these processes may have a considerable influence on the metal ion chemistry of warm molecular astrophysical environments known to contain these potential ligands. Our calculations also identify the infrared chromophoric brightness of various functional groups as a significant factor influencing the efficiency of the radiative association process.

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“…b CP-dG2thaw values, using Na + BDEs first reported in ref . c Static electric polarizability (ref , ).…”

Section: Resultsmentioning

confidence: 99%

Magnesium Monocationic Complexes: A Theoretical Study of Metal Ion Binding Energies and Gas-Phase Association Kinetics

Dunbar

Petrie

2005

J. Phys. Chem. A

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“…Many semiempirical methods of differing accuracy have been proposed for calculating molecular polarizabilities. − Molecular polarizability influences several other physical properties, including electronegativity, , dipole moment, and ionization potential. , A quantitative relationship between polarizability, hardness, and size of different systems, such as atoms, molecules, metal clusters, and carbon clusters, has been demonstrated. , Polarizability has also been related to the structural parameters, such as the bond length alteration (BLA) and π-electron bond order alteration (BOA) . Polarizability has been used as an independent variable for the prediction of vapor pressure and octanol−air partitioning coefficients .…”

Section: Simple Physical Properties Involving Single Molecular Speciesmentioning

confidence: 99%

“…159,174,177,271 Many semiempirical methods of differing accuracy have been proposed for calculating molecular polarizabilities. [272][273][274][275][276][277] Molecular polarizability influences several other physical properties, including electronegativity, 278,279 dipole moment, 280 and ionization potential. 281,282 A quantitative relationship between polarizability, hardness, 283 and size of different systems, such as atoms, molecules, metal clusters, and carbon clusters, has been demonstrated.…”

Section: Polarizabilitiesmentioning

confidence: 99%

Quantitative Correlation of Physical and Chemical Properties with Chemical Structure: Utility for Prediction

et al. 2010

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“…18 We cannot possibly compare all of these results with calculations of capture rate coefficients employing the present relationships. We can select a few representative examples only, emphasizing however that the calculation is straightforward when polarizabilities 19,20 a and dipole moments 19,21 m D are known. Table 1 illustrates the results.…”

Section: Practical Examples For Capture Rate Coefficientsmentioning

confidence: 99%

Modelling low-energy electron–molecule capture processes

Dashevskaya

Litvin

Nikitin

et al. 2008

Phys. Chem. Chem. Phys.

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Cross sections and rate coefficients for capture of low-energy electrons with polar and polarizable target molecules are calculated in the framework of Fabrikant and Hotop's extended version of the Vogt-Wannier model and an extension of this approach is given in the present article. Analytical approximations are derived in order to facilitate the application to experiments. A comparison with a selection of experimental electron attachment rate coefficients provides insight into the competition between anion formation through electron capture and scattering processes which do not follow this pathway.

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Parameters of average molecular polarizability in the MNDO, AM1 and PM3 methods

Cited by 11 publications

References 26 publications

Magnesium Monocationic Complexes: A Theoretical Study of Metal Ion Binding Energies and Gas-Phase Association Kinetics

Magnesium Monocationic Complexes: A Theoretical Study of Metal Ion Binding Energies and Gas-Phase Association Kinetics

Quantitative Correlation of Physical and Chemical Properties with Chemical Structure: Utility for Prediction

Modelling low-energy electron–molecule capture processes

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