Abinitio configuration interaction studies of the electronic states of S2N2

Ab initio SCF and CI calculations are reported for the sulfur nitride, SN, and disulfur dinitride, S2N2, molecules. Calculations on SN, varying the internuclear distance, are performed using a variety of basis sets to determine a suitable basis for S2N2. The total energy, internuclear distance, and force constant of SN are reported for several choices of basis. Extended basis computations on S2N2 are performed, and midbond polarization functions are found to contribute significantly to a description of the ground state, affecting the higher MO’s and the charge density. A prominent feature of the virtual spectrum is the existence of a low energy π* orbital which could play a role in low lying excited states, the polymerization process, and polymer conductivity. CI studies of the ground and excited states of S2N2 show several low lying singlet and triplet states of the type π→σ*, π→π*, and σ→π*, and possible identifications with experiment are discussed. A possibility of relating the observed paramagnetism ...

[1]  R. P. Messmer,et al.  A study of the electronic structures of SN, S2N2, S4N4, NO, and N2O2 and their implications for (SN)x , 1976 .

[2]  A. Zunger Band structure of the one-dimensional metallic (SN) x crystal , 1975 .

[3]  E. Clementi,et al.  Electronic structure of TTF–TCNQ complex , 1975 .

[4]  A. Heeger,et al.  Synthesis and structure of metallic polymeric sulfur nitride, (SN)x, and its precursor, disulfur dinitride, S2N2 , 1975 .

[5]  J. Whitten Ab initio studies of molecules and concepts of molecular structure , 1973 .

[6]  J. R. Wazer,et al.  Electron Behavior in Some Sulfur Compounds , 1972 .

[7]  W. Hehre,et al.  Self‐Consistent Molecular Orbital Methods. XIV. An Extended Gaussian‐Type Basis for Molecular Orbital Studies of Organic Molecules. Inclusion of Second Row Elements , 1972 .

[8]  P. O'hare Dissociation Energies, Enthalpies of Formation, Ionization Potentials, and Dipole Moments of NS and NS+ , 1970 .

[9]  S. Huzinaga,et al.  Gaussian‐Type Functions for Polyatomic Systems. II , 1970 .

[10]  J. L. Whitten,et al.  Configuration Interaction Studies of Ground and Excited States of Polyatomic Molecules. I. The CI Formulation and Studies of Formaldehyde , 1969 .

[11]  M. V. Evans,et al.  Vibrational Spectra and Structure of S4N4 and S2N2 , 1969 .

[12]  W. L. Jolly,et al.  Reactions of disulfur dinitride with antimony pentachloride , 1969 .

[13]  D. Chapman,et al.  The infra-red spectrum and structure of disulphur dinitride , 1966 .