Search for a trans-Disulfide: Structural Analysis of Di-tert-adamantyl Disulfide by Photoelectron Spectroscopy, Derivation of σI (t-Ad), and Molecular Mechanics Calculations for Related Bulky Disulfides

TY - JOUR

T1 - Search for a trans-Disulfide

T2 - Structural Analysis of Di-tert-adamantyl Disulfide by Photoelectron Spectroscopy, Derivation of σI (t-Ad), and Molecular Mechanics Calculations for Related Bulky Disulfides

AU - Jørgensen, Flemming S.

AU - Snyder, James P.

PY - 1980/1/1

Y1 - 1980/1/1

N2 - Photoelectron spectroscopy of t-Ad-SS-t-Ad yields an IE(n) - IE(n+) energy difference of 0.51 eV at the frontier orbital gap suggesting to an S-S dihedral angle of θ(CSSC) = 103°. Molecular mechanics calculations with Allinger's MMI yield a shallow energy minimum with respect to rotation about the S-S bond. Two conformations differing by 0.7 kcal/mol are located at θ(CSSC) = 100 and 114°. Regression analysis of dialkyl disulfide ionization energies and substituent inductive parameters (σI) leads to σ(t-Ad) = -0.089, indicating t-Ad to be a better electron donor than t-Bu. Finally force field calculations for several sterically congested disulfides suggest that trans disulfides may be realizable for very large alkyl substituents such as the (t-Bu)3C, polymethyladamantyl, and trimethylperhydrotriquinicenyl moieties.

AB - Photoelectron spectroscopy of t-Ad-SS-t-Ad yields an IE(n) - IE(n+) energy difference of 0.51 eV at the frontier orbital gap suggesting to an S-S dihedral angle of θ(CSSC) = 103°. Molecular mechanics calculations with Allinger's MMI yield a shallow energy minimum with respect to rotation about the S-S bond. Two conformations differing by 0.7 kcal/mol are located at θ(CSSC) = 100 and 114°. Regression analysis of dialkyl disulfide ionization energies and substituent inductive parameters (σI) leads to σ(t-Ad) = -0.089, indicating t-Ad to be a better electron donor than t-Bu. Finally force field calculations for several sterically congested disulfides suggest that trans disulfides may be realizable for very large alkyl substituents such as the (t-Bu)3C, polymethyladamantyl, and trimethylperhydrotriquinicenyl moieties.

UR - http://www.scopus.com/inward/record.url?scp=0007438193&partnerID=8YFLogxK

U2 - 10.1021/jo01294a020

DO - 10.1021/jo01294a020

M3 - Journal article

AN - SCOPUS:0007438193

SN - 0022-3263

VL - 45

SP - 1015

EP - 1020

JO - Journal of Organic Chemistry

JF - Journal of Organic Chemistry

IS - 6

ER -