@article{lee_jeong_lee_2003, title={An efficient method to compute partial atomic charges of large molecules using reassociation of fragments}, volume={24}, number={3}, journal={Bulletin of the Korean Chemical Society}, author={Lee, J. G. and Jeong, H. Y. and Lee, H.}, year={2003}, pages={369–376} }
 @article{shultz_fico_lee_kampf_kirschbaum_pinkerton_boyle_2003, title={Mechanisms of Exchange Modulation in Trimethylenemethane-type Biradicals:  The Roles of Conformation and Spin Density}, volume={125}, ISSN={["0002-7863"]}, DOI={10.1021/ja037787o}, abstractNote={The molecular structures and magnetic properties of six dinitroxide biradicals are described. Five of the dinitroxides are trimethylenemethane-type (TMM-type) biradicals; that is, the intramolecular exchange parameter, J, is modulated by a carbon-carbon double bond. However, the efficacy of the carbon-carbon double bond as an exchange coupler is determined by the molecular conformation. Our results show that the exchange parameters correlate with phenyl-ring torsion angles (phi) via a simple Karplus-Conroy-type relation: J = 44 cos(2) phi - 17. Comparison of these results to those obtained for our isostructural series of bis(semiquinone) biradicals shows that both the magnitude of J and the resistance of ferromagnetic J to bond torsions is proportional to the spin density adjacent to the exchange coupler.}, number={50}, journal={Journal of the American Chemical Society}, author={Shultz, D.A. and Fico, R.M., Jr. and Lee, H. and Kampf, J.W. and Kirschbaum, K. and Pinkerton, A.A. and Boyle, P.D.}, year={2003}, pages={15426–15432} }
 @article{shultz_bodnar_lee_kampf_incarvito_rheingold_2002, title={Singlet-triplet gap in triplet ground-state biradicals is modulated by substituent effects}, volume={124}, ISSN={["0002-7863"]}, DOI={10.1021/ja020154+}, abstractNote={Three S = 1 bis(semiquinone) complexes have been prepared. To ensure ferromagnetic intramolecular exchange coupling, the two semiquinones are attached 1,3 to a 5-substituted phenylene ring. The biradical complexes differ in their meta-substituents: 1-NMe(2)(), X = N,N-dimethylamino; 1-t-Bu, X = tert-butyl; 1-NO(2)(), X = nitro. All three structures have been determined by X-ray crystallography. Results of structural studies indicate that the biradical ligands of all three complexes have nearly identical conformations with average semiquinone ring torsions of 32 degrees +/- 2 degrees relative to the 5-substituted phenylene ring. The exchange parameter, J (Eta = -2JS(1).S(2)), ranges from +31.0 +/- 0.6 cm(-)(1) for 1-NO(2)() to +59.3 +/- 1.2 cm(-)(1) for 1-t-Bu, with J = +34.9 +/- 0.7 cm(-)(1) for 1-NMe(2)(). Since the conformations are nearly identical, the differences in exchange coupling parameter J are due to substituent effects. The experimental results are supported by Hückel theory arguments and previous computational work.}, number={34}, journal={JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, author={Shultz, DA and Bodnar, SH and Lee, H and Kampf, JW and Incarvito, CD and Rheingold, AL}, year={2002}, month={Aug}, pages={10054–10061} }