Skip to main content Accessibility help

Semi-Empirical Calculations and Measurements of Modified Carbocyanines Optical Properties

  • Daniel G. McLean (a1), Paul Day (a2), Zhiqiang Wang (a2), Nansheng Tang (a3), Weijie Su (a2), Donna M. Brandelik (a1), Jiaoshi Si (a4) and Ruth Pachter (a5)...


We report semi-empirical calculations of modified 3,3'-diethylthiacyanine iodide (DTC1), 3,3'-diethylthiacarbocyanine iodide (DTC3) and 3,3'-diethylthiadicarbocyanine iodide (DTC5), particularly with halogen substitution at the meso position in the polymethine bridge. Primarily we investigate geometrical changes and infer spectral trends from the molecular orbital levels. The semi-empirical calculations for the unsubstituted DTC3 agree well with an ab initio Hartree-Fock result. In all molecules multiple conformations are examined. Significant changes in dipole moments are noted between the cis and trans forms. Calculated electronic spectra at the CI singles level are compared to the measured spectra with reasonable agreement. Halogenation effects show a rotation of the benzthiazole groups out of planarity. We draw conclusions about consequent effects on solubility and excited state spectral changes.



Hide All
1. Sturmer, D. M. and Heseltine, D. W., Chapter 8 in “The Theory of the Photographic Process,” Mees, C. E. K. Ed., Macmillan Publishing Co., N.Y. 1977, pgs 194ff.
2. Awad, M. M., McCarthy, P.K., and Blanchard, G. J. J. Phys. Chem. 98, 1454 (1994).
3. Ishchenko, A. A., Russian Chem. Rev. 60, 865 (1991).
4. Ponterini, Glauco and Momiccholi, Fabio, Chem. Phys. 151, 111 (1991).
5. Fabian, J. and Hartmann, H., “Light Absorption of Organic Colorants,” Springer-Verlag, N.Y. 1980, pgs 167ff.
6. Darmanyan, A. P., Chem. Phys. Lett. 102, 329 (1983).
7. Stewart, J. J. P., J. Comp. Chem. 10, 209 (1989).
8. Klamt, A. and Schüürmann, G., Perkin Transactions, pg 799, 1993.
9. Schmidt, M. W., Baldridge, K. K., Boatz, J. A., Elbert, S. T., Gordon, M. S., Jensen, J. H., Koseki, S., Matsunaga, N., Nguyen, K. A., Su, S.,. Windus, T. L., Dupuis, M., and Montgomery, J. A., J. Comput. Chem. 14,1347 (1993).
10. Dunning, T. H. Jr. and Hay, P. J., Chapter 1 in “Methods of Electronic Structure Theory”, Shaefer, H. F. III, Ed. Plenum Press, N.Y. 1977, pp 127. Note that GAMESS uses inner/outer scale factors of 1.2 and 1.15 for DH's hydrogen. For the polarization functions added to this basis, the exponents used were 0.75, 0.80, and 0.85 for the d-type functions on carbon, nitrogen, and oxygen, respectively, and 1.0 for the p-type functions on hydrogen.
11. Ridley, J. E. and Zemer, M. C., Theoret. Chim. Acta 32, 111 (1973).
12. Hamer, Frances M., “The Cyanine Dyes and Related Compounds,” Interscience Publishers, N.Y. 1964, pgs.96ff, 162ff.
13. Baraldi, I., Camevali, A., Momicchioli, F., and Ponterini, G., Spectrochimica Acta, 49A, 471 (1993).
14. Fabian, J. and Hartman, H., “Light Absorption of Organic Colorants,” Springer-Verlag, New York, NY 1980, p 163.


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed