Studies in crystal engineering: crystal packing, topological photodimerization and structure–reactivity correlations in fluoro-substituted styrylcoumarins

Abstract

In continuation of our studies on the influence of fluoro substitution on the solid state photobehaviour and packing pattern of styrylcoumarins, the results obtained for 4-(3-fluorostyryl)coumarin 1, 4-styryl-6-fluorocoumarin 2 and 4-styryl-7-fluorocoumarin 3 are presented. The configuration of the dimers was established on the basis of crystal packing of 1 and 2 (α-packed). A rationale for the significantly lower dimer yield in the crystal for 2 is proposed. In the observed centrosymmetric arrangement of the reactants the C=O · · · π (phenyl) contacts seem to provide additional attractive interactions. C–H · · · O and C–H · · · F hydrogen bonding seems to provide stability in these structures.

References

1. M. D. Cohen and G. M. J. Schmidt, J. Chem. Soc., 1964, 1996; M. D. Cohen, G. M. J. Schmidt and F. I. Sonntag, J. Chem. Soc., 1964, 2000; G. M. J. Schmidt, J. Chem. Soc., 1964, 2014; V. Ramamurthy and K. Venkatesan, Chem. Rev., 1987, 87, 433.
2. J. Narasimha Moorthy and K. Venkatesan, Bull. Chem. Soc. Jpn., 1994, 67, 1; J. Narasimha Moorthy, S. D. Samant and K. Venkatesan, J. Chem. Soc., Perkin Trans. 2, 1994, 1223.
3. K. Vishnumurthy, T. N. Guru Row and K. Venkatesan, J. Chem. Soc., Perkin Trans. 2, 1996, 1475.
4. L. Zsolnai, XPMA/ZORTEP, University of Heidelberg, 1995.
5. W. D. S. Motherwell and W. Clegg, PLUTO, Program for Production of Crystal and Molecular Illustrations, Crystallographic Data Centre, Cambridge, 1978.
6. G. S. Murthy, P. Arjunan, K. Venkatesan and V. Ramamurthy, Tetrahedron, 1987, 43, 1225.
7. L. Addadi and M. Lahav, Pure Appl. Chem., 1979, 39, 1269; K. Ueno, H. Nakanishi, M. Hasegawa and Y. Sasada, Acta. Crystallogr., Sect. B, 1978, 34, 2034.
8. D. Kanagapushpam, V. Ramamurthy and K. Venkatesan, Acta Crystallogr., Sect. C, 1987, 43, 1128.
9. V. Amarendhra Kumar, N. S. Begum and K. Venkatesan, J. Chem. Soc., Perkin Trans. 2, 1993, 463.
10. V. Amarendhra Kumar and K. Venkatesan, J. Chem. Soc., Perkin Trans. 2, 1993, 2429.
11. U. K. Joshi, R. M. Keltaar and M. V. Paradker, Ind. J. Chem., Sect. B, 1983, 22, 1151.
12. G. M. Sheldrick, SHELXS 86, Program for Crystal Structure Solution, Gottingen University, Germany.
13. G. M. Sheldrick, SHELXL 93, Program for Crystal Structure Solution, Gottingen University, Germany.