Unusual photodimerization of 7-fluoro-4-methylcoumarin and 6-fluoro-4-methylcoumarin in the solid state

Vishnumurthy, Kodumuru and Row, Tayur N Guru and Venkatesana, Kailasam (1998) Unusual photodimerization of 7-fluoro-4-methylcoumarin and 6-fluoro-4-methylcoumarin in the solid state. In: Tetrahedron, 54 (37). pp. 11235-11246.

PDF Unusual_Photodimerization.pdf - Published Version Restricted to Registered users only Download (623kB) | Request a copy

Abstract

Photodimerization of 7-fluoro-4-methylcoumarin 1 is topochemical while 6-fluoro-4-methylcoumarin 2 does not lead to the expected product based on the topochemical principles. Compound 1 yield an anti-MT photodimer with a lower dimer conversion while compound 2 results in a syn-HH photodimer. The packing features of 1, 2 and 2a (the photodimer of 2) have been unequivocally established by single crystal X-ray diffraction studies. The rationale for the significant lower dimer conversion in 1 is provided. The defect induced dimerization reaction in 2 as a function of temperature is analyzed which verifies that the reaction proceeds with an induction period. The details of the interactions involving fluorine are analyzed.

Item Type:	Journal Article
Publication:	Tetrahedron
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit Division of Chemical Sciences > Organic Chemistry
Date Deposited:	15 Dec 2009 12:06
Last Modified:	19 Sep 2010 05:28
URI:	http://eprints.iisc.ac.in/id/eprint/19437

Actions (login required)

View Item