The use of mixed crystals for engineering organic solid-state reactions: application to benzylbenzylidenecyclopentanones

Abstract

The concept of chloro/methyl group interchange as a tool in crystal engineering is discussed with respect to derivatives of 2-benzyl-5-benzylidenecyclopentanone (1-4). A study of the mixed crystals containing either 1 and 2 (X) or 3 and 4 (Y) demonstrates that molecules which otherwise crystallize into photostable crystal structures may be incorporated into a light-sensitive form. Furthermore, such mixed crystals are demonstrated (using four-circle diffractometry) to undergo single-crystal --* single-crystal reaction with the formation of the product dimer molecules identified within the reactant lattice. The final R for X is 0.0418, for Y it is 0.0578, and for irradiated X it is 0.0394.It is clear that the controlled variation of the substituent groups present on an organic molecule may allow subsequent crystalli-zation into particular and desired packing arrangements2. One particular strategy for this so-called crystal-engineering concept 0002-7863/84/ 1506-3606$01Supplementary Material Available: Tables of final atomic parameters and lists of bond lengths, bond angles, and observed and calculated structure factors (33 pages). Ordering information is given on any current masthead page. 53-0. (1 1) Swiatkiewicz, J.; Eisenhardt, G.; Prasad, P. N.; Thomas, J. M.; Jones, W.; Theocharis, C. R.

Single-crystal-to-single-crystal [2 + 2] photodimerizations: from discovery to design

“…The SCSC nature of the reaction has been subsequently confirmed by dynamic X-ray measurements [46], Raman phonon spectroscopy [47], and, more recently, AFM observations [17]. Three derivatives of the cyclic ketone, out of five reported photoactive derivatives, were also found to exhibit SCSC reactivity [28, 48,49]. The in situ observation of the reaction of the parent ketone using dynamic X-ray diffraction (Fig.…”

“…While the conformations of 2-(p-chlorobenzyl)-5-benzyli- denecyclopentanone, 2-(p-methylbenzyl)-5-benzylidenecyclopentanone, and 2-(p-methylbenzyl)-5-(p-bromobenzylidene)cyclopentanone in the pure solids were suitable for photoreaction, the conformation of (p-chlorobenzyl)-5-(pbromobenzylidene)cyclopentanone was not. In a mixed crystal of the molecule with 2-(p-methylbenzyl)-5-(p-bromobenzylidene)cyclopentanone, however, the ketone adopted a conformation suitable for [2 þ 2] photodimerization [49] (Fig. 6).…”

Professor William Jones and His Materials Chemistry Group: Innovations and Advances in the Chemistry of Solids

“…[17][18][19] Following Kitaigorodskii's pioneering studies of solidstate solubility and isomorphism in molecular crystals 20 , and prompted by the discovery of isomorphous crystals in the BBCP family 11 , Jones and co-workers explored the use of functional-group interchangeability principles to engineer solid-state cross-photodimerization reactions. In a landmark crystal-engineering study in organic solid-state photochemistry, 21 Jones and Desiraju accomplished the cross-photodimerization of various Cl-and CH 3 derivatives of BBCPs in their solid solutions. A particularly impressive feat was the crossphotodimerization of two non-isostructural Br-BBCPs, one of which was known to be photostable in the solid state as a consequence of its unfavorable molecular conformation in the solid state.…”

Solid-state study of cyclic thiohydroxamic acids: 1-hydroxy-2(1H)-pyridinethione and 3-hydroxy-4-methyl-2(3H)- thiazolethione

“…Strategies which are adopted for structure modification include the production of new polymorphs, solvates and mixed molecular crystals. 4,5 We are currently studying the solid-state chemistry of cyclic thiohydroxamic acids, which find application in two diverse areas. First, materials based on pyridinethiones, such as 1-hydroxy-2(1H)-pyridinethione (pyrithione, 1), are widely used as fungicides.…”