The effect of fluorinated aryl substituents on the crystal structures of 1,2,3,5-dithiadiazolyl radicalsElectronic supplementary information (ESI) available: Experimental details, analysis, tables of bond lengths and angles, details of theoretical calculations. CCDC reference numbers 736245–736251. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/b911636b

The crystal structures of six new partially fluorinated aryl 1,2,3,5-dithiadiazolyls [ArCNSSN] are reported [Ar = 2,6-F2C6H3(4); Ar = 3,4-F2C6H3(5); Ar = 3,5-F2C6H3(6); Ar = 2,3,6-F3C6H2(9); Ar = 2,4,6-F3C6H2(11); and Ar = 3,4,5-F3C6H2(12)] and compared with three previously reported structures in this series (Ar = 2,3-F2C6H3(1); Ar = 2,5-F2C6H3(3); Ar = 2,3,4-F3C6H2(7)]. Radical 4is shown to be polymorphic. Molecular electrostatic potential maps have been used to rationalise these structures. These reveal that whilst single F atoms appear to have little structure-directing influence, combinations of an ortho-F on the phenyl ring and a heterocyclic ring N, or several F atoms located in mutually orthopositions with respect to each other, generate significant regions of negative charge which have a substantial structure-directing influence. [ABSTRACT FROM AUTHOR]