Mixed radical iodine charge-transfer salts of dithiadiazolyl diradicals. Structural characterization of the pyridine-bridged 2:1 salt 2,6-[(S2N2C)C5H3N(CN2S2)](2)[I]

by Cordes, A. Wallace; George, Noel A.; Haddon, Robert C.; Kennepohl, Dietmar K.; Oakley, Richard T.; Palstra, Thomas T. M.; Reed, Robert W.

Cosublimation of 2,5-furanbis(1,2,3,5-dithiadiazolyl) [F-2,5-S] and iodine affords 1:1 and 2:1 charge-transfer salts, [F-2,5-S][I] and [F-2,5-S](2)[I]. Cosublimation of 2,6-pyridinebis-(1,2,3,5-dithiadiazolyl) [P-2,6-S] and iodine affords uniquely the 2:1 charge-transfer salt [P-2,6-S](2)[I]. Crystals of the latter belong to the space group P2(1)/c, a = 3.434(3), b = 9.8914(9), c = 30.803(4) Angstrom, beta = 91.52(3)degrees, V = 1045.9(9) Angstrom(3), Z = 2. The structure consists of [P-2,6-S] molecules stacked along the x direction. Pairs of stacks are linked head-on through iodine atoms, which themselves form disordered stacks running parallel to x. The internal structural parameters of the two CN2S2 rings within each molecule suggest that one (linked to iodine) is formally uncharged, while the other is partially oxidized. This latter ring is heavily coordinated through S---N linkages to neighboring CN2S2 rings and pyridine. Magnetic susceptibility measurements on [P-2,6-S](2)[I] indicate that it is diamagnetic below 220 K.

Journal
Chemistry of Materials
Volume
8
Issue
12
Year
1996
Start Page
2774
ISBN/ISSN
1520-5002; 0897-4756
DOI
10.1021/cm960262t