A NOVEL ANTIMONY SULFIDE TEMPLATED BY DIMETHYLAMMONIUM - ITS SYNTHESIS AND STRUCTURAL CHARACTERIZATION USING SYNCHROTRON IMAGING PLATE DATA/

Hydrothermal synthesis at 200 degrees C produced a new open antimony s ulfide framework, [C2H8N](2)[Sb8S12(S-2)], designated DMA-SbS-SB8. The structure (Cmca, a = 9.9704(7), b = 11.652(2), and c = 25.979(3) Angs trom), determined from data collected on a small single crystal (20 x 30 x 40 mu m in size) utilizing the synchrotron/imaging plate system i nstalled at the X3A1 beamline of the NSLS, consists of [Sb8S12(S-2)](2 -) double chains formed from Sb4S72- single chains joined through S-S bridges. The double chains contain 18-membered Sb8S10 rings and are in terlocked to form sheets perpendicular to the b axis. Dimethylammonium ions, assumed to be protonated to charge balance the anionic [Sb8S12( S-2)](2-) framework, reside within 18-membered rings. The structural b uilding units of the new open framework are similar to those described previously in other members of the antimony sulfide system. Experimen ts carried out at different temperatures and reaction times show that DMA-SbS-SB8 is formed from a distinct poorly crystallized phase (desig nated DMA-SbS-SB8'), which is the dominant phase at 100 degrees C.