Expanding Bismuth Trihalide Coordination Chemistry with Trimethyltriazacyclohexane and Trimethyltriazacyclononane.

1,3,5-Trimethyltriazacyclohexane, Me 3 tach, readily adds to bismuth triiodide to form a variety of new coordination compounds depending on the stoichiometry, solvent, and crystallization conditions. X-ray crystallographic evidence has been obtained for both 2:1 and 1:1 Me 3 tach:Bi complexes with formulas of [(Me 3 tach) 2 BiI 2 ][(Me 3 tach)BiI 4 ], [(Me 3 tach) 2 BiI 2 ] 3 [Bi 2 I 9 ][I][HMe 3 tach]·THF, and (Me 3 tach)BiI 3 (py) 2 . The related chloride structure (Me 3 tach)BiCl 3 (py) 2 forms from BiCl 3 . The structure of (Me 3 tacn)BiI 3 with the larger chelate, 1,4,7-trimethyltriazacyclononane, Me 3 tacn, was obtained for comparison, and the polymeric structure of BiI 3 in THF was defined as [BiI(THF)(μ-I) 2 ] n .