Concerted formation of S-methyldithizonium and 2,3-diphenyl-5-methyl-thiotetrazolium cations in the reaction of S-methyldithizone and iodine in chloroform. Part 8. Crystal structures of S-methyldithizone hydrogen tri-iodide and 2,3-diphenyl-5-methyltetrazolium tri-iodide–chloroform

Abstract

S-Methyldithizone reacts with iodine in chloroform solution giving, in a single reaction, the cations S-methyldithizonium and 2,3-diphenyl-5-methylthiotetrazolium, which have been identified via X-ray structure analysis of the crystalline reaction products S-methyldithizone hydrogen tri-iodide (3) and 2,3-diphenyl-5-methylthiotetrazolium tri-iodide–chloroform (4). Compound (3) is triclinic [a= 12.367(8), b= 10.084(7), c= 8.451(6)Å, α= 109.9(1), β= 97.5(1), γ= 96.9(1)°, Z= 2, space group P]. Stacks of antiparallel protonated S-methyldithizone cations are interleaved by isolated I₃^– ions, directed parallel to the normals to the cation planes. Compound (4) is monoclinic [a= 15.923(8), b= 10.218(7), c= 16.118(8)Å, β= 109.91(1)°, Z= 4, space group Cc]. There are two sets of interacting I₃^– ions directed along [110] and [10], respectively; the distance between the terminal iodines of adjacent I₃^– ions is 3.608(1)Å, indicating appreciable interaction.