UNUSUAL SULFUR INSERTION IN A COPPER(I)-MERCAPTOBENZOTHIAZOLE COMPLEX - SYNTHESIS AND STRUCTURAL STUDY OF [CUI(C7H5NS2)(C14H8N2S5)](CLO4).2CHCL3

The title complex was obtained from a chloroform solution of mercaptobenzothiazole (Hmbt) which was reacted with solid copper(II) perchlorate hexahydrate. The infrared spectrum of this species was consistent with the presence of the ligand under two different forms such as Hmbt and mbt, involving different coordination sites. This was confirmed by an X-ray structure determination which also revealed an unusual sulfur insertion. Crystals are monoclinic, of space group P21/C, with a=14.746 (6) υ, b=10.883 (5) υ, c=12.296 (6) A, and β=94.51 (1)°. The structure was solved by the heavy-atom method. The final agreement index Rw was 0.06. The perchlorate anion exhibits a statistical distribution between two sites, in the ratio 0.65/0.35. The cuprous complex cation is tetrahedral; it contains mercaptobenzothiazole under two different forms: (i) a Hmbt form S bonded to the metal through the exocyclic sulfur atom (Cu-S=2.221 (4) υ) and (ii) an unusual oxidized form RSSSR in which an additional sulfur atom has been inserted. This mbt-S-mbt unit is coordinated through both thiazolic nitrogen atoms (Cu-N=2.04 (1), 2.01 (1) A) and the central sulfur atom (Cu-S=2.486 (4) A). The molecular structure of both forms is discussed. © 1979, American Chemical Society. All rights reserved.