New ligand behavior of 4-amino-3-R-1,2,4-Δ2-triazoline-5-thione. Crystal structures of silver(I) [R=H] and copper(I) [R=CH2CH3] complexes

The molecular structures of [Ag(HL1)2]NO3 and [CuCl(HL2)3] (HL1=4-amino-1,2,4-Δ2-triazoline-5-thione; HL2=4-amino-3-ethyl-1,2,4-Δ2-triazoline-5-thione) have been determined by single crystal X-ray analyses. Unusual dimeric and polymeric species are present in the silver compound due to the versatile coordination ability of the ligand. The tetrahedral copper(I) complex (C3 symmetry) is chiral owing to the conformational helicoidal disposition of the three S-coordinated triazoline molecules interacting via hydrogen bonds with the coordinated chlorine atom and, in a head-to-tail fashion, with other complexes forming chains running parallel to c. A spontaneous resolution is observed and in the crystal structure only Λ conformers are present.