Spectroscopic studies and X-ray crystal structures of charge-transfer complexes of 1,4,7-trithiacyclononane with diiodine

✍ Scribed by Franco Cristiani; Francesco A. Devillanova; Francesco Isaia; Vito Lippolis; Gaetano Verani; Francesco Demartin

• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 700 KB
• Volume: 4
• Category: Article
• ISSN: 1042-7163
• DOI: 10.1002/hc.520040609

✦ Synopsis

Abstract

1,4,7‐Trithiacyclononane ([9]aneS~3~) reacts with molecular diiodine in CH~2~Cl~2~ to form a 1:1 adduct. The formation constant and the thermodynamic parameters of this adduct have been determined by UV‐visible spectra of several solutions at the temperatures of 15, 20, 25, 30, and 35°C. The ^13^C NMR spectra show that adducts with higher ligand/diiodine molar ratios are formed. Two neutral charge‐transfer molecular compounds having formula 2[9]aneS~3~ · 4I~2~ (I) and [9]aneS~3~ · 3I~2~ · (II) have been obtained as crystals. The crystals of I are triclinic (a = 8.498(2) Å, b = 13.984(4) Å, c = 14.898(6) Å, α = 65.57(2)°, γ = 89.19(2)°, γ = 81.26(2)°, Z = 2, space group P1; R = 0.025) and contain units formed by two [9]aneS~3~ molecules connected by a diiodine molecule; one [9]aneS~3~ binds two other diiodine molecules, while the second binds only one other diiodine molecule. The crystals of II are monoclinic (a = 13.810(2) Å, b = 9.829(4) Å, c = 16.198(6) Å, β = 113.41(2)°, Z = 4, space group P2~1~/c; R = 0.019) and contain molecules of [9]aneS~3~ binding three diiodine molecules. FT‐Raman spectra in the characteristic v(I–I) region, carried out on the solid adducts, are discussed in comparison with the structural parameters.