Synthesis, Spectroscopic and Structural Characterization of Novel Diiodine Adducts with the Heterocyclic Thioamides, Thiazolidine-2-thione (tzdtH), Benzothiazole-2-thione (bztzdtH) and Benzimidazole-2-thione (bzimtH)

Abstract

Direct reaction of thiazolidine‐2‐thione (tzdtH), an anti‐thyroidal agent with diiodine in a molar ratio of 1:2 caused the heterolytic cleavage of diiodine and formation of [{(tzdtH)2I+}·I3−·2I2] (1), whereas the reaction of benzothiazole‐2‐thione (bztzdtH) with diiodine in a molar ratio of 1:2 and 1:1 resulted in the formation of the [{(bztzdtH)I2}·I2] (2) and [(bztzdtH)I2] (3) charge‐transfer (c.t.) complexes. In addition, the reaction between benzimidazole‐2‐thione (bzimtH) with diiodine in a molar ratio 1:2 yielded the c.t. complex [{(bzimtH)I2}2·I2·2H2O] (4). All reactions were carried out in dichloromethane. The molecules have been characterized by m.p., elemental analyses, and FT‐Raman, FT‐IR, UV/Vis and 1H NMR spectroscopy. Crystal structures of the named complexes have been determined by X‐ray diffraction at −103 °C (1), 20 °C (2 and 3) and −168 °C (4). The charge‐transfer nature of the bonds of the adducts (1−4) has been verified by the lengthening of the I−I bond lengths as compared to the S−I bond lengths, by the characteristic c.t. bands observed in the UV spectra and by the shifts of frequencies measured for the I−I bond vibration in the FT‐Raman spectra of the complexes. Compound 1 (C3H5NS2I4) is monoclinic with a space group P21/n and a = 9.145(2) Å, b = 13.259(2) Å, c = 10.615(2) Å, β = 106.30(2)°, Z = 4. The complex is ionic, containing an S−I+−S linkage and an I3− counter anion. Compound 2 [C7H5NS2I4, monoclinic, space group P21/n, a = 8.357(2) Å, b = 17.829(4) Å, c = 9.603(2) Å, Z = 4, β = 94.39(3)°] consists of a benzothiazole‐2‐thione ligand bonded with an iodine atom through a sulfur atom. A neutral diiodine molecule is also co‐crystallized. A benzothiazole‐2‐thione ligand is also bonded through its sulfur atom to an iodine atom in molecule 3 [C7H5NS2I2, orthorhombic, space group P212121, a = 4.189(1) Å, b = 9.770(3) Å, c = 27.704(8) Å, Z = 4]. Extended intramolecular N−H···I contacts link the molecules forming a supramolecular assembly. The crystal structure of 4 (C7H6N2SI3·H2O) reveals a monoclinic space group P21/c and a = 13.4828(14) Å, b = 4.6704(4) Å, c = 21.267(2) Å, β = 101.029(8)°, Z = 4. It consists of a benzimidazole‐2‐thione ligand bonded to an iodine atom through a sulfur atom. An extended intramolecular linkage via I(2)···H(4)[C(4)] leads to the formation of dimers, while an extended hydrogen‐bonding network {H(12w)[O(12)w]···N(3), O(1w)···N(3)} links the alternate parallel dimers forming a supramolecular assembly. Attempts to draw conclusions on the behavior of a thione, when used as an anti‐thyroidal agent, towards diiodine have been made. (© Wiley‐VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)

Hypervalent Adducts of Chalcogen-Containing peri-Substituted Naphthalenes; Reactions of Sulfur, Selenium, and Tellurium with Dihalogens

“…15,22 Ionic compounds, often accompanied by counteranions of polyhalides adopting unusual and sometimes complex structures are also known. 15,22,24,25,26,27,28,29,30,31,32,33 The neutral charge-transfer (C.-T.) "spoke" adduct (R 2 E-X-Y, 8-E-3) and the "seesaw" (X-ER 2 -Y, 10-E-4) insertion adduct, characteristic of quasi-linear hypervalent E-X-Y 15,22,28,34,35 and X-E-Y 14,15,22,28,31,36,37 fragments respectively are the most common structural motifs generated from the reaction of diorganochalcogen-donors [R 2 E] with inter-or dihalogens.…”

Investigation of the reaction of 1-methylimidazoline-2-thione with molecular iodine

“…. (5) The corresponding logarithms of the stability con stants of the diiodide dication are 3.64 and 9.16. The coordinating ability of compound 2 to molecular iodine was estimated for the first time.…”

“…4 The reaction of thiazolidine 2 thione with molecu lar iodine in a ratio of 1 : 2 affords the polyiodide [(C 3 H 5 NS 2 ) 2 I + ]•I 3 -•2I 2 as a result of heterolytic dispro portionation of the iodine molecule. 5 The structure con tains the linear S-I + -S fragment, the I 3 -counterion, and two independent iodine molecules.…”

Solvent mediated reaction of 1-methyl-1H-tetrazoline-5-thione with iodine

“…These compounds have anti-inflammatory, antilipemic, antimicrobial, and antiallergic activities [1]. Moreover, such compounds possess anti-thyroidal effect same N-methylimidazoline-2-thione (methimazole) or 3-methyl-2-thioxo-4-imidazoline-1-ethylcarboxylate (carbimazole) [2].…”