Hydrogen-Bonding Networks in Heterocyclic Thioureas

Synthesis and structural characterization of novel 2-benzimidazolylthioureas: adducts of natural isothiocyanates and 2-amino-1-methylbenzimidazole

“…The yields (42-63%) are the mean values of at least three experiments and correspond to the amounts of products isolated following chromatographic purification. Although the target thioureas 2 were obtained only in moderate yields, these results are quite similar to those achieved during aminolysis of aliphatic ITC with various 2-amino substituted nitrogen heterocycles [4,16]. The reason why the reaction tends to stop at moderate conversion even after a prolonged reaction time ([3 days) is not understood at the present time.…”

“…The thiocarbonyl C=S chemical shift of 184.7 ppm (the same for all 2) is different from that of other unsymmetrical thioureas containing alkyl and heteroaryl residues (d = 176-181 ppm) [4,16]. This extra deshielding is caused by the partial ionic character of the C=S bond (vide infra the observed C-S bond length in crystal).…”

Structural studies and biological activity evaluation of Pd(II), Pt(II) and Ru(II) complexes containing N‐phenyl, N`‐(3‐triazolyl)thiourea

“…The disappearance of C = S signal in the 13 C NMR analysis and the triazole ‐ exo‐NH in the 1 H NMR (Figure S4) reveal the enolization of the ‐NH‐C = S‐ group. The liberation of the phenyl‐NH group from the well‐known H‐bond interaction in thiourea derivatives upon the complex formation results in the up‐field shift of the NH signal.…”

Copper(I) complexes of heterocyclic thiourea ligands

“…Microanalyses for C, H, and N were carried out by Atlantic Microlab, Inc., Norcross,GA. HetTu ligands, (1), N-(2-pyridyl)-N´-methylthiourea (2), N- (3-pyridyl)- N´-phenylthiourea (3), N-(3-pyridyl)-N´-methylthiourea (4), N- (4-pyridyl)- N´-phenylthiourea (5), N-(2-pyrimidyl)-N´-phenylthiourea (6), N-(2-pyrimidyl)-N´-methylthiourea (7), N-(2-thiazolyl)-N´-methylthiourea (8), N-(2-benzothiazolyl)-N´-methylthiourea (9), N,N´-bis (2-pyridyl)thiourea (10) and N,N´-bis (3pyridyl)thiourea (11), were synthesized as previously described [6]. Copper(I) chloride and bromide were freshly recrystallized from aqueous HCl or HBr.…”

“…In the following study we have examined the network-forming behavior of thiourea ligands bearing nitrogen heterocycle groups with copper(I) halides and nitrate. The heterocyclic thiourea molecules (HetTu) 1-11 shown in Chart 2 are themselves network-formers through hydrogen-bonding [6]. It was expected that they would show a variety of bridging behaviors involving the sulfur (monodentate or SAB) and nitrogen centers, leading to network formation.…”