Chemistry of Heterocyclic 2-Thiones: In Situ Generation of 3-(2-Thiazolin-2-yl)thiazolidine-2-thione and 1,1'- Dimethyl-2,2'-diimidazolyl Sulfide and Their Coordination to Cu~I and Cu~(II)

摘要

The chemical reactivity of copper(I) chloride/copper(I) bromide, [Cu~I(NCCH_3)_4](BF_4), and copper(II) nitrate towards a series of heterocyclic-2-thiones under aerobic conditions is described. Thiazolidine-2-thione (NC_3H_5S_2) inCH_3CN in the presence of copper(I) chloride/bromide and [Cu~I(NCCH_3)_4]- (BF_4) was transformed into 3-(2-thiazolin-2-yl)thiazolidine-2- thione (C_3H_4S_2N-C_3H_4SN) through C-S bond cleavage and the formation of a C-N bond between two heterocyclic rings. This new thio ligand (C_3H_4S_2N-C_3H_4SN) chelates to Cu~I through N,S-donor atoms, and the third site is occupied by the halogen atoms (Cl, Br), which leads to the formation of three-coordinate Cu~I complexes, [Cu~IX(κ~2-N,S-C_3H_4S_2NC_3H_4SN)] [X = Cl (1), Br (2)], and a four-coordinate N,S-chelated complex, [Cu~I(κ~2-N,S-C_3H_4S_2N-C_3H_4SN)_2](BF_4) (3), is obtained in the presence of BF_4-. In each case, the formation of CuSO_4?5H_2O was also observed. Upon reaction of 1-methylimidazoline-2-thione (N_2C_4H_6S) with [Cu~I(NCCH_3)_4](BF_4) or copper(II) nitrate in CH_3CN or CH_3CN/MeOH, respectively, the thio ligand is converted into 1,1'-dimethyl-2,2'-diimidazolyl sulfide (N_2C_4H_5)_2S (a thioether), which prefers to bind to Cu~(II) (in situ formed) to yield six-coordinate N,N-chelated octahedral complexes, namely, {Cu~(II)[κ~2-N,N-(N_2C_4H_5)_2- S]_2(κ~1-OH_2)_2}X_2 [X = BF_4 (6), NO_3 (7)], with water in the axial positions. The transformation of the thio ligand into 1,1'-dimethyl- 2,2'-diimidazolyl sulfide is also observed in its copper(I) chloride reaction in acetonitrile, which yields an N,Nchelated chloro-bridged dimer, {Cu_2~(II) [κ~2-N,N-(N_2C_4H_5)_2S]_2- (μ-Cl)_2Cl_2} (5). Reaction of copper(I) iodide with thiazolidine- 2-thione and 1-methylimidazolidine-2-thione (N_2C_4H_8S) in acetonitrile yields an iodo-bridged dimer, [Cu_2(κ~1-SNC_3H_5S_2) 4(μ-I)_2] (4), and a novel polymer, [Cu_4(μ_3-I)_2(μ-I)_2(μ- S-N_2C_4H_8S)_2(κ~1-S-N_2C_4H_8S)]_n (8), respectively.