Tetraaquabis(thiourea-κS)cadmium(II) triaquatris(thiourea-κS)cadmium(II) disulfate

Abstract

The title compound, [Cd(CH4N2S)2(H2O)4][Cd(CH4N2S)3(H2O)3](SO4)2, contains two mol­ecules of each of the Cd complexes and four sulfate ions in the asymmetric unit: all the Cd atoms exhibit distorted octa­hedral geometries. The Cd—S and Cd—O bond lengths around the Cd atoms in the bis­(thio­urea) cations are in the ranges 2.580 (4)–2.599 (4) and 2.323 (8)–2.421 (9) Å, respectively, and the S atoms are in a cis orientation. In the tris­(thio­urea) cations, the corresponding bond lengths around the Cd atoms are slightly longer and are in the ranges 2.559 (4)–2.706 (3) and 2.303 (7)–2.480 (10) Å, respectively, and the S atoms are in a fac disposition. The crystal structure features numerous N—H⋯O, N—H⋯N, O—H⋯O and O—H⋯N hydrogen bonds. Two O atoms of a sulfate anion were found to be disordered over two orientations in a 0.620 (9):0.380 (9) ratio. The crystal studied was a racemic twin with BASF = 0.17 (5)

Cadmium(II) Complex Formation with Selenourea and Thiourea in Solution: An XAS and 113Cd NMR Study

“…The crystal structure of a hydrated cadmium thiourea sulfate showed both cis -[Cd(TU) 2 (H 2 O) 4 ](SO 4 ) and fac -[Cd(TU) 3 (H 2 O) 3 ](SO 4 ) complexes co-crystallized in the unit cell, with the mean Cd-S (Cd-O) bond distances 2.59 (2.37) Å and 2.62 (2.41) Å, respectively. 52 A mean Cd-S distance of 2.53 ± 0.02 Å is expected for a [Cd(TU) 4 ] 2+ complex from EXAFS, as obtained for the solid [Cd(TU) 4 ](NO 3 ) 2 compound (Table 5 and Figure S-7). …”

“…We are unable to ascertain the degree of hydration m in the [Cd(TU) 3 (H 2 O) m ] 2+ complex, which is a minor species in solution according to the stability constants (Figure S-1), but propose that the [Cd(TU) 3 (H 2 O) 3 ] 2+ complex is formed, as in the crystal structure. 52 …”

“…We are unable to ascertain the degree of hydration m in the [Cd(TU) 3 (H 2 O) m ] 2+ complex, which is a minor species in solution according to the stability constants (Figure S-1), but we propose that the [Cd(TU) 3 (H 2 O) 3 ] 2+ complex is formed, as in the crystal structure. 52 Comparison between Cd(II) Complex Formation with Selenourea and Thiourea in MeOH at ∼200 K. The 113 Cd NMR spectra of 0.1 mol dm −3 Cd(CF 3 SO 3 ) 2 solutions (Figure 1) in methanol containing 0.1−0.3 mol dm −3 selenourea (S1− S3) or thiourea (T1−T3) at 203 K show similar peaks in the 93−97 ppm and 189−194 ppm range, which were assigned to complexes with Cd(Se/S)O 5 and Cd(Se/S) 2 O 4 coordination geometries, respectively. In this case the chemical shifts are very similar when one or two S/Se-donor ligands replace the Odonor ligands (methanol and CF 3 SO 3 − in the current case), in contrast to the generally observed trend with decreasing shielding of donor atoms in the following order: O ≫ Se > S. 43 Also, the formation constants for the CdL 2+ and CdL 2 2+ species are virtually the same for the SeU and TU systems, while Cd(SeU) 3 2+ and Cd(SeU) 4 2+ are more stable than the corresponding Cd(TU) 3 2+ and Cd(TU) 4 2+ complexes.…”

2D polymeric cadmium(II) complexes containing 1,3-imidazolidine-2-thione (Imt) ligand, [Cd(Imt)(H 2 O) 2 (SO 4 )] n and [Cd(Imt) 2 (N 3 ) 2 ] n

“…In some cases, polymeric species are formed through bridging sulfur or nitrogen atoms [21,[24][25][26][27][28][29], e.g., [Cd(Metu) 2 (SCN) 2 ] n [24] and [Cd(Imt) 2 (SCN) 2 ] n [25]. [31]. The complexes with a Cd:thione ratio of 1:4 may be ionic or nonionic.…”

Synthesis and characterization of cadmium(II)-imprinted poly(1-allyl-2-thiourea-co-ethylene glycol dimethacrylate) particles for selective separation

“…The results revealed that the highest binding capacity was observed for imprinted polymer, which was produced from 1-allyl-2-thiourea (M4) ( Table 2). Based on the literature data [18][19][20], we could suppose that 1-allyl-2-thiourea (M4), the monomer which possesses thiocarbonyl group, can strongly interact with cadmium(II) ions. The interactions between thiourea and cadmium(II) ions by X-ray diffraction method [18] as well as the properties of triallylthiourea cadmium chloride crystals by infrared spectroscopy and thermogravimetry were investigated [19,20].…”