Abstract
A reaction of copper(II) carbonate and potassium 4-sulfo-benzoic acid in water acidified with hydro-chloric acid yielded two crystalline products. Tetra-aqua-bis-(4-carb-oxy-benzene-sulfonato)-copper(II) dihydrate, [Cu(O3SC6H4CO2H)2(H2O)4]·2H2O, (I), crystallizes in the triclinic space group P with the Cu2+ ions located on centers of inversion. Each copper ion is coordinated to four water mol-ecules in a square plane with two sulfonate O atoms in the apical positions of a Jahn-Teller-distorted octa-hedron. The carboxyl-ate group is protonated and not involved in coordination to the metal ions. The complexes pack so as to create a layered structure with alternating inorganic and organic domains. The packing is reinforced by several O-H⋯O hydrogen bonds involving coordinated and non-coordinated water mol-ecules, the carb-oxy-lic acid group and the sulfonate group. Hexa-aqua-copper(II) 4-carb-oxy-benzene-sulfonate, [Cu(H2O)6](O3SC6H4CO2H)2, (II), also crystallizes in the triclinic space group P with Jahn-Teller-distorted octa-hedral copper(II) aqua complexes on the centers of inversion. As in (I), the carboxyl-ate group on the anion is protonated and the structure consists of alternating layers of inorganic cations and organic anions linked by O-H⋯O hydrogen bonds. A reaction of silver nitrate and potassium 4-sulfo-benzoic acid in water also resulted in two distinct products that have been structurally characterized. An anhydrous silver potassium 4-carb-oxy-benzene-sulfonate salt, [Ag0.69K0.31](O3SC6H4CO2H), (III), crystallizes in the monoclinic space group C2/c. There are two independent metal sites, one fully occupied by silver ions and the other showing a 62% K+/38% Ag+ (fixed) ratio, refined in two slightly different positions. The coordination environments of the metal ions are composed primarily of sulfonate O atoms, with some participation by the non-protonated carboxyl-ate O atoms in the disordered site. As in the copper compounds, the cations and anions cleanly segregate into alternating layers. A hydrated mixed silver potassium 4-carb-oxy-benzene-sulfonate salt dihydrate, [Ag0.20K0.80](O3SC6H4CO2H)·2H2O, (IV), crystallizes in the monoclinic space group P21/c with the Ag+ and K+ ions sharing one unique metal site coordinated by two water mol-ecules and six sulfonate O atoms. The packing in (IV) follows the dominant motif of alternating inorganic and organic layers. The protonated carboxyl-ate groups do not inter-act with the cations directly, but do participate in hydrogen bonds with the coordinated water mol-ecules. (IV) is isostructural with pure potassium 4-sulfo-benzoic acid dihydrate.
Highlights
The aqueous reaction of copper(II) carbonate, potassium 4-sulfobenzoic acid, and hydrochloric acid produced two copper-containing products
Two sulfonate O atoms at 2.3934 (8) Aoccupy the apical positions to complete a classic Jahn–Teller-distorted octahedral coordination of the copper ion. This type of bis(sulfanato)copper(II) complex with the sulfonate ligands in the more distant apical position has been reported by Cai et al (2001) with Cu—O distances ca 0.1–0.4 Alonger than the Cu1—O4 distance in (I)
Colorless needle-shaped crystals were identified as Ag0.69K0.31(O3SC6H4CO2H), (III), an anhydrous mixed silver/potassium salt of 4-sulfobenzoic acid
Summary
The aqueous reaction of copper(II) carbonate, potassium 4-sulfobenzoic acid, and hydrochloric acid produced two copper-containing products. The second product of the silver reaction crystallizes as colorless hexagonal plates determined to be Ag0.20K0.80(O3SC6H4CO2H)Á2H2O, (IV) This compound is isostructural with K(O3SC6H4CO2H)Á2H2O, one of the polymorphs of the starting material potassium 4-sulfobenzoic acid whose structure has been reported (Gunderman & Squattrito, 1994; Kariuki & Jones, 1995). The unique cation site was modeled as disordered with Ag+ and K+ present at occupancies fixed at 20% and 80%, respectively This composition is supported by EDX analysis of the data crystal. Symmetryequivalent water molecules and sulfonate oxygen atoms are included to show the complete coordination environment of the cation. In silver potassium 5-sulfosalicylic acid, the Ag+and K+ ions occupy separate sites in the structure with very different coordination environments and no indication of mixed-occupancy (Li et al, 2006). All of the oxygen-bound H atoms participate in strong approximately linear O—HÁ Á ÁO hydrogen bonds to the unprotonated sulfonate and carboxylate O atoms or in the case of the carboxylic H atom to a coordinated water O atom (Table 2)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Acta crystallographica. Section E, Crystallographic communications
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
