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We prepared and characterized a high-t tetragonal polymorph of diamminesilver(I) sulfate (a = 8.6004(4) Å, c = 6.2123(6) Å) (compound 1-HT). The phase transformation of the low-temperature polymorph of diamminesilver(I) sulfate (compound 1-LT) into the high-temperature polymorph (compound 1-HT) partly coincides with the initial stage of the thermal decomposition of 1-LT. Selecting appropriate conditions, we separated the two processes and determined the standard heat of formation of the LT polymorph (ΔH298 = −1208.92 kJ/mol) and the enthalpy of polymorphic transformation (ΔHLT→HT = 13.18 kJ/mol). The high-temperature XRD results showed that the lattice constants of the LT polymorph (1-LT) extend in the direction of a, b, and compress in the direction of c in the 1-HT polymorph. According to high temperature SXRD data, the Ag–Ag distance (in the direction of c) shortens from 3.20 Å (1-LT) to 3.11 Å (1-HT), while the extension in the a,b direction weakens/disrupts the N-H...O-S hydrogen bonds and the coordinative Ag...O-S interactions. The IR and Raman spectroscopic data confirm the weakening/breaking of N-H...O-S hydrogen bonds. A vacuum-assisted thermal deammoniation experiment of 1-LT in the preparation of monoamminesilver(I) sulfate showed that the product is the mixture of silver(I) sulfate and the initial diamminesilver(I) sulfate complex. [ABSTRACT FROM AUTHOR]

[Hg2(L1)2I4] (1), [Cd2(L1)2I4] (2), {[Cd(L1)2(SO4)(H2O)]·4H2O}n(3), {[Zn2(L2)2(Cl)4]·0.5H2O} (4), {[Cu2(L2)2(SO4)2(H2O)4]·2.5H2O} (5), and {[Cd(L2)2(SO4)(H2O)]·3H2O}n(6), based on N–(3–picolyl)–N′–(3–pyridyl)urea (L1) or N–(4–picolyl)–N′–(3–pyridyl)urea (L2), have been synthesized and characterized by elemental analyses, IR spectra, single-crystal and powder X-ray diffraction, and thermogravimetric analyses. Complexes1and2are isomorphous and feature similar rectangular metal organic loops, which were further extended into 2-D supramolecular structures through hydrogen bonds. Complex3possesses a 2-Dsqlsheet, and the channels between the neighboring sheets are filled with lattice water molecules, which formed a 1-D water tape. Complex4also exhibits a rectangular metal organic loop and a 3-D supramolecular structure with the help of hydrogen bonding interactions. Complex5also possesses a metal organic loop, and the water molecules interacted with sulfates, constructing a 1-D water–sulfate tube. Complex6features a 1-D loop polymeric chain. Moreover, the solid state luminescences of1–4and6have been investigated. [ABSTRACT FROM AUTHOR]

Two new complexes, {[Zn(imb)(SO4)]·H2O}n(1) and {[Cd2(imb)2(SO4)2(H2O)]·CH3OH}n(2) (imb?=?2-(1H-imidazol-1-methyl)-1H-benzimidazole), have been solvothermally synthesized. Single-crystal X-ray diffraction shows that1displays a 2-D (4,4) network, which is further extended to a 3-D supramolecular structure by hydrogen bonding interactions. Complex2exhibits a 3-D framework with (3,5)-connected (42·6)2(42·65·83)2topology. The results indicate that changing metal ions can influence the coordination modes of sulfate, and then affect the structures of the complexes. In addition, IR and UV–vis spectra, powder X-ray diffraction patterns, thermogravimetric analyses, and fluorescent properties of both complexes have been investigated. Two new complexes, {[Zn(imb)(SO4)]·H2O}n(1) and {[Cd2(imb)2(SO4)2(H2O)]·CH3OH}n(2), have been synthesized and characterized by single crystal X-ray diffraction. Additionally, their UV–vis, IR, Thermogravimetric analyses and fluorescent properties are also investigated. [ABSTRACT FROM AUTHOR]

Zinc and cadmium sulfate and nitrate complexes with hexamethylenetetramine, [Zn(hmta)2(H2O)4]2+·[Zn(H2O)6]2+··6H2O (1),·n·2nH2O (2), [Zn(H2O)6]2+·2(hmta)··4H2O (3) and [Cd(hmta)(NO3)2(H2O)2]n(4), have been synthesized and characterized by elemental and thermal analysis, IR spectroscopy, and X-ray crystallography. [ABSTRACT FROM AUTHOR]

The liquid-liquid extraction of copper(II) with Schiff bases in chloroform from sulfate media is studied for pH and concentration of the extractant. Stoichiometry coefficients of the extracted species are determined by the slope analysis method. With salicylideneaniline, the copper(II) is extracted as a mixed chelate complex, CuL2HL. In the presence of substituent, the copper is extracted as simple chelates, CuL2. The trends in the values of extraction constants were explained in terms of the nature of the substituents. [ABSTRACT FROM AUTHOR]

The synergistic solvent extraction of copper(II) from 0.33 mol dm-3 Na2SO4 aqueous solutions with capric acid (HL) in the absence and presence of tri-n-octylphosphine oxide (TOPO) in chloroform at 25°C has been studied. The extracted species when capric acid was used alone is CuL2(HL)2. In the presence of TOPO, the extracted complex is CuL2(HL)2(TOPO). The TOPO-HL interaction strongly influences the synergistic extraction efficiency. The extraction constants were calculated. [ABSTRACT FROM AUTHOR]

We have synthesized furan-based vanadium complexes, bis(5-nitrofuran-2-carboxylato)oxovanadium(IV) - [VO(5NF)2], bis(1-furan-2-yl-ethanonato)oxovanadium(IV) sulfate - [VO(2AF)2]SO4, and bis(5-methyl-2-furalato)oxovanadium(IV) sulfate - [VO(MFFA)2]SO4 possessing [VO(O4)] coordination mode. These complexes are characterized by physico-chemical and spectroscopic methods. Based on electron paramagnetic resonance parameters, the proposed geometry is close to a distorted square pyramid. Animal study was carried out using standard protocol and the complete profile of glucose, protein, and total cholesterol levels were analyzed followed by an oral glucose tolerance test. [ABSTRACT FROM AUTHOR]

Solvent extraction of copper(II) from sulfate medium with N-(2-hydroxybenzylidene)aniline is studied with the following parameters: pH, concentration of the extractant, nature of diluent, and temperature. The extraction of copper(II) proceeds by a cation exchange mechanism and the extracted species are CuL2 in cyclohexane and toluene and CuL2 with some CuL2HL in chloroform. The equilibrium constants have been calculated as well as thermodynamic parameters ΔH°, ΔS°, and ΔG°. The temperature effect on the solvent extraction of copper(II) with N-(2-hydroxybenzylidene)aniline in cyclohexane is discussed. [ABSTRACT FROM AUTHOR]

A new chelate ligand, 5-methyl-1H-pyrazole-3-carboxylic acid (mpca), has been synthesized. This ligand reacts with cupric sulfate to give two supramolecular compounds [Cu(mpca)2(H2O)] · 3H2O (1) and [Cu2(mpca)2(pyr)4] (Pyr = pyridine) (2), which were characterized by elemental analysis and X-ray crystal diffraction. Helical water chain and strong π-π interaction are important for the stability of the 3-D structure of these supramolecules. [ABSTRACT FROM AUTHOR]

A new lanthanide complex K[Gd(ox)(SO4)(H2O)] (1) with sulfate and oxalate ligands has been synthesized under hydrothermal conditions. The compound crystallizes in the monoclinic space group P21/c with a = 6.5849(1) Å, b = 8.5660(1) Å, c = 14.7660(2) Å, β = 112.470(1)°, C2H2GdKO9S, M = 398.46, Z = 4, V = 769.66(2) Å3, F(000) = 740, R1 = 0.0199 and ωR = 0.0514. The solid-state DC magnetic susceptibility measurements of 1 revealed antiferromagnetic behavior with an S = 7/2 ground spin state. [ABSTRACT FROM AUTHOR]

The liquid-liquid extraction of copper(II) from sulfate medium with di(2-ethylhexyl)phosphoric acid (D2EHPA, HL) at 25°C is studied with the following parameters: pH, concentration of the extractant, and the nature of diluent. The effect of the diluent using polar and nonpolar solvents in the extraction of copper(II) is discussed. The extracted copper(II) species were CuL2 in 1-octanol and methyl isobutyl ketone and CuL2 · 2HL in toluene, carbon tetrachloride, and cyclohexane. The extraction constants are evaluated for different diluents. [ABSTRACT FROM AUTHOR]

Two new complexes, [Zn(phen) 2 (H 2 O) 2 ]2L·H 2 O ( 1 ) and [Cu(phen)(L)(H 2 O) 2 ]L·3H 2 O ( 2 ), where HL = 4-aminobenzenesulfonic acid and phen = o -phenanthroline, have been synthesized and their crystal structures determined by X-ray diffraction. In the complexes the Cu(II) and Zn(II) atoms revealed two different coordination environments. Complex 1 consists of a cation [Zn(phen) 2 (H 2 O) 2 ] 2+ , in which Zn(II) is six-coordinated by four nitrogen atoms from two o -phenanthroline molecules and by two water molecules. Complex 2 has two crystallographically unique Cu(II) ions, where Cu(II) ion is five-coordinate with two nitrogen atoms of o -phenanthroline, two water molecules and one sulfonate oxygen atom. The electrochemical behavior and FT-IR of the two compounds have also been studied in detail. [ABSTRACT FROM AUTHOR]

The preparation, spectroscopic, magnetic properties and crystal structure of [Cu(en) 2 (OH 2 ) 2 ][stz] 2 ·2H 2 O (en = ethylenediamine; stz stands for the deprotonated form of sulfathiazole, 4-amino-N-2-thiazolylbenzenosulfonamide) are reported. The complex crystallizes in the triclinic system, space group P1, with cell constants a = 8.321(1) Å, b = 7.441(1) Å, c = 13.627(3) Å, α = 86.02(1)°, β = 101.81(1)°, γ = 97.88(1)° and Z = 1. The metal ion is six coordinate by four N atoms of two ethylenediamine ligands in the basal plane and two O atoms of two water molecules in the axial positions. The stereochemistry of the metal center is irregular and can be considered a distorted octahedron. Two deprotonated sulfathiazole molecules are present in the complex and a center of symmetry is located at the copper(II) ion. This is the first crystallographic evidence of sulfathiazole acting as a counter ion. The susceptibility of certain strains of bacterium towards the complex was measured, it shows good antibacterial activity against Salmonella typhimurium strain. [ABSTRACT FROM AUTHOR]