Carbohydrate metal ion complexes. Interaction of D-glucono-1,5-lactone with Zn(II), Cd(II), and Hg(II) ions in the solid and aqueous solution, studied by 13C-NMR, FT-IR, and X-ray powder diffraction measurements

1989 ◽  
Vol 67 (4) ◽  
pp. 651-654 ◽  
Author(s):  
H. A. Tajmir-Riahi
Keyword(s):  
Aqueous Solution ◽  
Metal Ions ◽  
Powder Diffraction ◽  
Metal Ion ◽  
Binding Mode ◽  
X Ray ◽  
Group Metal ◽  
Carboxylate Oxygen ◽  
Ft Ir ◽  
C Nmr

D-Glucono-1,5-lactone interaction with zinc group metal ions has been studied in aqueous solution and solid salts of the type Zn(D-gluconate)2.2H2O, Cd(D-gluconate)2 and Hg(D-gluconate)2 have been isolated. These metal sugar salts were characterized by elemental analysis, 13C-NMR, FT-IR spectroscopy, and X-ray powder diffraction measurements.X-ray powder diffraction diagrams and other spectroscopic evidence showed that Zn(D-gluconate)2.2H2O is isomorphous with the structurally identified Mn(D-gluconate)2.2H2O, suggesting a similar metal–sugar binding mode, through a carboxylate oxygen atom (O-1) and an OH group of the two sugars anions as well as to two H2O molecules, resulting in a six-coordinate Zn(II) ion. The Cd(II)- and Hg-D-gluconate salts are not similar and show dissimilarities to the Zn(II) compound. The Cd(II) ion binds to two D-gluconate anions possibly through the carboxylate O-1 and sugar O(2)—H, and O(3)—H groups of each anion, giving a six-coordinate Cd(II) ion. The Hg(II) ion is possibly four-coordinate, binding to two sugar anions via a carboxylate O-1 and O(2)—H groups of each D-gluconate anion. The zinc group metal-D-gluconate salts are aggregated through bridging sugar OCO− groups with sugar anion possibly having bent-chain conformation. Keywords: carbohydrate, metal ions, 13C-NMR, FT-IR, X-ray powder diffraction.

Conformational changes in serine on methylmercury complexation

1988 ◽  
Vol 66 (6) ◽  
pp. 1379-1385 ◽  
Author(s):  
Marie-Claude Corbeil ◽  
André L. Beauchamp
Keyword(s):  
Aqueous Solution ◽  
Conformational Changes ◽  
Hydroxyl Group ◽  
Side Chain ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carboxylate Oxygen ◽  
Zwitterionic Complex ◽  
Ligand Conformation ◽  
C Nmr

The CH3Hg+ cation forms a zwitterionic complex CH3Hg[HOCH2CH(NH2)CO2—N,O,O] with serine in aqueous solution. X-ray diffraction (P212121, a = 5.821, b = 8.052, c = 14.307 Å, R = 0.021) shows that mercury is linearly bonded to the NH2 end of the amino acid, whereas one carboxylate oxygen and the side-chain hydroxyl group establish secondary Hg—O bonds. Coordination leads to characteristic changes in the infrared and Raman spectra of serine. From the 1H and 13C nmr spectra, N-coordination is found to be retained in aqueous solution, whereas the ligand conformation observed in the solid accounts for 76% of the conformer distribution.

Sugar Interaction with Metals in Aqueous Solution: Indirect Determination from Infrared and Direct Determination from Nuclear Magnetic Resonance Spectroscopy

2003 ◽  
Vol 57 (4) ◽  
pp. 466-472 ◽  
Author(s):  
Philippe Rondeau ◽  
Sandrine Sers ◽  
Dhanjay Jhurry ◽  
Frederic Cadet
Keyword(s):  
Aqueous Solution ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Metal Ion ◽  
Direct Determination ◽  
Resonance Spectroscopy ◽  
Absorption Bands ◽  
Ft Ir ◽  
C Nmr ◽  
Nuclear Magnetic

In this article, mid-infrared Fourier transform (Mid-FT-IR) and carbon thirteen nuclear magnetic resonance (13C NMR) spectroscopy have been used to determine possible interactions between sucrose and various alkali or alkaline earth metals in aqueous solution. In the presence of these metals, significant shifts in the absorption bands of sucrose were noted by mid-FT-IR coupled with principal component analysis (PCA). These shifts were explained on the basis of weakening of the H-bond network between sucrose and water and possible interactions between sucrose and the metal ion. Factorial maps were established and the spectral patterns obtained show that these interactions vary according to the nature of the metal ion. 13C NMR analysis showed that the carbon atoms of sucrose undergo shielding or deshielding in the presence of metal ions in aqueous solutions. Two factors were invoked to account for the variation of chemical shifts: the rupture of hydrogen bonds due to hydration of the metal ion and the possible coordination of the metal ion to the oxygen atoms of sucrose.

scholarly journals Structures of dipotassium rubidium citrate monohydrate, K2RbC6H5O7(H2O), and potassium dirubidium citrate monohydrate, KRb2C6H5O7(H2O), from laboratory X-ray powder diffraction data and DFT calculations

2020 ◽  
Vol 76 (10) ◽  
pp. 1566-1571
Author(s):  
Andrew J. Cigler ◽  
James A. Kaduk
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Metal Ion ◽  
Density Functional ◽  
Three Dimensional ◽  
Hydroxyl Group ◽  
Powder Diffraction Data ◽  
Coordination Polyhedra ◽  
X Ray ◽  
Carboxylate Oxygen

The crystal structures of the isostructural compounds dipotassium rubidium citrate monohydrate, K2RbC6H5O7(H2O), and potassium dirubidium citrate monohydrate, KRb2C6H5O7(H2O), have been solved and refined using laboratory X-ray powder diffraction data, and optimized using density functional techniques. The compounds are isostructural to K3C6H5O7(H2O) and Rb3C6H5O7(H2O), but exhibit different degrees of ordering of the K and Rb cations over the three metal-ion sites. The K and Rb site occupancies correlate well to both the bond-valence sums and the DFT energies of ordered cation systems. The MO6 and MO7 coordination polyhedra share edges to form a three-dimensional framework. The water molecule acts as a donor in two strong charge-assisted O—H...O hydrogen bonds to carboxylate groups. The hydroxyl group of the citrate anion forms an intramolecular hydrogen bond to one of the central carboxylate oxygen atoms.

Preparation and adsorption properties of dialdehyde 8-aminoquinoline starch

2013 ◽  
Vol 67 (2) ◽  
pp. 306-310 ◽  
Author(s):  
Wen Ding ◽  
Shen-yong Zhai ◽  
Jun-tao liu ◽  
Rou Wang ◽  
Rong Li
Keyword(s):  
Aqueous Solution ◽  
Heavy Metal ◽  
Metal Ions ◽  
Industrial Waste ◽  
Heavy Metal Ions ◽  
Adsorption Properties ◽  
X Ray Diffraction ◽  
Dialdehyde Starch ◽  
X Ray ◽  
Ft Ir

Dialdehyde 8-aminoquinoline starch (DASQA) was synthesized by the reaction of dialdehyde starch (DAS) and 8-aminoquinoline and was used to adsorb various ions from aqueous solution. DASQA was characterized by Fourier transform infrared (FT-IR) spectra, thermogravimetric analysis, X-ray diffraction analysis. The adsorption properties of the polymer for Pb2+, Cu2+, Cd2+, Ni2+, and Zn2+ were investigated. The result of the experiment reveals that the adsorption for Cd2+ and Zn2+were approximately 2.51 mmol/g, 2.17 mmol/g, followed by Pb2+ 1.93 mmol/g, Ni2+ 1.66 mmol/g, Cu2+ 1.19 mmol/g. Furthermore, the kinetic experiments indicated that the adsorption of DASQA for the above metal ions achieved equilibrium within 2 h. Therefore, DASQA is an effective adsorbent for the removal of different heavy metal ions from industrial waste solutions.

Structure of the Solvated Strontium and Barium Ions in Aqueous, Dimethyl Sulfoxide and Pyridine Solution, and Crystal Structure of Strontium and Barium Hydroxide Octahydrate

1995 ◽  
Vol 50 (1) ◽  
pp. 21-37 ◽  
Author(s):  
Ingmar Persson ◽  
Magnus Sandström ◽  
Haruhiko Yokoyama
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Metal Ions ◽  
Dimethyl Sulfoxide ◽  
Metal Ion ◽  
Water Molecules ◽  
Barium Ions ◽  
X Ray ◽  
Pyridine Solution ◽  
Oxygen Atoms

Single crystal X-ray data, collected at 298 K, are used to redetermine the crystal structure of the non-isomorphic compounds [Sr(H2O)8](OH)2 and [Ba(H2O)8](OH)2. The eight water oxygen atoms form distorted Archimedean antiprisms around the octahydrated metal ions with mean metal ion-oxygen distances 2.62 and 2.79 Å for strontium and barium, respectively. A second coordination shell of 24 hydrogen-bonded oxygen atoms with mean metal ion-oxygen distances M…OII 4.76 and 4.80 Å, respectively, is observed. The hydroxide ions in both structures have an unusual hydrogen bond arrangement with 5 bonds accepted and one donated.The structure of the solvated strontium and barium ions in aqueous, dimethyl sulfoxide and pyridine solutions has been studied by means of large angle X-ray scattering and extended X-ray absorption fine structure spectroscopy techniques. In aqueous solution independent determinations of the first-sphere metal-oxygen coordination by the two techniques resulted in the bond lengths Sr-O 2.63 (2) and Ba-O 2.81 (3) Å, and for both metal ions a hydration number of 8.1 (3). The second coordination spheres are very diffuse with only about 13 water molecules at similar M…OII distances as in the crystal structures and 2-3 water molecules closer to the metal ions. In dimethyl sulfoxide solution both ions were found to coordinate 6.0 (5) solvent molecules with the distances Sr-O 2.54(1), Sr…S 3.77(1) Å, and Ba-O 2.76(1), Ba…S 3.99(1) Å. For the solvated ions in pyridine solution EXAFS measurements yielded the distances Sr-N 2.57 (2) and Ba-N 2.78 (3) Å, with a probable solvation number of 6.Correlations of hydration enthalpies and partial molar volumes with experimental M-O bond distances in aqueous solution are used to discuss hydration numbers and bond character for all of the alkaline earth metal ions.

scholarly journals Multidimensional Ln-Aminophthalate Photoluminescent Coordination Polymers

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1786
Author(s):  
Carla Queirós ◽  
Chen Sun ◽  
Ana M. G. Silva ◽  
Baltazar de Castro ◽  
Juan Cabanillas-Gonzalez ◽  
...  
Keyword(s):  
Water Content ◽  
Coordination Polymers ◽  
Metal Ion ◽  
Low Cost ◽  
Microwave Assisted Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wide Range ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

The development of straightforward reproducible methods for the preparation of new photoluminescent coordination polymers (CPs) is an important goal in luminescence and chemical sensing fields. Isophthalic acid derivatives have been reported for a wide range of applications, and in addition to their relatively low cost, have encouraged its use in the preparation of novel lanthanide-based coordination polymers (LnCPs). Considering that the photoluminescent properties of these CPs are highly dependent on the existence of water molecules in the crystal structure, our research efforts are now focused on the preparation of CP with the lowest water content possible, while considering a green chemistry approach. One- and two-dimensional (1D and 2D) LnCPs were prepared from 5-aminoisophthalic acid and Sm3+/Tb3+ using hydrothermal and/or microwave-assisted synthesis. The unprecedented LnCPs were characterized by single-crystal X-ray diffraction (SCRXD), powder X-ray diffraction (PXRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM), and their photoluminescence (PL) properties were studied in the solid state, at room temperature, using the CPs as powders and encapsulated in poly(methyl methacrylate (PMMA) films, envisaging the potential preparation of devices for sensing. The materials revealed interesting PL properties that depend on the dimensionality, metal ion, co-ligand used and water content.

scholarly journals Base-enhanced catalytic water oxidation by a carboxylate–bipyridine Ru(II) complex

2015 ◽  
Vol 112 (16) ◽  
pp. 4935-4940 ◽  
Author(s):  
Na Song ◽  
Javier J. Concepcion ◽  
Robert A. Binstead ◽  
Jennifer A. Rudd ◽  
Aaron K. Vannucci ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Proton Transfer ◽  
Water Oxidation ◽  
Proton Acceptor ◽  
Half Time ◽  
X Ray ◽  
X Ray Crystallography ◽  
Buffer Base ◽  
Electron Proton Transfer ◽  
C Nmr

In aqueous solution above pH 2.4 with 4% (vol/vol) CH3CN, the complex [RuII(bda)(isoq)2] (bda is 2,2′-bipyridine-6,6′-dicarboxylate; isoq is isoquinoline) exists as the open-arm chelate, [RuII(CO2-bpy-CO2−)(isoq)2(NCCH3)], as shown by 1H and 13C-NMR, X-ray crystallography, and pH titrations. Rates of water oxidation with the open-arm chelate are remarkably enhanced by added proton acceptor bases, as measured by cyclic voltammetry (CV). In 1.0 M PO43–, the calculated half-time for water oxidation is ∼7 μs. The key to the rate accelerations with added bases is direct involvement of the buffer base in either atom–proton transfer (APT) or concerted electron–proton transfer (EPT) pathways.

scholarly journals Crystallographic and X-ray absorption spectroscopic characterization of Helicobacter pylori UreE bound to Ni2+ and Zn2+ reveals a role for the disordered C-terminal arm in metal trafficking

2012 ◽  
Vol 441 (3) ◽  
pp. 1017-1035 ◽  
Author(s):  
Katarzyna Banaszak ◽  
Vlad Martin-Diaconescu ◽  
Matteo Bellucci ◽  
Barbara Zambelli ◽  
Wojciech Rypniewski ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Metal Ions ◽  
Metal Binding ◽  
Metal Ion ◽  
Mutual Influence ◽  
Accurate Information ◽  
Metal Ion Binding ◽  
X Ray ◽  
X Ray Absorption

The survival and growth of the pathogen Helicobacter pylori in the gastric acidic environment is ensured by the activity of urease, an enzyme containing two essential Ni2+ ions in the active site. The metallo-chaperone UreE facilitates in vivo Ni2+ insertion into the apoenzyme. Crystals of apo-HpUreE (H. pylori UreE) and its Ni2+- and Zn2+-bound forms were obtained from protein solutions in the absence and presence of the metal ions. The crystal structures of the homodimeric protein, determined at 2.00 Å (apo), 1.59 Å (Ni2+) and 2.52 Å (Zn2+) resolution, show the conserved proximal and solvent-exposed His102 residues from two adjacent monomers invariably involved in metal binding. The C-terminal regions of the apoprotein are disordered in the crystal, but acquire significant ordering in the presence of the metal ions due to the binding of His152. The analysis of X-ray absorption spectral data obtained using solutions of Ni2+- and Zn2+-bound HpUreE provided accurate information of the metal-ion environment in the absence of solid-state effects. These results reveal the role of the histidine residues at the protein C-terminus in metal-ion binding, and the mutual influence of protein framework and metal-ion stereo-electronic properties in establishing co-ordination number and geometry leading to metal selectivity.

Removal of Heavy Metals from Aqueous Solution by Hydroxyapatite/Chitosan Composite

2013 ◽  
Vol 789 ◽  
pp. 176-179 ◽  
Author(s):  
Eny Kusrini ◽  
Nofrijon Sofyan ◽  
Dwi Marta Nurjaya ◽  
Santoso Santoso ◽  
Dewi Tristantini
Keyword(s):  
Heavy Metals ◽  
Aqueous Solution ◽  
Metal Ions ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Removal Of Heavy Metals ◽  
Sem Micrograph ◽  
Pseudo Second Order ◽  
Chitosan Composite

Hydroxyapatite/chitosan (HApC) composite has been prepared by precipitation method and used for removal of heavy metals (Cr6+, Zn2+and Cd2+) from aqueous solution. The HAp and 3H7C composite with HAp:chitosan ratio of 3:7 (wt%) were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy-energy dispersive X-ray spectroscopy. The SEM results showed that HAp is spherical-shaped and crystalline, while chitosan has a flat structure. SEM micrograph of 3H7C composite reveals crystalline of HAp uniformly spread over the surface of chitosan. The crystal structure of HAp is maintained in 3H7C composite. Chitosan affects the adsorption capacity of HAp for heavy metal ions; it binds the metal ions as well as HAp. The kinetic data was best described by the pseudo-second order. Surface adsorption and intraparticle diffusion take place in the mechanism of adsorption process. The binding of HAp powder with chitosan made the capability of composite to removal of Cr6+, Zn2+and Cd2+from aqueous solution effective. The order of removal efficiency (Cr6+> Cd2+> Zn2+) was observed.

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