Glycine Complexes Research Articles

Perturbational and variational energy decomposition analysis on hydrogen bonds of coordinated glycine with water molecule.

Three types of hydrogen bonds of coordinated glycine and water had been investigated: NH/O of α-amino group, O1/HO involving oxygen coordinated to the metal ion (O1), and O2/HO involving α-carbonyl oxygen (O2). Various glycine complexes were investigated: octahedral cobalt(III) and nickel(II), square pyramidal copper(II), and square planar copper(II), palladium(II), and platinum(II) complexes. Nature of these three hydrogen bond types was analysed using symmetry-adapted perturbation theory (SAPT) and variational energy decomposition analysis (EDA) method (TPSS-D3/def2-TZVPP). The results of the EDA decomposition are in good agreement with the reliable SAPT2+3/def2-TZVPP and its total interaction values with CCSD(T)/CBS energies. Electrostatic interaction is generally the dominant attractive energy term in most of the interactions, followed by orbital relaxation, and lastly dispersion as the weakest. We compared EDA results of various complexes to determine the effects of complex charge, metal oxidation, coordination, and atomic number on the energy decomposition terms. The complex charge influences the values of decomposition terms the most, followed by metal oxidation and coordination number, while atomic number effects them the least. All complex and metal changes have a more significant effect on the results of NH/O and O1/HO then O2/HO interactions, due to its location further away from the metal ion.

An Investigation of the Structures of [(Glycine)(1-Methyluracil)]M+ Complexes (M = H, Li, Na, K) in the Gas Phase by IRMPD Spectroscopy and Theoretical Methods.

The presence of ions in the complexation of molecules can profoundly affect the structure, resulting in changes to functionality and stability. These non-covalent interactions drive many biological processes both necessary and inimical and require extensive research to understand and predict their effects. Protonated and alkali metalated complexes of glycine (Gly) and 1-methyluracil (1-mUra) were studied using infrared multiphoton dissociation (IRMPD) spectroscopy and density functional theory (DFT) calculations. The experimental and simulated vibrational spectra were compared to help elucidate the structure of each complex. The lowest energy structure for [(Gly)(1-mUra)]H+ consists of amine protonated Gly bound to O4 of canonical 1-mUra through a single ionic hydrogen bond with another, intraglycine ionic hydrogen bond between the protonated amine group and the carbonyl oxygen. For [(Gly)(1-mUra)]Li+, [(Gly)(1-mUra)]Na+ and [(Gly)(1-mUra)]K+, the experimental spectra are most consistent with the metal cations binding in a trigonal planar geometry with 1-mUra bound to the metal cation via the O4 carbonyl. In [(Gly)(1-mUra)]Li+ and [(Gly)(1-mUra)]Na+, the metal cation is bound to canonical Gly via the carbonyl oxygen and amine nitrogen, but in [(Gly)(1-mUra)]K+, Gly is bound through both oxygens and contains an intraglycine hydrogen bond from the hydroxyl to the amine nitrogen.

Synthesis of NaLTA zeolite confined CuO catalysts and superior catalytic properties for alkene epoxidation with H2O2 as oxidant

The NaLTA zeolite confined CuO catalyst CuO@NaLTA was prepared via the method of ligand protected in situ with Cu2+-glycine complex as Cu source, and characterized by multiple characteristic techniques. The results revealed that CuO nanoparticles were highly dispersed on NaLTA zeolite, and the catalytic properties of CuO@NaLTA were investigated in the alkene epoxidation with H2O2 as oxidant in dioxane. For styrene oxidation, catalyst CuO@NaLTA exhibited excellent catalytic activities with 83 % conversion and 63 % selectivity to styrene epoxide, and could be easily recycled several times without obvious activity loss. The excellent catalytic activities could be attributed to the highly dispersed active CuO species. Besides, multiple electronic effects and coordinative interactions exited in Cu ion and the Si-Al zeolite skeleton framework played a key role in the catalytic recyclability.

Synthesis, thermal and spectroscopic analysis, antimicrobial activities and molecular modeling of zinc(II) metal complex of benzoyl glycine

To analyze ligand characteristics and use, a benzamide-derived ligand(benzoyl glycine) was synthesized and characterized before complexing it with zinc(II) ions. The ligand was formed from benzamide and glycine, obtained upon purification and precipitation. FTIR and 1H NMR were used to characterize the ligand. Furthermore, thermogravimetric analysis (TGA) was used to study the thermal behavior of the ligand and its Zn(II) complex, revealing important thermodynamic characteristics. The zinc complex was subjected to X-ray powder diffraction experiments, which yielded structural insights. Density Functional Theory (DFT) calculations were used in molecular modeling to clarify structure and characteristics of the molecules. Moreover, anti-microbial tests were used to assess biological activity against E. Coli and A. Niger. This thorough investigation lays the foundation for future research in this area by offering insightful information about the synthesis, characterization, and possible uses of the ligand and its Zn(II) metal complexes.

Preparation of copper glycinate and study of its effect on the germination of winter barley seeds

We analyzed the encrustation of winter barley seeds, which includes its preliminary treatment with cuprum glycinate, with the purpose of increasing yield and biochemical indicators of grain, and also improving the ecological condition of the soil. The objective of the research was to select methods for the synthesis of cuprum glycinate, study its chemical composition and the possibility of using this compound as a chelated micro-fertilizer for pre-sowing encrustation of winter barley seed as part of a tank mixture. Two well-known synthesis methods were used to obtain cuprum glycinate. The first method was the interaction between CuO with a solution of glycine during heating, during which pink metallic copper inclusions were noticed in the mixture of reaction products. It was found that it is expedient to synthesize the glycine complex of cuprum by the reaction of a suspension of Cu2CO3(OH)2 with glycine during heating (the yield is 97%), since a complex compound Cu(NH2CH2COO)2•H2O of sufficient purity is formed. The composition of the synthesized substance and the confirmation of the formula of the compound Cu(NH2CH2COO)2•H2O were obtained by determining the infrared and the atomic absorption spectrum of the aqueous solution. Based on the obtained differences in the atomic absorption spectra of the synthesized copper sulfate and copper glycinate the formation of the latter was confirmed. The IR spectrum confirms the formula of the complex compound and the formation of strong covalent bonds between the metal cation and the ligands. The study of the effect of cuprum glycinate on the germination of winter barley Tutankhamun seeds was carried out in comparison with the similar effect of a complex compound of cuprum with ethylenediaminetetraacetate. The study of the influence of cuprum glycinate on the germination of winter barley revealed positive results in which the germination exceeded the control by 9–27%. Winter barley seeds treated with distilled water served as a control. Treatment of winter barley seeds with an aqueous solution of cuprum glycinate in the amount of 20 g of cuprum per 1 ton of grain led to better germination than pre-treatment of seeds with a twice concentrated corresponding solution. Treatment with a complex compound of copper with ethylenediaminetetraacetate had no significant effect on the germination and characteristics of sprouts. The results of laboratory studies confirmed the feasibility of using complex compounds of biometal copper with organic chelating ligands as microfertilizers for pre-sowing seed encrustation, as they have high stability and sufficient solubility in water, are non-toxic, are better absorbed by plants and are considered cost-effective and environmentally safe.

Preparation, Characterization and Biological Activity of some Metals (II) with Glycine Complexes

In this work-study metals (II) coordination compound of Glycine were preparation and characterized using by infrared and UV-V is spectroscopy technique and Magnetic Susceptibility Measurements (BM). The complexes were studed for biological activity (an antibacterial activity of the complex).The stoichiometric the reaction between the metal(II) ion and ligands ion molar ratio(1:2)[where M= Ni,Co, Zn and glycine].

Oxidovanadium(IV) Salicylidene Glycine Complex with Phenanthroline as Co-ligand: Synthesis, Characterization, and Catalytic Degradation of Methyl Orange with H2O2

Oxidovanadium(IV) Salicylidene Glycine Complex with Phenanthroline as Co-ligand: Synthesis, Characterization, and Catalytic Degradation of Methyl Orange with H2O2

Analysis of Anodic Linear Sweep Voltammograms Considering Insufficient Lability of Cu|Cu(II), Glycine System

Anodic LS voltammograms of the alkaline Cu|Cu(II), glycine system were converted into mass-transport corrected Tafel plots considering that the glycinate anion L− takes part in the first stage of copper ionization. The anodic current density was normalized relative to the surface concentration of L− species, which was determined using the mass transfer model of chemically interacting species. The lability of the system was assessed based on available kinetic characteristics and specific experimental data. To linearize the Tafel plots, corrections were made to account for the insufficient mobility of the proton attached to glycine amino group. Obtained Tafel constants indicate that the second step of copper ionization, involving the oxidation of the intermediate copper(I)-glycine complex, is the rate-determining step.

Synergistic Effect and Phase Behavior of SCG-CAPB-H2O Ternary Compound System

The physical properties of sodium cocoyl glycinate (SCG) and the synergistic effects within the SCG/CAPB complex system were investigated using visible–ultraviolet spectrophotometry and a surface tension meter. Analysis of the synergistic parameters of the complex system revealed that the combination of SCG and cocamidopropyl betaine (CAPB) yielded superior results compared to the individual use of SCG. Building upon this, the ternary phase behavior of the SCG/CAPB/H2O system was further explored. Different lyotropic liquid crystal phases were identified using polarized optical microscopy (POM) and small-angle X-ray scattering (SAXS). Surfactant solutions with varying mass fractions exhibited diverse phase behaviors, including the micellar phase (L1), micelle–solid mixed phase (L1-S), hexagonal phase (H), and lamellar phase (Lα), with the insoluble solid phase predominating. The investigation of the ternary phase diagram of SCG/CAPB/H2O provided valuable guidance for detergent formulation screening, enriched the understanding of sodium cocoyl glycinate complex systems, and further promoted the utilization of amino acid-based surfactants in the field of personal care products.

Physical Grinding of Prefabricated Co3O4 and MCM-22 Zeolite for Fischer-Tropsch Synthesis: Impact of Pretreatment Procedure on the Dispersion and Catalytic Performance.

To improve the mess-specific activity of Co supported on zeolite catalysts in Fischer-Tropsch (FT) synthesis, the Co-MCM-22 catalyst was prepared by simply grinding the MCM-22 with nanosized Co3O4 prefabricated by the thermal decomposition of the Co(II)-glycine complex. It is found that this novel strategy is effective for improving the mess-specific activity of Co catalysts in FT synthesis compared to the impregnation method. Moreover, the ion exchange and calcination sequence of MCM-22 has a significant influence on the dispersion, particle size distribution, and reduction degree of Co. The Co-MCM-22 prepared by the physical grinding of prefabricated Co3O4 and H+-type MCM-22 without a further calcination process exhibits a moderate interaction between Co3O4 and MCM-22, which results in the higher reduction degree, higher dispersion, and higher mess-specific activity of Co. Thus, the newly developed method is more controllable and promising for the synthesis of metal-supported catalysts.

Hydrogen bonds of a water molecule in the second coordination sphere of amino acid metal complexes: influence of amino acid types on different complex geometries

Quantum chemical calculations at the M06L-GD3/def2-TZVPP level were done to investigate hydrogen bonds between amino acid metal complexes and a free water molecule. Octahedral nickel(II) and square planar palladium(II) complexes of glycine, cysteine, phenylalanine, and serine with different charges of metal complexes (+1, 0, and −1) were investigated. The following hydrogen bonds were considered: NH/O (amino acid is a H-donor), O1/HO (coordinated O1 oxygen from amino acid is a H-acceptor), and O2/HO (non-coordinated O2 oxygen from amino acid is a H-acceptor). Amino acid type has a small influence on interaction energies, both for octahedral nickel(II) and square planar palladium(II) complexes. The influence is the largest for NH/O and the smallest for O2/HO hydrogen bonds. For NH/O interaction, palladium(II) complexes showed stronger hydrogen bonds than nickel(II), up to −11.8 kcal mol−1 for singly positively charged complexes. Nickel(II) complexes demonstrated higher O1/HO hydrogen bond strength than palladium(II) with interaction energies up to −8.9 kcal mol−1 for singly negative complexes. With up to −9.0 kcal mol−1 interaction energy for singly negative complexes, O2/HO interactions were also stronger for nickel(II) complexes than palladium(II).

Importance of the drying method in crystalline phase formation and metallic elements distribution of glycine complexes

In this work, for the first time, the multi mineral complexes composed of three and four elements FeII, MnII, CuII & ZnII and CuII, MnII & ZnII, respectively) bounded to glycine have been produced to be used as a feed additive for farm animals. To the best of our knowledge, all products were synthesized for the first time as novel compounds containing several transition metals. The impact of the drying procedure on the microstructure, chemical composition and crystalline phase was evaluated using different analytical techniques. The trace element concentration distributions and homogeneity were also studied. A single crystal of dehydrated metal glycinate compound was synthesized from drying of glycine and a multi-metal sulphate solution under room temperature. On the other hand, both spray drying and spray granulation of this similar solution results to the formation of crystalline powders. The crystalline powders obtained present a typical metal-sulphate-glycinate dehydrated crystalline form and a homogeneous distribution of the metals within the product particles. The developed products have been compared and their differences have been underlined.

Hydrogen bond reorientations driven phase transitions leading to dielectric anomaly in bis(glycinium)oxalate at high pressure and low temperature

Glycine complexes are of immense importance to fundamental science and technological applications. Bis(glycinium)oxalate is stabilized by an unusually strong hydrogen bond at ambient conditions in a centrosymmetric crystal structure. Here, using high pressure and low temperature infrared spectroscopic studies, supported by first principles density functional theory calculations, we present the mechanism of phase transformation in dense Bis(glycinium)oxalate, both at a pressure of 1.7 GPa and at temperatures below 50 K. The transition is governed by reorientations in strong hydrogen bonding network mediated by displacements in carboxylate ions, which modifies glycine conformation driving the loss of inversion symmetry. Further, we have carried out dielectric measurements, which show that the phase transformation is accompanied with a dielectric transition in the non-centrosymmetric phase of the crystal, making it a potential candidate to search for a new ferroelectric material in glycine family.

Computational and crystallographic study of hydrogen bonds in the second coordination sphere of chelated amino acids with a free water molecule: Influence of complex charge and metal ion

Hydrogen bonds of glycine complexes were calculated using quantum chemistry calculations at M06L-GD3/def2-TZVPP level and by analyzing the crystal structures from the Cambridge Structural Database (CSD). One hydrogen bond where amino acid plays the role of the H-donor (NH/O), and two where it plays the role of the H-acceptor (O1/HO, O1 is a coordinated oxygen atom, and, O2/HO, O2 is a non-coordinated oxygen atom) were investigated. The calculations were done on octahedral nickel(II), square pyramidal copper(II), square planar copper(II), palladium(II), and platinum(II) glycine complexes with different charges adjusted using water(s) and/or chlorine ion(s) as the remaining ligands. For NH/O hydrogen bond, interaction energies of neutral complexes are the weakest, from −5.2 to −7.2 kcal/mol for neutral, stronger for singly positive, from −8.3 to −12.1 kcal/mol, and the strongest for doubly positive complex, −16.9 kcal/mol. For O1/HO and O2/HO interactions, neutral complexes have weaker interaction energies (from −2.2 to −5.1 kcal/mol for O1/HO, and from −3.7 to −5.0 kcal/mol for O2/HO), than for singly negative complexes (from −6.9 to −8.2 kcal/mol for O1/HO, and from −8.0 to −9.0 kcal/mol for O2/HO). Additionally to the complex charge, metal oxidation number, coordination number, and metal atomic number also influence the hydrogen bond strength, however, the influence is smaller.

An experimental study on the adsorption behavior of gold glycinate complex on graphene oxide

Graphene oxide (GO) has recently gained plenty of attention as an effective adsorbent for gold recovery from leaching solutions, primarily due to its larger surface area compared to activated carbon (AC). In this study, the adsorption behavior of gold glycinate complex (Augly2−) on GO surface was investigated using equilibrium isotherm and kinetic studies for the first time. The optimal conditions for adsorption were determined using an experimental design software (DX-13) based on the response surface method (RSM). These conditions were found to be a pH of 10.5, GO dosage of 0.6 g L−1, gold concentration of 6 mg L−1, and contact time of 10 h, resulting in the adsorption percentage of 74.2% and adsorption capacity of 7.4 mg g−1. The equilibrium isotherm studies indicated that the adsorption process adhered to the Freundlich isotherm model. Additionally, the results of the kinetic study revealed that the pseudo-second-order model exhibited a stronger correlation with the experimental data compared to other kinetic models. Surface analysis studies using Fourier transform infrared (FTIR) spectrometer, X-ray diffraction (XRD), and scanning electron microscope with energy dispersive X-ray (SEM-EDX) spectroscopy demonstrated that the remarkable recovery of Augly2− was mainly attributed to the presence of oxygen containing functional groups on the GO surface.

313 Effect of Dietary Trace Mineral Source on Performance, Bones Mineralization and Mineral Status in Fattening Pigs

Abstract Several papers report greater bioavailability of dietary trace mineral fed as organic in pigs compared with inorganic sources. However, only a few studies have tried to assess the variability of the trace mineral bioavailability among different organic sources. Growing barrows (n = 54; initial BW = 28.9 ± 1.3 kg) were used to determine the effects of trace mineral source on growth performance, bones mineralization and mineral status over the entire fattening period (d0-d73). Pigs were blocked by BW and randomly assigned to supplementation of trace minerals as inorganic (ITM) or one of 2 organic sources (OTM): glycine complex (GLY) or amino acids complex (AA). During the two feeding phases (growing: d0-d35; finishing: d35-d73), the experimental diets were supplemented with 5, 35 and 5 mg/kg of Cu, Zn and Mn, respectively. Pigs were fed restricted all through the experimental period. Feed intake was therefore comparable all through the experimental period for all pigs. Growth performance did not differ among the three experimental groups during the growing phase. However, Feed:Gain ratio measured during the finishing period tended to be affected by the dietary treatments (P=0.10). When grouping the GLY and AA pigs, the Feed:Gain ratio measured from d35 to d73 for the OTM pigs was significantly lower compared with ITM pigs (-0.07, P = 0.03). There was no significant effect of the dietary treatment on plasma trace mineral concentrations and alkaline phosphatase activity measured at day 34. At the end of the growing phase, plasma ceruloplasmin activity tended to be greater for the GLY and AA groups in comparison with the ITM pigs (+6.9%, P = 0.06). The zinc deposition in the proximal phalanx was significantly increased when the trace minerals were offered as organic compared with the group ITM (+10.9%, P = 0.06). Zinc content in the liver was greater for the pigs fed the OTM sources compared with the others (+6.0%, P = 0.10). The quantity of copper deposited in the liver did not differ significantly among the 3 trace mineral sources. This study indicates that the total replacement of inorganic Zn, Cu and Mn by organic sources brings benefits in terms of feed efficiency in fattening pigs. A better bioavailability as suggested by greater deposition levels in bone and liver as well as the increased circulating ceruloplasmin activity could explain the improvement of performance during the finishing period. Regardless of the variable considered, no significant differences were noticed between the two organic trace mineral sources.

An Experimental and DFT Study on Using the Thiosulfate–Glycine Complex as an Alternative Agent of Cyanide in the Gold Leaching Process

An Experimental and DFT Study on Using the Thiosulfate–Glycine Complex as an Alternative Agent of Cyanide in the Gold Leaching Process

Selective complexation leaching of copper from copper smelting slag with the alkaline glycine solution: An effective recovery method of copper from secondary resource

In the process of copper smelting, amounts of copper droplets inevitably enter the copper smelting slag (CSS), resulting in a high loss of copper. As the grade of exploitable copper ore decreases gradually, the recovery of copper from copper slag is very important to ensure the safe supply of copper. In this study, a new method was proposed to recover copper via selective complexation leaching process by using the alkaline glycine solution. Various leaching parameters, including initial pH, particle size, stirring speed, liquid-solid ratio, temperature and glycine concentration were investigated. Under the optimum leaching conditions, the copper extraction of 86.40 % was achieved, while the other valuable metal elements were barely leached. The results of leaching kinetics indicated that the mixed control, a combination of internal diffusion and interfacial chemical reaction, was the rate-limiting step in the leaching process, where the apparent activation energy was calculated to be 34.66 kJ/mol. After leaching process, the leaching solution rich in copper–glycine complex was obtained, and the copper grade in the leaching residue was 0.22 wt%, while the unseparated copper was tightly wrapped by gangue minerals. Therefore, glycine was successfully used as the leaching agent to extract copper from CSS with high efficiency and selectivity, which provided a prospective method for the green recovery of CSS.

An electrochemical study of the dissolution behavior of gold in a novel glycine-thiosulfate system

Ammonia-free thiosulfate systems are known for their non-toxicity, low reagent consumption, and excellent leaching efficiency in gold extraction studies. This study proposes a novel and environmentally friendly glycine-thiosulfate system and comprehensively investigates the dissolution behavior of gold through the application of electrochemical methods. Electrochemical quartz crystal microbalance (EQCM) has demonstrated that the anodic dissolution of gold is predominantly influenced by the forms of copper(II)-glycine complexes as catalysts, and the presence of Cu(C2H4NO2)3− complex in strong alkaline has enhanced dissolution rate of gold, in contrast to Cu(C2H4NO2)20 complex in near-nurture condition. Such excellent catalytic capability of the Cu(C2H4NO2)3− complex for gold dissolution can be attributed to the lowest corrosion potential, slighter passivation behavior, and rapid electron transfer from the analysis of corrosion electrochemistry (OCP, PDP, and EIS) and advanced spectrum technologies (LA-ICP-MS and XPS). The dissolution of gold in the novel glycine-thiosulfate system undergoes a typical ligand exchange process (Au+→Au(C2H4NO2)2−→Au(S2O3)23−), and the formation of passivation species on the gold surface is predominantly formed by Au(I)-glycine coordination, rather than the sulfur-containing products from thiosulfate decomposition. Based on these results, the proposed two electrochemical reaction mechanisms will contribute to the optimization of leaching conditions in the novel glycine-thiosulfate system.

Study of gold leaching from pre-treated waste printed circuit boards by thiosulfate‑cobalt-glycine system and separation by solvent extraction

The recovery of gold (Au) from waste printed circuit boards (WPCBs) derived from discarded mobile phones is crucial for the resource preservation and environmental protection. In this context, thiosulfate has emerged as a viable alternative to the toxic compound cyanide for Au leaching. However, the conventional thiosulfate leaching system has a main problem that is large thiosulfate consumption, which limits its commercial application. In this study, we developed a novel thiosulfate leaching system that utilizes a cobalt (Co(II))-glycine (gly) complex as the catalyst. Our findings demonstrate that the Co(II)-glycine-thiosulfate system exhibits excellent Au leaching performance coupled with low thiosulfate consumption. The effects of several parameters on Au leaching efficiencies and thiosulfate consumption were investigated. Increasing the concentrations of Co(II), thiosulfate, or glycine was beneficial to the Au leaching. However, increasing temperature promoted the oxidative decomposition of thiosulfate and reduced cobalt stability, negatively impacting Au leaching. Additionally, small amounts of base metals remained after pretreatment of WPCBs using HCl system and H2SO4-H2O2 system. Therefore, the roasting-assisted leaching process eliminated the adverse effects of these impurity metals and further improved Au leaching efficiency to 97.8% while also decreased thiosulfate consumption. The recovery of Au from the pregnant leach solution was also studied, and our findings demonstrated that N1923 can efficiently extract Au from the solution through anion exchange. Our study developed a novel and efficient Au thiosulfate leaching system catalyzed by the Co(gly)3/Co(S2O3)34− redox couple, and put forward a promising approach to enhance Au recyclability from WPCBs while significantly reducing thiosulfate consumption.