Crystal structure, ir-spectrum and electrochemical behaviour of cu(creatinine)2cl2

Abstract: Abstract In this paper, guanidine copper compounds are reviewed with an emphasis on structural characteristics and their application in bioinorganic chemistry and catalysis. The literature survey includes the copper coordination chemistry of biological guanidine derivatives, peralkylated guanidines including bicyclic ones and of further nitrogen-rich guanidine-type systems such as azoimidazoles, triazolopyrimidines and triaminoguanidines. From a sporadic interest dating back to the 1960s, research on this ligand class and its use in copper coordination chemistry has gained new impetus since 2000. With the synthesis of examples with sophisticated substitution at the characteristic CN3 framework, complex problems can be addressed in several fields of chemistry. This paper analyses the different types of guanidines for their special donor properties and highlights the specific advantages of guanidines as neutral donor ligands in copper coordination chemistry where a great variety of coordination modes was found. These compounds offer the ability to distribute the formal positive charge of the metal throughout the guanidine unit and represent more than simple σ-donating ligands.

Abstract: The nature of the peptide seems to be a very important factor for the reactivity of copper(II) peptide complexes with bioligands. Thus, although we have tried to obtain all the ternary complexes derived from the dipeptides l -ala-gly, gly- l -tyr and gly- l -trp with benzimidazole and creatinine, only four new ternary Cu(II) peptide complexes have been obtained: [Cu(gly- l -tyr)(benzimidazole)] · H2O (1), [Cu( l -ala-gly)(benzimidazole)] · 3H2O (2), [Cu(gly- l -trp) (creatinine)] · 1.25H2O (4) and [Cu( l -ala-gly)(H2O)(creatinine)] · 2H2O (5). Compounds 1, 2 and 4 exist as slightly distorted square planar complexes with the four coordination sites occupied by the tridentate peptide dianion and a nitrogen of the ligand, while compound 5 present a square pyramidal co-ordination in which the axial position is occupied by a water molecule. In the ternary benzimidazole complexes the lateral chain of the peptide moiety seems to determine the relative orientation of the ligand. In contrast, in the creatinine complexes the presence of two important intramolecular hydrogen bonds, involving the exocyclic NH2 and CO groups of the creatinine molecule, yield a nearly co-planar system which is independent of the nature of the peptidic lateral chain. These compounds do not present catalase-like activity nor remarkable SOD-like activity but the values of IC50 permit to distinguish a different behavior between benzimidazole and creatinine ternary complexes. Thus, benzimidazole compounds show lower IC50 (similar to free Cu(II)) values than creatinine ones.

Abstract: An electrochemical impedimetric sensor based on molecular imprinted polymer (MIP) has been developed for the detection of creatinine. Creatinine MIP was prepared by using the functional monomer methylacrylate and cross-linker ethylene glycol dimethacrylate in presence of the template creatinine. The resultant polymer was washed with water, methanol and 1 M HCl to extract the template from the polymer matrix. Formations of MIP, NIP (non-imprinted polymer) and template extraction were confirmed with vibrational Raman spectroscopic analysis. MIP incorporated carbon paste electrodes were used to develop a sensor for creatinine by applying electrochemical impedance spectroscopy (EIS) as transduction principle. Charge-transfer impedance ( R ct ) of the sensor system was determined in the absence and presence of creatinine. Interestingly, magnitude of R ct was found to increase with increasing concentrations of creatinine, which suggests the accumulation of creatinine into the polymer matrix. From the calibration plot, the low-detection-limit value was found to be ~20 ng mL −1 . The MIP electrode showed very good selectivity towards the specific recognition of creatinine in the presence of possible interferents like l -ascorbic acid and l -tryptophan. From the observations, we can conclude that the prepared imprinted polymer works successfully as an artificial biomolecular recognition element.

Abstract: Study of copper complex of creatinine and urea is very important in life science and medicine. In this paper, spectroscopic and structural study of a newly synthesized heteroligand complex of copper with creatinine and urea has been discussed. Structural studies have been carried out using DFT calculations and spectroscopic analyses were carried out by FT-IR, Raman, UV–vis absorption and fluorescence techniques. The copper complex of creatinine and the heteroligand complex were found to have much increased water solubility as compared to pure creatinine. The analysis of FT-IR and Raman spectra helps to understand the coordination properties of the two ligands and to determine the probable structure of the heteroligand complex. The LIBS spectra of the heteroligand complex reveal that the complex is free from other metal impurities. UV–visible absorption spectra and the fluorescence emission spectra of the aqueous solution of Cu–Crn–urea heteroligand complex at different solute concentrations have been analyzed and the complex is found to be rigid and stable in its monomeric form at very low concentrations.

Abstract: Article history: Creatinine (2-amino-1-methyl-5H-imidazol-4-one) is an amino acid that occurs in vertebrate tissues and in urine. The mid and far infrared spectra of creatinine were recorded in the solid phase. The optimized structure of creatinine was obtained using DFT/B3LYP method with 6-311+G(d,p) and LANL2DZ basis sets. The harmonic frequencies of creatinine were calculated using DFT/B3LYP/6-311+G(d,p) method. The complete assignments were performed on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. The creatinine-metal {cadmium (Cd(II)), zinc (Zn(II)) and mercury (Hg(II))} halogen (chloride (Cl - ) and bromide (Br - )) complexes were synthesized. DFT calculations, DFT-B3LYP/LANL2DZ were performed for the determination of geometrical structure and vibrational assignment for metal- complexes.

Abstract: Principles of biochemistry , Principles of biochemistry , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

Abstract: was developed for solving the integral equations obtained from the boundary value problems, and extensive data were calculated which permit construction of stationary electrode polarograms from theory. Correlations of kinetic and experimental parameters made it possible to develop diagnostic criteria so that unknown systems can be characterized by studying the variation of peak current, half-peak potential, or ratio of anodic to cathodic peak currents as a function of rate of voltage scan.