Tin(IV) Schiff base complexes: Synthesis, thermodynamic and anti bacterial investigation, experimental and theoretical studies

A series of five coordinated diorganotin(IV) unsymmetrical Schiff base complexes have been synthesized. The structure determination and characterization of these complexes were made on the basis of UV-Vis, IR, (1H and 119Sn) NMR spectroscopy as well as elemental analysis. The binding site of the ligand was identified by IR spectroscopic measurement. Computational analyses at the level of DFT were performed to study its electronic and molecular structures. The molecular geometry, infrared vibrational frequencies, HOMO-LUMO energy gap, dipole moment, Mulliken charges, HF energies were calculated. The theoretical results were consistent with the experimental data reported. The Schiff base ligands and synthesized tin(IV) complexes were screened for their in vitro growth inhibiting activity against different strains of bacteria. Results indicated that the complexes exhibited good antibacterial activities than the ligands. Also the thermodynamic formation constants of the Schiff bases as donors with Me2SnCl2 as an acceptor were measured using UV-Vis spectrophotometric titration for 1:1 complex formation at constant ionic strength (I = 0.1 M NaClO4) and at 25 ºC.               KEY WORDS: Tin(IV) complexes, Thermodynamic parameter, Biological activity, Computational analyses Bull. Chem. Soc. Ethiop. 2019, 33(1), 77-90DOI: https://dx.doi.org/10.4314/bcse.v33i1.8            

Formation constants and thermodynamic parameters of bivalent Co, Ni, Cu and Zn complexes with Schiff base ligand: Experimental and DFT calculations

Formation constant (Kf) values of Schiff base ligand, L = methyl-2-{[1-methyl-2-(aceton)ethylidynenitrilo]ethyl}amino-1-cyclopentenedithiocarboxylate, with Co(II), Ni(II), Cu(II) and Zn(II) ions has been determined spectrophotometrically for 1:1 complex formation at constant ionic strength 0.01 M (NaClO4), and at various temperatures in DMF solvent. Thermodynamic studies of the complexes have been carried out and their stability were found in the order CoL > CuL > NiL > ZnL. The enthalpy, entropy and Gibbs free energy changes of the complexation reaction have been evaluated from the temperature dependence of the formation constant. Our experimental results revealed that the complexation process is spontaneous, exothermic and entropically unfavorable. Also, B3LYP/(LANL2DZ and 6-311G٭٭) level density functional theory is applied on the structure and stability of Schiff base ligand and their complexes. HOMO-LUMO and binding energies were calculated to obtained stability of the complexes. The theoretical results are compared with experimental data

Synthesis, physical characterization, antibacterial activity and thermodynamic studies of five coodrdinate cobalt(III) Schiff base complexes

Some five-coordinated cobalt(III) complexes were synthesized and characterized using elemental analysis, 1H NMR and IR spectra. The formation constants and the thermodynamic parameters were measured spectrophotometrically for the 1:1 adduct formation of [Co(Chel)(PBu3)]ClO4.H2O where Chel = cd3OMesalen, cd4OMesalen, cd5OMesalen: methyl-2-{[1-methyl-2-(2-hydroxy-3-, 4-, 5-methoxyphenyl)methylidynen-itrilo]ethyl}amino-1-cyclopentene-dithiocarboxylate, as acceptors, with some linear and cyclic amines as donors, in different solvents at constant ionic strength (I = 0.1 M NaClO4), and at various temperatures (T = 283-313 K). The results revealed that the formation constants of the Co(III) Schiff base complexes toward a given amines donor are as follow: [Co(cd4OMesalMeen)(PBu3)]+ > [Co(cd3OMesalMeen)(PBu3)]+ > [Co(cd5OMesalMeen)(PBu3)]+. The trend of the formation constants of the donors (amines) toward a given cobalt(III) complex is as follow: Im > 4-MeIm > BzIm and n-butylamine > sec-butylamine > tert-butylamine. Also the effect of the solvents on the formation constants of a given cobalt(III) Schiff base complex toward a given donor are as follow: CH3CN > DMF > EtOH. The ligands and their cobalt complexes have been screened for their antibacterial activities. All the free Schiff base ligands exhibit higher antibacterial activity than the cobalt(III) complexes

The effect of earthworm (Eisenia foetida) meal with vermi-humus on growth performance, hematology, immunity, intestinal microbiota, carcass characteristics, and meat quality of broiler chickens

The present investigation was aimed to evaluate the effect of varied amount of earthworm meal (EW) and vermihumus (VH) on the growth performance of broiler chickens. Three hundred 1-d-old broiler chickens were assigned to 5 starter treatments with 5 pens per treatment, and 12 broiler chickens per pen in a completely randomized design from d 0–14 of the study. Dietary treatments were [per kilogram dry matter (DM)]: control (0 g EW and 0 g VH/kg of DM), and the diets containing 10 g VH/kg of DM supplemented with 0, 10, 20, or 30 g EW/kg of DM. At the end of the study (d 42), one representative broiler chicken per pen, close to the average body weight, was selected for blood sampling using a sterile needle and heparinized vacuum tube. The outcomes of the study depicted the greater overall feed intake value in broiler chicken fed the control diet than those fed the diets containing VH or EW or both, and it decreased linearly and quadratically (P<0.05) as the amount of EW supplementation increased. The average weight gain for the chickens was numerically increased as supplementation of EW was increased (linear, =0.3; quadratic P=0.4). On the other hand, overall feed conversation ratio was slightly greater (P=0.02) in broiler chickens fed the control diet, and it decreased linearly (P=0.03) as dietary EW supplementation increased. Additionally, the serum total protein, albumin, Ca, and P concentrations were lower in broiler chickens fed the control diet, and those variables increased linearly (P<0.05) as dietary EW increased. In like manner, humoral immune response (except heterophil/lymphocyte ratio) and relative weights of immune organs were lower in broiler chickens fed the control diet. Remarkable differences were observed between carcass and ileum characteristics of broiler chickens under treatments. Varied concentrations of EW showed increased total counts of lactic acid bacteria (linear, P<0.05; quadratic, P=0.3) and reduced population of pathogenic intestinal microbiota (linear, P0.05). Similarly, the meat quality of broiler chicken was markedly affected linearly (P<0.05) by the supplementation of increased dietary EW. Briefly, diets containing 30 g EW/kg of DM can positively affect the growth performance of broiler chickens and produce meat with better characteristics

PARTICLES SIZE DISTRIBUTION EFFECT ON 3D PACKING OF NANOPARTICLES INTO A BOUNDED REGION

Abstract In this paper, the effects of two different Particle Size Distributions (PSD) on packing behavior of ideal rigid spherical nanoparticles using a novel packing model based on parallel algorithms have been reported. A mersenne twister algorithm was used to generate pseudorandom numbers for the particles initial coordinates. Also, for this purpose a nanosized tetragonal confined container with a square floor (300 * 300 nm) were used in this work. The Andreasen and the Lognormal PSDs were chosen to investigate the packing behavior in a 3D bounded region. The effects of particle numbers on packing behavior of these two PSDs have been investigated. Also the reproducibility and the distribution of packing factor of these PSDs were compared. Keyword

Ultrasonic irradiation to modify the functionalized bionanocomposite in sulfonated polybenzimidazole membrane for fuel cells applications and antibacterial activity

In this article the new proton exchange membranes were prepared from sulfonated polybenzimidazole (s-PBI) and various amounts of sulfonated titania/cellulose nanohybrids (titania/cellulose-SO3H) via ultrasonic waves. The ultrasonic irradiation effectively changes the rheology and the glass transition temperature and the crystallinity of the composite polymer. Ultrasonic irradiation has a very strong mixing and dispersion effect, much stronger than conventional stirring, which can improve the dispersion of titania/cellulose-SO3H nanoparticles in the polymer matrix. The strong –SO3H/–SO3H interaction between s-PBI chains and titania/cellulose-SO3H hybrids leads to ionic cross-linking in the membrane structure, which increases both the thermal stability and methanol resistance of the membranes. After acid doping with phosphoric acid, s-PBI/titania/cellulose-SO3H nanocomposite membranes exhibit depressions on methanol permeability and enhancements on proton conductivity comparing to the pristine s-PBI membrane. The chemical structure of the functionlized titania was characterized with FTIR, and energy-dispersive X-ray. Imidazole and sulfonated groups on the surface of modified nanoparticles forming linkages with s-PBI chains, improved the compatibility between s-PBI and nanoparticles, and enhanced the mechanical strength of the prepared nanocomposite membranes. From SEM and TEM analysis could explain the homogeneous dispersion of titania/cellulose-SO3H in nanocomposite membranes. Moreover, the membranes exhibited excellent antibacterial activities against S. aureus and E. col

The effect of earthworm (Eisenia foetida) meal with vermi-humus on growth performance, hematology, immunity, intestinal microbiota, carcass characteristics, and meat quality of broiler chickens

8 páginas, 8 tablas.The present investigation was aimed to evaluate the effect of varied amount of earthworm meal (EW) and vermihumus (VH) on the growth performance of broiler chickens. Three hundred 1-d-old broiler chickens were assigned to 5 starter treatments with 5 pens per treatment, and 12 broiler chickens per pen in a completely randomized design from d 0–14 of the study. Dietary treatments were [per kilogram dry matter (DM)]: control (0 g EW and 0 g VH/kg of DM), and the diets containing 10 g VH/kg of DM supplemented with 0, 10, 20, or 30 g EW/kg of DM. At the end of the study (d 42), one representative broiler chicken per pen, close to the average body weight, was selected for blood sampling using a sterile needle and heparinized vacuum tube. The outcomes of the study depicted the greater overall feed intake value in broiler chicken fed the control diet than those fed the diets containing VH or EW or both, and it decreased linearly and quadratically (P < 0.05) as the amount of EW supplementation increased. The average weight gain for the chickens was numerically increased as supplementation of EW was increased (linear, =0.3; quadratic P=0.4). On the other hand, overall feed conversation ratio was slightly greater (P=0.02) in broiler chickens fed the control diet, and it decreased linearly (P=0.03) as dietary EW supplementation increased. Additionally, the serum total protein, albumin, Ca, and P concentrations were lower in broiler chickens fed the control diet, and those variables increased linearly (P < 0.05) as dietary EW increased. In like manner, humoral immune response (except heterophil/lymphocyte ratio) and relative weights of immune organs were lower in broiler chickens fed the control diet. Remarkable differences were observed between carcass and ileum characteristics of broiler chickens under treatments. Varied concentrations of EW showed increased total counts of lactic acid bacteria (linear, P < 0.05; quadratic, P=0.3) and reduced population of pathogenic intestinal microbiota (linear, P 0.05). Similarly, the meat quality of broiler chicken was markedly affected linearly (P < 0.05) by the supplementation of increased dietary EW. Briefly, diets containing 30 g EW/kg of DM can positively affect the growth performance of broiler chickens and produce meat with better characteristics.We are grateful to the Islamic Azad University, Sanandaj Branch, Sanandaj, Iran for the financial and technical supports, and financial supports of Amize Tabiat Co (Iran) is also gratefully acknowledged.Peer reviewe