ESTIMATING THE STABILITY OF METAL–LIGAND BONDING IN CARBOXYL-CONTAINING POLYMER COMPLEXES BY IR SPECTROSCOPY

2020 ◽  
Vol 61 (12) ◽  
pp. 1876-1887
Author(s):  
T. V. Berestova ◽  
K. N. Nosenko ◽  
O. V. Lusina ◽  
L. G. Kuzina ◽  
E. I. Kulish ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Polymer Complexes ◽  
The Stability ◽  
Metal Ligand

Electrical Conductivity of Chloro(phenyl)glyoxime and Its Co(II), Ni(II) and Cu(II) Complexes

2003 ◽  
Vol 68 (7) ◽  
pp. 1233-1242 ◽  
Author(s):  
Orhan Turkoglu ◽  
Mustafa Soylak ◽  
Ibrahim Belenli
Keyword(s):  
Electrical Conductivity ◽  
Temperature Dependence ◽  
Electric Conductivity ◽  
Crystal Structures ◽  
Elemental Analysis ◽  
Analysis Data ◽  
Elemental Analysis Data ◽  
The Stability ◽  
Xrd Patterns ◽  
Metal Ligand

Chloro(phenyl)glyoxime, a vicinal dioxime, and its Ni(II), Cu(II) and Co(II) complexes were prepared. XRD patterns of the complexes point to similar crystal structures. IR and elemental analysis data revealed the 1:2 metal-ligand ratio in the complexes. The Co(II) complex is a dihydrate. Temperature dependence of electrical conductivity of the solid ligand and its complexes was measured in the temperature range 25-250 °C; it ranged between 10-14-10-6 Ω-1 cm-1 and increased with rising temperature. The activation energies were between 0.61-0.80 eV. The Co(II) complex has lower electric conductivity than the Ni(II) and Cu(II) complexes. This difference in the conductivity has been attributed to differences in the stability of the complexes.

On the durability of low-density polyethylene nanocomposites

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Jitendra K. Pandey ◽  
Raj Pal Singh
Keyword(s):  
Ir Spectroscopy ◽  
Morphological Changes ◽  
Diffusion Path ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Neat Polymer ◽  
The Matrix ◽  
Ft Ir ◽  
The Stability ◽  
Artificial Uv

Abstract Low-density polyethylene (PE) containing nano-particulate clay was prepared after functionalization with maleic anhydride (MA) by reactive grafting in the presence of peroxide followed by blending of maleated PE with neat polymer in different concentrations. Four classes of composites were obtained: (i) exfoliated, (ii) intercalated, (iii) microcomposites, and (iv) intermediate of intercalated and microcomposites, as evidenced by wide-angle X-ray diffraction. All samples were kept for artificial UV irradiation (λ ≥ 290 nm) and for composting to study their photo- and bio-durability. Fourier-transform IR spectroscopy (FT-IR) and scanning electron microscopy were used to monitor the functional group and morphological changes, respectively, whereas biodurability was evaluated by measuring the weight loss. MA functionalization and nature of composites have detrimental effects on the overall durability of composites. Nanocomposites showed higher resistance than microcomposites during initial weathering and composting with a long induction period. The stability of nanocomposites decreases with time and overall durability was worse than of pristine polymer in both environments. It was concluded that the initial protection is due to the filler-generated long diffusion path, which decreases the oxygen diffusion through the matrix. The bio-durability of composites decreased with oxo-degradation. Biodegradation of PE nanocomposites during composting follows the mechanism described by Albertsson et al. as evidenced by FT-IR spectroscopy.

scholarly journals Potentiometric and spectrophotometric studies of the complexation of Schiff-base hydrazones containing the pyrimidine moiety

2003 ◽  
Vol 68 (10) ◽  
pp. 729-749 ◽  
Author(s):  
H.S. Seleem ◽  
B.A. El-Shetary ◽  
S.M.E. Khalil ◽  
M. Shebl
Keyword(s):  
Schiff Base ◽  
Ionic Strength ◽  
Thermodynamic Parameters ◽  
Stability Constants ◽  
Elemental Analysis ◽  
Mass Spectra ◽  
Dissociation Constants ◽  
The Stability ◽  
Pyrimidine Moiety ◽  
Metal Ligand

Three Schiff-base hydrazones (ONN ? donors) were prepared by condensation of 2-amino-4-hydrazino-6-methylpyrimidine with 2-hydroxyacetophenone 2-methoxybenzaldehyde and diacetyl to yield 2-OHAHP, 2-OMeBHPand DHP respectively. The structures of these ligands were elucidated by elemental analysis, UV, IR, 1H-NMR and mass spectra. The metal?ligand stability constants of Mn2+, Fe3+,Co2+,Ni2+,Cu2+, Zn2+,Cd2+,UO22+ and Th4+ chelates were determined potentiometrically in two different media (75%(v/v) dioxane?water and ethanol?water) at 283, 293, 303 and 313 K at an ionic strength of 0.05 M (KNO3). The thermodynamic parameters of the 1:1 and 1:2 complexes were evaluated and are discussed. The dissociation constants of 2-OHAHP, 2-OMeBHP and DHPligands and the stability constants of Co2+, Ni2 and Cu2+ with 2-OHAHP were determined spectrophotometrically in 75 % (v/v) dioxane?water.

Synthesis, Spectroscopic Properties, and Crystal Structure of the Oxonium Acid [H(OEt2)2]+[Ti2Cl9]–

2003 ◽  
Vol 58 (8) ◽  
pp. 745-750 ◽  
Author(s):  
Stefan Rannabauer ◽  
Tassilo Habereder ◽  
Heinrich Nöth ◽  
Wolfgang Schnick
Keyword(s):  
Crystal Structure ◽  
Ir Spectroscopy ◽  
Single Crystals ◽  
Nmr Spectra ◽  
Spectroscopic Properties ◽  
Partial Hydrolysis ◽  
Distorted Tetrahedron ◽  
Methyl Carbon ◽  
H Nmr ◽  
The Stability

The oxonium acid [H(OEt2)2]+[Ti2Cl9]− (1) was obtained by the reaction of TiCl4 with Et2O in n-pentane and subsequent partial hydrolysis. Suitable single crystals of 1 were obtained by sublimation at 5° C ([H(OEt2)2]+[Ti2Cl9]−, P212121 (no. 19), Z = 4, a = 1101.08(8), b = 1328.4(2), c = 1525.0(2) pm, T = 193(2) K, 4489 independent reflections, 197 parameters, R1 = 0.049). The cation is made up from two independent Et2O molecules and one disordered proton on two split positions. Both ether molecules exhibit a W form, and their molecular planes include an angle of 74.1(7)°. Thus a distorted tetrahedron is formed by the four methyl carbon atoms of the two ether molecules. The distance O···O amounts to 237.7(1) pm. The proton of the cation was characterized both by 1H NMR (CDCl3, T = 23 °C: δ = 11.7 ppm, w1/2 = 100 Hz) and IR spectroscopy (3120 cm−1, ν vbr). The [Ti2Cl9]− ion consists of two face sharing octahedra. 47Ti and 49Ti NMR spectra were recorded in solution (CH2Cl2, T = 23 °C: δ 49Ti = 137 ppm, w1/2 = 175 Hz; δ 47Ti = −124 ppm, w1/2 = 250 Hz). The absence of a signal for TiCl4 at δ 49Ti = 0 ppm indicates the stability of the dinuclear anion in solution.

DLC-coated Substrate for Infrared Absorption Spectroscopy in Supercritical Water

2011 ◽  
Vol 1309 ◽  
Author(s):  
Takuji Ube ◽  
Takashi Ishiguro
Keyword(s):  
Ir Spectroscopy ◽  
Zinc Selenide ◽  
Supercritical Water ◽  
Fused Silica ◽  
Diamond Like Carbon ◽  
Infrared Absorption Spectroscopy ◽  
Coated Substrate ◽  
Ft Ir ◽  
The Stability ◽  
Ft Ir Spectroscopy

ABSTRACTThe stability of several kinds of substrates, such as Corning #1737 glass, fused silica, synthetic silica, water free synthetic silica, zinc selenide, silicon, and diamond like carbon (DLC) coated Si in supercritical water (663K and 25MPa) were examined. Their reaction with the water was evaluated by using Fourier transform infrared (FT-IR) spectroscopy. As a result of the present experiment, it was found that DLC-coated Si is one of the most stable and useful substrates for IR spectroscopy in supercritical water.

scholarly journals Assessing the stability of alanine-based helices by conformer-selective IR spectroscopy

2016 ◽  
Vol 18 (29) ◽  
pp. 19950-19954 ◽  
Author(s):  
Waldemar Hoffmann ◽  
Mateusz Marianski ◽  
Stephan Warnke ◽  
Jongcheol Seo ◽  
Carsten Baldauf ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Gas Phase ◽  
Overall Stability ◽  
The Stability

Systematic amide-to-ester substitution suggests that a single backbone H-bond has only little influence on the overall stability of gas-phase α-helices.

Potentiometric and thermodynamic studies of 3-methyl-1-phenyl-{p-[N-(pyrimidin-2-yl)-sulfamoyl]phenylazo}-2-pyrazolin-5-one and its metal complexes

2006 ◽  
Vol 60 (1) ◽  
Author(s):  
A. Fouda ◽  
A. Al-Sarawy ◽  
E. El-Katori
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Stability Constants ◽  
Dissociation Constants ◽  
Transition Metal Ions ◽  
Effect Of Temperature ◽  
Water Mixture ◽  
Dissociation Process ◽  
The Stability ◽  
Metal Ligand

AbstractThe dissociation constants of 3-methyl-1-phenyl-{p-[N-(pyrimidin-2-yl)sulfamoyl]phenylazo}-2-pyrazolin-5-one and metal-ligand stability constants of its complexes with some transition metal ions have been determined potentiometrically in 0.1 M-KCl and ethanol—water mixture (30 vol. %). The order of the stability constants of the formed complexes increases in the sequence Mn2+, Co2+, Ni2+, Cu2+, La3+, Hf3+, UO22+, Zr4+. The effect of temperature was studied and the corresponding thermodynamic parameters (ΔG, ΔH, and ΔS) were derived and discussed. The dissociation process is nonspontaneous, endothermic, and entropically unfavourable. The formation of the metal complexes was found to be spontaneous, exothermic, and entropically favourable.

scholarly journals A Solution Study of Complex Formation of Some Diamines with Lanthanones

2009 ◽  
Vol 6 (1) ◽  
pp. 270-272 ◽  
Author(s):  
J. J. Vora ◽  
D. R. Patel ◽  
Asha D. Patel ◽  
Kanu Patel ◽  
Sangita Sharma ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Complex Formation ◽  
Metal Complex ◽  
Steric Effect ◽  
Ring Size ◽  
Titration Method ◽  
The Stability ◽  
Diamine Ligands ◽  
Metal Ligand

To study the metal ligand equilibrium in aqueous solution, the well known Irving-Rossotti titration method was used. The temperature selected is 30±0.10C at ionic strength 0.2 M (NaClO4) which was maintained constant through out the work. The binary metal complex (ML2) formation was studied. The metals selected are Sm3+, Gd3+, Dy3+and Yb3+. The diamine ligands taken are ethylenediamine, 1,2 diamino propane, 1,3 diamino propane,N-Ndiethyl ethylenediamine andN-N -dimethyl ethylenediamine. Factors that affected the stability of the complexes are size and ionic potential of lanthanone ions, basicity of ligands, ring size and steric effect of ligands.

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