Optical and magnetic resonance studies of the interaction of metallo tetraphenylporphyrins with nitrobenzofuroxan

Metallo tetraphenylporphyrins form I : I molecular complexes with 4,6-dinitrobenzofuroxan. The molecular association is described in terms of T-n. interaction with porphyrins functioning as donors. The association constants and thermodynamic parameters have been evaluated using optical absorption and 'H nmr spectral methods. Based on the binding constants, the donor ability of various metalloporphyrins can be arranged in the following order: Pd(I1) > Co(I1) > Cu(I1) > Ni(I1) - VO(1V) - 2H > Zn(l1). Electron paramagnetic resonance studies of the complexes reveal that the IT-complexation results in changes in the electronic structure of the central metal ions which are reflected in the changes in the M-N 5 bonding. The dipolar contribution to the acceptor proton chemical shifts in the CoTPP complex has been partitioned from ring current contributions using the shifts observed in the ZnTPP complex. The shifts, along with the line broadening ratios observed for the CoTPP complex, are used to arrive at the possible solution structures of the complexes.

(v, k, λ) Configurations and self-dual codes

The incidence matrix of a (v, k, λ) configuration is used to construct a (2v, v) and a (2v + 2, v + 1) self-dual code. If the incidence matrix is a circulant, the codes obtained are quasi-cyclic and extended quasi-cyclic, respectively. The weight distributions of some codes of this type are obtained.

A Comparative Study of Electrochemical Kinetic Parameters by the Potential Step Method. Electrode Reactions of CyDTA and EDTA Complexes of Cu(II) at DME

By using the same current-time (I-t) curves, electrochemical kinetic parameters are determined by two methods, (a) using the ratio of current at a given potential to the diffusion-controlled limiting current and (b) curve fitting method, for the reduction of Cu(II)–CyDTA complex. The analysis by the method (a) shows that the rate determining step involves only one electron although the overall reduction of the complex involves two electrons suggesting thereby the stepwise reduction of the complex. The nature of I-t curves suggests the adsorption of intermediate species at the electrode surface. Under these circumstances more reliable kinetic parameters can be obtained by the method (a) compared to that of (b). Similar observations are found in the case of reduction of Cu(II)–EDTA complex.

Temperatura vozdukha v Krymu v 1925-1926 s.kh.g. v gradisokh T︠S︡elʹt︠s︡ii︠a︡

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Godovoe razpredelenie osadkov (izogiety) v Krymu v 1925-1926 c.kh. g.

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Mnogoletneee srednee godovoe raspredelenie osadkov v Krymu (izogiety)

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Skorostʹ i napravlenie vetra v Krymu 3-go i︠u︡li︠a︡ 1926 goda

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Skorostʹ i napravlenie vetra v Krymu 4-go i︠u︡li︠a︡ 1926 goda

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Karta Evreĭskikh koloniĭ v Krymu obsluzhivaemykh Agro-Dzhoĭntom

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Ogorody kolkhoza imeni Molotova v poselke "Gortenshtadt"

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Zapys zemelʹnyĭ Na pravo korystovanni︠a︡ zemli︠u︡, shcho znakhoditʹsi︠a︡ v Odeskoï guberni Peryletravenʹsʹkyĭ okruzi Kantakuzenʹsʹy raʹoni pid nazvoi︠u︡ Trudovyshyĭ artilʹ Slava

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Zapys zemelʹnyĭ Na pravo korystovanni︠a︡ zemli︠u︡, shcho znakhoditʹsi︠a︡ v Odeskoï guberni Peryletravenʹsʹkyĭ okruzi Kantakuzenʹsʹy raʹoni pid nazvoi︠u︡ Trudovyshyĭ artilʹ Slava

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Lanthanide coordination in dimethyl sulphoxide and antipyrine complexes of rare earth nitrates

Abstract is not available.

Pyridine-1-oxide complexes of lanthanide iodides

Pyridine-1-oxide complexes of lanthanide iodides of the formulaLn(PyO)8I3 whereLn=La, Pr, Nd, Tb, Dy, Er, and Yb have been prepared and characterised by analyses, molecular weight, conductance, infrared and proton NMR data. Proton NMR and IR data have shown the coordination of the ligand to the metal through the oxygen atom of the N–O group. NMR data have been interpreted in terms of a distorted square antiprismatic geometry in solution.