Coordination compounds of heterocyclic azo derivatives. III. Co(II), Ni(II) and Cu(II) complexes of some arylazo-4,5-diphenylimidazole derivatives

The 3d transition metalion [Co(II), Ni(II) and Cu(II)] complexes of some 4,5-diphenylimidazole azo derivatives have been isolated and characterized by chemical analysis, conductance, electronic and IR spectra. These dyes are characterized by a high tendency towards complex formation with the neutral molecules coordinated to the metal ion as bidentate ligands. The molecular formula of the 1:1 and 1:2 complexes are suggested to be [MLX ₂(H₂O)₂] and [ML ₂ X ₂] or [ML ₂ X ₂]·2H₂O respectively, whereX=Cl^– or NO₃. the different bands observed in the visible spectra of methanolic solutions of the complexes have been assigned to the possible electronic transition type (L MCT and d-d). It is suggested that the complexes studied have a distorted octahedral geometry.

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Koordinatsverbindungen von heterocyclischen Azo-Derivaten, 3. Mitt.: Co(II)-, Ni(II)- und Cu(II)-Komplexe einiger Arylazo-4,5-diphenylimidazol-Derivate

Zusammenfassung Es wurden einige Komplexe von 4,5-Diphenylimidazol-azo-Derivaten mit den 3 d-Übergangsmetallen Co(II), Ni(II) und Cu(II) isoliert und mittels chemischer Analyse, Leitfähigkeitsmessungen und den Elektronen- bzw. IR-Spektren charakterisiert. Diese Farbstoffe zeigen eine sehr starke Tendenz zur Komplexbildung, wobei die neutralen Moleküle als zweizähnige Liganden an das Metallion koordinieren. Die Formeln für die 1:1- und 1:2-Komplexe werden mit [MLX ₂(H₂O)₂] und [ML ₂ X ₂] bzw. [ML ₂ X ₂]·2H₂O vorgeschlagen (X=Cl^– oder NO ₃ ^– ). Die verschiedenen Absorptionsbanden in den VIS-Spektren in methanolischer Lösung werden den möglichen e-Übergängen (L MCT und d-d) zugeordnet. Für die Komplexe werden verzerrte oktaedrische Geometrien vorgeschlagen.

     

The (4,0) mode of HF dimer at 14,700 cm(-l)

The deltaK = 0 and 1 subbands of the (4,0) <-- (0,0) transition of (HF)2, near 14,700 cm(-1), have been measured by molecular-beam intracavity laser-induced fluorescence. The hydrogen interchange tunneling is basically quenched in (4, 0) for both K = 0 and 1 levels, consistent with the early suggestion from a phenomenological model [H.-C. Chang and W. Klemperer, J. Chem. Phys. 104, 7830 (1996)]. The band origin upsilon0 = 14,700.458(7) cm(-1) and rotational constant (B + C)/2 = 0.22278(31) cm(-1) are determined for K = 0 of the (4, 0) mode. From the observed deltaK = 1 <-- 0 spectrum, we determined that A = 24.3 cm(-1), (B + C)/2 = 0.22296(20) cm(-1), and (B-C) = 4.5(2) x 10(-3) cm(-1). The predissociation linewidths of both K = 0 and 1 levels are 470(30) MHz with no apparent rotational dependence.     

The use of the rotating Pt-electrode for microdetermination of hydrazine with potassium permanganate in fluoride medium

Summary An amperometric method is described for the microdetermination of hydrazine using the rotating Pt-electrode vs S. C. E. and zero applied e. m. f. It is based on oxidation of N₂H₄ with KMnO₄ under the following conditions: Acidity 0.01–0.6N H₂SO₄; NaF: 0.8–1.5%; CuSO₄: 0.013–0.15N; amounts of N₂H₄: 3.7g-5.97 mg. The method is accurate and can be used at concentrations lower than that with the potentiometric procedure.

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Zusammenfassung Eine amperometrische Methode zur Mikrobestimmung von Hydrazin mit Hilfe einer rotierenden Pt-Elektrode gegen eine gesättigte Kalomelelektrode wurde beschrieben. Sie beruht auf der Oxydation des Hydrazins mit Permanganat unter nachstehenden Bedingungen: 10 ml 0,01-bis 0,6-n schwefelsaures Milieu, 0,8–1,5% ig an NaF und 0,013-bis 0,15-n an CuSO₄. Hydrazinmenge: 3,7g–5,97 mg. Die Methode ist genau und eignet sich für geringere Konzentrationen als das potentiometrische Verfahren.

     

The use of the rotating pt-electrode at zero applied e. m. f. for the microdetermination of monovalent phosphorus in hypophosphorous acid or hypophosphite

Summary An amperometric method is described for the microdetermination of monovalent phosphorus using the rotating Pt-electrode vs S. C. E. and zero applied e. m. f. It is based on oxidation of hypophosphorous acid and hypophosphite with KMnO₄ to phosphorous acid and phosphite respectively under the following conditions: Acidity 0.05–0.6 and 0.2–1.68N H₂SO₄ for H₃PO₂ and NaH₂PO₂ respectively; NaF: 0.4–1.5%; amounts of P (I): 2.4g-2.1 mg and 5.4g-7.24 mg corresponding to hypophosphorous acid and hypophosphite respectively. The method is accurate and can be utilized at concentrations lower than that with the potentiometric method.

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Die Verwendung einer rotierenden Pt-Elektrode bei EMK=0 zur Mikrobestimmung von P (I) in unterphosphoriger Säure oder Hypophosphit

Zusammenfassung Die amperometrische Mikrobestimmung einwertigen Phosphors mit einer rotierenden Pt-Elektrode gegen eine ges. Kalomelelektrode bei EMK=0 wurde beschrieben. Sie beruht auf der Oxydation der unterphosphorigen Säure bzw. des Hypophosphits mit KMnO₄ zu phosphoriger Säure bzw. Phosphit bei einer Acidität von 0,05-0,6 bzw. 0,2-1,68N H₂SO₄ für H₃PO₂ bzw. NaH₂PO₂; 0,4-1,5% NaF; 2,4g-2,1 mg bzw. 5,4g-7,24 mg P (I) als H₃PO₂ bzw. H₂PO₂ ^–. Das Verfahren ist genau und für geringere Konzentrationen geeignet als die Potentiometrie.

     

Reaction of 2,3-Dichloro-1,4-naphthoquinone with Some Active Methylene Compounds in Different Basic Media

Reaction of 2,3-dichloro-1,4-naphthoquinone with some active methylene compounds, such as malononitrile and cyanoacetamide, under various basic conditions has been investigated. A mechanism for these reactions is proposed.     

The reaction of malononitrile with thioglycolic acid. A novel procedure for the synthesis of thiazolone derivatives

Malononitrile (I) reacted with thioglycolic acid to yield the thiazolin-4-one derivatives II or III depending on the molar ratio of the reactants. Compound II reacted with benzaldehyde in refluxing pyridine to yield the arylidene derivative IV. On the other hand, the benzylidine bis derivative VIII was obtained when II was reacted with benzaldehyde in refluxing ethanol. The structure of IV was established via its synthesis from the reaction of benzylidenemalononitrile (VI) and thioglycolic acid in refluxing acetic acid. Similar to II, compound III condensed with benzaldehyde to yield the benzylidene derivative IX.     

Synthesis of some thiopyrimidine and thiazolopyrimidines starting from 2,6-dibenzylidene-3-methylcyclohexanone and its antimicrobial activities

A series of novel N-substituted arylidene, pyrazole, thioxopyrimidine and thiazolopyrimidine derivatives 2–7 were synthesized by initial reactions of 2-methyl-cyclohexanone with aromatic aldehydes to give 2,6-dibenzylidene-3-methylcyclohexanone 2. Some of the synthesized compounds were tested as antimicrobial agents. The detailed synthesis, spectroscopic data, and antimicrobial activities of the synthesized compounds were reported.     

A Soft-Computing Algorithm-based Cognitive Observer for an Elastic Robotic Arm

This paper proposes the use of Support Vector Machine (SVM) algorithm for modeling and states estimation of an elastic robotic arm. Due to the complexity of the elastic robotic arm, an accurate mathematical model and large number of sensors are needed to achieve accurate estimation. Initially, it is assumed that all system states are measurable for a short period of time. Additionally, the system output and input signals are being continuously measured. The modeling module builds two models, the internal model which will capture the dynamics of the elastic robotic arm and the data-driven observer model which will estimate the system states. The internal model and data-driven observer are obtained based on the experimental measurements using SVM algorithm in contrast to classical methods that uses the mathematical system model to drive an observer. The internal model is able to make multi-steps ahead predictions of all system states; therefore it can be used to generate a suitable control strategy. Once the models are ready, the main sensors can be removed or turned off. The proposed modeling module will eliminate the need for mathematical modeling and reduces the number of permanent sensors needed. If the main sensors are removed completely, the hardware price can be radically reduced. The simulation result demonstrates the efficiency and high performance of the modeling module. (© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Aryudene Polymers. II Synthesis and Characterization of some New Polyesters of Diarylidenecyclopentanone

New polyesters formed by interfacial polycondensation of 2,5-bis(4-hydrox-ybenzylidene)cyclopentanone (I) and 2,5-bis(4-hydroxy-3-methoxybenzyli-dene)cyclopentanone (II) with 4,47prime;-diphenic, isophthaloyl, terephthaloyl, adi-poyl, suberoyl, and sebacoyl dichlorides were obtained. The yield and the values of the reduced viscosity of the produced polyesters were found to be affected by the type of organic phase, the quantitative ratio of organic to aqueous phase, the concentration of the hydrogen chloride acceptor, and the contribution of benzyltriethylammonium chloride as a catalyst. In order to characterize these polymers, the necessary model compounds were prepared from I, II, and benzoyl chloride. The resulting polyesters were confirmed by IR, elemental analysis, viscometry, DTA, DSC measurements, and thermogravi-metric analysis. The crystallinities of all polyesters were examined by x-ray analysis, and the electrical properties of the polyesters were tested.     

Oxidation with permanganate in presence of fluoride: Determination of hypophosphite

A rapid method is described for the determination of hypophosphite by oxidation with permanganate in acid medium in the presence of fluoride to prevent formation of insoluble oxides of manganese. The optimum conditions for visual and potentiometric end-point detection are given. Hypophosphite is oxidized to H(2)PO(-)(3). Under optimum conditions the titrations are fast and exhibit a reasonable potential change at the end-point. The method demonstrates the feasibility of determining amounts of H(2)PO(-)(2) corresponding to 0.08-7 mg of phosphorus.