Neue rhodanilatähnliche Verbindungen mit Morpholin

Substitution reactions of K₃[Cr(NCS)₆] with morpholine were studied. The formula of the complex anion, [Cr(NCS)₄(morph)₂]^–, was established.23 new complex compounds of these types have been prepared from the hydrochlorides of some aliphatic or heterocyclic amines, alkaloids and cobalt(III)ammine bases resp.Their thermal behaviour and the mechanism of pyrolysis of these salts was studied by derivatographic methodes. From UV and IR spectra some structural problems are resolved and discussed.

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Mit 3 Abbildungen     

Ir spectroscopy of 2,3-polymethylene-3,4-dihydroquinazolines and their complexes

We have investigated the IR spectra in the region of stretching vibration of N⁺–H and OH groups of the hydrochlorides of 2,3-trimethylene-3,4-dihydroquinazoline (deoxypeganine, DOP), 2,3-tetramethylene-3,4-dihydroquinazoline (tetrazoline), and 2,3-pentamethylene-3,4-dihydroquinazoline (pentazoline) and peganol and peganine and the corresponding complexes with ZnCl₂, CoCl₂, and MnCl₂. The appearance of two additional absorption bands in the 3100–3300 cm^–1 region in the complexes investigated as compared with the corresponding hydrochlorides witnesses the formation of interionic hydrogen bonds between the quinazoline cation and the (MeCl₄)^2– anion.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 40 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 6., pp. 854–857, November–December, 1997.     

An SCF XαSW study of the electronic structure and X-ray and photoelectron spectra of Fe(II) and Fe(III) hexacyano complexes in a cluster approach

The electronic structure of the hexacyano complexes [Fe(CN)₆]^4– and [Fe(CN)₆]^3– as clusters of the cyanide complex salts has been calculated by the SCF XSW method. Theoretical photoelectron, X-ray emission and absorption spectra have been constructed. The contribution of the resonance emission to the X-ray emission spectra has been estimated. On the basis of detailed comparison of the theoretical and experimental spectra an assignment of the fine structure of the spectra has been proposed.     

Investigation of some aminophosphonates by high-resolution NMR in the solid

Conclusion By high-resolution NMR in the solid it was possible to demonstrate unambiguously that the nitrogen atom is protonated through the phosphono group in the investigated compounds. The order of substitution of the protons in N-PMG was established from the obtained data on the anisotropy of the³¹P chemical shift in variously substituted salts of N-PMG with CHA. Slow rotation of the phosphono group about the P–C bond was detected during investigation of the hydrochlorides.All-Union Scientific-Research Technological Institute of Herbicides and Plant Growth Regulators. Translated from Zhurnal Strukturnoi Khimii, Vol. 27, No. 3, pp. 60–64, May–June, 1986.     

Electrochemical and spectroscopic studies of metal cyclam complexes with thiocyanate. Evidence for mixed ligand complex formation

Complexes of Ni^II, Co^II and Cu^II containing the macrocyclic ligand, 1,4,8,11-tetraazacyclotetradecane (cyclam), and their ability to form mixed ligand complexes with thiocyanate have been studied. These complexes in a 1:2 mole ratio, exhibit new absorption peaks at 450, 538 and 512 nm respectively. Addition of thiocyanate to the nickel–cyclam complex (1:2:5 mole ratio) led to the formation of a purple complex, exhibiting three distinct new absorption peaks at 330, 455 and 662 nm. A purple complex (1:2:10 mole ratio) separated, having absorption peaks at 352, 503 and 693 nm in CHCl₃. The Co^II–cyclam complex with thiocyanate in the same mole ratio exhibits two absorption peaks at 437 and 519 nm without appearance of any precipitate. The Cu^II–cyclam complex with thiocyanate did not form a mixed ligand complex. Electrochemical studies also confirmed the complex formation of Ni^II–cyclam with the thiocyanate with the appearance of two new oxidation peaks close to 1.25 and 1.60 V versus Ag/AgCl in H₂O and CHCl₃. The Co^II–cyclam complex with thiocyanate exhibited an oxidation peak at 1.2 V versus Ag/AgCl, while no peak was observed for the Cu^II–cyclam complex with thiocyanate. Based on spectroscopic and electrochemical studies the geometry of the complex has been evaluated.     

Activity and osmotic coefficients oft-butylammonium chloride; Activity coefficients of HCl in mixtures with tris hydrochloride ort-butylammonium chloride at 25°C

In an earlier study, the activity coefficients of aqueous mixtures of HCl with the hydrochlorides of tris(hydroxymethyl)aminomethane (Tris) ort-butylamine (t-B) were determined at ionic strengths of 0.1, 0.5, and 1.0 mol-kg^–1. The work has been extended to ionic strengths of 2.0 and 3.0 through emf measurements with hydrogen and AgCl/Ag electrodes at 25°C. The results are considered in terms of Harned's rule and the Pitzer and Rush-Johnson-Scatchard treatments of activity coefficients in electrolyte mixtures. In order to compare ionic interaction parameters in the two systems, the activity coefficients and osmotic coefficients of t-butylammonium chloride at molalities up to saturation (7.14 mol-kg^–1) were determined by the gravimetric isopiestic method with solutions of NaCl as reference. The behavior for both systems can be accounted for satisfactorily in terms of binary (H⁺–N⁺) and ternary (H⁺–N⁺–Cl^–) interactions, where N⁺ is either Tris·H⁺ or t-B·H⁺.     

Infrared absorption spectra of some derivatives of 1,2,3,4-tetrahydro-Β-carboline

The IR absorption spectra in 3800-1400 cm^–1 region of 1-propyl-, 1-carboxy-, 1-carboxy-1-methyl-, and 1-benzyl-1-carboxy-6-hydroxy-1,-tetrahydro--carbolines, their O-methyl derivatives, and their hydrochlorides are discussed. An assignment of the bands due to the stretching vibrations of NH, NH ₂ ⁺ , OH, COO^–, and COOH groups is proposed. The hypothesis has been put forward that strong intermolecular and intramolecular hydrogen bonds exist in the substances studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 6, pp. 775–778, June, 1970.     

Benzoxazolylacrolein derivatives as ligands for extraction atomic absorption analysis

The extraction of chelate and ion-association complexes formed by various metal ions and two new organic reagents (derivatives of benzoxazolylacrolein) has been investigated in order to evaluate the possibilities for analytical application. The composition of the extracted species and their conditional extraction constants are given. Two simple extraction procedures for flame atomic absorption analysis of high purity lead salts have been developed. The proposed methods permit determination of (a) 1 × 10^–5% Co, Fe and Ni and 5 × 10^–6% Cu and Zn and (b) 1 × 10^–5% Pd and 5 × 10^–6% Ag and Au, with relative standard deviations in the range 4–8%.     

Charge-transfer interaction of some pyridinium salts with hen egg-white lysozyme

The charge-transfer interaction of pyridinium salts with lysozyme and L-tryptophan has been investigated by visible absorption, circular dichroism and fluorescence spectroscopy. Four quaternized and substituted pyridinium salts were used as electron acceptors. L-tryptophan was used as a model compound of electron donor for the purpose of the comparison with lysozyme. The binding constants obtained from absorption and circular dichroism spectra were 2.0–13 M^–1 and the sequence of the magnitude was found as EPCl(1-ethylpyridinium chloride) < MPCl(1-methylpyridinium chloride) < MNCl(1-methylnicotinamide chloride) < MNMCl(1-methyl-3-carbomethoxypyridinium chloride), which could be explained by the electron affinity of the pyridinium salt. The fluorescence spectra of lysozyme and L-tryptophan in the absence and presence of pyridinium salts were interpreted by Stern-Volmer plot. The static constants thus determined were in agreement with the binding constants obtained by other methods.     

Kinetics and mechanism of oxidation of copper(I) ions with thiuram disulfide

The kinetics of the oxidation of copper(I) perchlorate with thiuram disulfide (tds) in acetonitrile and its mixtures with benzene or ethyl bromide have been investigated. It has been shown that the rate of the reaction is limited by the inner-sphere transfer of an electron from the copper(I) ion to tds in a complex of the type [Cu^I(tds)]⁺. The subsequent dissociation of the anionradical tds —proceeds rapidly and leads to the formation of copper(II) dithiocarbamate which is recorded in the absorption spectra and by EPR. The rate constant of electron transfer has been determined (3·10^–4sec^–1) and it was found that it is practically independent of the polarity of the medium. The absence of such a correlation is attributed to the negligible energies of reorganization of the solvent in the inner-sphere electron transfer.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 24, No. 4, pp. 450–455, July–August, 1988.     

Thermal investigations of the structure of two humic acid salts by in situ FTIR spectroscopy

Diffuse reflectance infrared Fourier-transformed (DRIFT) spectra of two humic sodium salts (ALDRICH, SERVA) have been recorded to study structural changes caused by heating. In situ investigations during the heating process has been accomplished by using a reaction chamber. The equilibrium of carbonate species dissolved in pore water (HCO ₃ ^– , CO ₃ ^2– ) has been studied. Decreasing OH and C=O band intensities and the formation of CO₂ and CH₄ have been observed. An increasing absorption of the band at 2170 cm^–1 indicates changes of nitrogen linkages in the molecule. Observable amounts of nitrile groups have been formed only at temperatures around 400°C.Dedicated to Professor Dr. H. Kriegsmann on the occasion of his 70th birthday     

Extractive spectrophotometric determination of molybdenum(V) in molybdenum steels

An extraction spectrophotometric method has been developed for the determination of traces of molybdenum present in molybdenum steels which is based on the extraction of the orange-red molybdenum-thiocyanate-acetonethiosemicarbazone complex into chloroform from hydrochloric acid medium. The complex has an absorption maximum at 472 nm with a molar absorptivity of 1.9 × 10⁴ liters mol⁻¹ cm⁻¹. Beer's law is valid over the concentration range 0.1–9.5 ppm of molybdenum with an optimum concentration range of 0.4–9 ppm. The equilibrium shift method indicates 1:4:2 composition for molybdenumthiocyanate-acetonethiosemicarbazone complex. The effect of acidity, reagent concentrations, temperature, and interferences from various ions are reported.     

Synthesis and properties of disulfonated (2-benzimidazolyl)(phenyl)methanone 5-nitro-2-pyridylhydrazone (S2BINPH) and spectrophotometric determination of trace amounts of nickel with S2BINPH

Disulfonated (2-benzimidazolyl)(phenyl)methanone 5-nitro-2-pyridylhydrazone (S₂BINPH) has been synthesized and its reactivity with metal ions investigated. A sensitive and selective spectrophotometric method for the determination of nickel with this reagent has been developed. S₂BINPH reacts with nickel(II) to form a stable 12 (metal ligand) complex with an absorption maximum at 501 nm. The complex formation is quantitative in the pH range 7.2–8.5. Beer's law is obeyed over the range 60–700 ng ml^–1 of nickel and the apparent molar absorptivity of the complex is 8.86 × 10⁴ mol^–1 1 cm^–1 at 501 nm. The proposed method was applied to the determination of nickel in a standard iron- and -steel sample with satisfactory results. Furthermore, proton dissociation constants of S₂BINPH and the overall formation constant of its nickel complex were also determined spectrophotometrically.     

O-Complexes of 1,3,2,5-dioxaboraphosphorinanes with copper(I) and silver(I) salts

1,3,2,5-Dioxaboraphosphorinanes interact stereospecifically with Cu(I) and Ag(I) salts to form the corresponding O-complexes. The three-dimensional structure of the ligands has been established from³¹P NMR and¹H NMR data.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 906–912, April, 1991.     

Electronic absorption spectra,ESR spectra,and structure of coordination polyhedrons of titanium(III) in molten and “instantly cooled” systems of sodium phosphates and halides

The structure of Ti(III) coordination polyhedrons in both individual NaPO₃ and 70 mole % NaPO₃-30 mole % Na_nX mixtures (X=PO₃ ^3–, P₂O₇ ^4–, F^–, Cl^–) in the molten and solid states has been investigated on the basis of data from electronic absorption and ESR spectra. The formation of tetragonally distorted Ti(III) coordination polyhedrons with D_4h symmetry coordinated only by (PO₃ ^–)_n chains with the following values of the spectroscopic parameters for the molten (and solid) states has been established in all the phosphate systems investigated: 10Dq=17,300 (18,000) cm^–1 (Ds=50 cm^–1, Dt=5600, g=1.959, g₁=1.930, =93. cm^–1). It has been shown that the greater is the extent of depolymerization of the phosphate chains in the melt, the stronger is the Ti(III) coordination polyhedron formed; the following relative series of the depolymerizing strength of the anions has accordingly been established: PO₄ ^3–2O₇ ^4–––.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 5, pp. 610–614, September–October, 1989.     

Spectrophotometric and derivative spectrophotometric determination of copper (II) with dithizone in aqueous phase

A Spectrophotometric and derivative Spectrophotometric study of Cu-dithizonate complex in aqueous phase in the presence of Triton X-100, a neutral surfactant, is reported. The system obeys Beer's law between 1.0 × 10^–6–9.0 × 10^–6 mol/l of Cu²⁺; detection limit is 12 ng/ml. The molar absorption coefficient, specific absorptivity and Sandell's sensitivity of the complex are 3.06 × 10⁴ 1 mol^–1 cm^–1, 0.4825 ml g^–1 cm^–1 and 2.1 × 10^–3 g cm^–2, respectively. The conditional stability constant of the 1 2 complex, calculated considering simultaneously existing equilibria, has been found to be 1.73 × 10¹¹ I² mol² (I = 0.07, pH 1.4, temperature = 10 °C). Absorption studies in the derivative mode have been carried out to determine the absorption maximum of the complex and to overcome interference due to the presence of certain metal ions. The method has been validated by determination of copper in beers, wines, human hair, goat liver and fly ash samples.     

Infrared absorption spectra of some C-halogenated 1, 2, 4-triazole derivatives

The IR absorption spectra of 3(5)-halo and 3, 5-dihalo derivatives of 1, 2, 4-triazoles and of their potassium and silver salts as solids in the 3500-400 cm^–1 range were studied. The characteristic absorption bands of the triazole ring and the C-H and N-H bonds were established.     

Extraction and spectrophotometric determination of uranium(VI) withN-phenylcinnamohydroxamic acid

Uranium(VI) reacts withN-phenylcinnamohydroxamic acid to form an orange-yellow complex in the pH range 5.5–8.5. The orange-yellow complex, having the composition of 12 (metal:ligand), is quantitatively extractable into ethyl acetate. The spectrum of the complex exhibits a maximum absorption at 400 nm with a molar absorptivity of 6500 M^–1·cm^–1. The coloured system obeys Beer's law in the concentration range 2–40g·ml^–1 of uranium(VI). The photometric sensitivity of the colour reaction is 0.037 g·cm^–2 of uranium(VI). Most of the common ions do not interfere and the method has been found to be simple, precise, and free from the rigid control of experimental conditions. The method has been applied to the determination of uranium in synthetic matrices and potable water.     

Spectrophotometric determination of palladium(II) with phenylfluorone in the presence of hexadecylpyridinium bromide

Phenylfluorone reacts with palladium(II) in the presence of hexadecylpyridinium bromide to form a water-soluble chelate with an absorption maximum at 630 nm, the absorbance being constant in the pH-range of 9.0–10.2. At this wavelength Beer's law is obeyed up to 7.25 × 10^–5 mol/L palladium(II). The sensitivity is very high and the molar absorptivity is 8.5 × 10⁴ L mol^–1 cm^–1, permitting the determination of palladium(II) at µg level. The ratio of palladium to phenylfluorone in the complex is 1:1. The method has successfully been applied to the determination of palladium in titanium alloys.     

Isolation,properties and association phenomena of alkaline salts and their crown complexes of a radical anion

The obtention of (tetradecachloro-4-oxidotriphenylmethyl)^–. M⁺ (M=Li, Na, K, n-Bu₄N) salts in ethereal solution and the isolation of some alkaline complexed salts (M=Li-12C4, Na-18C6, K-18C6, K(THF)₁–(H₂O)_3–4, n-Bu₄N) are described and discussed. The association phenomena of these salts has been studied by electronic spectroscopy, osmometry and electron spin resonance. Linear correlations between radii counterions and the position maxima of the electronic spectra bands permit the study of the species present in solution (free ions, ion pairs and quadrupolar aggregates).