Polyaminoalkohole als bifunktionelle Extraktionsmittel für Kupfer(II)

Polyamino Alcohols as Bifunctional Extractants for Copper(II) Polyamino alcohols obtained by the addition of mono- or bifunctional epoxides to disecondary diamines are studied with regard to their applicability to copper(II) extraction. The simple diamino diols IV, V , and VI proved to be inefficient. But, depending on the anion, distribution ratios D up to 1000 were measured with the polyamino alcohol III (chloroform as a diluent) in weakly acidic solution. This is a result of the special structure of the copper(II) complex of III which is both a metal chelate and a substituted ammonium salt. The ammonium part, because of its high affinity to the chloroform phase, has the function of a phase-transfer reagent of the chelate part.     

Sulfonamide mit heterocyclischen Substituenten als Extraktionsmittel für Kupfer(II)

Sulfonamides with Heterocyclic Substituents as Extractants for Copper(II) With 2-picolylbenzenesulfonamide (N2NHO₂SC₆H₅) as a model of the technical extractant LIX 34, the influence of functional variations on the extraction of copper(II) is studied and estimated by a comparison of the pH_1/2 values. The relation pH_1/2～–σ_p is observed for extractants with substituents in p-position of the benzene ring. Turning to 2-pyridylethylbenzenesulfonamide, which forms six-membered rings, an increase of pH_1/2 is observed. But no direct comparison is possible with 2-pyridylbenzenesulfonamide as the copper(II) complexes are dimeric having a structure analogous to copper(II) acetate. The substitution of the methylene group by an SO₂–(PSA? H) or an NH-residue (PTSH? H) is connected with an with an increase of pH_1/2 in the first case, but a decrease of pH_1/2 in the second one (7,2₅ and 2,7₀). The application of PTSH? H as an extractant for copper(II) is confined by a slow redox reaction with this ion. π-electron delocalization within the chelate rings, which are derived from sulfonylhydrazones of heterocyclic ketones, is a factor which, in general, improves the extraction properties. There is a strong differentiation of PH_1/2 (APSH? H 1,4; BBSH? H 6,9). An increase of the tetrahedral distortion of the chromophore CuN₄, as it is indicated by ESR, measurements, is connected with a decrease of pH_1/2. The benzenesulfonyl group influences the copper(II) extraction by bidentate nitrogen containing ligands in a twofold may: The protonation of the pyridyl and also that of other heterocyclic residues is rendered more difficult, but NH-acidity is increased. Some of the new extractants (APSH? H, BPSH? H) are as active as LIX reagents.     

Cyclotetrasilazane als precursor für cyclotrisilazane und bis(cyclodisilazan-1-yl)silane

Di-lithiated octamethylcyclotetrasilazane (OMCTS, 1) reacts with halosilanes in different ways. Ring contraction with formation of the isomeric cyclodisilazanes 2, 3 occurs in the reaction with chloro- and fluorotrimethylsilanes. Substitution (6) and ring contraction with formation of the isomeric six-membered ring 7 occurs with chlorodimethylsilane. 2, 3, 6 and 7 are excellent precursors of silyl-bridged, SiH-functional, four-membered ring systems (4, 5, 9–11). The mechanism of the isomerization reactions are discussed.     

5-(Thiazol-4-yl)-1,2,4-triazoles

By reaction of arylhydrazones of benzoyl chloride with 4-aminomethylthiazole in the presence of triethylamine, the corresponding amidrazones were obtained, which upon oxidation gave 5-(thiazol-4-yl)-1,2,4-triazoles with fungicidal and bactericidal activity.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2111–2112, September, 1991.     

Lithium-silylindolide als Precursor für 1,2-, 1,3-Bis(silyl)indole und Bis(indol-1,3-yl)silane

Lithium-silylindolide as Precursor of 1,2-, 1,3-Bis(silyl)indoles and Bis(indole-1,3-yl)silane Lithium-indolide reacts with difluorosilanes (F₂SiR₂: R = CHMe₂ ( 1 ); CMe₃ ( 2 )) in a molar ratio 2 : 1 with formation of bis(indole-1-yl)silanes. The 1-(di-tert-butylfluorosilyl)-3-(fluorodiisopropylsilyl)indole ( 3 ) is obtained in the reaction 1-(di-tert-butylfluorosilyl)-3-lithium-indolide and F₂Si(CHMe₂)₂. In a molar ratio 2 : 1 the bis(1-di-tert-butylfluorosilyl-indole-3-yl)diisopropylsilane 4 is formed. As a byproduct bis(1-di-tert-butylfluorosilyl-indole-3-yl)dimethylmethane ( 5 ) is isolated. A cleavage of THF and the formation of (indole-1-yl)diisopropylvinyloxysilan ( 6 ) occurs in the reaction of 1-diisopropylfluorosilylindole with t-BuLi in THF. 1-(di-tert-butylfluorosilyl)indole reacts with n-BuLi/TMEDA accompanied by an 1,2-anionic silyl group migration to give the 2-(di-tert-butylfluorosilyl)-1-lithiumindolide 7 . Hydrolysis of 7 gives the 2-(di-tert-butylfluorosilyl)indole ( 8 ). In the reaction of 7 with F₂Si(CHMe₂)₂ the 1-(diisopropylfluorosilyl)-2-(di-tert-butylfluorosilyl)indole 9 is obtained. 1-n-Butyl-diisopropylsilylindole ( 10 ) is the product of the reaction of F₂Si(CHMe₂)₂, n-BuLi/TMEDA and indole at –70 °C. Lithium-indolide reacts with 3 to give the 1-(di-tert-butylfluorosilyl)indole-3-yl)(indole-1-yl)-diisopropylsilane ( 11 ), the first example of this class of substances. In the reaction of 1 , F₂SiMe₂, and t-BuLi in THF the 1-(diisopropyl(indole-1-yl)silyl)-3-dimethyl-(3.3-dimethylbutylsilyl)indole 12 is isolated. The crystal structures of 2 , 5 and 9 are discussed.     

Untersuchungen an mechanisch aktivierten Kontakten. XI. Kupfer(II)-oxid als Kontakt für den N2O-Zerfall

Catalytic activity of mechanically activated and reheated CuO on the N₂O decomposition may be explained by the semiconductor properties of the catalyst. Longer mill treatment of powdered CuO increases its p-typness. This rise is due to creating excess oxygen in the lattice of CuO and probably also to the creation of lattice disturbance after short milling times. Acceptor centers are produced as the result of both processes followed by lowering of the Fermi level and rise of hole concentration.     

Untersuchungen an mechanisch aktivierten Kontakten. X. Kupfer(II)-oxid als Kontakt für die ortho-para-Wasserstoffumwandlung

CuO is mechanically activated in a vibrating mill. The samples were characterized by pore size distribution, specific surface area, susceptibility, o-p-H₂ conversion, primary particle size, lattice disturbance and lattice distortion. These properties of CuO change by mill treatment. The catalytic activity of the o-p-H₂ conversion is a function of susceptibility and lattice distortion.     

Synthese und Charakterisierung neuer fünf‐ und sechsfach koordinierter Mangan(II)‐Komplexe als Modellsysteme für manganabhängige Catecholdioxygenasen

Synthesis and Characterization of Novel Five‐ and Six‐coordinate Manganese Complexes as Catechol Dioxygenase Models The five‐ and six‐coordinate manganese complexes [Mn(tphhp)Cl₂] {tphhp = N,N′‐bis(2‐pyridylmethyl)‐2‐(2‐pyridyl)hexahydropyrimidine} ( 1 ), [Mn(bpma)Cl](ClO₄) {bpma = bis((2‐pyridylmethyl)((1‐methylbenzimidazol‐2‐yl)‐methyl)amine} ( 2 ) and [Mn(L)TCC] {HL = (1‐hydroxy‐4‐nitrobenzyl)((1‐methylimidazol‐2‐yl)methyl)(2‐pyridylmethyl)amine} ( 3 ) were synthesized and characterized by various techniques such as single crystal X‐ray structure analysis, mass spectrometry, IR and UV/vis spectroscopy, cyclic voltammetry, and elemental analysis. 1 and 2 crystallize in the monoclinic space group P2₁/n (No. 14) ( 1 ) and P2₁/c (No. 14) ( 2 ). The ligand and the chlorine ions provide the N₃Cl₂‐donorset in 1 and the N₃Cl₂‐donorset in 2 , respectively. Compounds 1 and 2 show catalytic activity regarding the oxidation of 3,5‐di‐tertbutylcatechol to 3,5‐di‐tert‐butylchinon. To our knowledge, 1 and 2 are the first five‐coordinate manganese complexes that show catecholase activity. 3 crystallize in the orthorhombic space group P2₁2₁2₁ (No. 19) and the ligand and tetrachlorocatechol (TCC) build the N₃O₃‐donorset in 3 .