Hydrophile Polymergele mit reaktiven Gruppen, 4. Mitt.: Chelatharze mit schwefelhaltigen Ankergruppen auf Basis von Saccharosemethacrylaten

Chelating resins with thioglycolate anchor groups have been synthesized by reaction of sucrosemethacrylate gels with thioglycolic acid. The capacities of the gels were found to be extremely high for Ag⁺ (5,3 mmol/g) and Hg²⁺ (4,9 mmol/g). About 1 mmol Hg²⁺/g could be recovered from the gel reversibly by treatment with hydrochloric acid. The removal of Hg²⁺ from aqueous 3M alkalichloride solutions was possible with capacities of 1 mmol/g.Sucrosemethacrylate gels with primary aromatic amino group were reacted with CS₂/NH₃ to yield gels with dithiocarbamate groups. Gels with thiorea groups were prepared by reaction of the amino groups with NH₄SCN/HCl. Diazotation of the amino groups, subsequent reaction with potassium xanthogenate and hydrolysis afforded gels with thiol groups. Thiol containing gels were synthesized also by reaction of the diazotised gels with Na₂S₂ and subsequent reduction with Na₂S. Reaction of the diazotised gels with mercaptans yielded resins with thioether anchor groups. The capacities of the sulfur containing gels were found to be max. 4,1 mmol/g for Hg²⁺ and 5,9 mmol/g for Ag⁺. About 35% of the bonded Hg²⁺ could be eluted resersibly with 3N-HCl.

     

Hydrophile Polymergele mit reaktiven Gruppen, 2. Mitt.: Chelatharze auf Basis von Glucose- und Saccharosemethacrylaten

A widely applicable method for the preparation of chelating resins based on glucose- and sucrosemethacrylate-gels is described. Primary aromatic amino groups were bonded to the carrier by esterification with 4-nitrobenzoylchloride and subsequent reduction of the nitro groups with sodium dithionite. Diazotation and coupling with various chelating ligands (8-hydroxyquinoline, dithizone, anthranilic acid, salicylic acid and pyrogallol) afforded chelating resins with capacities of max. 1.7 mmol/g. Sucrosemethacrylate-gels were etherified with 4-nitrobenzylchloride, epichlorohydrin, 4-nitrophenyl glycide ether (IIb), acrylonitrile and 4-nitrophenylacrylamide (IVb). Reaction of the gels with IIb or IVb and subsequent reduction of the nitro groups yielded reactive carriers with ether-linked primary aromatic amino groups. Diazotation and coupling with 8-hydroxyquinoline yielded chelating resins. The capacities of the gels were 0.6–0.7 mmol/g and these resins were extremely stable to changes inpH.

     

Hydrophile Polymergele mit reaktiven Gruppen, 5. Mitt.: Chelatharze mit phosphorhaltigen Ankergruppen auf Basis von Saccharosemethacrylaten

Phosphorus containing chelating resins were synthesized by reaction of sucrosemethacrylate gels with various dialkylester halides of phosphoric acid and thiophosphoric acid. The sorption capacities of the hydrophilic gels were found to be max. 3.7 mmol/g and equilibrium was achieved within 5 minutes. The recycle of adsorption and elution was found to be satisfactory for Zn²⁺ and Cu²⁺ whereas only 50% of the bonded Hg²⁺ could be recovered reversibly.

     

Komplexe von Acetylaceton und Acetonylaceton mit Alkali- und Erdalkaliionen. MO-SCF-Berechnungen und UV-Spektroskopie

In analogy to previous investigations on main group metal ion complexes with diacetyl², model calculations within the LCGO MO SCF framework using minimal basis sets are used in combination with UV spectrocopy in order to investigate complex formation tendencies, eventual ion specifities and ion binding energies of Li, Na, K, Mg and Ca ions with dicarbonyl ligands. The influence of the separation of the coordinative centers by methylene groups on the interaction with these metal ions is discussed. The simple quantum chemical models seem to work in the case of diacetyl and acetylacetone, whereas they fail in the prediction of the experimentally observed interaction of acetonylacetone with the metal ions.

     

Ein Beitrag zur Kristallchemie der Kobaltoxoniobate: CoNb2O6 mit Rutilstruktur

CoNb₂O₆ can be prepared by reaction of stoichiometric amounts of CoO (thermical decomposition of cobaltoxalate) and Nb₂O₅ in argon-atmosphere up to 1,400 °C. The isolated red-brown single crystals have tetragonal symmetry (a=472.6;c=305.4 pm; space group P4₂/mnm-D _4h ¹⁴ ). Electron probe micro-analysis of the single crystals verifies the composition Co_0.33Nb_0.67O₂. Co²⁺ and Nb⁵⁺ occupy statistically the metal positions of the rutil-type structure. The differences between Co_0.5Nb_0.5O₂ (CoNbO₄AlNbO₄-type) and Co_0.38Nb_0.67O₂ (CoNb₂O₆) are discussed.

     

Umsetzungen von Metall- und Metalloidverbindungen mit mehrfunktionellen Molekülen, 16. Mitt.

The reaction of trimethylsilylcarbonamides with halogeno-diorganyl-boranes resp. trihalogenoboranes or organodihalogenoboranes gives monomeric resp. dimeric amidoboranes (borylcarbonamides) and derivatives of 4,8-diaza-1,5-dibora-2,6,9-trioxabicyclo[3.3.1]nonadienes. By reaction of the free acylamides with halogenoboranes in most cases the imide halides could be isolated as the only products. By reaction of the hydrochloride of bis(dimethylamino)-hydroxyborane withn-butyl-lithium followed by addition of the imide halides, the corresponding imidoylamines were formed.¹H,¹¹B, and¹⁹F-nmr spectra, mass spectra and characteristic ir group frequencies are reported.

15. Mitt.:W. Maringgele undA. Meller, Z. anorg. allg. Chem., im Druck.     

Hydrophile Polymergele mit reaktiven Gruppen, 1. Mitt.: Herstellung und Polymerisation von Glucose- und Saccharosemethacrylaten

The synthesis of new hydrophilic polymer carriers on the basis of glucose-and sucrosemethacrylates is described. The monomer mixtures were prepared by reaction of glucose or sucrose with methacrylic anhydride or methacry-loylchloride in pyridine and by transesterification of sucrose with methylmethacrylate. Mixtures of methacrylic esters of glucosides could be obtained by analogous reaction of glucosides with methylmethacrylate. Radical polymerisation of the resulting mixtures of mono-and polyfunctional methacrylic esters of glucose and sucrose yielded crosslinked hydrophilic gels, swellable in water and polar organic solvents. The degree of crosslinking is determined by the ratio of mono- to polyfunctional esters in the monomer mixture, which depends on the molar ratio of reactants in the starting mixture. These neutral reactive carriers are stable to changes inpH and to biological degradation.

     

Über die Reaktionen von Guanidin bzw. Harnstoff mit Aminonitrilen

The aminonitriles3a–f react with guanidine inDMF to yield the 5,5-resp. 5-subtituted imidazolidine-2,4-diimines2a–d resp.2f, whereas2e could not be isolated. 7,14-diazadispiro[5.1.5.2]-pentadecan-15-on (7)¹, 4-imino-1,3-diazaspiro[4.5]decan-2-one (8a)¹ and the 2,4-diaminotriazine (9)¹ were isolated as byproducts.1-Aminocyclohexancarbonitrile (3a) reacts with urea to the 4-imino-1,3-diazaspiro[4.5]decan-2-one (8a)¹;8a can be prepared from (1-cyancyclohexyl)urea (11a) as well. The structures of the new compounds are proved by NMR-, IR- and mass spectra and the mechanism of the reaction is discussed.

Herrn Prof. Dr.G. Zigeuner zum 60. Geburtstag gewidmet.     

Asymmetrische Hg(II)-Komplexe mit Organothiolato- bzw. Organoselenolato-und Triazenato-Liganden

The mixed mercury complexes (2XC₆H₄)₂N₃HgY (X=CH₃, F, Cl, Br, I;Y=SC₂H₅, SC₆H₅, SeC₆H₅) have been prepared. Both the Hg–S and Hg–Se bonds and, in contrast to other mixed triazenato-mercury compounds, the triazenato-mercury bonds have been shown to be kinetically labile on the NMR time scale by means of⁷⁷Se and¹⁹⁹Hg NMR spectroscopy. Evidence has been obtained for the presence of (2XC₆H₄)₂N₃HgY together with HgY ₂ and [(2XC₆H₄)₂N₃]₂Hg in solution.

     

Diels-Alder-Reaktion eines elektronenarmen C-Acylimins mit Tetraethoxyethylen

Summary The synthesis of two C-acylimines and their reactivity towards electron rich dienophiles inDiels-Alder reactions is described. A [4+2] cycloadduct is obtained only in one case: from the reaction of a C-acylimine substituted by two methoxycarbonyl groups with tetraethoxyethylene. No [2+2] cycloadducts are observed.

     

Umsetzung von Metall- und Metalloidverbindungen mit mehrfunktionellen Molekülen, 22. Mitt.: Die Reaktion von Trimethylsilylcarbonsäureamiden mit Halogen(diorganyl)boranen

Trimethylsilylacetamide and trimethylsilyltrifluoroacetamide react with halogenodiorganylboranes to monomeric or dimeric amidoboranes depending on the organyl substituents. The compounds were characterized analytically and spectroscopically (NMR:¹H,¹⁹F,¹¹B; MS; IR).

21. Mitt.:A. Meller, W. Maringgele, K. Hennemuth undU. Sicker, J. Z. anorg. allg. Chem., im Druck.     

Zur Reaktion von Hydrazinen mit Fluorsilanen und lithiierten Aminen

Lithium salts of hydrazines react with fluorosilanes under formation of fluorosilylhydrazines and LiF. Five membered rings are obtained in the reaction of bis(fluorosilyl)-hydrazines with lithiated amines. The mass,¹H-and¹⁹F-nmr spectra of the compounds are reported.

     

Synthese und Konformation einiger Azaspirane mit Alkyl-bzw. Aryl-Sulfonamid-Gruppen

Preferred conformations of some azaspiran systems substituted with large groups at the nitrogen atoms were established by UV absorption spectroscopy. These groups prohibit the inversion at nitrogen, as was deduced from the¹H NMR spectra.

     

Quantitative Trennung von Schwermetallen mit Chelataustauschern auf der Basis von Polystyrol

Zusammenfassung Die Trennung und Isolierung von folgenden Schwermetallen bei einem hohen Überschuß an Fremdionen mit Hilfe neuer selektiver Chelataustauscher wird beschrieben: Cu²⁺/Zn²⁺, Cu²⁺/Pb²⁺, Ag⁺/Cu²⁺, Ag⁺/Pb²⁺, Hg²⁺/Zn²⁺, Hg²⁺/Cd²⁺; Abtrennung von Hg²⁺. Unter gleichen Bedingungen war mit dem handelsüblichen Austauscher Dowex A-1 keine Trennung möglich.

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Quantitative separation of heavy metals by means of chelating exchangers based on polystyrol

Summary The separation and isolation of the following heavy metals in presence of a high excess of foreign ions by means of new selective chelating exchangers is described: Cu²⁺/Zn²⁺, Cu²⁺/Pb²⁺, Ag⁺/Cu²⁺, Ag⁺/Pb²⁺, Hg²⁺/Zn²⁺, Hg²⁺/Cd²⁺; separation of Hg²⁺. Under the same conditions no separation could be achieved by the ion-exchanger Dowex A-1.

     

Über die Umsetzung von Dibenzylidensulfamiden mit Aminen

Addition of amines to dibenzylidene sulfamide1 a yields the correspondingSchiff bases3 a, b and monobenzylidene sulfamide2. Reaction of several dibenzylidene sulfamides1 with various lithium-amides gives N¹-substituted N²-benzylsulfamoyl-benzamidines7 a-k via an intramolecular hydride transfer reaction, whereas by treatment of1 a with sodium amide 2-benzyl-3,5-diphenyl-3,4-dihydro-2H-1,2,4,6-thiatriazine-1,1-dioxide8 is obtained, which on hydrolysis yields9 and11. Alkylation products are described, the isomeric products12a/13a and12b/13b are isolated, their structures are confirmed by synthesis, IR and NMR-spectra.

     

Über Erdalkalimetalloxogallate. VIII Synthese und Aufbau eines neuen Calciumoxogallats: Ca3Ga4O9

The hitherto unknown compound Ca₃Ga₄O₉ was prepared and investigated by X-ray single crystal methods. Ca₃Ga₄O₉ has orthorhombic symmetry:a=1435.8;b=1682.5;c=532.1 pm; space group C _2v ¹¹ –Cmm2,Z=6. The tetrahedra network (circles of 4 and 5 GaO₄-tetrahedra) and the surrounding of Ca²⁺ are described and discussed with respect to other oxogallates.

     

Der Einfluß großer Salzkonzentrationen auf die Oxydationsreaktion von Fe(phen) 3 2+ mit Ce(IV) in Schwefelsäure

The influence of NaClO₄, NaCl and Na₂SO₄ on the oxidation of Fe(phen) ₃ ²⁺ by Ce(IV) was investigated by means of the stopped-flow method. At the concentrations range of NaClO₄ and NaCl 0.1–1.0M the rate constant values decrease from 1.03·10⁵ to 0.56·10⁵M^–1s^–1 and from 1.08·10⁵ to 0.81·10⁵M^–1s^–1 respectively.In varying concentrations of Na₂SO₄ solutions (0.05–0.35M) the rate constant values decrease from 1.05·10⁵M^–1s^–1 to 0.45·10⁵M^–1s^–1.Taking into account the negative salt effect the mechanism of the reaction progress is proposed.

     

Biosorption of metal ions with Penicillium chrysogenum

Biosorption of metal ions with Penicillium chrysogenum mycelium is described in this article. Alkaline pretreatment was used to remove proteins and nucleic acids from cells, and this treatment increased the adsorption capacities, for Cr³⁺ from 18.6 mg g⁻¹ to 27.2 mg g⁻¹, for Ni²⁺ from 13.2 mg g⁻¹ to 19.2 mg g⁻¹, for Zn²⁺ from 6.8 mg g⁻¹ to 24.5 mg g⁻¹. The adsorption of metal ions was strongly pH dependent. The mycelium could beused for large-scale removal of Cr³⁺ from tannery wastewater. The results show that this inexpensive mycelium adsorbent has potential in industry because of its high adsorption capacity. The main chelating sites are amino groups (−NH₂) of chitosan in the mycelium. A new model is established, which describes the relation of adsorption of metal ions on pH according to amino group chelating with metal ions and H⁺. The relative errors of simulation for Cu²⁺, Ni²⁺, Zn²⁺, and Cr³⁺ are 4.66%, 5.45%, 11.55%, and 1.69%, respectively.     

Abtrennung von toxischen Schwermetallen aus L?sungen mit chelatbildenden Celluloseaustauschern

Zusammenfassung Die Abtrennung von Spurenelementen (Hg, Cd, As, Mo, Cr) an drei Celluloseaustauschern mit chelatbildenden Ankergruppen wird beschrieben. An den Austauschern mit den Ankergruppen o-Aminothiophenol und Glyoxal-bis(2-mercaptoanil) werden hohe Verteilungskoeffizienten für Hg²⁺, Hg ₂ ²⁺ , CH₃Hg⁺ und Cd²⁺ gefunden, niedrigere für Arsenit und Arsenat; (CH₃)₂Hg wird nicht gebunden. Der mit Fe³⁺ beladene Hyphan-Austauscher weist hohe Verteilungskoeffizienten für Arsenat auf, etwas niedrigere für Arsenit, Chromat und Molybdat. In Trennsäulen werden die Kationen Hg²⁺ und Cd²⁺ und die Anionen Arsenat und Molybdat voneinander getrennt.

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Separation of toxic heavy metals from solutions by means of chelating cellulose exchanges

Summary The separation of trace elements (Hg, Cd, As, Mo, Cr) on three cellulose exchangers with chelating anchor groups is described. On exchangers with the anchor groups o-aminothiophenol and glyoxal-bis(2-mercaptoanil) high distribution coefficients are found for Hg²⁺, Hg ₂ ²⁺ , CH₃Hg⁺ and Cd²⁺, lower ones for arsenite and arsenate; (CH₃)₂Hg is not bound. The exchanger Hyphan loaded with Fe³⁺ shows high distribution coefficients for arsenate, somewhat lower ones for arsenite, chromate and molybdate. In separation columns the cations Hg²⁺ and Cd²⁺ and the anions arsenate and molybdate are separated from each other.

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Herrn Prof. Dr. H. Weisz zum 60. Geburtstag gewidmet     

Kinetische Untersuchungen über die Silicium—Aryl-Spaltung mit Bromwasserstoff

Rate constants of the cleavage reaction of silicon aryl linkages with HBr were estimated for various aryl derivatives by means of NMR. A row of substituents was obtained, dependent on the cleavage rates. Correlation with theHammett function shows the electrophilic character of the reaction. The different cleavage rates give the possibility for specific cleavages of aryl groups from silanes.