Reversible protection of oligomeric ethylene glycols by bis (2,4-dinitrophenylation) and basic ethanolysis

Bis-(2,4-dinitrophenyl)glycols are stable in the presence of triethylamine but undergo ethanolysis in the presence of hydroxide ions. The quantitative removal of the DNP blocking group allows an integrated scheme to pure glycols from commercially available polyethylene glycol mixtures

1 Mixtures of ethylene glycol oligomers are obtained by anionic polymerization of ethylene oxide. See, for example, G. O. Curme and F. Johnston, Glycols, Reinhold, New York, 1953. They are commercially available (as PEG-200, PEG-400, etc., to indicate the average molecular weight of the major components).

by bis-dinitrophenylation, chromatographic separation, and end-group removal, using high performance liquid chromatography (HPLC) of the bis-(2,4-dinitrophenyl)glycols for purity monitoring. A facile synthetic method for the production of penta-to dodecaglycols in a mixed, aqueous, dioxane solvent system, with fair yields, is also described. The bis-(2,4-dintrophenyl) protection of glycols is a reversible reaction that can be used as (1) a preparative method for pure glycols from readily available commercial polyethylene glycol mixtures; (2) a highly sensitive and accurate analytical method

2 A. Warshawsky, A. Tishbee, and N. Shoef, J. Liq. Chromatogr., submitted for publication.

coupled with HPLC.     

Reactions of bis(2,4-dinitrophenyl) phosphate with hydroxylamine

For dephosphorylation of bis(2,4-dinitrophenyl) phosphate (BDNPP) by hydroxylamine in water, pH region 4-12, the observed first-order rate constant, k(obs), initially increases as a function of pH, but is pH-independent between pH 7.2 and pH 10. The initial BDNPP cleavage by nonionic NH(2)OH (<0.2 M) involves attack by the OH group and follows first-order kinetics, but the overall initial reaction of BDNPP liberates ca. 1.7 mol of 2,4-dinitrophenoxide ion (DNP). This initial reaction generates a short-lived O-phosphorylated hydroxylamine, 2, followed by three possible reactions: (1) reaction of 2 with hydroxylamine, generating 2,4-dinitrophenyl phosphate (DNPP, 3), which subsequently forms DNP; (2) intramolecular displacement of the second DNP group and rapid decomposition of the cyclic intermediate to form phosphonohydroxylamine and eventually inorganic phosphate; (3) a novel rearrangement with intramolecular aromatic nucleophilic substitution involving a cyclic intermediate and migration of the 2,4-dinitrophenyl group from O to N. Values of k(obs) increase modestly with pH > 10, the reaction is biphasic, and the yield of DNP increases. An increase in [NH(2)OH] also increases the yield of DNP, due largely to accelerated hydrolysis of DNPP.     

Hydrogen bonding and sodium coordination in the crystal structure of tetrasodium (3-((2,4-dinitrophenyl)amino)-1-hydroxypropane-1,1-diyl)-bis-phosphonate pentahydrate – a N-substituted Pamidronate

The reaction of 1-fluoro-2,4-dinitrobenzene with (3-amino-1-hydroxypropane-1,1-diyl)bis(phosphonic acid) (pamidronic acid) 1a in combination with NAOH leads to disodium (3-((2,4-dinitrophenyl)amino)-1-hydroxy-propane-1,1-diyl)bis(phosphonate) heptahydrate 2 and further to tetrasodium (3-((2,4-dinitrophenyl)amino)-1-hydroxy-propane-1,1-diyl)bis(phosphonate) pentahydrate 3. The crystal structure of 3 is composed of the organic anion, which is coordinated to the sodium counter cations and furthermore is involved in hydrogen bonds. The 2,4-dinitrophenyl moiety gives rise to π–π connected hydrophobic layers. The hydrophilic moiety of the anions, sodium cations and water molecules form a hydrophilic layer. The individual conformation of this N-substituted pamidronate anion is a compromise between its geometric limitations and the intermolecular interactions with sodium and the water molecules.     

A Micro-Scale Preparation of Affinity-Purified Fab'-Enzyme Conjugates with High Purity for Enzyme Immunoassay

Abstract

A micro-scale method was developed for conjugating a small amount of affinity-purified Fab' to enzymes through thiol groups in the hinge of Fab'. 2,4-Dinitrophenyl groups were introduced into rabbit anti-hCG F(ab')₂ before affinity-purification, and the 2,4-dinitrophenyl F(ab')₂ (0.2–2.0 mg) was affinity-purified by elution from a column of hCG-Sepharose 46 with 0.1 M glycine-HC1 buffer, pH 2.5, containing normal rabbit F(ab')₂ (1.0 mg) as a carrier. The affinity-purified 2,4-dinitrophenyl F(ab')2 mixed with normal F(ab')₂ was split into Fab' by reduction, reacted with maleimide groups introduced into enzymes and subjected to gel filtration to separate the conjugates from unconjugated components. Finally, the affinity-purified 2,4-dinitrophenyl anti-hCG Fab'-enzyme conjugates were separated from normal Fab'-enzyme conjugates and unconjugated enzyme, if any, by affinity chromatography on a column of (anti-2,4-dinitro-phenyl) IgG-Sepharose 4B. The conjugate preparations obtained by the micro-scale method were satisfactory in purity, antigen-binding activity and usefulness for sandwich enzyme immunoassay.

This method is applicable to the conjugation not only with horseradish peroxidase but with other enzymes, while a previously reported method is applicable only to the conjugation with horseradish peroxidase.     

Design and Synthesis of Novel Amino Acid‐Bearing Macrocyclic Calix[4]Arenes

Abstract

A new family of macrocyclic calix[4]arenes (4a–d) potentially capable of chiral recognition were synthesized by incorporating the chirality inducing moieties, bis α‐amino acylated polyethylene glycols, or tripeptide bis‐Phe Cystine(OMe)₂ to the lower rim.     

Thiol peroxidase-like activity of some intramolecularly coordinated diorganyl diselenides

Several new diaryl diselenides having intramolecular coordinating groups have been synthesized by ortho-lithiation/Na2Se2 routes in good yield. Bis[2-(N-phenylferrocenecarboxamide)] diselenide (10), bis[2-(N-tert-butylferrocenecarboxamide)] diselenide (11), (S)(S)-bis[2(-N-phenethylferrocene-carboxamide)] diselenide (12) were synthesized by the ortho-lithiation route. Bis[2-(N,N-dimethyl-aminomethylnaphthyl)] diselenide (13) was synthesized by lithium/bromide exchange reaction whereas bis(2,4-dinitrophenyl) diselenide (14) was prepared by the reaction of disodium diselenide with 2,4-dinitro-1-chlorobenzene. Thiol peroxidase-like activities of the diorganodiselenides have been evaluated by using H₂O₂ as substrate and PhSH as cosubstrate. Diselenides (13) and (14) with dimethylami-nomethyl- or nitro-donor groups in close proximity to selenium, show much better thiol peroxidase-like activities compared to diselenides10–12 with amide donor groups. Cyclic voltammetry study of diselenides10–12 derived from redox-active ferrocenamide has been carried out. Dedicated to the memory of the late Professor Bhaskar G Maiya.     

Substitutionsreaktionen an Bis(iminoboranen)

Zusammenfassung 2,2,4,4-Tetrachlorcyclodiborazane von Bis(iminoboran)-Typ geben in nicht-äther. Lösung mit Butylmagnesiumchlorid entsprechende 2,4-Dibutyl-2,4-dichlorverbindungen, mit Butyl-Li 2,2,4,4-Tetrabutylderivate. Die Azidierung von 2,2,4,4-Tetrahalogenocyclodiborazanen mit NaN₃ in CH₃CN führt zu den B-Tetrazidoverbindungen, jene von 2,4-Dihalogeno-2,4-dialkylcyclodiborazanen zu 2,4-Diazido-2,4-dialkylcyclodiborazanen. Bei großem Azidüberschuß können in 2,2,4,4-Tetraalkylcyclodiborazanen auch Halogenatome an den Iminkohlenstoffen azidiert werden. In einigen Fällen wurde Spaltung des Cyclodiborazans beobachtet.

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Substitution reactions of bis(iminoboranes)

2.2.4.4-Tetrachlorocyclodiborazanes of bis(iminoboran) type can be alkylated in non-etheric solvents to yield the corresponding 2,4-dibutyl derivates by C₄H₉MgCl while C₄H₉Li yields the tetrabutyl compounds. Reaction of 2.2.4.4-tetrahalogenocyclodiborazanes with NaN₃ in CH₃CN gives B-tetrazidocyclodiborazanes, while 2.4-dialkyl-2.4-dihalogenocyclodiborazanes lead to dialkyldiazido compounds. Upon full alkylation on the B-atoms also halogeno substituents on the imino C-atoms are substituted by N₃ using a large excess of NaN₃. In some cases splitting of the cyclodiborazane ring was observed.

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Mit 2 Abbildungen     

The reactions of non-gem-hexanedioxytetrachlorocyclotriphosphazene with 2-(2-hydroxyethyl)thiophene,benzyl alcohol and 1,1,3,3-tetramethylguanidine. Spectroscopic studies of the derived products

Abstract

Reactions of non-gem-hexanedioxytetrachlorocyclotriphosphazene (1) with monofunctional nucleophilic reagents, 2-(2-hydroxyethyl)thiophene (2), benzyl alcohol (3) and 1,1,3,3-tetramethylguanidine (4) were investigated. The reactions, using an excess of NaH, in THF solutions, under refluxing conditions and with 1:2?mole ratios allow the synthesis of the following novel cyclotriphosphazene derivatives: 2,4-dichloro-2,4-(hexane-1,6-dioxy)-6,6-[2-(2-ethoxy)hiophene]-cyclotriphosphazatriene, N₃P₃Cl₂[O(CH₂)₆O-(C₆H₈OS)₂] (5); 2,4-(hexane-1,6-dioxy)-2,4,6,6-[2-(2-ethoxy) thiophene]-cyclotriphosphazatriene, N₃P₃[O(CH₂)₆O-(C₆H₈OS)₄] (6); 2,4-dichloro-2,4-(hexane-1,6-dioxy)-6,6-(methoxybenzene)-cyclotriphosphazatriene, N₃P₃Cl₂[O(CH₂)₆O-(C₆H₅CH₂O)₂] (7); 2,4-(hexane-1,6-dioxy)-2,4,6,6-(methoxybenzene)-cyclotriphosphazatriene, N₃P₃[O(CH₂)₆O-(C₆H₅CH₂O)₄] (8); and 2,4-dichloro-2,4-(hexane-1,6-dioxy)-6,6-(1,1,3,3-tetramethyguanidine)-cyclotriphosphazatriene, N₃P₃Cl₂[O(CH₂)₆O-HN-CN₂(CH₃)₄] (9). The structures of the synthesized compounds (5–9) have been characterized by elemental analysis, TLC-MS, ¹H, ¹³C and ³¹P {+¹H} and {?¹H} NMR spectral data.     

Homodinuclear glycolate derivatives of bismuth(V) and arsenic(III): synthesis and spectroscopic studies

Ligand bridged homodinuclear derivatives of bismuth(V) of the type, (1a–1d) [where R =–C(CH₃)₂CH₂CH(CH₃)–(1a),–CH(CH₂CH₃)CH₂–(1b),–CH(CH₃)CH(CH₃)–(1c),–CH(CH₃)CH₂–(1d)] have been synthesized by reactions of equimolar oxobis(triphenylbismuth)dichloride, {[Ph₃Bi]₂O}Cl₂ with glycols, HOROH in the presence of NaOMe. Reactions of sodiumtetraisopropoxoarsonate, NaAs(OPrⁱ)₄ with in 1 : 1 molar ratio yielded homodinuclear alkoxo derivatives of arsenic(III) containing glycols, (2a–2d). All compounds were characterized by elemental analysis, molecular weight determinations, IR and NMR (¹H and ¹³C) spectral studies.     

Zur Umsetzung von metallierten (Di)Alkylaminosilylaminen mit Chlorsilanen

Zusammenfassung Na- und Li-metallierte Dialkylaminodimethylsilylamine reagieren mit ClSi(CH₃)₃, ClSi(CH₃)₂Cl oder ClSi(CH₃)₂N(C₂H₅)₂, wie aus den Gl. (1) bis (12) ersichtlich, zu in 1-oder auch in 1- und 3-Stellung dialkylamino- und chlorsubstituierten Disilazanen (I bis IV) bzw. zu den Tris(silyl)aminen V und VI. — Ein Über-blick orientiert über sämtliche Reaktionsschritte alkylamino-oder phenoxysubstituierter Silylamine, wie sie in unseren Mitteilungen über SiN-Verbindungen 51 bis 55 und 73 bis 74 aus-führlich beschrieben sind.

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Na- and Li-metallated (di)alkylaminodimethylsilylamines react according to equations (1)–(12) with ClSi(CH₃)₃, ClSi(CH₃)₂Cl or ClSi(CH₃)₂N(C₂H₅)₂, to give the dialkylamino and chloro substituted disilazanes (I–IV) and tris(silyl)amines (V–VI). A review is given of all reaction steps of alkylamino or phenoxy substituted silylamines described earlier and in detail in the authors papers 51 to 55 and 73 to 74 on Si–N compounds.

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73. Mitt.:U. Wannagat undG. Schreiner, Mh. Chem.99, 1372 (1968).

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Mit Auszügen aus der DissertationG. Schreiner, Techn. Hochschule Graz, 1965.     

Archetypical Conductive Polymer Structure for Specific Interaction with Proteins

A series of 2,4-dinitrophenyl (DNP) functionalized polypyrrole terpolymers, capable of specific binding to IgE antibodies (proteins), have been synthesized using oxidizing initiator, ammonium persulfate and were characterized by ¹H-NMR, IR, DSC, Light Scattering etc. The terpolymers were composed of monomers and macromonomers: monomer (pyrrole), macromonomer A (pyrrole with pendant ethylene glycol) and macromonomer B (pyrrole with pendant DNP) with specific functionality of conductance, processiblity and binding, respectively. The terpolymers are found to be semiconductive, (5 × 10^?6 S cm^?1) by itself without the addition of doping agents. Molecular dynamics simulation of terpolymer shows that the DNP-(2,4-dinitrophenyl) functional group extends out from the polymer backbone and thus, is available for binding. The DNP functional groups on the terpolymer achieve steady state binding with anti-DNP IgE proteins at nanomolar concentrations in solution. The terpolymer was blended with sulfonated polystyrene and processed in fibers which exhibited effective specific binding to fluorescently tagged IgE proteins and therefore, possessed the potential to be an active component in biosensor.     

Einige Neue N,S-Substituierte 2-Nitrodienverbindungen Aus Reaktionen Von Mono(p-fluorarylthio)substituierten Dienen Mit Aminen

2-Nitrodiene compound 1 was stirred with p-fluorothiophenol for a long time and compound 3 was obtained. Compound 1 gave bis(thio)substituted 2-nitrodiene compound 4 and tris(thio)substituted compound 5 with 2 moles of p-fluorothiophenol in the presence of NaOH in ethanol. The compounds 9a–g have been prepared from 8a–g and 3. Compound 7 was obtained from the reaction of mono(thio)substituted 2-nitrodiene with morpholine. Compound 3 gives 11a–d in the reaction with piperidines in CH₂Cl₂ (or ether). Compound 13a–b have been obtained from the reaction of compound 3 with primary amines 12a–b. Compound 3 gives 15 and 16 in the reaction with 2,5-dimethylpiperazine in CH₂Cl₂.

     

Thiophosphorylation of Pharmacophoric Phenols,Diols, and Triols

Abstract

Novel organyldithiophosphonic and bis(aryldithiophosphonic) acids were obtained by the reaction of 2,4-diorganyl 1,3,2,4-dithiadiphosphetane-2,4-disulfides with paracetamol, 4-(1H-pyrrol-1-yl)phenol, ethambutol dihydrochloride, vitamin B₆, and its acetonide derivatives.     

New polyfunctional silicon-containing amines C6[CH2CH2SiMe(OCH2CH2NR2)2]6 (R = H,Me) and their reactions with cobalt(ii) chloride and dicobalt octacarbonyl

Hexakis[bis(2-aminoethoxy)methylsilylethyl]benzene and hexakis[bis(N,N-dimethyl-2-aminoethoxy)methylsilylethyl]benzene C₆[(NR₂CH₂CH₂O)₂SiMeCH₂CH₂]₆ (4, R = H; 5, R = Me) were prepared from hexakis(methyldichlorosilylethyl)benzene C₆(Cl₂MeSiCH₂CH₂)₆ and 2-aminoethanol or N,N-dimethyl-2-aminoethanol, respectively. Compounds 4 and 5 react with anhydrous cobalt (ii) chloride to give poorly soluble dodecachloro{hexakis[bis(2-aminoethoxy)methylsilylethyl]benzene}hexacobalt and dodecachloro{hexakis[bis(N,N-dimethyl-2-aminoethoxy)methylsilylethyl]benzene}hexacobalt {Co₆[(NR₂CH₂CH₂O)₂SiMeCH₂CH₂]₆C₆}Cl₁₂ (R = H or Me), respectively. Polyfunctional amine 4 reacts with dicobalt octacarbonyl to produce hexakis[bis(2-aminoethoxy)methylsilylethyl]benzenedicobalt(ii) tetrakis(tetracarbonylcobaltate) {Co₂[(NH₂CH₂CH₂O)₂SiMeCH₂CH₂]₆C₆}[Co(CO)₄]₄. N,N-Dimethyl-substituted polyfunctional amine 5 is lowly reactive in the reaction with Co₂(CO)₈, whereas the simplest model of this compound, viz., bis(N,N-dimethyl-2-aminoethoxy)dimethylsilane (NMe₂CH₂CH₂O)₂SiMe₂, slowly reacts with Co₂(CO)₈ to give tris[bis(N,N-dimethyl-2-aminoethoxy)dimethylsilane]cobalt(ii) bis(tetracarbonylcobaltate) {Co[(NMe₂CH₂CH₂O)₂SiMe₂]₃}[Co(CO)₄]₂. Thermal decomposition and transformations of the resulting complexes under the action of oxygen and water were studied.     

PHOSPHORORGANISCHE VERBINDUNGEN 851 SYNTHESE UND ANWENDUNG OPTISCH AKTIVER TERTIÄRER PHOSPHINE ALS CO-KATALYSATOREN DER HOMOGENHYDRIERUNG MIT RHODIUM-PHOSPHIN-KOMPLEXEN

Abstract

Die Darstellung der optisch aktiven Methyl-n-propyl(bzw.-isopropyl)arylphosphine 1 bis 8 wird beschrieben. Hierbei ist Aryl: p-Methoxyphenyl (1 und 2), p-Dimethylaminophenyl (3 und 4), o-Methoxyphenyl (5 und 6), o-Dimethyl-aminophenyl (7) und o-Aminophenyl (8).

Die Phosphine 1 bis 8 werden als optisch aktive Co-Katalysatoren bei der Homogenhydrierung von α- und ß-Methylzimtsäureethylester, der α-Acetaminoacrylsäure und der α-Acetaminozimtsäure mit Rhodium-Phosphinkomplexen eingesetzt und jeweils die optische Induktion bestimmt. Folgende Ergebnisse (Vgl. die Tabellen 1 bis 4) wurden erhalten:

1) Die CH₃O-Gruppe und N(CH₃)₂-Gruppe verändern unabhängig von ihrer Stellung die optische Induktion bei der Homogenhydrierung von α- und ß-Methylzimtsäureethylester nur unwesentlich im Vergleich zu den entsprechenden Methyl-n-propyl (bzw.-isopropyl)-phenylphosphinen.

2) Bei der Homogenhy drierung von α-Acetaminoacrylsäure und α-Acetaminozimtsäure üben para-ständige OCH₃- und (CH₃)₂N-Gruppen in den optisch aktiven Co-Katalysatoren (Verbindungen 1 bis 4) keinen Einfluß auf die Höhe der optischen Induktion aus.

3) In ortho-Stellung verknüpfte OCH₃- und (CH₃)₂N-Gruppen (Verbindungen 5 bis 7) führen jedoch bei der Homogenhydrierung von α-Acetaminoacrylsäure und α-Acetaminozimtsäure zu einer beachtlichen Erhöhung der optischen Induktion. Bei α-Acetaminozimtsäure und 7 als Co-Katalysator beträgt die optische Induktion 80%! Hierbei übertrifft die (CH₃)₂N-Gruppe die CH₃O-Gruppe an Wirksamkeit.

4) Methyl-n-propyl-o-aminophenylphosphin 8 ist als Co-Katalysator unbrauchbar, da es offenbar durch Wechsel-wirkung der NH₂-Gruppe mit Rhodium die Koordinierung des prochiralen Olefins mit dem Komplex unterdrückt.

5) Eine experimentell begründete Deutung für das Zusammenwirken der am Aufbau der Homogenkatalysatoren beteiligten Komponenten konnte nicht gegeben werden.

Tabelle 5 zeigt die Abhängigkeit der Hydriergeschwindigkeit von Art und Stellung der Substituenten im Phenylrest. Die Hydriergeschwindigkeit ist bei den induktionsstarken Co-Katalysatoren 5 bis 7 deutlich vermindert.

The preparation of the optically active methyl-n-propyl(isopropy) aryl phosphines 1 ± 8 is described, whereby the aryl group is p-methoxyphenyl (1, 2), p-dimethylaminophenyl (3, 4), o-methoxyphenyl (5, 6), o-dimethylaminophenyl (7) and o-aminophenyl (8).

The phosphines 1–8 were used as chiral co-catalysts at the rhodium complex in the homogeneous hydrogenation of α- and ß-methyl cinnamic acids, α-acetaminoacrylic acid and α-acetaminocinnamic acid. The optical induction in the products was measured. The following results (see Tables 1–4) were obtained:

1) The methoxy and dimethylamino groups, independent of their site, have only negligible influence on the optical yield in the reduction of α- and ß-methylcinnamic acids compared with the parent methyl-propylphenylphosphine.

2) In the hydrogenation of acetaminoacrylic acid and α-acetaminocinnamic acid, para methoxy- or dimethylamino groups (compounds 1–4) show likewise no special influence on the optical yield.

3) Ortho methoxy or dimethylamino groups (compounds 5–7), however, result in a measurable increase in optical yield in the reduction of α-acetaminoacrylic- and α-acetaminocinnamic acids. In the case of compound 7 with α-acetaminocinnamic acid, an optical purity of 80% was obtained! The dimethylamino group is in this case more effective than the methoxy group.     

Cleavage of the sulfur-sulfur bond in 2,4-dinitrophenyl 4-substituted phenyl disulfides by trans-[IrX(CO)(PPh3)2]

A series of 2,4-dinitrophenyl 4-Y-phenyl disulfides (Y=NO₂, Br, F, H, CH₃, or CH₃O) have been shown to react with trans-IrX(CO)(PPh₃)₂ (X=Cl, Br, or I) in refluxing benzene to form “oxidative-elimination” products of the type, [IrX(SC₆h₄Y)(SC₆H₃(NO₂)₂)(CO)(PPh₃)]₂. The physical properties of these complexes are discussed in relation to their structure in the solid state and in solution. In particular, available infrared spectral data indicate that these complexes contain 2,4-dinitrobenzenethiolato bridging groups and that the substituted arenethiolato ligand is trans to carbon monoxide.     

Mixed Chloro Bis[Alkylenedithiophosphato] Antimony(III) and Their Heterobinuclear Derivatives with Boron Tetraisopropoxide: Synthesis and Characterization

Chloro bis(alkylenedithiophosphato)antimony(III) complexes of the type [OGOP(S)S]₂SbCl (1–5) [where G = —C(Me)₂—CH₂—CH(Me)—1 —C(Me)₂—C(Me)₂—2, —CH₂—C(Me)₂—CH₂—3, —CH(Me)—CH(Me)—4 and –CH(Me)—CH₂—CH₂—5] have been synthesized by the reaction of SbCl₃ with sodium salts of alkylenedithiophosphoric acids in a 1:2 molar ratio in refluxing benzene. Reactions of chloro bis(alkylenedithiophosphato) antimony(III) compounds, [OGOP(S)S]₂SbCl with sodium tetraisopropoxoborate, NaB(OPrⁱ)₄, in a 1:1 molar ratio in refluxing benzene yielded some new heterobinuclear derivatives of antimony(III) and boron(III) of the type[OGOP(S)S]₂Sb(μ—OPrⁱ)₂B(OPrⁱ)₂. These newly synthesized complexes have been characterized by elemental analysis and molecular weight measurement, and their plausible structures have been proposed on the basis of IR, NMR (¹H, ¹³C,³¹P,¹¹B), and FAB-mass spectral studies. On the basis of the spectroscopic evidence, a pseudo octahedral geometry around antimony and tetrahedral geometry around boron atom has been proposed. Cyclic O,O′-alkylenedithiophosphate ligands and their corresponding chloro bis(alkylenedithiophosphato)antimony(III) compounds have been screened for microbial activities. These compounds showed significant antifungal activity against Fusarium and Trichoderma and antibacterial activity against E. Coli and Pseudomonas.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

A Fast,Simple Method for Analysis of Phenoxy Acid Salt and Ester Formulations by High Performance Liquid Chromatography

Abstract

Salt formulations of 2,4-D (2,4-dichlorophenoxyacetic acid), 2,4,5-T (2,4,5-trichlorophenoxyacetic acid) and dichlorprop [2-(2,4-dichlorophenoxy)propanoic acid] have been analysed by reversed-phase HPLC using a C18-column with 50:50 (v/v) acetonitrile/2% acetic acid as eluant. Internal and external standard HPLC methods are compared.

Ester formulations of 2,4-D and 2,4,5–T are analysed, without hydrolysis, on the same column using 60:40 (v/v) acetonitrile/2% acetic acid as eluant. The method has been used in this laboratory to determine free phenoxy acid in ester formulations, and for the identification of esters in mixed ester formulations.

The methods are fast and accurate, and offer some advantages over previously-described methods.     

Synthesis,structure and antioxidant properties of manganese(II), zinc(II) and cobalt(II) complexes with bis(benzimidazol-2-ylmethyl)allylamine

Three new metal complexes, namely: [Mn(AIDB)Cl₂]·DMF (1), [Zn(AIDB)Br₂]·CH₃OH (2) and [Co(AIDB)Cl₂]·CH₃OH (3) having a ligand bis(benzimidazol-2-ylmethyl)allylamine (AIDB), have been synthesized in high yields and characterized by elemental analyses, molar conductivities, IR, UV–Vis spectra and single-crystal X-ray diffraction. The structural analysis revealed that all the three complexes 1–3 have five-coordinated trigonal bipyramid geometry where the degree of distorting is 1>3>2. In vitro antioxidant activity assay demonstrates that the complexes 1 and 3 display high scavenging activity against hydroxyl (OH·) and superoxide (O₂^−·) radicals.

     

Novel Copolymers of Vinyl Acetate with Alkyl and Alkoxy Ring‐Disubstituted 2‐Phenyl‐1,1‐dicyanoethylenes

Electrophilic trisubstituted ethylene monomers, alkyl and alkoxy ring‐disubstituted 2‐phenyl‐1,1‐dicyanoethylenes, RC₆H₃CH?C(CN)₂ (where R is 2,4‐(CH₃)₂, 2,5‐(CH₃)₂, 2,3‐(CH₃O)₂, 2,4‐(CH₃O)₂, 2,5‐(CH₃O)₂, 3,4‐(CH₃O)₂, 3‐C₂H₅O‐4‐CH₃O, 4‐CH₃O‐3‐CH₃), were synthesized by piperidine catalyzed Knoevenagel condensation of ring‐disubstituted benzaldehydes and malononitrile, and characterized by CHN elemental analysis, IR, ¹H‐ and ¹³C‐NMR. Novel copolymers of the ethylenes and vinyl acetate were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator (ABCN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, ¹H and ¹³C‐NMR, GPC, DSC, and TGA. High T _g of the copolymers, in comparison with that of polyvinyl acetate, indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. The gravimetric analysis indicated that the copolymers decompose in the 190–700°C range.