Komplexone XLIII. Die Komplexe des dreiwertigen Antimons mit Polyaminocarboxylaten

If a strong base is added to solutions containing complexes of trivalent antimony with aminopolycarboxylates, these ligands are displaced, and oversaturated solutions of antimony (III) hydroxide are formed. This reaction has been used to investigate the formation of complexes of Sb^III with the following ligands: N′-hydroxyethyl-ethylenediamine-N,N,N′-triacetate ion, ethylenediamine-N,N,N′,N′-tetraacetate ion, 1,2-diaminocyclohexane-N,N,N′,N′-tetraacetate ion, and diethylenetriamine-N,N,N′,N″,N″-pentaacetate ion.     

Synthesis of N,N,N-4,4＂-Di-（4-methylphenyl）-2,2＇：6＇,2＂- terpyridine-N,N,N-tris（isothiocyanato） Ruthenium（Ⅱ） and Application to Colorimetric Hg^2＋ Sensor

A terpyridine derivative DPTP [di-（4-methylphenyl）-2,2＇：6＇,2＂-terpyridine] was conveniently synthesized from 2-bromopyridine via halogen-dance reaction, Kharash coupling and Stille coupling reaction. Then its corresponding ruthenium complex Ru-DPTP [N,N,N-4,4＇＇-di-（4-methy,phenyl）-2,2＇：6＇,2＂-terpyridine-N,N,N-tris（is,-thi,cyanat,）- ruthenium（H） ammonium] was obtained and fully characterized by IR, UV-Vis, ESI MS and elemental analysis. The MLCT absorption band of Ru-DPTP was blue-shifted from 570 to 500 nm upon addition of Hg^2＋. Among a series of surveyed metal ions, the complex showed a unique recognition to Hg^2＋, indicating that it can be used as a selective colorimetric sensor for Hg^2＋.     

Five-membered 2,3-dioxo heterocycles: LXII. Reaction of 3-aroyl-1H-pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones with N,N′-dihydroxycyclohexane-1,2-diamine. Unusual rearrangement in the spiro[quinoxaline-2,2′-pyrrole] system

3-Aroyl-1H-pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones reacted with N,N′-dihydroxycyclohexane-1,2-diamine to give 3-aroyl-1′,4,4′-trihydroxy-1-(2-hydroxyphenyl)-4a′,5′,6′,7′,8′,8a′-hexahydro-1′H-spiro[pyrrole-2,2′-quinoxaline]-3′,5(1H,4′H)-diones which underwent rearrangement into 1′-aroyloxy-4,4′-dihydroxy-1-(2-hydroxyphenyl)-4a′,5′,6′,7′,8′,8a′-hexahydro-1′H-spiro[pyrrolidine-2,2′-quinoxaline]3′,4,5(4′H)-triones via [1,4]-migration of the aroyl group. The product structure was proved by X-ray analysis.     

New approaches towards the synthesis and characterization of alkoxy substituted spirobifluorenes and spirosilabifluorenes for organic optoelectronics

Alkoxy substituted spirobifluorene derivatives namely 2,2′,7,7′-tetrabromo-3,6-bis(methoxy)-9,9′spirobifluorene (MSBF), 2,2′,7,7′-tetrabromo-3,6-bis(ethoxy)-9,9′spirobifluorene (ESBF), 2,2′,7,7′-tetrabromo-3,6-bis(butoxy)-9,9′spirobifluorene (BSBF), 2,2′,7,7′-tetrabromo-3,3′,6,6′-tetra(methoxy)-9,9′-spiro-9-silabifluorene (MSSiBF) and their key intermediates have been synthesised successfully. All compounds have been fully characterised by ¹H and ¹³C NMR, FTIR, UV-visible spectroscopy, MS spectrometry. TGA analysis revealed good thermal stability. The systematic investigation on the solubility, thermostability and photophysical property of synthesized compound showed that alkoxy substituted spirobifluorene were unique in rigidity and have wide range of applications in molecular electronics and can be used as building units for optoelectronics material.     

Synthesis of Functionalized Hemi‐1,2,4‐triazinyl‐[2,2′]‐bipyridines via Telescoped Condensation of [2,2′]‐bipyridinyl‐6‐carbonitrile

Partitioning of neutron‐poisoning lanthanides from minor actinides in used nuclear fuel using liquid–liquid separation techniques with moderately soft Lewis basic heterocyclic scaffolds is an area of intense research focus. Nitrogen heterocycles have demonstrated potential for the selective separation of Am³⁺ from Eu³⁺ in separations processes. Improved synthetic strategies are required to access more diversified complexant scaffolds for further study. The present work describes an efficient synthetic strategy for the preparation of functionalized [2,2′]‐bipyridinyl scaffolds using Pd catalysis to prepare the requisite starting material and telescoped condensation to afford direct access to hemi‐1,2,4‐triazinyl‐[2,2′]‐bipyridines with aliphatic character and potentially greater solubility in less polar diluents. Synthetic method development, optimization, and substrate scope are reported herein.     

Masking of Lewis acidity trends in the solid‐state structures of trichlorido‐ and tribromido(2,2′:6′,2′′‐terpyridine‐κ3N,N′,N′′)gallium(III)

The molecular structures of trichlorido(2,2′:6′,2′′‐terpyridine‐κ³N,N′,N′′)gallium(III), [GaCl₃(C₁₅H₁₁N₃)], and tribromido(2,2′:6′,2′′‐terpyridine‐κ³N,N′,N′′)gallium(III), [GaBr₃(C₁₅H₁₁N₃)], are isostructural, with the Ga^III atom displaying an octahedral geometry. It is shown that the Ga—N distances in the two complexes are the same within experimental error, in contrast to expected bond lengthening in the bromide complex due to the lower Lewis acidity of GaBr₃. Thus, masking of the Lewis acidity trends in the solid state is observed not only for complexes of group 13 metal halides with monodentate ligands but for complexes with the polydentate 2,2′:6′,2′′‐terpyridine donor as well.     

Diorganotin(IV) compounds derived from n‐methyl‐2,2′‐diphenolamine and 2,2′‐diphenolamine

The reaction of N‐methyl‐2,2′‐diphenolamine 1 and 2,2′‐diphenolamine 2 with some diorganotin(IV) oxides [R1/2SnO: R¹ = Me, n‐Bu, t‐Bu and Ph] led to the syntheses of diorgano[N‐methyl‐2,2′‐diphenolato‐O,O′,N]tin (IV) 3–6 and diorgano[2,2′‐diphenolato‐O,O′,N]tin (IV) 7–9 . All compounds (except 7 ) studied in this work were characterized by ¹H, ¹³C, ¹¹⁹Sn NMR, infrared, and mass spectroscopy. Their ¹¹⁹Sn NMR data show that the tin atom is tetracoordinated in CDCl₃ but penta and hexacoordinated in DMSO‐d₆. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 133–139, 1999     

Metallionen und H2O2. VI. Über Struktur und Aktivität der den H2O2-Zerfall katalysierenden Ni2+-Komplexe

The catalytic properties in H₂O₂ decomposition of Ni²⁺-chelates of the following ligands have been investigated: ethylenediamine, diethylenetriamine, triethylenetetramine, 2,2′-bipyridine, pyrophosphate and ethylenediamine-N, N, N′, N′-tetra-acetic acid, and of the following peptides and peptide-like ligands: glycylglycine, N,N′-diglycyl-ethylenediamine, N, N′-diglycyl-1, 5-diaminopentane and polymyxin B.     

Complexation Studies of Bidentate Heterocyclic N-Donor Ligands with Nd(III) and Am(III)

A new bidentate nitrogen donor complexing agent that combines pyridine and triazole functional groups, 2-((4-phenyl-1H-1,2,3-triazol-1-yl)methyl)pyridine (PTMP), has been synthesized. The strength of its complexes with trivalent americium (Am³⁺) and neodymium (Nd³⁺) in anhydrous methanol has been evaluated using spectrophotometric techniques. The purpose of this investigation is to assess this ligand (as representative of a class of similarly structured species) as a possible model compound for the challenging separation of trivalent actinides from lanthanides. This separation, important in the development of advanced nuclear fuel cycles, is best achieved through the agency of multidentate chelating agents containing some number of nitrogen or sulfur donor groups. To evaluate the relative strength of the bidentate complexes, the derived constants are compared to those of the same metal ions with 2,2′-bipyridyl (bipy), 1,10-phenanthroline (phen), and 2-pyridin-2-yl-1H-benzimidazole (PBIm). At issue is the relative affinity of the triazole moiety for trivalent f element ions. For all ligands, the derived stability constants are higher for Am³⁺ than Nd³⁺. In the case of Am³⁺ complexes with phen and PBIm, the presence of 1:2 (AmL₂) species is indicated. Possible separations are suggested based on the relative stability and stoichiometry of the Am³⁺ and Nd³⁺ complexes. It can be noted that the 1,2,3-triazolyl group imparts a potentially useful selectivity for trivalent actinides (An(III)) over trivalent lanthanides (Ln(III)), though the attainment of higher complex stoichiometries in actinide compared with lanthanide complexes may be an important driver for developing successful separations.     

Antibacterial,Antioxidant and Binding Studies of Some Novel Diaryl Sulphide Derivatives

Abstract

A series of novel acyclic and cyclic diaryl sulphides was synthesized from 2,2′-dithiobenzoic acid. The various diaryl sulphides were characterized by use of spectral (IR, ¹H and ¹³C NMR, ESI/MS) and elemental analyses. The antimicrobial activities of the compounds were evaluated in terms of their minimum inhibition concentration (MIC) against a panel of clinical isolates bacteria and were found to possess only moderate antimicrobial activities. N,N′-Bis(2-hydroxyphenyl)-2,2′-thiodibenzamide (13), exhibiting a hydroxy group at the phenyl ring, was the most active antimicrobial agent within the series, with MIC values of 0.05 mg mL^–1 and 10 mg mL^–1 against Staphylococcus aureus and Bacillus cereus, respectively. The antioxidant efficiency of the diaryl sulphides was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity with 13 being the most active compound. The interaction of 2,2′-thiodibenzanilide, N,N′-bis(2-methylphenyl)-2,2′-thiodibenzamide, and N,N′-bis(2-hydroxyphenyl)-2,2′-thiobenzamide with guanine, glutamic acid, and urea were studied quantitatively with binding constants ranging from 1 × 10³ M^?1 to 2.7 × 10⁴ M^?1.     

Synthese,Komplexbildung und Kristallstrukturen von Cyclotriphosphazenen mit N,N,N′,N′‐Tetramethylguanidingruppen

Synthesis, Complex Formation, and Crystal Structures of Cyclotriphosphazenes with N,N,N′,N′‐Tetramethylguanidine Groups The reactions of monochloropentaphenoxycyclotriphosphazene and hexachlorocyclotriphosphazene with N,N,N′,N′‐tetramethylguanidine yield the mono and tetra substituted products 2‐(N,N,N′,N′‐tetramethylguanidine)‐2,4,4,6,6‐pentaphenoxy‐2 λ⁵,4 λ⁵,6 λ⁵‐cyclotriphosphaza‐1,3,5‐trien ( 1 ) and 2,2‐dichlor‐4,4,6,6‐tetra‐(N,N,N′,N′‐tetramethylguanidine‐2 λ⁵,4 λ⁵,6 λ⁵‐cyclotriphosphaza‐1,3,5‐trien ( 2 ) respectively; no hexa functionalized product could be obtained, even with high excess of the nucleophile. Electron release from the exocyclic amino substituent reduces the acceptor ability of the phosphorus atoms. Reactions of ( 2 ) with copper(II) chloride and palladium(II) bis(acetonitrilo)dichloride yield metal complexes with a ligand : metal ratio of 1 : 2. The X‐ray structure analyses of N₃P₃Cl₂(NC(N(CH₃)₂)₂)₄ · 2 CuCl₂ ( 2 a ) and N₃P₃Cl₂(NC(N(CH₃)₂)₂)₄ · 2 PdCl₂ ( 2 b ) show that each metal atom is coordinated by two imino nitrogen atoms in geminal positions and two chloride atoms in a square planar arrangement.     

Uptake behavior of americium on alginic acid and alginate polymer gels

The uptake behavior of Am³⁺ was investigated by using alginic acid and alginate polymer gels. The affinity of radioactive nuclides for carboxyl groups in gel matrices increased in the order of Na⁺ < Cs⁺ < Co²⁺ < Pd²⁺, Sr²⁺, Fe³⁺ < Eu³⁺, Am³⁺. Among alginate gels, calcium alginate exhibited relatively higher uptake rate and distribution coefficient of Am³⁺. The column packed with calcium alginate beads was effective for the removal of trace amounts of Am³⁺ from acidic nitrate solutions.     

Cyclopropanation of 2-arylmethylidenemalononitriles,alkyl 3-aryl-2-cyanoprop-2-enoates,and N-substituted 3-aryl-2-cyanoprop-2-enamides with bromine-containing zinc enolates

Zinc enolates derived from 2,2-dibromoindan-1-one and 2,2-dibromo-1,2,3,4-tetrahydronaphthalen-1-one reacted with 2-arylmethylidenemalononitriles, alkyl 3-aryl-2-cyanoprop-2-enoates, and N-substituted 3-aryl-2-cyanoprop-2-enamides to give, respectively, 3-aryl-1′-oxo-1′,3′-dihydrospiro[cyclopropane-1,2′-indene]-2-2-dicarbonitriles, 3-aryl-1′-oxo-3′,4′-dihydro-1′H-spiro[cyclopropane-1,2′-naphthalene]-2,2-dicarbonitriles, alkyl 3-aryl-2-cyano-1′-oxo-1′,3′-dihydrospiro[cyclopropane-1,2′-indene]-2-carboxylates, alkyl 3-aryl-2-cyano-1′-oxo-3′,4′-dihydro-1′H-spiro[cyclopropane-1,2′-naphthalene]-2-carboxylates, and N-substituted 3-aryl-2-cyanol-1′-oxo-3′,4′-dihydro-1′H-spiro[cyclopropane-1,2′-naphthalene]-2-carboxamides as a single diastereoisomer. The stereoconfiguration of the products was determined by ¹H and ¹³C NMR spectroscopy.     

Conformational dynamics of bis(BF2)‐2,2′‐bidipyrrins revealed by through‐space 13C?19F and 19F?19F couplings

The conformation of [bis‐(N,N′‐difluoroboryl)]‐3,3′‐diethyl‐4,4′,8,8′,9,9′,10,10′‐octamethyl‐2,2′‐bidipyrrin (1) in solution was studied by analyzing the ¹³C? ¹⁹F and ¹⁹F? ¹⁹F through‐space spin–spin couplings. The ¹H and ¹³C NMR spectra were assigned on the basis of nuclear Overhauser effect spectroscopy (NOESY), heteronuclear single‐quantum correlation (HSQC), and heteronuclear multiple‐bond correlation (HMBC) experiments. The ¹⁹F spectrum of 1 was compared with that of 2‐ethyl‐1,3,5,6,7‐pentamethyl‐4,4‐difluoro‐4‐bor‐3a,4a‐diaza‐s‐indacen (2). The ¹⁹F? ¹⁹F through‐space spin? spin coupling in 1 was thus assigned and the coupling constant was obtained by simulating the coupling patterns. The obtained conformation of 1 was compared with those of the known complexes [bis‐(N,N′‐difluoroboryl)]‐3,3′,8,8′,9,9′‐hexaethyl‐4,4′,10,10′‐tetramethyl‐6,6′‐(4‐methylphenyl)‐2,2′‐bidipyrrin (3)and [bis‐(N,N′‐difluoroboryl)]‐9,9′‐diethyl‐4,4′,8,8′,10,10′‐hexamethyl‐3,3′‐bis(methoxycarbonylethyl)‐2,2′‐bidipyrrin (4). The conformational dynamics of 1, 3, and 4 was surveyed by observing the temperature dependence of the through‐space coupling constants between 253 and 333 K. The ¹³C? ¹⁹F and ¹⁹F? ¹⁹F through‐space spin–spin couplings thus confirm similar conformations of different BisBODIPYs in solution in contrast to earlier findings in the solid state. Copyright © 2009 John Wiley & Sons, Ltd.     

Nonglycoside analogs of nucleotides

N¹-(2′,3′-Dihydroxypropyl)uracil, -thymine, -cytosine, and N⁹-(2′,3′-dihydroxypropyl)adenine were synthesized by alkylation of nucleic bases with 2,3-O-isopropylideneglycerol chlorohydrin, subsequent separation of the resulting mixtures, and removal of the protective groupings. Phosphorylation of these compounds or of their selectively substituted derivatives gave 2′(3′)-monophosphates, which were converted to 2′,3′-cyclophosphates by reaction with N,N′-dicyclohexylcarbodiimide. Thionation of the corresponding cytosine derivatives gave N¹-(2′,3′-dihydroxypropyl)-4-thiouracil and its 2′(3′) phosphate.     

Regioselective Transformations of 2′,3′-Seconucleosides into Anhydro Structures and Chiral Crown Ethers

Intramolecular cyclisation of properly protected and activated derivatives of 2′,3′-secouridine ( = 1-{2-hydroxy-1-[2-hydroxy-1-(hydroxymethyl)ethoxy]-ethyl}uracil; 1 ) provided access to the 2,2′-, 2,3′-, 2,5′-, 2′,5′-, 3′,5′-, and 2′,3′-anhydro-2′,3′-secouridines 5, 16, 17, 26, 28 , and 31 , respectively (Schemes 1–3). Reaction of 2′,5′-anhydro-3′-O-(methylsulfonyl)- ( 25 ) and 2′,3′-anhydro-5′-O-(methylsulfonyl)-2′,3′-secouridine ( 32 ) with CH₂CI₂ in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene generated the N(3)-methylene-bridged bis-uridine structure 37 and 36 , respectively (Scheme 3). Novel chiral 18-crown-6 ethers 40 and 44 , containing a hydroxymethyl and a uracil-1-yl or adenin-9-yl as the pendant groups in a 1,3-cis relationship, were synthesized from 5′-O-(triphenylmethyl)-2′,3′-secouridine ( 2 ) and 5′-O,N⁶-bis(triphenylmethyl)-2′,3′-secoadenosine ( 41 ) on reaction with 3,6,9-trioxaundecane-1,11-diyl bis(4-toluenesulfonate) and detritylation of the thus obtained (triphenylmethoxy) methylcompound 39 and 43 , respectively (Scheme 4).     

Preparation of Anti-Cadmium-EDTA Complex Polyclonal Antibody and Its Application for Determination of Cadmium in Aqueous Solution

Abstract

A polyclonal antibody that can recognize cadmium-ethylenediaminetetraacetic acid (CD-EDTA) complex was prepared via the injection of New Zealand white rabbits with Cd-1-(4-isothiocyanatobenzyl) ethylenediamine-N,N,N′,N′-tetraacetic acid–BSA (Cd-ITCBE-BSA). The polyclonal antibody displayed high levels of affinity for Cd-1-(4-isothiocyanatobenzyl) ethylenediamine-N,N,N′,N′-tetraacetic acid-OVA (Cd-ITCBE-OVA) with favorable titer of 1.28 × 10⁶. A simple, reliable, and economical indirect competitive immunoassay based on this polyclonal antibody was developed and validated for detection of cadmium. Assay optimization was performed with respect to chelator concentration, ionic strength, blocking solution, pH, and reaction time. The detection limit of the assay was 0.21 µg L^?1, and the effective linear range was from 10^?1 to 10³µg L^?1. The coefficient of variation (CV) of intra- and interassay were 1.0–8.2% and 2.3–6.9%, respectively. Results yielded low cross-reactivity of the assay to other tested metals such as Pb²⁺, Ni²⁺, Mg²⁺, Ca²⁺, Cu²⁺, Mn²⁺, Zn²⁺, Co²⁺, Cr³⁺, and Fe³⁺, except Hg²⁺, which showed a cross-reactivity of 7.4%. Spike recoveries of ultrapure water, tap water, and samples of the Yangtze River were 85.5–116.3%. These results show that this assay is suitable for quantitative detection of cadmium at trace levels in water samples.     

Asymmetric oxidation of verbenone ethylene dithioacetal

Asymmetric oxidation of verbenone ethylene dithioacetal with m-chloroperoxybenzoic acid at different substrate-to-oxidant ratios in methylene chloride at ?10°C gave previously unknown (1S,1′S,2S,3′S,5S)-4,6,6-trimethylspiro[bicyclo[3.1.1]hept-3-ene-2,2′-[1,3]dithiolane] 1′,3′-dioxide, (1S,2S,3′S,5S)-4,6,6-trimethylspiro[bicyclo[3.1.1]hept-3-ene-2,2′-[1,3]dithiolane] 1′,1′,3′-trioxide, and (1S,5S)-4,6,6-trimethylspiro[bicyclo-[3.1.1]hept-3-ene-2,2′-[1,3]dithiolane] 1′,1′,3′,3′-tetraoxide whose structure was determined by X-ray analysis.     

An Efficient Synthesis of Spiro‐oxindole Derivatives by Three‐Component Reactions in Water

An efficient synthesis of (3S)‐1,1′,2,2′,3′,4′,6′,7′‐octahydro‐9′‐nitro‐2,6′‐dioxospiro[3H‐indole‐3,8′‐[8H]pyrido[1,2‐a]pyrimidine]‐7′‐carbonitrile is achieved via a three‐component reaction of isatin, ethyl cyanoacetate, and 1,2,3,4,5,6‐hexahydro‐2‐(nitromethylidene)pyrimidine. The present method does not involve any hazardous organic solvents or catalysts. Also the synthesis of ethyl 6′‐amino‐1,1′,2,2′,3′,4′‐hexahydro‐9′‐nitro‐2‐oxospiro[3H‐indole‐3,8′‐[8H]pyrido[1,2‐a]pyrimidine]‐7′‐carboxylates in high yields, at reflux, using a catalytic amount of piperidine, is described. The structures were confirmed spectroscopically (IR, ¹H‐ and ¹³C‐NMR, and EI‐MS data) and by elemental analyses. A plausible mechanism for this reaction is proposed (Scheme 2).     

The influence of the ligands on the catalytic activity of a series of RhI complexes in reactions with phenylacetylene: Synthesis of stereoregular poly(phenyl) acetylene

The catalytic activity of a series of [Rh L-L chel]X complexes, in which we have varied the unsaturated ligand [L-L = cis, cis-cycloocta 1,5-diene(cod) or 2,5-norbornadiene(nbd) the nitrogen chelating ligand [chel = 2,2′-bipyridine(bipy), 2,2′-dipyridylamine(dipyam), 2,2′-bipyrazine (bipz), 4,4′-dimethyl-2,2′-bipyridine (4,4′-Me₂bipy)] and the counter ion [X = PF₆, ClO₄, BPh₄], has been examined in reactions with phyenylacetylene (PA). The catalytic behaviour of the [Rh(cod)Cl₂],tmeda (tmeda = N,N,N′,N′tetramethylethylendiamine), [Rh(cod)Cl₂],teda] (teda = triethylendiamine), of the dimer [Rh(cod)Cl]₂, and the use of NaOH as cocatalyst in different reaction conditions was also examined. The influence of the ligands on the catalytic activity of these Rh^I complexes is discussed. ¹H and ¹³C NMR spectra have shown that highly stereoregular polyphenylacetilene can be obtained. Conditions for homogeneous doping of PPA, to obtain materials whose conductivity varies over 10–11 magnitude orders, are proposed. The stability of the doped polymers is also discussed.