Synthesis of fluorescein derivatives containing metal-coordinating heterocycles

Fluorescein derivatives that contain Lewis basic heterocycles have been synthesized by concise reaction sequences. The preparation of these compounds proceeds by functionalization of an electron-rich aromatic precursor and subsequent condensation to form the fluorophore. These compounds are envisioned as components of metal-based sensors.     

Synthesis of conjugates of 5,15-disubstituted aminoporphyrins and terpyridine derivatives with potential chelating properties

meso-Arylporphyrin containing two external chelating 2,2':6',2'-terpyridine fragments and its zinc complex were synthesized. The key step comprised the amide bond formation between the porphyrin diamine derivative and 4'-(4-carboxyphenyl)-2,2':6',2'-terpyridine. The compounds obtained seem to be potent for photodynamic therapy and diagnosis.     

Preparation and analytical properties of chelating resins containing heterocyclic formazane derivatives

Chromatographia - By introducing pyridine and thiazole rings into polyacrolein, poly[1-(2-pyridyl)-3-(vinyl)-5-(phenyl)-formazane] (PPF), poly[1-(2-pyridyl)-3-(vinyl)-5-(2-arsonophenyl)-formazane]...     

Synthesis and properties of a chelating resin containing triazolethiol groups

A macroreticular poly(acrylic acid)-based resin with triazolethiol as the functional group has been synthesized. The stability of the resin in acidic media and the behaviour in sorption and desorption of various metal ions have been investigated and compared with those of the acylthiosemicarbazide resin which is an intermediate in synthesis of the triazolethiol resin. Both resins show high affinity for copper(II) silver, cadmium and mercury(II), and high selectivity for silver and mercury(II) at low pH (1–2), and even at pH 7 if EDTA is present. The triazolethiol resin sorbs metal ions faster than the acylthiosemicarbazide resin does and sorbs mercury(II) from high concentrations of acids and neutral salt solutions. This resin has been applied to the concentration of silver and mercury(II) from sea-water samples by column operation.     

Synthesis and properties of phosphinothricin derivatives

Abstract

The synthesis and properties of phosphinothricin derivatives which have different alkyl groups attached to phosphorus or bear a substituent on the nitrogen are described and their biological activities discussed.     

Synthesis and properties of sym-triazine derivatives

N-Substituted 2,4-diamino-6-furyl-sym-triazines were synthesized by cyclocondensation of furancarboxylic acid esters with biguanides. 2-Amino-4,6-disubstituted sym-triazines containing furyl residues were obtained by reacting furancarboxylic acid nitriles with guanidine or furancarboxylic acid esters with N-imidoylguanidines. Aminotriazines of this type are also formed in condensation of N-acylguanidines with nitriles or imino esters.See [1] for 8.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1250–1256, September, 1992.     

Synthesis and properties of a temperature-sensitive chelating hydrogel and its metal complexes

A temperature-sensitive chelating hydrogel was synthesized by the copolymerization of 1-(β-acrylamidoethyl)-3-hydroxy-2-methyl-4(1H)-pyridinone (AHMP) and N-isopropylacrylamide (NIPAA) in the presence of N,N' -ethylene-bis-acrylamide as a crosslinking agent. The AHMP-NIPAA hydrogel formed a red complex with iron(III) and a pale green complex with Cu(II), respectively. It was observed that the hydrogel and its metal complexes had a high swelling ratio below the temperature of 35°C, while above that temperature the swelling ratios were dramatically decreased. Furthermore, the swelling ratio of the metal complexes was much lower at the swelling temperature (below 35°C) than that of the hydrogel itself, which might be due to the lower flexibility of the complexes. The iron(III) chelating study showed that the hydrogel had a high chelating efficiency at its swelling temperature, while the chelating efficiency of the hydrogel was very low at its deswelling temperature (>35°C). It was found that the chelating efficiency depended on the swelling ratio of the hydrogel in water, which could be explained by the difference in contactable internal surfaces at different temperatures. The hydrogel and its metal complexes could be easily separated at their deswelling temperature. It was also convenient to regenerate the hydrogel with 1 M HCl for reuse.     

Synthesis and properties of alkylthiomethylated urea derivatives

Novel N,N′-bis[(alkylsulfanyl)methyl]ureas were prepared by three-component condensation of urea with formaldehyde and thiol in a NaOH solution, and alkylthiomethylated polymethyleneureas were prepared by the condensation of the same reactants in the presence of glacial acetic acid and without it. Polymethyleneureas efficiently sorb silver(I) from nitric acid solutions and palladium(II) from hydrochloric acid solutions. Alcoholsoluble N,N′-bis[(alkylsulfanyl)methyl]ureas inhibit carbon dioxide corrosion of St.3 steel.     

Synthesis of bifunctional chelating agents based on mono and diphosphonic derivatives of diethylenetriaminepentaacetic acid

Bifunctional chelating agents (BFCAs) are small molecules containing a chelating unit, able to strongly coordinate a metal ion, and a reactive functional group, devised to form a stable covalent bond with another molecule. BFCAs are widely employed since their conjugation to a suitable biomolecule (e.g., a peptide or an antibody) allows the synthesis of diagnostic or therapeutic agents that specifically target diseased tissue with metals or radiometals. For this reason, BFCAs find application in diagnostic imaging, molecular imaging, and radiotherapy of cancer. The synthesis of new BFCAs based on a diethylenetriaminepentaacetic acid (DTPA) structure in which one or two carboxylic groups are replaced with phosphonic units is described. The phosphonic group, aside from being a classical isostere of the carboxylic acid in coordination chemistry, allows to modulate the physico-chemical properties of the ligands and of the corresponding complexes.     

Synthesis and electroluminescent properties of naphthalimide derivatives

Naphthalimide derivatives, N-ethyl-4-acetylamino-l ,8-naphthalimide (EAAN) and polymer with N-propyl-4-acetylamino-l,8-naphthalimide (PAAN) side-chain (P-PAAN) were successfully synthesized. Electroluminescent devices of ITO/PVK(120nm)/EAAN(50nm)/Al(150nm) (Ⅰ) and ITO/PVK P-PAAN( 10:1) (50nm)/Al(150nm) (Ⅱ) constructed with EAAN and P-PAAN as the emitting layer were investigated, whereas the single-layer devices of ITO/EAAN or P-PAAN(50nm)/Al(l50nm) (Ⅲ) were not observed to have any e-mission light. The emission results revealed that the exciton recombination formed by positive and negative charge carriers injected from electrodes of devices Ⅰ and Ⅱ was much more balanced than that of devices Ⅲ, which implied that naphthalimide derivatives are a new type of electron-transporting materials with high performance. The electron-transporting properties of naphthalimide derivatives were also elucidated by investigation of the electroluminescent behaviors from both devices of ITO/PPV (80nm)/Al and ITO/P     

Synthesis and properties of pentane amino derivatives

Synthesis of pentane amino derivatives by the reaction of the corresponding amines with 1-bromopentanes of n- and iso-structure by environmentally safe methods in water medium was carried out. The structure of the compounds obtained was confirmed by elemental analysis, IR, ¹H and ¹³C NMR spectroscopy. The products synthesized were tested as reagents for the suppression of growth of the sulfate-reducing bacteria and as the anticorrosive substances. It was found that they are effective bactericides for the sulfate-reducing bacteria and exhibit high anticorrosive properties.     

Synthesis and electrical properties of polyacetylene derivatives

Cyclopolymerization of 1,6‐heptadiyne derivatives containing the bulky substitutents was carried out by metathesis catalyst systems. The catalytic activity of molybdenum (V) chloride (MoCl₅) in homopolymerization is greater than that of the MoCl₅‐cocatalyst system, and copolymerization is vice versa in catalytic activity. Newly synthesized homo‐ and copolymers were soluble in common organic solvents and could afford thin film by solution‐casting onto the indium–tin oxide coated glass substrate. The NMR, Fourier transform infrared spectroscopic, and UV–visible spectra indicated that these polymers have a linear conjugated cyclic polyene structure having a bulky substitutent as a pendant group. The number‐average molecular weight of these polymers was in the range of 2.4–6.27 × 10³. The copolymers exhibited a relatively higher molecular weight than that of the homopolymers. The copolymers were stable up to 380 °C. The electrical conductivities of the I₂‐doped copolymer thin film by the four‐point probe method and surface plasmon resonance spectroscopy were about 500 and 600 S/cm, respectively. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 958–964, 2002     

Synthesis and photobiological properties of acetylpsoralen derivatives

In an investigation to find monofunctional reactants for DNA which can act as new agents in the photochemotherapy of psoriasis, we have synthesized and studied some methylpsoralen derivatives which contain an acetyl group at one of the two reactive sites of the furocoumarin skeleton (at the 3 or 5' positions). The compounds do not react easily with DNA; their photobiological properties (e.g. the lack of an ability to inhibit DNA synthesis in Ehrlich ascites tumour cells, to induce T2 phage sensitization and to induce erythema in guinea-pig skin) are exactly in line with this behaviour. Some interesting features are shown by 4,8-dimethyl-5'-acetylpsoralen: it is capable of producing a very large amount of singlet oxygen--an order of magnitude higher than the other compounds and 8-methoxypsoralen (used as reference). In spite of this property, 4,8-dimethyl-5'-acetylpsoralen is non-phototoxic to the skin, and its other photobiological properties appear to be in line with its lack of interaction with DNA rather than its enhanced singlet oxygen production.     

Synthesis and interfacial properties of sophorolipid derivatives

Biosurfactants made by fermentation from renewable resources provide “environmental friendly” processes and products. A natural sophorolipid mixture was produced by the yeast Candida bombicola when cultured on glucose and oleic acid. The sophorolipid mixture was chemically modified to form the corresponding sophorolipid alkyl (methyl, ethyl, propyl, and butyl) esters by reaction with the corresponding sodium alkoxides. Interfacial properties of these surfactants, such as surface tension reduction, aggregation, and adsorption, were systematically studied. It was found that the critical micelle concentration of sophorolipid esters decreases to about 1/2 per additional one CH₂ group to the alkyl ester moiety. Interestingly, these surfactants were found to adsorb strongly on alumina but weakly on silica. They have properties that make them attractive candidates for uses in detergents, cosmetics, soil remediation, and enhanced oil recovery.     

Synthesis and properties of a new chelating resin containing the oxime group

A macroreticular polystyrene-based chelating resin with oxime and diethylamino functional groups has been synthesized. The resin is stable in acid and alkaline solutions; no decrease in nitrogen content or capacity for sorption of copper(II) is observed when it is exposed to 3M hydrochloric acid and 1M sodium hydroxide for 7 days. The resin has higher selectivity for copper(II) than for other metal ions tested and the time required for 50% uptake of copper(II) is 15 min. The highest capacity for copper(II) is 2.0 mmole/g at pH 6.0. In a column operation, quantitative recovery of copper(II) is achieved by elution with 1M hydrochloric acid, and the resin can be used repeatedly.     

Synthesis and properties of azoles and their derivatives

Dihydrochlorides of diimino esters of 4,4-dinitropimelic acid are formed from 4,4-dinitropimelic acid dinitrile and alcohols in the presence of hydrogen chloride. The dihydrochloride of the methyl diimino ester condenses with ethylenediamine, o-phenylenediamine, and o-aminophenol to give the corresponding 1,5-bisheteryl-3,3-dinitropentanes.     

Synthesis and properties of azoles and their derivatives

The 1,3-dipolar cycloaddition reaction of nitrile N-oxides, and also the thermal condensation of arylhydroxamic acid chlorides with unsaturated derivatives of the adamantane series leads to the corresponding 3,5-disubstituted isoxazolines and isoxazoles.     

Synthesis and properties of azoles and their derivatives

Thermal condensation of 1-cyanoadamantane with arylhydroxamic acid chlorides gave 5-(1′-adamantyl)-1,2,4-oxadiazoles containing aromatic groupings in the 3 position. The same 1,2,4-oxadiazoles were synthesized by reaction of the N-oxides of the appropriate nitriles with adamantane-1-carboxylic acid methyl imino ester obtained from 1-cyanoadamantane. The corresponding 5-(1′-adamantyl)-3-substituted 1,2,4-oxadiazoles were obtained by condensation of the latter with amidoxines.