Search results for "ethylenediamine"
showing 10 items of 142 documents
Ruthenium Metallodendrimers Based on Nitrile‐Functionalized Poly(alkylidene imine)s
2005
The preparation of the first- and second-generation of nitrile-functionalized poly(alkylidene imine) dendrimers with the organometallic ruthenium complex [Ru(η5-C5H5)(PPh3)2Cl] peripherally attached is described. The reaction of N,N′-bis(cyanomethyl)piperazine (1), N,N′-bis[N′′,N′′′-bis(cyanoethyl)aminoethyl]piperazine (2), or N,N,N′,N′-tetrakis(cyanoethyl)ethylenediamine (3) with [Ru(η5-C5H5)(PPh3)2Cl] (4) in the presence of TlPF6 gives the new air-stable ruthenium metallodendrimers 5, 6, and 7, respectively. These stable metallodendrimers are easily prepared and represent a novel quantitative method to solidify and chromatographically purify the otherwise semi-liquid nitrile-functionalize…
Preparation and Characterization of Novel Poly(alkylidenamine) Nitrile Ruthenium Metallodendrimers
2010
Complete functionalization of N,N,N',N'-[tetrakis(cyanoethyl)-hexamethylenediamine] [N≡C(CH 2 ) 2 ] 2 N(CH 2 ) 6 N[(CH 2 ) 2 -C≡N] 2 (4) and N,N,N',N'-(tetrakis(cyanoethoxypropyl)hexamethylenediamine] [N≡C(CH 2 ) 2 O(CH 2 ) 3 ] 2 N(CH 2 ) 6 N[(CH 2 ) 3 -O(CH 2 ) 2 C≡N] 2 (7) with the organometallic moiety [Ru(η 5 -C 5 H 5 )(PPh 3 ) 2 Cl] and the five-coordinate cis-[RuCl(dppe) 2 ]-[PF 6 ] [dppe = 1,2-bis(diphenylphosphanyl)ethane] was attained with good yield, respectively, by treating the metallo-fragment with the core in methanol (at room temperature and in presence of TIPF 6 as a chloride abstractor) and in 1,2-dichloroethane (under reflux). These novel nitrile-functionalized poly(alkyli…
Interferometric microscopy study of the surface roughness of Portland cement under the action of different irrigants
2013
Objectives: Some investigations suggested common Portland cement (PC) as a substitute material for MTA for endodontic use; both MTA and PC have a similar composition. The aim of this study was to determine the surface roughness of common PC before and after the exposition to different endodontic irrigating solutions: 10% and 20% citric acid, 17% ethylenediaminetetraacetic (EDTA) and 5% sodium hypochlorite. Study Design: Fifty PC samples in the form of cubes were prepared. PC was mixed with distilled water (powder/liquid ratio 3:1 by weight). The samples were immersed for one minute in 10% and 20% citric acid, 17% EDTA and 5% sodium hypochlorite. After gold coating, PC samples were examined …
New cyanide-bridged Mn(III)-M(III) heterometallic dinuclear complexes constructed from [M(III)(AA)(CN)4]- building blocks (M = Cr and Fe): synthesis,…
2011
Three Mn(III)-M(III) (M = Cr and Fe) dinuclear complexes have been obtained by assembling [Mn(III)(SB)(H(2)O)](+) and [M(III)(AA)(CN)(4)](-) ions, where SB is the dianion of the Schiff-base resulting from the condensation of 3-methoxysalicylaldehyde with ethylenediamine (3-MeOsalen(2-)) or 1,2-cyclohexanediamine (3-MeOsalcyen(2-)): [Mn(3-MeOsalen)(H(2)O)(µ-NC)Cr(bipy)(CN)(3)]·2H(2)O (1), [Mn(3-MeOsalen)(H(2)O)(µ-NC)Cr(ampy)(CN)(3)][Mn(3-MeOsalen)(H(2)O)(2)]ClO(4)·2H(2)O (2) and [Mn(3-MeOsalcyen)(H(2)O)(µ-NC)Fe(bpym)(CN)(3)]·3H(2)O (3) (bipy = 2,2'-bipyridine, ampy = 2-aminomethylpyridine and bpym = 2,2'-bipyrimidine). The [M(AA)(CN)(4)](-) unit in 1-3 acts as a monodentate ligand towards th…
Iron(ii) complexes of tris(2-pyridylmethyl)amine (TPMA) and neutral bidentate ligands showing thermal- and photo-induced spin crossover
2018
Three new mononuclear Fe(ii) complexes have been prepared and characterized by the combination of tetradentate tris(2-pyridylmethyl)amine (TPMA) with three neutral bidentate ligands, such as ethylenediamine (en), 1,2-diaminopropane (pn) and 2-picolylamine (2-pic), in compounds [FeII(TPMA)(en)](ClO4)2 (1), [FeII(TPMA)(2-pic)](ClO4)2 (2) and [FeII(TPMA)(pn)](ClO4)2 (3). Structural and magnetic characterization demonstrates that the three compounds present a complete SCO behavior. The absence of strong intermolecular interactions and solvent molecules leads to reversible and gradual spin transitions. The different ligands allow tuning T1/2 from 130 K (2) to 325 K (3). The compound with the low…
Cyanido‐Bearing Cobalt(II/III) Metalloligands – Synthesis, Crystal Structure, and Magnetic Properties
2014
New examples of cyanido-bearing cobalt(III/II) complexes have been obtained by treatment of CoCl2·6H2O with bidentate nitrogen donors and potassium cyanide in a methanol/water mixture. Depending on the chelating ligand, the cobalt(III) complexes PPh4[Co(en)(CN)4] (1, en = ethylenediamine), PPh4[Co(ampy)(CN)4]·1.5H2O [2, ampy = 2-(aminomethyl)pyridine], and PPh4[Co(phen)(CN)4]·CH3OH·0.25H2O (3, phen = 1,10-phenanthroline) and the cobalt(II) complex PPh4[Co(dmphen)(CN)3]·3H2O (4, dmphen = 2,9-dimethyl-1,10-phenanthroline) were obtained. The complexes were characterized by single-crystal X-ray diffraction and variable-temperature magnetic measurements. They are all mononuclear species with six…
Synthesis, spectroscopic, and X-ray structural study of aqua-bis(thymine-N 1 ,N 4 )-ethylenediamine copper(II)dihydrate [Cu(Thy) 2 (en)(H 2 O)].2H 2 O
2016
International audience; A new compound of thyminato anions and ethylenediamine with five-coordinate Cu(II) is synthesized. Elemental analysis and spectroscopic techniques (IR, UV-visible) were used to characterize this compound and its crystal structure was determined by single-crystal X-ray diffraction. The crystal structure consists of the neutral mononuclear complex [Cu(Thy)(2)(en)(H2O)]center dot 2H(2)O. The environment around Cu(II) ion exhibits a square pyramidal geometry with two nitrogen atoms of ethylenediamine and two other nitrogen atoms of the monodentate monoanions of thymine building the equatorial plane. The oxygen atom from H2O molecule occupies the apical position. The comp…
In-tube solid-phase microextraction and liquid chromatography using a monolithic column for the selective determination of residual ethylenediamine i…
2009
The selective determination of the diamine ethylenediamine (EDA) in the presence of a higher amount of residual dimethylamine in cationic polymers has been developed. The strategy uses both a solution derivatization with a selective agent of primary amines such as o-phthaldialdehyde-N-acetyl-L-cysteine (OPA-NAC) and an in-tube solid-phase microextraction (IT-SPME) coupled to liquid chromatography (LC). A 70 cm long, 0.32 mm internal diameter, and 3 microm thick commercially available capillary column coated with 95% polydimethylsiloxane and 5% polydiphenylsiloxane was employed to replace the injection loop of a Rheodyne injection valve. A volume of 1 mL of derivatized sample was passed thro…
Flow-injection spectrophotometric determination of arylamines and sulphonamides by diazotization and coupling in a micellar medium
1991
Abstract In a sodium dodecyl sulphate (SDS) micellar solution, the rate of coupling of a diazonium ion with N-(1- naphthyl)ethylenediamine (NED) increases greatly, the protonation of the resulting azo dyes takes place at higher pH values and the dyes are more soluble. These favourable features were applied to the development of a simple flow-injection spectrophotometric procedure for the determination of diazotizable substances of pharmaceutical interest. Limits of detection in the range 0.2–0.5 μg ml−1 (signal-to-noise ratio=3), with relative standard deviation of 0.7–3% (n=3) for 5 μg ml−1 standards, were obtained.
Preconcentration and speciation of chromium in waters using solid-phase extraction and atomic absorption spectrometry
2000
Abstract A method for the preconcentration and speciation of chromium was developed. After formation of an anionic compound with ethylenediaminetetraacetic acid (CrY − ), Cr (VI) and Cr (III) are retained on a strong anionic phase (SAX) and controlled elution with 0.5 M NaCl permits their speciation. The retention and elution conditions were optimised, and interferences due to the presence of other ions such as Mg(II), Mn(II), Sn(II), Fe(III), Ba(II), Al(III), Ca(II), chloride, iodine, bromide, fluoride, sulphate, phosphate, bicarbonate and nitrate were studied. The detection limits were 0.4 μg l −1 and 1.1 μg l −1 for Cr(III) and Cr(VI), respectively, and reproducibility was 9%. The result…