Search results for "Amine gas treating"
showing 10 items of 252 documents
Theoretical study of a hydration mechanism in an enaminone pro-drug prototype
2003
Enaminones may act as pro-drugs releasing via proton-catalyzed hydrolysis a primary amine, which may be an actual drug. A hydration mechanism of prototype enaminone (2-propenal-3-amine) has been subjected to quantum chemical studies. All involved compounds were investigated in a search for the most likely reactive form. Results revealed that the proposed reaction pathway is thermodynamically possible.
Catalytic aminomercuration of olefins in a tandem aminomercuration-deoxymercuration; One-step synthesis of secondary n-arylallylamines from allylalco…
1990
Abstract Allyl alcohols react with primary aromatic amines and stoichiometric amounts of mercury(II) tetrafluoroborate to give mixtures of mono- and diallyl anilines. However, the use of the tandem aminomercuration-deoxymercuration promoted by catalytic mercury(II) tetrafluoroborate allows to perform regiospecifically the monoallylation reaction with very high yields. A mechanism is proposed to account for the observed results.
A ferromagnetic methoxido-bridged Mn(III) dimer and a spin-canted metamagnetic μ(1,3)-azido-bridged chain.
2012
Two new Mn(III) complexes of formulas [MnL(1)(N(3))(OMe)](2) (1) and [MnL(2)(N(3))(2)](n) (2) have been synthesized by using two tridentate NNO-donor Schiff base ligands HL(1){(2-[(3-methylaminoethylimino)-methyl]-phenol)} and HL(2) {(2-[1-(2-dimethylaminoethylimino)methyl]phenol)}, respectively. Substitution of the H atom on the secondary amine group of the N-methyldiamine fragment of the Schiff base by a methyl group leads to a drastic structural change from a methoxido-bridged dimer (1) to a single μ(1,3)-azido-bridged 1D helical polymer (2). Both complexes were characterized by single-crystal X-ray structural analyses and variable-temperature magnetic susceptibility measurements. The ma…
Chemoselektive mono- und disilyletherbildung aus tertiären und sekundären silanen
1985
Abstract Tertiary and secondary silanes are O-selective. With alcohols the corresponding silyl ethers are formed. Cesium fluoride/imidazole (CsF/Im) is a better activating system than CsF alone. Primary OH groups are silylated remarkably faster under CsF/Im activation than secondary OH groups. Tertiary alcohols do not react. Primary OH groups are selectively protected also in the presence of secondary OH groups by silanes with bulky ligands such as triisopropylsilane ((i-Pr) 3 SiH ( 4 )). Ketones are neither reduced to silyl ethers nor transformed to silylenol ethers under the conditions employed. Secondary silanes form monosilyl ethers by amine activation; with CsF the formation of disilyl…
Efficient Resolution of Menthylamine with Inexpensive (R,R)-Tartaric Acid by Dielectrically Controlled Resolution (DCR)
2013
A practical procedure for the resolution of menthylamine 2 with (R,R)-tartaric acid [(R,R)-3] as resolving agent is presented. Variation of the solvent system allows both enantiomers of 2 to be selectively crystallized. Performing the resolution in methanol containing 6 % water leads to (–)-2·(R,R)-3·MeOH. The other, less-soluble diastereomeric salt is obtained by applying a solvent system consisting of methanol with 19 % water with a yield of 14 %. Subsequent basic workup with aqueous sodium hydroxide gave the free menthylamine compounds. Further workup of the mother liquors and an additional recrystallization step allowed the (–)-2·(R,R)-3·MeOH salt to be obtained in an overall yield of 2…
Bioresponsive poly(amidoamine)s designed for intracellular protein delivery.
2013
Poly(amidoamine)s with bioreducible disulfide linkages in the main chain (SS-PAAs) and pH-responsive, negatively charged citraconate groups in the sidechain have been designed for effective intracellular delivery and release of proteins with a net positive charge at neutral pH. Using lysozyme as a cationic model protein these water soluble polymers efficiently self-assemble into nanocomplexes by charge attraction. At pH 5 (the endosomal pH) the amide linkages connecting the citraconate groups in the sidechains of the SS-PAAs are hydrolyzed by intramolecular catalysis, resulting in expulsion of the negative citraconate groups and formation of protonated amine groups, resulting in charge reve…
Design of Porphyrin-dota-Like Scaffolds as All-in-One Multimodal Heterometallic Complexes for Medical Imaging
2013
A series of four multimodal ligands incorporating one porphyrin moiety and one or more dota-like macrocycles all-in-one in the same molecular architecture have been synthesized and full characterized. The corresponding gadolinium(III) complexes were also synthesized and heterometallic complexes incorporating both gadolinium(III) and copper(II) ions were prepared as potential MRI/PET multimodal contrast agents. One ligand (L4) includes an amine moiety that can be activated for easy conversion into an isothiocyanate group for further anchoring to a biological vector. Preliminary relaxivity, cytotoxicity, and MRI studies showed that the complexes developed in this work are very promising medic…
Synthesis and Characterization of Copper Complexes Containing the Tripodal N7 Ligand Tris{2-[(pyridin-2-ylmethyl)amino]ethyl}amine (=N′-(Pyridin-2-yl…
2005
The stability constants of the CuII chelates with the tripodal heptadentate ligand tris{2-[(2-pyridylmethyl)amino]ethyl}amine (=N′-(pyridin-2-ylmethyl)-N,N-bis{2-[(pyridin-2-ylmethyl)amino]ethyl}ethane-1,2-diamine; tpaa), determined by potentiometry and UV spectrometry, show the formation of [Cu(tpaaH)]3+ and [Cu(tpaa)]2+ species. In the solid state, two mononuclear CuII compounds, [Cu(tpaa)](PF6)2 (1) and [Cu(tpaaH)](ClO4)3⋅H2O (2), and one trinuclear [Cu3(tpaa)2(ClO4)2](ClO4)4⋅2 H2O (3) complex were isolated and characterized by IR, UV/VIS, and EPR spectroscopy. An X-ray structure of the mononuclear protonated complex 2 shows that the Cu2+ ion has a distorted square-pyramidal geometry (τ=…
Zinc-salophen complexes as selective receptors for tertiary amines
2007
Zinc-salophen compounds 1-3 incorporating in the given order 1,2-diaminobenzene, 2,3-diaminonaphthalene, and 9,10-diaminophenantrene moieties were synthesised. Their binding properties toward a series of tertiary amines were assessed by UV-Vis and fluorescence spectroscopy in chloroform solution. Unprecedented selectivities of quinuclidine vs. triethylamine higher than 105 were recorded, thereby revealing the dramatic influence of steric effects on axial coordination of tertiary amines. X-Ray diffraction analyses showed that in the solid state compound 2 is dimeric, but its 1 : 1 quinuclidine complex is monomeric. Strong indications were obtained that both free receptors and their amine add…
Influence of a sterically hindered amine on the photo-oxidation of low density/linear low density polyethylene blends
1990
Abstract Low density/linear low density polyethylene blends show a rate of degradation of the mechanical properties during photo-oxidation which increases with the content of the linear polymer. The use of a sterically hindered amine as UV stabilizer greatly improves the resistance of these blends to UV irradiation. The effectiveness of the stabilizer increases with the content of linear low density polyethylene.