Search results for "Amine gas treating"
showing 10 items of 252 documents
Calixarenes as Stoppers in Rotaxanes
1998
The synthesis of the amide-based rotaxane 7a bearing calix[4]arene blocking groups is described for the first time. While rotaxane formation fails if a calix[4]arene is functionalized at the upper rim with only an amino or methylamino group lacking any spacer, the prolonged amine 5a works successfully as stopper unit preventing dethreading of the dimeric wheel 1a by its size. Rotaxane formation of 8b was observed only by MALDI-TOF mass spectrometry of the reaction mixture of the amine 5b, the axle 6 and 1a. With the larger trimeric wheel 1b no stable rotaxane could be obtained. It either does not act as a concave template or its opening is too wide, even for the bulky calixarene stoppers.
Über die wirksamkeit von lewis-basen als initiatoren der anionischen polymerisation von formaldehyd. 27. Mitt. über polyoxymethylene
1966
Die anionische Polymerisation des monomeren Formaldehydes mit LEWIS-Basen wurde bei −78°C in Ather, Aceton und Toluol untersucht. Die Basizitat der LEWIS-Basen ist ein wichtiger Faktor for ihre Initiatoraktivitat, ist jedoch nicht allein entscheidend; es spielen auch strukturelle und steren rische Faktoren eine Rolle. Primare Amine sind wahrscheinlich deshalb schlechte Initiatoren, weil sie mit Formaldehyd Methylol- und Dimethylolamine bilden. Verzweigungen aliphatischer Substituenten wirken sich um so starker retardierend aus, je naher sich die Verzweigungsstelle am Stickstoffatom befindet. Die Polymerisationsgeschwindigkeit steigt bei den meisten Aminen mit zunehmender Polaritat des Losun…
ChemInform Abstract: Heterocycles from α-Aminonitriles
2014
Owing to their various modes of reactivity, α-aminonitriles represent versatile building blocks for the construction of a wide range of nitrogen heterocycles. The present Concept article focuses on synthetic methodologies using their bifunctional nature which is the basis of their reactivity as α-amino carbanions and as iminium ions. Reactions exclusively taking place on either the amine or on the nitrile moiety will not be considered.
ChemInform Abstract: Reversal of Asymmetric Induction in Stereoselective Strecker Synthesis on Galactosyl Amine as the Chiral Matrix.
1989
Abstract The reversal of the direction of asymmetric induction in Lewis acid catalyzed Strecker synthesis using the 2,3,4,6-tetra-O-pivaloyl-β-D-galactopyranosyl amine 1 is described. In isopropanol or tetrahydrofuran 1 had given ( R )-diastereomers of the corresponding α-amino nitriles preferably. However, in chloroform in the presence of heterogeneous zinc chloride the same auxiliary alternatively leads to an excess of the ( S )-diastereomers.
Ethyl 1-acetyl-3-amino-1H-pyrazole-4-carboxylate, a tetragonal structure with Z′ = 4
2006
The title compound, C8H11N3O3, crystallizes with Z' = 4. One pyrazole N atom is substituted and excluded from intermolecular contacts. The amine N, acetyl O and an ester O atom are involved in the formation of nearly planar molecular layers. The layers are perpendicular to the c axis, with an interlayer distance of 3.333 Å. The hydrogen-bonding patterns are similar for each molecule, i.e. intramolecular N-H...O, as well as intermolecular N-H...O and C-H...N(pyrazole), bonds are present.
Crystal structure and magnetic properties of (tris{4-[1-(2-methoxyethyl)imidazol-2-yl]-3-azabut-3-enyl}amine)iron(II) bis(hexafluoridophosph…
2019
The title compound, [Fe(C27H41N10O3)](PF6)2, is an example of an iron(II) spin-crossover compound. In this compound, C⋯F and CH⋯F/O contacts, present between the cations and anions, extend the structure into a three-dimensional supramolecular network.
N-Methyl-4-(4-nitrophenyl)-N-nitroso-1,3-thiazol-2-amine
2017
The title compound, C10H8N4O3S, is almost planar [dihedral angle between the rings = 2.2 (2)°; r.m.s. deviation for the non-H atoms = 0.050 Å]. In the crystal, C—H...O and C—H...N hydrogen bonds link the molecules into (10-2) layers.
{Bis[2-(diisopropylphosphanyl)ethyl]amine}carbonyl(tetrahydroborato)cobalt(I)
2018
In the structure of title borohydride pincer complex, [Co(BH4)(C16H37NP2)(CO)], the cobalt(I) metal exhibits a distorted square-pyramidal coordination geometry with the basal positions occupied by the P and N atoms of the tridentate ligand and by the C atom of the carbon monoxide ligand. In the crystal, molecules interact only by van der Waals forces.
4,4′-(1,2-Diazaniumylethane-1,2-diyl)dibenzoate trihydrate
2016
The title compound, C16H16N2O4·3H2O, was synthesized from (1R,2R)-1,2-bis(2-hydroxyphenyl)ethylenediamine and terephthalaldehydic acid. The compound crystallizes from water as a double zwitterion with protonated amine groups and deprotonated carboxylate groups. The dihedral angle formed by the aromatic rings is 3.86 (11)°. In the crystal, N—H...O and O—H...O hydrogen bonds link molecules into a three-dimensional network.
Crystal structure of (E)-2-(tert-butylamino)-4-(tert-butylimino)naphthalen-1(4H)-one
2018
The title compound is the first example of a naphthoquinone imine derivative crystallizing in the 4-imine/2-amine tautomeric form having bulky tert-butyl substituents at the N atoms.