Search results for "Organo"

Morphogenic potential of mechanically isolated single cells from Digitalis obscura L. callus

1989

Calli from hypocotyl and root explants of Digitalis obscura L. showed regeneration of adventitious shoots, roots and embryos when transferred to Murashige & Skoog medium supplemented with cytokinins alone or in combination with auxins. Optimum shoot-bud formation was achieved in the presence of IAA and BA, while roots mainly appeared either in absence of growth regulators or with IAA and Kn. Embryo formation took place only in those combinations that included Kn. Embryo development was influenced by the type of auxin, and precocious germination occurred in media with NAA. Mechanically isolated cells from hypocotyl- and root-derived calli were plated in MS medium supplemented with several IA…

The Effect of Montmorillonite Type Nanoparticles on Stiffness and Flammability of Rapeseed Oil Based Polyisocyanurate Foams

2013

Polyisocyanurate foams incorporating polyols derived from rapeseed oil are developed, with the polyol system comprising up to 80% of rapeseed oil esters. To enhance the mechanical characteristics and fire resistance of the foams, they are filled with three different types of organically modified clay (organoclay) in the range of loading from 1 to 5% by weight. Marked increase in tensile stiffness of nanocomposite foams is observed.

The first radical salt of the polyoxometalate cluster [P2W18O62]6⊖with bis(ethylenedithio)tetrathiafulvalene (ET): ET11[P2W18O62] · 3H2O

1996

Polymere acroleine, I. Mitt. Untersuchungen über die polymerisation des acroleins.

1955

Unter der Einwirkung typischer Polymerisations-Katalysatoren wie z. B. Azoisobuttersaurenitril, Peroxyde, Redox-Systeme, metallorganische Verbindungen und Friedel-Crafts-Katalysatoren geht Acrolein in polymere Produkte uber. Deren physikalische Eigenschaften (thermische Bestandigkeit, Viskositat der Losungen u. a.) hangen von den Polymerisationsbedingungen ab. Einige der erhaltenen polymeren Produkte unterscheiden sich deutlich von den bisher bekannten Polyacroleinen. By the action of typical catalysts of polymerisation (e.g. azo-bis-isobutyronitrile, peroxides, redox-systems, organometallic compounds, Friedel-Crafts-catalysts) acrolein forms polymeric products. The physical properties of s…

Enantioselective addition of sodium bisulfite to nitroalkenes. A convenient approach to chiral sulfonic acids

2021

An enantioselective organocatalytic addition of sodium bisulfite to (E)-nitroalkenes has been developed by using a chiral bifunctional organocatalyst. The present methodology provides a variety of chiral β-nitroethanesulfonic acid compounds (17 examples) with excellent results: up to 99% yield and excellent enantioselectivity (up to 96% ee). The reaction tolerates (hetero)aryl and alkyl substituents on the β-nitroalkenes, and β,β-disubstituted nitroalkenes.

ChemInform Abstract: A Liquid-Liquid Biphasic Homogeneous Organocatalytic Aldol Protocol Based on the Use of a Silica Gel Bound Multilayered Ionic Li…

2012

Key feature of the title protocol is the use of a cis-ion-tagged proline dissolved in a liquid film on a multilayered ionic liquid covalently bound to silica. The resulting catalytically active material is soaked in cyclohexanone and water to form a semi-transparent gel which then reacts with the aldehyde.

ChemInform Abstract: A Catalyst Designed for the Enantioselective Construction of Methyl- and Alkyl-Substituted Tertiary Stereocenters.

2016

Tertiary methyl-substituted stereocenters are present in numerous biologically active natural products. Reported herein is a catalytic enantioselective method for accessing these chiral building blocks using the Mukaiyama-Michael reaction between silyl ketene thioacetals and acrolein. To enable remote enantioface control on the nucleophile, a new iminium catalyst, optimized by three-parameter tuning and by identifying substituent effects on enantioselectivity, was designed. The catalytic process allows rapid access to chiral thioesters, amides, aldehydes, and ketones bearing an α-methyl stereocenter with excellent enantioselectivities, and allowed rapid access to the C4-C13 segment of (-)-b…

Crystal structure of 2-methyl-1H-imidazol-3-ium aquatrichlorido(oxalato-κ2O,O′)stannate(IV)

2015

N—H⋯O, N—H⋯Cl and O—H⋯O hydrogen bonds between cations and anions in the complex salt (C4H7N2)+[Sn(H2O)Cl3(C2O4)]− are responsible for the formation of a three-dimensional network structure.

rac-1,1,1,6,6,6-Hexachlorohex-3-yne-2,5-diol hemihydrate

2017

The asymmetric unit of the title compound, C6H4Cl6O2·0.5H2O, contains one molecule of 1,1,1,6,6,6-hexachlorohex-3-yne-2,5-diol and half a water molecule located on a twofold rotation axis. In the crystal, pairs of hexachlorohexynediol molecules form centrosymmetric dimers connectedviapairwise O—H...O hydrogen bonds. These dimers are connected by water molecules, resulting in layers parallel to theabplane.

Separation of aromatic aminophosphonic acid enantiomers by capillary electrophoresis with the application of cyclodextrins

2002

The detailed studies concerning capillary electrophoresis separation of aminophosphonic acid enantiomers with various commercially available cyclodextrins are presented. The obtained results show that the separation of these stereoisomers is dependent on pH of background electrolyte, concentration of cyclodextrin as well as on the type of applied chiral selector. The separation mechanism is based on the co-operative effect of hydrogen bond type interactions enhanced by hydrophobic forces and sterical constrains between aminophosphonate and cyclodextrin. With application of elaborated method, enantiomeric baseline or partial separation of 18 alpha-aminophosphonic acids was achieved. This sep…