Solvent-induced partial cyanoethylation and hydroxylation of cyanoethyl group

2006 ◽  
Vol 102 (1) ◽  
pp. 183-191 ◽  
Author(s):  
A. Selva Subha ◽  
S. Thambidurai
Keyword(s):  
Cyanoethyl Group

Direct observation of deuterium migration in crystalline-state reaction by single-crystal neutron diffraction. III. Photoracemization of 1-cyanoethyl cobaloxime complexes

2001 ◽  
Vol 57 (4) ◽  
pp. 551-559 ◽  
Author(s):  
Takashi Ohhara ◽  
Hidehiro Uekusa ◽  
Yuji Ohashi ◽  
Ichiro Tanaka ◽  
Shintaro Kumazawa ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Single Crystal ◽  
Bond Cleavage ◽  
Cobalt Complexes ◽  
Crystal Form ◽  
Xenon Lamp ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Stereogenic Center ◽  
Cyanoethyl Group

The H atoms bonded to the chiral C atoms (stereogenic center) of the 1-cyanoethyl groups in two cobalt complexes, [(R)-1-cyanoethyl]bis(dimethylglyoximato)(pyridine)cobalt(III) (2) and [(R,S)-1-cyanoethyl]bis(dimethylglyoximato)(piperidine)cobalt(III) (3), were replaced with D atoms, such as Co—C*D(CH3)CN. The crystals of the two cobalt complexes were irradiated with a xenon lamp for 72 h and 27 d, respectively. The unit-cell dimensions were gradually changed with retention of the single-crystal form. The crystal structures after irradiation were determined by neutron diffraction. In each crystal the chiral 1-cyanoethyl group of one of the two crystallographically independent molecules was partly inverted to the opposite configuration, whereas that of the other molecule kept the original configuration. The C*—D bond in the inverted group was completely conserved in the process of the inversion of the chiral alkyl group. This suggests that the inversion of the chiral 1-cyanoethyl group proceeds with the rotation of the cyanoethyl radical after the Co—C bond cleavage by photo-irradiation so that the opposite side of the radical faces the Co atom. This is followed by recombination of the Co—C bond to form the inverted 1-cyanoethyl group.

Four polymorphs of a cobaloxime complex with different solid-state photoisomerization rates

1996 ◽  
Vol 52 (2) ◽  
pp. 303-313 ◽  
Author(s):  
K. Sawada ◽  
D. Hashizume ◽  
A. Sekine ◽  
H. Uekusa ◽  
K. Kato ◽  
...  
Keyword(s):  
Solid State ◽  
Quantitative Relationship ◽  
Molecular Structures ◽  
Energy Calculation ◽  
Xenon Lamp ◽  
Powdered Sample ◽  
X Rays ◽  
Crystal Forms ◽  
First Order Kinetics ◽  
Cyanoethyl Group

The complex (2-cyanoethyl)bis(dimethylglyoximato)(triphenylphosphine)cobalt(III), [Co(C4H7N2O2)2(C3H4N){P(C6H5)3}], when it was crystallized rapidly from an aqueous methanol solution, has four crystal forms, three of which were obtained separately from different solvents in large amounts. The crystal structures of the four forms were determined by X-rays. The molecular structures in the four forms have different conformations around the Co—C and Co—P bonds. The packing energy calculation indicated that the four forms have approximately the same energy. The 2-cyanoethyl group of this complex was isomerized to the 1-cyanoethyl group when the powdered sample of the complex was irradiated with a xenon lamp. For three crystal forms prepared separately, the solid-state photoisomerization rates were measured from the change in the IR spectra, assuming first-order kinetics. A quantitative relationship between the rate constant and the size of the reaction cavity for the 2-cyanoethyl group has been obtained for the three crystal forms.

Size effects of imidazolium cations bearing cyanoethyl group on performance of dye-sensitized solar cells

2019 ◽  
Vol 246 ◽  
pp. 137-140 ◽  
Author(s):  
Donghoon Song ◽  
Young-Seop Choi ◽  
Byung Su Kim ◽  
Hoon Sik Kim ◽  
Yong Soo Kang
Keyword(s):  
Solar Cells ◽  
Size Effects ◽  
Dye Sensitized Solar Cells ◽  
Imidazolium Cations ◽  
Dye Sensitized ◽  
Sensitized Solar Cells ◽  
Cyanoethyl Group

Highly Dielectric Rubber Bearing Cyanoethyl Group with Various Side-Chain Structures

2020 ◽  
Vol 53 (22) ◽  
pp. 10128-10136
Author(s):  
Ryosuke Matsuno ◽  
Yuusaku Takagaki ◽  
Takamasa Ito ◽  
Hitoshi Yoshikawa ◽  
Shigeaki Takamatsu ◽  
...  
Keyword(s):  
Side Chain ◽  
Rubber Bearing ◽  
Cyanoethyl Group

Modified photoreactivity due to mixed crystal formation. II. Enhanced reactivity upon conformational mimicry and cavity enlargement

2002 ◽  
Vol 58 (6) ◽  
pp. 986-997 ◽  
Author(s):  
Champika Vithana ◽  
Hidehiro Uekusa ◽  
Akiko Sekine ◽  
Yuji Ohashi
Keyword(s):  
Reaction Rate ◽  
Mixed Crystal ◽  
Reaction Rates ◽  
Mixed Crystals ◽  
Crystal Formation ◽  
Xenon Lamp ◽  
Cell Parameters ◽  
Reactive Groups ◽  
Mixed Crystal Formation ◽  
Cyanoethyl Group

The 2-cyanopropyl (β-cyanopropyl) group in the cobaloxime complex of (2-cyanopropyl)(3-methylpyridine)bis(dimethylglyoximato)cobalt(III) takes a trans conformation around the Co—C—C—CN bond in the crystal and undergoes isomerization to the 1-cyanopropyl (α-cyanopropyl) group with a low reaction rate when the powdered crystals are irradiated with a xenon lamp. When the complex was mixed with (2-cyanoethyl)(3-methylpyridine)bis(dimethylglyoximato)cobalt(III) or (2-cyanoethyl)(3-ethylpyridine)bis(dimethylglyoximato)cobalt(III), a mixed crystal, Mix-I or Mix-II, was obtained. The cell parameters of Mix-I and Mix-II were considerably different. When the crystals of Mix-I and Mix-II were irradiated with the xenon lamp, the 2-cyanopropyl group and the 2-cyanoethyl group isomerized to the 1-cyanopropyl and 1-cyanoethyl groups, respectively, in the crystalline state as well as in the solid state. The isomerization rates of the 2-cyanopropyl and 2-cyanoethyl groups of the mixed crystals became significantly higher than the corresponding rates in the component crystals. For the 2-cyanopropyl group, the conformational change from trans to cis in the mixed crystals caused reaction rates to be enhanced, and the expanded volume of the reaction cavity in the mixed crystals increased the reactivity for the 2-cyanoethyl group, when compared with the reactivity of each component crystal. A quantitative discussion of the increased rate constants is presented, which is based on the crystal structures. The shapes of the reaction cavities for the reactive groups undergoing isomerization control the conformation and configuration of the produced1-cyanoethyl and 1-cyanopropyl groups.

Sign in / Sign up

Export Citation Format

Share Document