Adiabatic One-Way Internal Rotation around the Single Bond Connecting the 2-Anthryl Group and C:N Double Bond in the Triplet State of (E)-N-Methoxy-1-(2-anthryl)ethanimine

1994 ◽  
Vol 98 (40) ◽  
pp. 9945-9949 ◽  
Author(s):  
Tatsuo Arai ◽  
Yasunori Furuya ◽  
Katsumi Tokumaru
Keyword(s):  
Double Bond ◽  
Triplet State ◽  
Internal Rotation ◽  
Single Bond

The Change in the Raman Spectra of Chloroprene and Isoprene in the Polymerization Process

1943 ◽  
Vol 16 (4) ◽  
pp. 841-847
Author(s):  
A. Gantmacher ◽  
S. Medvedev
Keyword(s):  
Raman Spectrum ◽  
Double Bond ◽  
Raman Spectra ◽  
Polymer Molecule ◽  
Polymerization Process ◽  
High Polymer ◽  
Single Bond ◽  
Double Bonds ◽  
Continuous Background ◽  
Single Bonds

Abstract 1. When chloroprene and isoprene polymerize, besides the frequency characterizing the conjugate double bond in the monomer, there appears a higher frequency corresponding to the isolated double bond in the polymer. In the polymerization process, the intensity of the frequency of the conjugate double bond decreases and the intensity of the frequency of the isolated double bond increases. Because of the increase in the number of single bonds in the polymer, the intensity of the frequency of the single bond 1005 in the polymer is considerably greater than in the monomer. 2. Even in the case of the samples with high polymer contents (greater than 50 per cent), the intensity of the frequency of the conjugate double bond is considerably greater than the intensity of the frequency of the isolated double bond. This is attributable to the fact that part of double bonds disappear during polymerization. 3. The Raman spectra of the chloroprene and isoprene polymers differ essentially from those of the monomers. To characterize the frequencies of vibration in the polymer molecule, it is essential to investigate its Raman spectrum in a medium free of the monomer. 4. The formation of highly polymeric molecules on polymerization does not result in an increase in the intensity of the continuous background in spectrograms.

scholarly journals Crystal structure ofN′′-benzyl-N′′-[3-(benzyldimethylazaniumyl)propyl]-N,N,N′,N′-tetramethylguanidinium bis(tetraphenylborate)

2015 ◽  
Vol 71 (12) ◽  
pp. o1086-o1087
Author(s):  
Ioannis Tiritiris ◽  
Willi Kantlehner
Keyword(s):  
Crystal Structure ◽  
Double Bond ◽  
Positive Charge ◽  
Planar Geometry ◽  
Methyl Groups ◽  
Two Dimensional ◽  
Single Bond ◽  
Double Bond Character ◽  
Bond Lengths ◽  
Bond Character

In the crystal structure of the title salt, C24H38N42+·2C24H20B−, the C—N bond lengths in the central CN3unit of the guanidinium ion are 1.3364 (13), 1.3407 (13) and 1.3539 (13) Å, indicating partial double-bond character. The central C atom is bonded to the three N atoms in a nearly ideal trigonal–planar geometry and the positive charge is delocalized in the CN3plane. The bonds between the N atoms and the terminal methyl groups of the guanidinium moiety and the four C—N bonds to the central N atom of the (benzyldimethylazaniumyl)propyl group have single-bond character. In the crystal, C—H...π interactions between the guanidinium H atoms and the phenyl C atoms of the tetraphenylborate ions are present, leading to the formation of a two-dimensional supramolecular pattern parallel to theacplane.

Photoreactions of Nitroso Compounds in Solution. XIX Stereochemistry of Nitrosamine Photoaddition to Olefin

1971 ◽  
Vol 49 (18) ◽  
pp. 3069-3071 ◽  
Author(s):  
Y. L. Chow ◽  
S. C. Chen ◽  
D. W. L. Chang
Keyword(s):  
Free Radical ◽  
Double Bond ◽  
Intermediate Stage ◽  
Nitroso Compounds ◽  
Radical Mechanism ◽  
Single Bond ◽  
Carbon Double Bond ◽  
Free Radical Mechanism ◽  
Cis And Trans

The stereochemical course of the photoaddition of nitrosamines to a carbon–carbon double bond was shown to follow a free radical mechanism initiated by aminium radicals. The photoaddition to cyclohexene was highly stereoselective in which the addendum approached in anti-diaxial mode. Similar photoadditions to cis- and trans-2-butenes were less stereoselective, giving mixtures of the erythro- and threo-adducts, owing to the rotation of the carbon-carbon single bond in the intermediate stage.

Hindered internal rotation about the C-N partially double bond in N-acyl derivatives of 1,2,3,4-tetrahydroquinoline

1980 ◽  
Vol 16 (8) ◽  
pp. 849-853
Author(s):  
L. B. Krivdin ◽  
V. N. Torocheshnikov ◽  
N. M. Sergeev ◽  
I. G. Il'ina ◽  
N. B. Kazennova
Keyword(s):  
Double Bond ◽  
Internal Rotation ◽  
Derivatives Of ◽  
Acyl Derivatives

scholarly journals Crystal structure of (1-ethoxyethylidene)dimethylazanium tetraphenylborate

2015 ◽  
Vol 71 (12) ◽  
pp. o984-o985
Author(s):  
Ioannis Tiritiris ◽  
Stefan Saur ◽  
Willi Kantlehner
Keyword(s):  
Crystal Structure ◽  
Double Bond ◽  
Bond Length ◽  
Single Bond ◽  
Charge Delocalization ◽  
Double Bond Character ◽  
Iminium Ions ◽  
Iminium Ion ◽  
Phenyl Rings ◽  
Bond Character

In the cation of the title salt, C6H14NO+·C24H20B−, the C—N bond lengths are 1.297 (2), 1.464 (2) and 1.468 (2) Å, indicating double- and single-bond character, respectively. The C—O bond length of 1.309 (2) Å shows double-bond character, pointing towards charge delocalization within the NCO plane of the iminium ion. In the crystal, C—H...π interactions between the iminium H atoms and the phenyl C atoms of the anion are present. The phenyl rings form aromatic pockets, in which the iminium ions are embedded.

scholarly journals N,N,N′,N′,N′′,N′′,N′′′,N′′′-Octamethyl(but-2-yne)bisamidinium bis(tetraphenylborate)

IUCrData ◽  
2016 ◽  
Vol 1 (2) ◽  
Author(s):  
Ioannis Tiritiris ◽  
Ralf Kress ◽  
Willi Kantlehner
Keyword(s):  
Double Bond ◽  
Bond Length ◽  
Triple Bond ◽  
Carbon Chain ◽  
Methyl Groups ◽  
Two Dimensional ◽  
Single Bond ◽  
Asymmetric Unit ◽  
Phenyl Rings ◽  
Bond Character

The asymmetric unit of the title salt, C12H24N42+.2C24H20B−, comprises half a cation and one tetraphenylborate ion. An inversion centre is situated at the mid-point of the triple C[triple-bond]C bond in the cation. The bisamidinium C—N bonds [1.3249 (11) and 1.3267 (11) Å] have double-bond character and both positive charges are delocalized between the dimethylamino groups. The bonds between the N atoms and the terminal C-methyl groups all have values characteristic for a typical single bond [1.4656 (12)–1.4687 (12) Å]. The acetylenic bond length [1.1889 (18) Å] is consistent with a triple C[triple-bond]C bond and the butyne carbon chain is almost linear. C—H...π interactions between the bisamidinium methyl H atoms and the phenyl C atoms of the tetraphenylborate ions are present. The phenyl rings form aromatic pockets, in which the cations are embedded. This leads to the formation of a two-dimensional supramolecular pattern in theabplane.

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