Photochemical Nitration by Tetranitromethane. XXIX. Adduct Formation in the Photochemical Reaction of Tetranitromethane and 1,5-Dimethylnaphthalene; Allylic Rearrangements of Adducts

1995 ◽  
Vol 48 (12) ◽  
pp. 1989 ◽  
Author(s):  
CP Butts ◽  
L Eberson ◽  
MP Hartshorn ◽  
WT Robinson
Keyword(s):  
Charge Transfer ◽  
Radical Cation ◽  
Charge Transfer Complex ◽  
Major Product ◽  
Adduct Formation ◽  
Allylic Rearrangement ◽  
X Ray ◽  
Structure Determinations ◽  
Carbon Radicals ◽  
Nitronic Ester

Photolysis of the 1,5-dimethylnaphthalene/tetranitromethane charge-transfer complex yields the triad of 1,5-dimethylnaphthalene radical cation, nitrogen dioxide and trinitromethanide ion. Recombination of this triad gives predominantly the epimeric 4,8-dimethyl-1-nitro-4-trinitromethyl-1,4-dihydronaphthalenes (18) and (27), the epimeric 1,5-dimethyl-1-nitro-4-trinitromethyl-1,4-dihydronaphthalenes (20) and (21), 4,8-dimethyl-r-1-nitro-t-2-trinitromethyl-1,2-dihydronaphthalene (19), 4,8-dimethyl-t-2-trinitromethyl-1,2-dihydronaph-thalen-r-1-ol (23), nitro cycloadduct (22), hydroxy cycloadduct (24), nitronic ester (25) and 4,8-dimethyl-1-nitronaphthalene (26). Adduct (19) is formed substantially by allylic rearrangement of 4,8-dimethyl-1-nitro-4-trinitromethyl-1,4-dihydronaphthalene (18), and adduct (23) and indirectly nitronic ester (25) by allylic rearrangement of a postulated intermediate 4,8-dimethyl-t-4-trinitromethyl-1,4-dihydronaphthalen-r-1-ol (32). Adducts (18), (19), (23), (25) and (27) are formed by attack of trinitromethanide ion at C 1 of the 1,5-dimethylnaphthalene radical cation, while adducts (20)-(22) and (24) are formed by the corresponding attack at C4, the reaction pathways being determined by the relative energies of the intermediate delocalized carbon radicals. Adduct formation is substantially suppressed for a photolysis when trifluoroacetic acid (0.7 M) is added to the dichloromethane solvent at 20°, 1,5-dimethyl-4-nitronaphthalene (26) being formed close to quantitatively. In contrast, photolysis of the 1,5-dimethylnaphthalene/tetranitromethane charge-transfer complex in 1,1,1,3,3,3-hexafluoropropan-2-ol gave substantial amounts of adduct (19), together with 1,5-dimethyl-4-nitronaphthalene (26) as the major product. Allylic rearrangements of 1-methoxy-4-nitro-1-trinitromethyl-1,4-dihydronaphthalene (34) and the epimeric 1,4,5,8-tetramethyl-1-nitro-4-trinitromethyl-1,4-dihydronaphthalenes (38) are seen as the mode of formation of 4-methoxy-r-1-nitro-t-2-trinitromethyl-1,2-dihydronaphthalene (33) and the epimeric 1,4,5,8-tetramethyl-1-nitro-2-trinitromethyl-1,2-dihydronaphthalenes (36), respectively. X-Ray crystal structure determinations are reported for adducts (19), (20), (22), (24) and (28), the last compound being formed only on chromatography of reaction mixtures.

Photochemical Nitration by Tetranitromethane. XVII. The Regiochemistry of Adduct Formation in the Photochemical Reaction of 1-Methylnaphthalene and Tetranitromethane

1994 ◽  
Vol 47 (8) ◽  
pp. 1591 ◽  
Author(s):  
JL Calvert ◽  
L Eberson ◽  
MP Hartshorn ◽  
n Maclaga ◽  
WT Robinson
Keyword(s):  
Crystal Structure ◽  
Charge Transfer ◽  
Radical Cation ◽  
Photochemical Reaction ◽  
Charge Transfer Complex ◽  
Adduct Formation ◽  
X Ray ◽  
Analogous Manner ◽  
Structure Determinations ◽  
Ion Recombination

Photolysis of the 1-methylnaphthalene/tetranitromethane charge-transfer complex yields the triad of 1-methylnaphthalene radical cation, nitrogen dioxide and trinitromethanide ion. Recombination of this triad gives predominantly 4-methyl-t-2-nitro-r-1-trinitromethyl-1,2- dihydronaphthalene (1), the epimeric 1-methyl-1-nitro-4-trinitromethyl-1,4-dihydronaphtha-lenes (2) and (3), 8-methyl-c-4-trinitromethyl-1,4-dihydronaphthalen-r-l-ol (4), nitro cyclo -adduct (5), 8-methyl-c-4-trinitromethyl-1,4-dihydronaphthalen-r-l-ol (6), hydroxy cyclo-adduct (7) and 4-methyl-t-1-trinitromethyl-1,2-dihydronaphthalen-r-2-ol (8). Adducts (1)- (3), (5), (7) and (8) are formed by attack of the trinitromethanide ion at C4 of the 1-methylnaphthalene radical cation, while adducts (4) and (6) are formed by corresponding attack at C5. Adduct (1) undergoes thermal cycloaddition to give the nitro cycloadduct (5) and it is assumed that the hydroxy cycloadduct (7) is formed in analogous manner from 4-methyl-t-1-trinitromethyl-1,2-dihydronaphthalen-r-2-ol (8). X-Ray crystal structure determinations are reported for adducts (1), (3)-(5) and (7).

Photochemical Nitration by Tetranitromethane. XXXII. Adduct Formation in the Photochemical Reaction of Phenanthrene and Tetranitromethane

1996 ◽  
Vol 49 (4) ◽  
pp. 469
Author(s):  
CP Butts ◽  
L Eberson ◽  
KL Fulton ◽  
MP Hartshorn ◽  
WT Robinson
Keyword(s):  
Crystal Structure ◽  
Charge Transfer ◽  
Nitrogen Dioxide ◽  
Photochemical Reaction ◽  
Charge Transfer Complex ◽  
Major Product ◽  
Adduct Formation ◽  
X Ray ◽  
Structure Determinations ◽  
Ion Recombination

Photolysis of the phenanthrene/tetranitromethane charge-transfer complex yields the triad of phenanthrene radical cation, nitrogen dioxide, and trinitromethanide ion. Recombination of this triad in dichloromethane at 20° gives 9-nitrophenanthrene (1), trans-10-trinitromethyl-9,10-dihydrophenanthren-9-yl nitrate (2a), trans-9-nitro-10-trinitromethyl-9,10-dihydrophenanthrene (2b), and trans-10-trinitromethyl-9,10-dihydrophenanthren-9-ol (2c). Adduct formation is partially suppressed when trifluoroacetic acid (0.7 M) is added to the dichloromethane solvent at 20°, the major product identified being 9-nitrophenanthrene (1). At -20° in dichloromethane, or in acetonitrile at 20°, 10'-nitro-9,9',10,10'-tetrahydro-9,9'-biphenanthren-10-yl nitrate (3) is formed, apparently by reaction of nitrogen dioxide with phenanthrene. X-Ray crystal structure determinations are reported for adducts (2a,b).

Photochemical Nitration by Tetranitromethane .XVI. The Regiochemistry of Adduct Formation in the Photochemical Reaction of 1,8-Dimethylnaphthalene and Tetranitromethane; Thermal 1,3-Dipolar Nitro Addition Reactions

1994 ◽  
Vol 47 (7) ◽  
pp. 1211 ◽  
Author(s):  
JL Calvert ◽  
L Eberson ◽  
MP Hartshorn ◽  
n Maclaga ◽  
WT Robinson
Keyword(s):  
Charge Transfer ◽  
Nitrogen Dioxide ◽  
Radical Cation ◽  
Photochemical Reaction ◽  
Charge Transfer Complex ◽  
Adduct Formation ◽  
Addition Reactions ◽  
X Ray ◽  
A Minor ◽  
Trinitromethyl Group

Photolysis of the 1,8-dimethylnaphthalene/tetranitromethane charge-transfer complex yields the triad of 1,8-dimethylnaphthalene radical cation, nitrogen dioxide, and trinitromethanide ion. In dichloromethane at +20° recombination of this triad gives predominantly the adducts (8), (9), (11), and (14), each of which is formed by attack of the trinitromethanide ion at C4 of the 1,8-dimethylnaphthalene radical cation; a minor adduct (10) is formed by similar attack but at C3 of the aromatic radical cation. The cycloadducts (12) and (13) arise by cycloaddition of the trinitromethyl group to the alkene function in adducts (9) and (14). The cycloaddition (9)→(12) has been shown to be a thermal, not photochemical, reaction. X-Ray crystal structures are reported for adducts (8) and (12).

scholarly journals Isolation and X-ray Crystal Structure of an Electrogenerated TEMPO–N3 Charge-Transfer Complex

2021 ◽  
Author(s):  
Hosea M. Nelson ◽  
Juno C. Siu ◽  
Ambarneil Saha ◽  
Duilio Cascio ◽  
Samantha N. MacMillan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Charge Transfer ◽  
Charge Transfer Complex ◽  
X Ray

Homeotropic alignment through charge-transfer-induced columnar mesophase formation in an unsymmetrically substituted triphenylene derivative

2010 ◽  
Vol 82 (11) ◽  
pp. 1993-2003 ◽  
Author(s):  
Juanjuan Li ◽  
Zhiqun He ◽  
Huan Zhao ◽  
Hemant Gopee ◽  
Xiangfei Kong ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Charge Transfer Complex ◽  
X Ray Diffraction ◽  
Hexagonal Symmetry ◽  
X Ray ◽  
Mesophase Formation ◽  
Homeotropic Orientation ◽  
Donor Acceptor ◽  
Homeotropic Alignment ◽  
Spectroscopy Optical

An unsymmetrically substituted triphenylene, with two adjacent chloroethoxyethyl lateral flexible chains, was synthesized and characterized. Although this compound showed no mesomorphic behavior, it formed a donor–acceptor charge-transfer complex with 2,4,7-trinitrofluorenone (TNF). The resulting 1:1 complex has been investigated using UV–vis and IR spectroscopy, optical microscopy, thermal analysis, and X-ray diffraction. A columnar mesophase with hexagonal symmetry was found. More interestingly, this charge-transfer complex can be easily aligned on a glass surface in a homeotropic orientation, which is stable at room temperature (RT) and over a wide temperature range.

scholarly journals Isolation and X-ray Crystal Structure of an Electrogenerated TEMPO–N3 Charge-Transfer Complex

2020 ◽  
Author(s):  
Hosea Nelson ◽  
Juno Siu ◽  
Ambarniel Saha ◽  
Duilio Cascio ◽  
Song-Bai Wu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Charge Transfer ◽  
Theoretical Analysis ◽  
Charge Transfer Complex ◽  
Reactive Intermediates ◽  
Structural Elucidation ◽  
Catalytic Reactions ◽  
X Ray ◽  
Increasing Demand ◽  
Computational Predictions

Recent advances in radical-based catalytic reactions have created an increasing demand for the understanding of their mechanistic underpinnings. Structural elucidation of transient reactive intermediates via diffraction techniques, though rarely possible, is one of the most decisive ways to support such mechanistic hypotheses. Here we present the isolation, structural elucidation, and theoretical analysis of an electrochemically generated and catalytically relevant charge-transfer species formed between the azidyl radical and (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO). The unusual bent N–N–N angle and the pancake bonding between these two fragments highlight the weak bonding interactions present in this complex. This X-ray structure validates computational predictions as well as mechanistic proposals of TEMPO-mediated radical azidation reactions.

Crystal structures of some eriostyl/nitrobenzoate derivatives

1980 ◽  
Vol 33 (2) ◽  
pp. 313 ◽  
Author(s):  
PR Jefferies ◽  
BW Skelton ◽  
B Walter ◽  
AH White
Keyword(s):  
Charge Transfer ◽  
Solid State ◽  
Single Crystal ◽  
Crystal Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Determinations

Following the suggestion made earlier, on the basis of solution spectroscopy, that a number of eriostyl/nitrobenzoate compounds form charge-transfer self-complexes, a number of these have been investigated structurally by single-crystal X-ray diffraction methods in order to ascertain the presence or otherwise of such interactions in the solid state. The substances thus studied were eriostyl 3,5-dinitrobenzoate (1), eriostyl p-nitrobenzoate (2), tetrahydroeriostyl 3,5-dinitrobenzoate (3), and eriostemyl 3,5-dinitrobenzoate (4);* structure determinations in all cases, although displaying the presence of strong charge-transfer interactions from the two moieties of each molecule, show that the interactions in the solid state are intermolecular in nature.

Structure, Stereochemistry and Novel 'Hydrogen Bonding' in Two Bipyridinium Salts of the B10H102- Anion

1987 ◽  
Vol 40 (12) ◽  
pp. 2097 ◽  
Author(s):  
DJ Fuller ◽  
DL Kepert ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Charge Transfer ◽  
Single Crystal ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
Full Matrix ◽  
X Ray ◽  
Structure Determinations ◽  
Positively Charged

Crystal structure determinations of (LH)2(B10H10), (1), and (LH2)(B10H10), (2), L = 2,2'- bipyridine , have been carried out by single-crystal X-ray diffraction methods at 295 K, being refined by full-matrix least squares to residuals of 0.041, 0.047 for 1758, 1771 'observed' independent reflections respectively. Crystals of (1) are monoclinic, P21/n, a 12.040(7), b 17.71(1), c 11.142(4) �, β 101.78(4)�, Z 4. Crystals of (2) are monoclinic, P21/c, a 9.937(4), b 10.837(3), c 14.856(5) �, β 109 2l(3)�, Z 4. The colour of the compounds is accounted for by charge-transfer interactions of a novel type, namely between the positively charged cationic acid hydrogen atoms and the negatively charged non-apical hydrogen atoms of the anion. In yellow (1), these distances are 2.26(5) �, while in red (2), they are much shorter, being 1.89(4), 1.97(3) �.

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