Molecular Topology of Linked Anthracenes: X-Ray Structure Analyses of Alkyl Di-9-anthryl-glycolates, 9-Anthryl 9-Anthrylmethyl Ethers and Their Photoisomers

1989 ◽  
Vol 42 (11) ◽  
pp. 1869 ◽  
Author(s):  
HD Becker ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Alder Reaction ◽  
Diels Alder ◽  
Molecular Structures ◽  
Molecular Topology ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diels Alder Reaction ◽  
Photochemical Isomerization ◽  
Spatial Demand

The molecular structures of ethyl di-9-anthrylglycolate (1) and methyl di-9-anthrylglycolate (2), as well as those of three isomerization products of (2), have been established by single-crystal X-ray diffraction studies. In both (1) and (2), the anthracenemoieties are characterized by marked deviations from planarity. The stereospecific course of the thermal and photochemical isomerization of (2) by Diels -Alder reaction is suggested to be governed by the spatial demand of the alkoxycarbonyl group. Base-catalysed isomerization of (2) by migration of 9-anthryl from carbon to oxygen is associated with steric relief.

High-yield, regiospecific bis-functionalization of C70 using a Diels–Alder reaction in molten anthracene

2014 ◽  
Vol 50 (73) ◽  
pp. 10584-10587 ◽  
Author(s):  
Venkata S. Pavan K. Neti ◽  
Maira R. Cerón ◽  
A. Duarte-Ruiz ◽  
Marilyn M. Olmstead ◽  
Alan L. Balch ◽  
...  
Keyword(s):  
Single Crystal ◽  
Thermal Gravimetric Analysis ◽  
Alder Reaction ◽  
Diels Alder ◽  
High Yield ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diels Alder Reaction

A regiospecific bis-adduct of C70 with anthracene was prepared with unusually high yield (68%) by the Diels–Alder reaction in the absence of solvent (melt). The structure of the bis-adduct was an unexpected 12 o'clock isomer, as determined by single crystal X-ray diffraction, thermal gravimetric analysis (TGA) and spectroscopy.

scholarly journals Cooperativity in the Reaction of 9-Methylanthracene With a 1,4-Dithiin Molecule

2014 ◽  
Vol 70 (a1) ◽  
pp. C913-C913
Author(s):  
Sanaz Khorasani ◽  
Manuel Fernandes
Keyword(s):  
Charge Transfer ◽  
Solid State ◽  
Single Crystal ◽  
Lattice Energy ◽  
Alder Reaction ◽  
Diels Alder ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diels Alder Reaction

Solid-state chemistry involves the manipulation of molecules and materials through photochemical, thermal, or mechanical reaction methods. Single-crystal-to-single-crystal (SCSC) reactions are rare, but offer the opportunity to study reaction mechanisms and molecular motions in the solid state at the atomic level using single crystal X-ray diffraction. This allows the effect of the surrounding molecules, and hence the reaction cavity, on the reacting molecules to be examined which may ultimately lead to postcrystallization methods for creating new materials or reaction products that cannot easily be obtained via solution. SCSC reactions involving two different molecules are relatively uncommon. A convenient system that allows the study of such reactions is the [4+2] Diels-Alder reaction of 1,4-dithiintetracarboxylic type compounds with anthracene derivatives. In the work reported here, electron donor to acceptor interactions between 9-Methylanthracene and bis(N-cyclobutylimino)-1,4-dithiin lead to the formation of chiral charge transfer (CT) crystals [1]. These undergo a topochemical thermal SCSC [4 + 2] Diels-Alder reaction in the solid state. CT crystals were reacted at 400C, their structures determined by X-ray diffraction at various degrees of conversion, and examined using Hirshfeld surfaces and lattice energy calculations to find evidence of reaction cooperativity and feedback mechanisms. In this case, a maximum reaction conversion of around 96% was obtained indicating that the reaction is non-random within the charge transfer stacks, with close contacts between product molecules in the reacted crystal also providing some evidence for reaction cooperativity along the b axis perpendicular to the CT stacking axis.

Two novel Diels-Alder adducts from Hippocratea celastroides roots and their insecticidal activity

2000 ◽  
Vol 78 (2) ◽  
pp. 248-254 ◽  
Author(s):  
M Jiménez-Estrada ◽  
R Reyes-Chilpa ◽  
S Hernández-Ortega ◽  
E Cristobal-Telésforo ◽  
L Torres-Colín ◽  
...  
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
X Ray Diffraction ◽  
Stored Grain ◽  
X Ray ◽  
Diels Alder Reaction ◽  
Antifeeding Activity ◽  
Hippocratea Celastroides ◽  
Stored Grain Insects

Two novel compounds, celastroidine A (1) and B (2), were isolated from the roots of Hippocratea celastroides K. Their structures were elucidated by spectroscopical and X-ray diffraction studies. Celastroidine A (1) (C50H74O5) was identified as a Diels-Alder adduct of a triterpene plus a diterpene and celastroidine B (2) as a beyerane, a type of dimer of two diterpene (C40H60O4). Both compounds could be formed in vivo by a Diels-Alder reaction. Celastroidine A showed some antifeeding activity against the stored grain insect Sitophyllus zeamays.Key words: Hippocratea celastroides, Hippocrataceae, roots, Diels-Alder adducts, diterpenoids, triterpenoids, x-ray diffraction, insect antifeedants, stored grain insects, Sitophyllus zeamays, insecticidal plants, Diels-Alderase.

Facile One-Pot Synthesis and Crystal Structure of 2:1 Adducts of Myrcene (or Ocimene) with Benzoquinones

2020 ◽  
Vol 17 (8) ◽  
pp. 624-627
Author(s):  
Sujata V. Bhat ◽  
Rohan S. Pawar ◽  
P. Rajakannu
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Alder Reaction ◽  
Diels Alder ◽  
One Pot ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
One Pot Synthesis ◽  
Diels Alder Reaction

One-pot tandem oxidation and double Diels-Alder reaction of myrcene or ocimene with in situ generated 1,4-benzoquinone or 1,2-benzoquinone at 0°C for 1.5 h yielded polyalkylated 1,4,4a,5,8,8a,9a,10a-octahydro-9,10-anthracenediones and bis(alkylated) 9,10-phenanthrenedione respectively. The structure of novel bis-adduct from ocimene, (1R,4aR,5S,8aS,9aS,10aR)-rel- 1,4,4a,5,8,8a,9a,10a-octahydro-2,6-dimethyl-1,5-bis(3-methyl-2-buten-1-yl)-9,10-anthracenedione, was elucidated through single crystal X-ray analysis.

Molecular Topology of Di(9-Anthryl)Ethanedione (9,9'-Anthril) and Some Generically Related Cyclic 1,2-Diketones

1991 ◽  
Vol 44 (2) ◽  
pp. 181 ◽  
Author(s):  
HD Becker ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Dihedral Angle ◽  
Molecular Structures ◽  
Dihedral Angles ◽  
Molecular Topology ◽  
Single Bond ◽  
X Ray Diffraction ◽  
X Ray ◽  
Intramolecular Cycloadditions ◽  
Crystal Modifications

The molecular structures of di (9-anthryl) ethanedione (9,9′-anthril) and those of four 1,2-diketones derived from 9,9′-anthril by way of intramolecular cycloadditions were investigated by single-crystal X-ray diffraction studies. Two crystal modifications of 9,9′-anthril were available and found to differ in the dihedral angles (43.9 and 178.3°) about the 1,2-dicarbonyl moiety. The 1,2-dicarbonyl group of the cyclobutanedione moiety in the anthril 4π+4π cyclomer is associated with a dihedral angle of 2.6°. In the anthril isomer derived by 4π+2π cycloaddition, an exceptionally long single bond is indicative of molecular strain. The molecular structures of a keto enol and of a novel 1,2-diketo substituted triptycene, both obtained from the 4π+2π cyclomer by acid-catalysed rearrangement and dehydrogenation, respectively, were established. The topological and spectroscopic differences between the keto en01 and its 1,2-diketo precursor are discussed.

Structural Study of an Unusual Diels-Alder Adduct

1992 ◽  
Vol 45 (12) ◽  
pp. 2089 ◽  
Author(s):  
EL Ghisalberti ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Diffraction Study ◽  
Structural Study ◽  
Spectroscopic Studies ◽  
Diels Alder ◽  
X Ray Diffraction ◽  
X Ray ◽  
Naturally Occurring ◽  
Chemical Evidence ◽  
Alder Adduct

The structure of the compound obtained on heating the naturally occurring clerodane furanoditerpene (1) had been formulated as (2) on the basis of spectroscopic studies. A single-crystal X-ray diffraction study on the dihydro derivative of (2) has confirmed this and provides support for the stereochemistry previously assigned to (1) on the basis of chemical evidence.

Photochemical cis-trans Isomerization of 2-Substituted 9-(2-Nitroethenyl)anthracenes. X-Ray Structure Analyses of (E)- and (Z)-9-(2-Nitro-2-phenylethenyl)anthracene

1989 ◽  
Vol 42 (4) ◽  
pp. 593 ◽  
Author(s):  
HD Becker ◽  
BW Skelton ◽  
H Sorensen ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Quantum Yields ◽  
X Ray Diffraction ◽  
X Ray ◽  
Photostationary State ◽  
Trans Isomerization ◽  
Photochemical Isomerization

(E)-9-(2-Nitropropeny1)anthracene and (E)-9-(2-nitro-2-phenylethenyl)anthracene have been prepared by piperidine-catalysed condensation of 9-anthraldehyde with nitroethane and nitro(phenyl)methane, respectively. The corresponding (Z)-compounds were obtained by photochemical isomerization, quantum yields of geometrical isomerlzation being measured in cyclohexane, benzene, dichloromethane and ethanol. In virtually all solvents the (Z)-isomers are favoured at the photostationary state. The structures of (E)- and (2)-942- nitro-2-phenylethenyl)anthracene have been established by single-crystal X-ray diffraction studies.

Lewis-Base Adducts of Group 1B Metal(I) Compounds. XXI The Crystal and Molecular Structures of the Unsolvated Forms of Dibromotris(triphenylphosphine)dicopper(I) and 'step' Tetrabromotetrakis(triphenyl-phosphine)tetracopper(I)

1985 ◽  
Vol 38 (8) ◽  
pp. 1243 ◽  
Author(s):  
JC Dyason ◽  
LM Engelhardt ◽  
C Pakawatchai ◽  
PC Healy ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Molecular Structures ◽  
Lewis Base ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Triphenyl Phosphine ◽  
X Ray ◽  
Crystal And Molecular Structures

The crystal structures of the title compounds have been determined by single-crystal X-ray diffraction methods at 295 K. Crystal data for (PPh3)2CuBr2Cu(PPh3) (1) show that the crystals are iso-morphous with the previously studied chloro analogue, being monoclinic, P21/c, a 19.390(8), b 9.912(5), c 26.979(9) Ǻ, β 112,33(3)°; R 0.043 for No 3444. Cu( trigonal )- P;Br respectively are 2.191(3); 2.409(2), 2.364(2) Ǻ. Cu(tetrahedral)- P;Br respectively are 2.241(3), 2.249(3); 2.550(2), 2.571(2) Ǻ. Crystals of 'step' [PPh3CuBr]4 (2) are isomorphous with the solvated bromo and unsolvated iodo analogues, being monoclinic, C2/c, a 25.687(10), b 16.084(7), c 17.815(9) Ǻ, β 110.92(3)°; R 0.072 for No 3055. Cu( trigonal )- P;Br respectively are 2.206(5); 2.371(3), 2.427(2) Ǻ. Cu(tetrahedral)- P;Br are 2.207(4); 2.446(2), 2.676(3), 2.515(3) Ǻ.

On the Reaction of ortho-Diphenoquinone Valence Isomers with Primary and Secondary Amines. X-Ray Structure Analysis of a 2,3-Dihydro-1H-azepinone and its Photochemical and Oxidative Conversion Products

1979 ◽  
Vol 32 (9) ◽  
pp. 1931 ◽  
Author(s):  
H Becker ◽  
K Gustafsson ◽  
CL Raston ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Secondary Amines ◽  
Reaction Products ◽  
Oxidative Conversion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Primary And Secondary Amines ◽  
Diffraction Structure ◽  
Structure Determinations ◽  
Photochemical Isomerization

Single-crystal X-ray diffraction structure determinations are reported for three reaction products and photoisomers formed from reactions between an o-diphenoquinone valence isomer and primary and secondary amines, namely: 3,5-di-t-butyl-7-(3,5-di-t-butyl-2-hydroxyphenyl)-1-methyl-2,3-dihydro-1H-azepin-2-one (8; R1 = R2 = But, R3 = Me), its photochemical isomerization product 4,6-di-t-butyl-1-(3,5-di-t-butyl-2-hydroxyphenyl)-2-methyl-2-azabicyclo[3,2,0]hept-6-en-3-one (9; R1 = R2 = But, R3 = Me) and 4',5,7-tri-t-butyl-3'-(2,2-dimethylpropionyl)-1'-methylspiro[benzofuran-3(2H)-2'- pyrrolidinel-2,5'-dione (12; R1 = R2 = But, R3 = Me).

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