scholarly journals Diels−Alder Topochemistry via Charge-Transfer Crystals:  Novel (Thermal) Single-Crystal-to-Single-Crystal Transformations

2001 ◽  
Vol 123 (1) ◽  
pp. 87-95 ◽  
Author(s):  
J. H. Kim ◽  
S. M. Hubig ◽  
S. V. Lindeman ◽  
J. K. Kochi
Keyword(s):  
Charge Transfer ◽  
Single Crystal ◽  
Diels Alder

A synthetic co-crystal prepared by cooperative single-crystal-to-single-crystal solid-state Diels–Alder reaction

2017 ◽  
Vol 53 (36) ◽  
pp. 4969-4972 ◽  
Author(s):  
S. Khorasani ◽  
M. A. Fernandes
Keyword(s):  
Charge Transfer ◽  
Solid State ◽  
Single Crystal ◽  
Charge Transfer Complex ◽  
Alder Reaction ◽  
Diels Alder ◽  
Energy Calculations ◽  
Diels Alder Reaction ◽  
Close Contacts

Solid-state Diels–Alder reaction in a 2 : 1 donor to acceptor charge-transfer complex leads to a synthetic co-crystal composed of product and unreacted donor. Analysis of close contacts and DFT energy calculations indicate that the reaction occurs cooperatively where the arrangement of molecules shown in (ii) is favoured.

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.

scholarly journals Tuning π-Acceptor/σ-Donor Ratio of the 2-Isocyanoazulene Ligand: Non-Fluorinated Rival of Pentafluorophenyl Isocyanide and Trifluorovinyl Isocyanide Discovered

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 981
Author(s):  
Mason D. Hart ◽  
John J. Meyers ◽  
Zachary A. Wood ◽  
Toshinori Nakakita ◽  
Jason C. Applegate ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Coordination Chemistry ◽  
Single Crystal ◽  
13C Nmr ◽  
Quantitative Assessment ◽  
X Ray ◽  
New Class ◽  
Linear Relationships ◽  
Ligand Charge Transfer ◽  
Donor Characteristics

Isocyanoazulenes (CNAz) constitute a relatively new class of isocyanoarenes that offers rich structural and electronic diversification of the organic isocyanide ligand platform. This article considers a series of 2-isocyano-1,3-X2-azulene ligands (X = H, Me, CO2Et, Br, and CN) and the corresponding zero-valent complexes thereof, [(OC)5Cr(2-isocyano-1,3-X2-azulene)]. Air- and thermally stable, X-ray structurally characterized 2-isocyano-1,3-dimethylazulene may be viewed as a non-benzenoid aromatic congener of 2,6-dimethyphenyl isocyanide (2,6-xylyl isocyanide), a longtime “workhorse” aryl isocyanide ligand in coordination chemistry. Single crystal X-ray crystallographic {Cr–CNAz bond distances}, cyclic voltametric {E1/2(Cr0/1+)}, 13C NMR {δ(13CN), δ(13CO)}, UV-vis {dπ(Cr) → pπ*(CNAz) Metal-to-Ligand Charge Transfer}, and FTIR {νN≡C, νC≡O, kC≡O} analyses of the [(OC)5Cr(2-isocyano-1,3-X2-azulene)] complexes provided a multifaceted, quantitative assessment of the π-acceptor/σ-donor characteristics of the above five 2-isocyanoazulenes. In particular, the following inverse linear relationships were documented: δ(13COtrans) vs. δ(13CN), δ(13COcis) vs. δ(13CN), and δ(13COtrans) vs. kC≡O,trans force constant. Remarkably, the net electron withdrawing capability of the 2-isocyano-1,3-dicyanoazulene ligand rivals those of perfluorinated isocyanides CNC6F5 and CNC2F3.

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.

scholarly journals Synthesis and Optoelectronic Properties of Iptycene–Naphthazarin Dyes

Synlett ◽  
2018 ◽  
Vol 30 (01) ◽  
pp. 54-58 ◽  
Author(s):  
Timothy Swager ◽  
Cagatay Dengiz ◽  
You-Chi Wu
Keyword(s):  
Single Crystal ◽  
Electronic Properties ◽  
Diels Alder ◽  
Optoelectronic Properties ◽  
Synthesis And Characterization ◽  
Nmr Analysis ◽  
X Ray ◽  
Vis Spectroscopy

We report the synthesis and characterization of iptycene–naphthazarin dyes by using a sequential Diels–Alder approach. The tautomerization of naphthazarin was used as the key step in the synthesis, with structures confirmed by single-crystal X-ray and NMR analysis. The systematic trends in electronic properties were investigated by UV/Vis spectroscopy. BF2 complexes of the dyes were prepared by reaction with BF3·OEt2 in CH2Cl2.

New, Homochiral Synthons Obtained through Simple Manipulations of Enzymatically Derived 3-Halo-cis-1,2-dihydrocatechols

2015 ◽  
Vol 68 (10) ◽  
pp. 1467 ◽  
Author(s):  
Lorenzo V. White ◽  
Ping Lan ◽  
Brett D. Schwartz ◽  
Anthony C. Willis ◽  
Martin G. Banwell
Keyword(s):  
Single Crystal ◽  
Cycloaddition Reaction ◽  
Diels Alder ◽  
X Ray

The bromoepoxide 5a, which is obtained from the homochiral and enzymatically derived cis-1,2-dihydrocatechol 1a, is readily and efficiently transformed into either isomer 8a or the corresponding methoxymethyl-ether 2a. Though both of these products can be fully characterized, they are somewhat unstable, with the former being converted into the crystalline enone 3a on standing and the latter readily participating in a Diels–Alder cycloaddition reaction with the potent dienophile N-phenyl-1,2,4-triazoline-3,5-dione to give adduct 7a. The single-crystal X-ray structures of compounds 3a and 7a are reported. Using the related chemistry the chloro-analogue, 3b, of enone 3a can be obtained.

FORMATION OF SURFACE DIPOLES FOR SMALL PALLADIUM CLUSTERS DEPOSITED ON α-(0001)Al2O3

1996 ◽  
Vol 03 (01) ◽  
pp. 973-977 ◽  
Author(s):  
S. OGAWA ◽  
S. ICHIKAWA
Keyword(s):  
Charge Transfer ◽  
Single Crystal ◽  
Work Function ◽  
Probe Method ◽  
Kelvin Probe ◽  
Electronic Interactions ◽  
Palladium Clusters ◽  
Metal Support ◽  
Pd Clusters ◽  
Kelvin Probe Method

The Kelvin-probe method is utilized to measure the work function of a single-crystal aluminum covered with palladium clusters. It is found that formation of interface dipoles occurs by charge transfer from Al 2 O 3 to Pd clusters, particularly for those less than 2 nm in diameter. These results provide valuable clue to the understanding of metal-support electronic interactions, which is important in catalysis.

Spectrophotometric and photocatalytic studies of H-bonded charge transfer complex of oxalic acid with imidazole: single crystal XRD, experimental and DFT/TD-DFT studies

2019 ◽  
Vol 43 (23) ◽  
pp. 9039-9051 ◽  
Author(s):  
Ishaat M. Khan ◽  
Kehkashan Alam ◽  
Mohammad Jane Alam ◽  
Musheer Ahmad
Keyword(s):  
Hydrogen Bonding ◽  
Photocatalytic Activity ◽  
Charge Transfer ◽  
Oxalic Acid ◽  
Single Crystal ◽  
Charge Transfer Complex ◽  
Single Crystal Xrd ◽  
Dft Studies ◽  
Td Dft ◽  
Ct Complex

The photocatalytic activity of a new CT complex was tested. Spectrophotometric studies were performed to understand its formation through N+–H⋯O− hydrogen bonding, and the structure was confirmed by single crystal XRD.

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