Determination of Absolute Configurations ofN-Formyl-3,3‘,4,4‘-tetrahydrospiro[naphthalene-1(2H),2‘(1‘H)-pyridine] (2) andN-Formyl-3‘,4‘-dihydrospiro[indan-1,2‘(1‘H)-pyridine] (3) by Analysis of Circular Dichroism Spectra. A Case of Two Compounds with Similar Configuration But Nearly Mirror Image CD Spectra

1997 ◽  
Vol 119 (24) ◽  
pp. 5701-5705 ◽  
Author(s):  
Lena Ripa ◽  
Anders Hallberg ◽  
Jan Sandström
Keyword(s):  
Circular Dichroism ◽  
Mirror Image ◽  
Cd Spectra ◽  
Circular Dichroism Spectra ◽  
Circular Dichroïsm

Absolute configuration determination of theanti-head-to-head photocyclodimer of anthracene-2-carboxylic acid through cocrystallization withL-prolinol

2013 ◽  
Vol 69 (11) ◽  
pp. 1411-1413 ◽  
Author(s):  
Yuko Kawanami ◽  
Hidekazu Tanaka ◽  
Jun-ichi Mizoguchi ◽  
Nobuko Kanehisa ◽  
Gaku Fukuhara ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Circular Dichroism ◽  
Carboxylic Acid ◽  
Absolute Configuration ◽  
Void Space ◽  
Circular Dichroism Spectra ◽  
The Absolute ◽  
Circular Dichroïsm ◽  
Hydrogen Bonded

The absolute configuration has been established of the enantiopureanti-head-to-head cyclodimer of anthracene-2-carboxylic acid (AC) cocrystallized with L-propinol and dichloromethane [systematic name: (S)-2-(hydroxymethyl)pyrrolidin-1-ium (5R,6S,11R,12S)-8-carboxy-5,6,11,12-tetrahydro-5,12:6,11-bis([1,2]benzeno)dibenzo[a,e][8]annulene-2-carboxylate dichloromethane monosolvate], C5H12NO+·C30H19O4−·CH2Cl2. In the crystal structure, the AC dimer interacts with L-prolinol through a nine-membered hydrogen-bonded ring [R22(9)], while the dichloromethane molecule is incorporated to fill the void space. The absolute configuration determined in this study verifies a recent assignment made by comparing theoreticalversusexperimental circular dichroism spectra.

Lateral, Chiral Tin(IV) Porphyrin Assemblies

1998 ◽  
Vol 02 (03) ◽  
pp. 273-284 ◽  
Author(s):  
BIANCA ROSENGARTEN ◽  
CHRISTOPH BÖTTCHER ◽  
ANDREA SCHULZ ◽  
J.-H. FUHRHOP ◽  
ULRICH SIGGEL
Keyword(s):  
Hydrogen Bonding ◽  
Lactic Acid ◽  
Circular Dichroism ◽  
Hydrochloric Acid ◽  
Protoporphyrin Ix ◽  
Mirror Image ◽  
Chloride Ions ◽  
Hydrogen Atoms ◽  
Circular Dichroism Spectra ◽  
Circular Dichroïsm

The μ-Oxo stacks of tin(IV) porphyrins rearrange to staircase-type and lateral aggregates upon replacement of the oxygen ligands by chloride ions. The lateral aggregation of tin(IV) 2,18-dipropionate porphyrins in hydrochloric acid at pH 0–0.5 is favoured by 8,13-ethyl groups instead of the natural 8,13-vinyl groups of protoporphyrin IX and is impeded by hydrogen atoms at these positions. Replacement of axial chloride counterions to the tin(IV) central ions by cyanate counterions at pH 4.5 leads to similar aggregates if the cyanate ions are connected by hydrogen bonding to acetic or lactic acid. In this case, aggregation is not necessarily impeded by hydrogen atoms at positions 8 and 13. D- and L-lactic acid enforce chiral assemblies of the tin(IV) deuteroporphyrin 1a with mirror image CD (circular dichroism) spectra (θ ≈ 8 × 105 deg cm 2 dmol −1), whereas the gluconoyl hydrazide-substituted tin(IV) deuteroporphyrin 1d does not form aggregates at all.

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