Molecular orbital studies on the conformation of hallucinogenic indolealkylamines and related compounds. Isolated molecules and the solvent effect

1974 ◽  
Vol 17 (4) ◽  
pp. 439-447 ◽  
Author(s):  
B. Pullman ◽  
Ph. Courriere ◽  
H. Berthod
Author(s):  
NAGAO KOBAYASHI

The synthesis of and spectroscopic data on subazaporphyrins, subphthalocyanines, subnaphthalocyanines and their related compounds reported to date are summarized, together with the results of molecular orbital (MO) calculations from our laboratory. Thus the problems and key points in the synthesis of these subazamacrocycles and their electronic absorption and magnetic circular dichroism (MCD) spectra are discussed, together with those of the monosubstituted-type low-symmetrical phthalocyanines obtained by their ring expansion reaction. The Q bands of these subazamacrocycles are orbitally doubly degenerate, and in the Soret band region, three transitions to the orbitally degenerate state are found. The MO calculations suggest that the HOMO levels destabilize considerably while the LUMO levels change slightly with increasing size of the π system. In addition, the electronic adsorption data are reproduced by the calculation only when the two pyrrole hydrogens in the monosubstituted-type phthalocyanines are assumed to be linked to the two pyrrole nitrogens along the short axis.


1985 ◽  
Vol 63 (6) ◽  
pp. 1228-1232 ◽  
Author(s):  
Robert L. Benoit ◽  
Danielle Boulet ◽  
Luc Séguin ◽  
Monique Fréchette

The ionization constants of the conjugated acids BH+ of purine, adenine, 9-methyladenine, adenosine, guanine, and hypoxanthine, and of the related compounds imidazole, N-methylimidazole, benzimidazole, and 4-amino-2,6-dimethylpyrimidine have been determined potentiometrically in Me2SO. The heats of solution and the heats of protonation of most of these bases have been obtained by calorimetry. Some additional determinations were carried out in water so that thermodynamic data in Me2SO and in water could be compared. Our discussion of the solvent effect on these data is largely based on a consideration of the enthalpies of transfer of B and BH+ and emphasizes the contrasting H-bonding properties of the solvents and of the functional groups on the solutes B and BH+.


1962 ◽  
Vol 40 (5) ◽  
pp. 864-869 ◽  
Author(s):  
R. A. Abramovitch ◽  
K. A. H. Adams

δ-Carboline, together with β-carboline, has been synthesized in reasonably good yield by the Fischer cyclization of cyclohexanone 3-pyridylhydrazone followed by dehydrogenation of the separated tetrahydro derivatives. The isomer ratios of products formed in this and similar reactions are discussed. Nitration of δ-carboline gives a mixture of the 6- and 8-nitro derivatives, the latter being the predominant product. The magnitude of the dipole moment of δ-carboline is appreciably higher than that predicted from molecular orbital calculations (15).


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