Optically Active Amines. III. The Optical Rotatory Dispersion Curves of the N-Salicylidene Derivatives of Some Open-Chain Primary Amines1

1965 ◽  
Vol 87 (8) ◽  
pp. 1757-1764 ◽  
Author(s):  
Mitchum E. Warren ◽  
Howard E. Smith
Keyword(s):  
Dispersion Curves ◽  
Optically Active ◽  
Optical Rotatory Dispersion ◽  
Rotatory Dispersion ◽  
Optical Rotatory ◽  
Open Chain ◽  
Derivatives Of

A Study of the Pfeiffer Effect in Systems containing Trisoxalatometallate(III) Complexes and Cinchonine Hydrochloride

1971 ◽  
Vol 49 (12) ◽  
pp. 2161-2165 ◽  
Author(s):  
K. T. Kan ◽  
D. G. Brewer
Keyword(s):  
Dispersion Curves ◽  
Active Species ◽  
Optically Active ◽  
The Other ◽  
Optical Rotatory Dispersion ◽  
Rotatory Dispersion ◽  
Optical Rotatory ◽  
Cotton Effects ◽  
Equilibrium Shift ◽  
Complex Ion

The Pfeiffer effect was studied in systems containing cinchonine hydrochloride and trisoxalatometallate(III) complexes of Al, Fe, Cr, Co, and Ir. The Pfeiffer rotatory dispersion curves of the Cr and Co complexes show Cotton effects analogous to that observed in the optical rotatory dispersion (o.r.d.) curves of the respective complexes. The source of the Pfeiffer effect in all these systems is attributed either to an association between the complex ion and the optically active species in solution alone, as in the case of the Ir(lII) complex, or to a combination of this association and an "equilibrium shift" between the two enantiomers in solution in favor of one of them, as in the case of the other complexes under investigation.

Synthesis, resolution, and absolute configuration of 1-phenyl-1-methyl-1-silacyclohexanone-2

1970 ◽  
Vol 48 (5) ◽  
pp. 818-823 ◽  
Author(s):  
A. G. Brook ◽  
H. W. Kucera ◽  
D. M. MacRae
Keyword(s):  
Absolute Configuration ◽  
Active Form ◽  
Dispersion Curves ◽  
Convincing Evidence ◽  
Optically Active ◽  
Optical Rotatory Dispersion ◽  
Rotatory Dispersion ◽  
Asymmetric Center ◽  
Optical Rotatory ◽  
Subsequent Oxidation

The synthesis and resolution of 1-phenyl-1-methyl-1-silacyclohexanone-2 by oxidative hydroboration of the related silacyclohexene to the silacyclohexanol, resolution of this via the strychnine salt of the phthalate half-ester, and subsequent oxidation of the silacyclohexanol to the silacyclohexanone is described. The carbon analog 1-phenyl-1-methylcyclohexanone-2 was also synthesized in optically active form. The (+)-enantiomers of the two ketones had similar optical rotatory dispersion curves, presenting convincing evidence for the identity of their configurations, and the carbon compound could be degraded without affecting the asymmetric center to (−)-(R)-2-phenyl-2-methylhexandioic acid, thereby establishing the absolute configurations of both compounds.

Carboxyl and aromatic chromophores: optical rotatory dispersion and circular dichroism studies

1967 ◽  
Vol 297 (1448) ◽  
pp. 66-78 ◽  
Keyword(s):  
Circular Dichroism ◽  
Theoretical Background ◽  
Optical Rotatory Dispersion ◽  
Rotatory Dispersion ◽  
Optical Rotatory ◽  
Open Chain ◽  
Structural Problems ◽  
Rigid Conformation ◽  
Extensive Collection ◽  
Circular Dichroïsm

Until recently the carbonyl chromophore has been of prime importance in the appli­cation of optical rotatory dispersion (o. r. d.) and circular dichroism (c. d.) to organic structural problems (Djerassi 1960; Crabbé 1965). The reasons were, first, the accessibility of the n → π * band of the carbonyl group at 290 nm to the first com­mercial spectropolarimeters; secondly, the availability of many carbonyl com­pounds of known stereochemistry, on which Djerassi and subsequently others worked so intensively; and, thirdly, a few years later the development of the octant rule as a theoretical background to the extensive collection of experimental data which had then been made by Djerassi (Moffitt et al . 1961). In this treatment we might say that one looks at the asymmetry of the molecule through the ‘eyes’ of the relevant chromophore; in less anthropomorphic terms, one considers the symmetry planes of the orbitals involved in the 290 nm transition as a frame of reference. It is appropriate to consider the logical order in which the octant rule was applied to carbonyl compounds of increasing flexibility. Djerassi had very wisely started with ketones of rigid conformation, trans -decalones (e. g. I) and their polycyclic ana­logues; the work then passed to more flexible compounds such as the cis -decalones (II), the monocyclic ketones (III) and then finally to open-chain ketones, including steroid side-chain ketones (e. g. IV); with these latter flexible compounds, the o. r. d. method is a valuable probe for conformational studies (Crabbé 1965, pp. 134-43). The c. d. treatment was applied initially by the Roussel-Uclaf group in Paris to similar series of ketones (Velluz, Legrand & Grosjean 1965).

THE EFFECTS OF OPTICALLY INACTIVE IONS ON THE ROTATORY DISPERSION OF ASYMMETRIC COMPLEX IONS

1961 ◽  
Vol 39 (11) ◽  
pp. 2360-2370 ◽  
Author(s):  
Marvin J. Albinak ◽  
Dinesh C. Bhatnagar ◽  
Stanley Kirschner ◽  
Anthony J. Sonnessa
Keyword(s):  
Water Solution ◽  
Inorganic Compounds ◽  
Optically Active ◽  
Optical Rotatory Dispersion ◽  
Rotatory Dispersion ◽  
Optical Rotatory ◽  
Complex Ions ◽  
Ionic Charge ◽  
Sodium Potassium ◽  
Active Anion

Considerable interest in the optical rotatory dispersion of asymmetric organic and inorganic compounds and its application to the elucidation of their structures has arisen in recent years. In order to study the effects of optically inactive ions on the rotatory dispersion of asymmetric complex ions, a series of salts was prepared of two active cations: levo cis-oxalato-bis(ethylenediamine)cobalt(III) and levo tris(ethylenediamine)chromium(III). Salts prepared included the fluoride, chloride, bromide, iodide, tetrafluoroborate, perchlorate, sulphate, and phosphate. In order to study this effect on an optically active anion, the lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, and barium salts of dextro and levo tris(oxalato)rhodate(III) were also prepared. Rotatory dispersion curves and absorption spectra were obtained for all salts in water solution. A comparison of the curves within a series showed definite trends in changes of wavelength and intensity of maxima of rotation and absorption with changes in both the ionic charge/size ratio (ionic potential) and polarizability of the optically inactive ions.

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