An Alternate Method for the Determination of Circular Dichroism

Abstract

A technique has been developed for determining the ellipticity, (from which a circular dichroism plot can be made), of light emerging from a solution containing an optically active species, using a mica plate and a Rudolph spectropolarimeter. This technique has the advantage over previous procedures using a quarter-wave plate, in that precise orientation of the plate is not required. For of less than one radian, = (r coscos 2r)/sin , where is the retardation of the plate, r is the azimuth of the incident elliptical polarization, and y is the azimuth of the resultant polarization with respect to the fast axis of the mica.

Suggested preliminary standards for calibration of optical rotatory dispersion and circular dichroism instruments

“…The Ae = FSSR/(C-l) where FS is the nominal full scale CD setting, SR is the scale reading (fraction of full scale), C is the molar concentration, / is the path length in centimeters. [9] = 3300 Ae (5). To set the full scale readings it is recommended that Ae29o• 2.49 be used for 10-camphorsulfonic acid which has [ ]||9.3 51.0.…”

“…Tris(ethylenediamine)cobalt triiodide hydrate is one possible candidate. It is readily prepared (6), and the CD curve has been measured by rough absolute techniques in the presence of bromide anion in two different laboratories (7, S) and for the iodide (9) in a third with relatively concordant results (about 8 % spread). 10-Camphorsulfonic acid is another possible candidate.…”

Radical-cation salt with novel BEDT-TTF packing motif containing tris(oxalato)germanate(IV)

“…The caesium cation is not included in the radical-cation salt but both the anion and donor packing obtained is novel in this family of materials. 15 BEDT-TTF, dichloromethane and 18-crown-6 were purchased from Sigma Aldrich and used as received.…”