New Developments in Fourier Transform Infrared Vibrational Circular Dichroism Measurements

A new FT-IR vibrational circular dichroism (VCD) spectrometer has been assembled to record VCD spectra with excellent signal quality up to ∼650 cm −1 . A special detector with 600 cm −1 cutoff ( D* = 4 × 10 10 ), a ZnSe modulator, and a KRS-5 polarizer were used in these measurements. Typical VCD spectra at 4 cm −1 resolution can be obtained within a one-hour data acquisition period, while those at 1 cm −1 resolution, in the ∼ 1500-650 cm −1 region, can be obtained within four hours of data acquisition per sample. VCD spectra for ã-pinene, 3-bromocamphor, and propylene oxide are presented.