To realize the experimental aspects of these studies, we have constructed instrumentation capable of measuring circular dichroism in the visible and infrared down to 600 cm-1. This includes our original dispersive spectrometer and a newly constructed, more compact version, as well as two FTIR instruments capable of VCD measurements at moderate resolution and high S/N. A multi-channel detector-based Raman spectrometer was also constructed which can be used for ROA measurements in a back scattering mode. Commercial instrumentation (shared with other groups) include a Jasco J-600 CD, Cary 17DX and OLIS modified Cary 14 uv-vis spectrometer. As an unrelated project, a two-photon excitation spectrometer was constructed for studies of electronic excited states transition metal complexes, modified to be part of a molecular-beam apparatus usable for multi-photon ionization studies, and now in storage.

The VCD instrumental developments are iterated in a series of papers following the early work by Nafie, Keiderling and Stephens (#____) on near IR VCD that progressively address extension to the mid IR, computer interfacing, use of the C-rod light source, as summarized in an early review. A series of reports in Applied Spectroscopy addressed: FTIR VCD artifact control using lens focusing, determination of zero path difference without baseline offset and phase problems of high resolution FT-MVCD, step-scan FT-VCD, and most recently a unique polarization modulator design that is variable speed and potentially capable of extension to the far IR.

The design of our VCD and ROA instruments, often just summarily described in the original literature, is fully documented in theses of the students involved in its development. These are available from University Microfilms or (for a fee covering copying charges) personal use copies can be obtained from the author or from us, provided no copyright problems occur.

--Research Topics--MVCD--Biopolymers--Instrumentation--Small Molecules--Other Interests--Keiderling Home--