Resumen de Beyond λmax Part 2:: Predicting Molecular Color
Darren L. Williams, Thomas J. Flaherty, Bassam K. Alnasleh
A concise roadmap for using computational chemistry programs (i.e., Gaussian 03W) to predict the color of a molecular species is presented. A color-predicting spreadsheet is available with the online material that uses transition wavelengths and peak-shape parameters to predict the visible absorbance spectrum, transmittance spectrum, chromaticity diagram, and the standard 24-bit color values, sRGB, at several theoretical concentrations. The technique is demonstrated on azulene derivatives and phenolphthalein. The use of this color-prediction spreadsheet in our introductory chemistry lectures and the physical chemistry laboratory is described along with the applicable topic areas. The theory behind color prediction is explained, but the tool is well-suited for novice users. It has been successful in increasing student engagement with the concepts of spectroscopic absorbance and transmittance while introducing the unfamiliar concepts of standard color spaces.
