Spectral Shift of 32S vs. 34S within the C-S Bond : Analyzing the Shift of Sulfur Within Isocyanate as a Coordinating Ligand to Copper (II)

Abstract

Distinguishing peaks in the fingerprint region of an infrared spectra can be extremely difficult and is often ignored due to the large number of overlapping peaks from various molecular vibrations. The specific peak associated with the carbon sulfur bond within a thiocyanate ligand is located in the fingerprint region. To determine the spectral shift, two copper containing compounds were synthesized and isolated. The metal centers were coordinated to two varied thiocyanate complexes, one containing natural abundance sulfur and one with isotopically labeled sulfur. The individual vibrations were analyzed using a Fourier-Transform Infrared spectroscopy and the small chemical shift was identified within the fingerprint region a spectral subtraction was completed. The unit cell structure and space groups were found using X-ray crystallography.