Application of Isotopic Labelling to the Infrared Spectra of the Linkage Isomers Pyridine(isothiocyanato)cobaloxime and Pyridine(thiocyanato)cobaloxime

Abstract

Abstract The infrared spectra of the isomeric complexes [Co(DH)2(py)(NCS)] and [Co(DH)2(py)(SCN)] (DH [dbnd] dimethylglyoximate anion, py [dbnd] pyridine) and their py-15N -, py-d5- and 15NCS -labelled derivatives have been determined. Band assignments are based on the shifts incurred by labelling and on previous labelling studies applied to the complexes [Co(DH)2(py)X] (X [dbnd] CH3, Cl, Br, I). v Co-N(py) occurs at 464 cm−1 in both complexes with an additional band at 450 cm−1 in the isothiocyanate complex, while vCo-N(DH) appears at 513 cm−1 in both complexes. vCo-NCS occurs at 377 cm−1 in the isothiocyanate complex while vCo-SCN appears at 356 cm−1 in the thiocyanate complex.