Nitrogen-15 NMR coordination shifts of β-alanine and glycine in cobalt(III) complexes

¹⁵N NMR chemical shifts of/g-alaninato chelates in cobalt(III) complexes were investigated in comparison to that of glycinato chelates, for the effect of trans influence and chelate ring size on amine nitrogen NMR coordination shifts. The coordination shifts of both chelates are found to be about 20 ppm larger for an amine group trans to the oxygen ligator than for one trans to the nitrogen ligator in a complex. It is also found that β-alanine exhibits on average 10 ppm smaller coordination shifts. Both effects may be considered as a consequence of NCo bond strength changes.