Chelate ring coupling constants

Inversion at the N center is coupled to conformational changes in a chelate ring. The kinetics of inversion at asymmetric N centers in complexes of tetraaza linear or macrocyclic ligands have received scant attention. There are five configurational isomers of the planar complex Ni([14]aneN4) +, Sec. 3.1.1. The interconversions between such structures are base catalyzed with second-order rate constants covering a small range from 1.2 x 10 to 2.4 x 10 M- s- Refs. 108-110. 

Variable temperature studies of [12], [13a], [17] and [19, M = Cr] show little change in coupling constants with temperature, except for [17a], for which the conformer with axial hydrogens has the lower energy. (20) Five-membered ring chelate complexes incorporating a... 

Chelate ring size 43, 54 Chemical Shift 48, 126 - 144 Chemical shift range 2, 3, 47 Coordination chemical shift 49, 57 Coordination number 36, 39, 53 Correlation time 10, 12 Coupling constant, one-bond to... 

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