The X-ray crystal structures of two related trans-N2S2 copper macrocycles are reported. One was isolated with the copper in the divalent form and the other with copper in its univalent form affording a valuable insight into the changes of geometry and metrical parameters that occur during redox processes in macrocyclic copper complexes. A variable temperature NMR study of the copper(I) complex is reported, indicative of a chair-boat conformational change within the alkyl chain backbone of the macrocycle. It was possible to extract the relevant kinetic and thermodynamic parameters (?G‡, 57.8 kJ mol-1; ?H‡, 52.1 kJ mol-1; ?S‡, -19.2 J K-1 mol-1) for this process at 298 K. DFT molecular orbital calculations were used to confirm these observations and to calculate the energy difference (26.2 kJmol-1) between the copper(I) macrocycle in a planar and a distorted tetrahedral disposition.
- macrocyclic complex
- dynamic behaviour
Trotter, K. D., Reglinski, J., Robertson, K., Forgie, J. C., Parkinson, J. A., Kennedy, A. R., Armstrong, D. R., Sowden, R. J., & Spickett, C. M. (2009). Structural studies of trans-N2S2 copper macrocycles. Inorganica Chimica Acta, 362(11), 4065-4072. https://doi.org/10.1016/j.ica.2009.05.060