Spin Interconversion of Heme-Peroxo-Copper Complexes Facilitated by Intramolecular Hydrogen-Bonding Interactions.

ABSTRACT: Synthetic peroxo-bridged high-spin (HS) heme-(μ-η²:η¹-O₂^2-)-Cu(L) complexes incorporating (as part of the copper ligand) intramolecular hydrogen-bond (H-bond) capabilities and/or steric effects are herein demonstrated to affect the complex's electronic and geometric structure, notably impacting the spin state. An H-bonding interaction with the peroxo core favors a low-spin (LS) heme-(μ-η¹:η¹-O₂^2-)-Cu(L) structure, resulting in a reversible temperature-dependent interconversion of spin state (5 coordinate HS to 6 coordinate LS). The LS state dominates at low temperatures, even in the absence of a strong trans-axial heme ligand. Lewis base addition inhibits the H-bond facilitated spin interconversion by c

SUBMITTER: Schaefer AW 

PROVIDER: S-EPMC6457345 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature