Spin Switching with Triazolate-Strapped Ferrous Porphyrins

Inorg Chem. 2019 Apr 15;58(8):5265-5272. doi: 10.1021/acs.inorgchem.9b00349. Epub 2019 Apr 2.

Abstract

Fe(III) porphyrins bridged with 1,2,3-triazole ligands were synthesized. Upon deprotonation, the triazolate ion coordinates to the Fe(III) ion, forming an overall neutral high-spin Fe(III) porphyrin in which the triazolate serves both as an axial ligand and as the counterion. The second axial coordination site is activated for coordination and binds p-methoxypyridine, forming a six-coordinate low-spin complex. Upon addition of a phenylazopyridine as a photodissociable ligand, the spin state of the complex can be reversibly switched with ultraviolet and visible light. The system provides the basis for the development of switchable catalase- and peroxidase-type catalysts and molecular spin switches.