Models for the trinuclear copper(II) cluster in the particulate methane monooxygenase from methanotrophic bacteria: Synthesis, spectroscopic and theoretical characterization of trinuclear copper(II) complexes - 17/01/12

Doi : 10.1016/j.crci.2011.11.014

Isiah Po-Chun Liu ^a , Peter P.-Y. Chen ^b,^⁎ , Sunney I. Chan ^c,^⁎
^a Department of Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10677 Taiwan, Republic of China
^b Department of Chemistry, National Taiwan Normal University, No. 88, Sec. 4, Ting-Chow Road, Taipei 11677, Taiwan, Republic of China
^c Institute of Chemistry, Academia Sinica, 128, Sec. 2, Academia Road, Nankang, Taipei 11529, Taiwan, Republic of China

Corresponding authors.

Bienvenue sur EM-consulte, la référence des professionnels de santé.
L’accès au texte intégral de cet article nécessite un abonnement.

pages	11
Iconographies	14
Vidéos	0
Autres	0

Abstract

Three trinuclear Cu(II) complexes [Cu₃(tacp)(μ₃-Cl)₂](Cl)₄ (1), [Cu₃(tacp)(μ₃-Br)₂](Br)₄ (2) and [Cu₃(tacp)(μ₃-OH)₂](Cl)₄ (3) (tacp, 1,10,19-trioxa-4,7,13,16,22,25-hexaazacycloheptaeicosane) are synthesized to model the oxidized tricopper cluster implicated in the particulate methane monooxygenase from Methylococcus capsulatus (Bath). In the enzyme, the three Cu(II) ions are coupled by weak ferromagnetic interactions. The Cu(II) ions in 1 and 2 are shown to be ferromagnetically coupled from magnetic susceptibility and electron paramagnetic resonance (EPR) measurements. EPR suggests anti-ferromagnetic interactions among the Cu(II) ions in 3. Density functional theory calculations reproduce well the geometric, electronic and magnetic properties observed in these complexes and provide insights into the spin-coupling interactions mediated by the bridging ligands.