Copper(ii) cubanes with a {Cu4O} core and well defined S = 1 ground state

Abstract

The reaction of 2-pyridinemethanol with copper 4-fluorobenzoate has yielded a family of type II cubanes with formula [Cu₄(pymO)₄(4-F-PhCOO)₃(NO₃)] (1), [Cu₄(pymO)₄(4-F-PhCOO)₄] (2) and [Cu₄(pymO)₄(4-F-PhCOO)₄(H₂O)] (3). These systems exhibit an unexpected S = 1 ground state and their magnetic properties have been unambiguously characterized and rationalized as a function of the asymmetry of the {Cu₄O₄} cage and Cu–O–Cu bond angles. Analysis of the coupling constants was performed applying new interaction schemes. Magneto-structural correlations have been performed from the analysis of previously reported type II copper cubanes.