[NaCu<sup>II</sup><sub>4</sub>] Cluster from Alkali Template Assembly of Two Asymmetric End-On Azido-Bridged [Cu<sup>II</sup><sub>2</sub>] Units

The cluster [NaCu<sub>4</sub>L<sub>2</sub>(N<sub>3</sub>)<sub>2</sub>](ClO<sub>4</sub>) [<b>1</b>; H<sub>3</sub>L is 2-(2‘-hydroxyphenyl)-1,3-bis[3‘-aza-4‘-(2‘ ‘-hydroxyphenyl)prop-4‘-en-1‘-yl]-1,3-imidazolidine] has been synthesized and structurally characterized. Complex <b>1</b> is formed by the template assembly of two [Cu<sub>2</sub>L(N<sub>3</sub>)] neutral fragments through their weak oxophilic interactions with a central Na<sup>+</sup> cation as observed in metallacrowns. The cluster exhibits a combination of ferro- and antiferromagnetic interactions. End-on N<sub>3</sub><sup>-</sup> bridging of copper ions within the [Cu<sup>II</sup><sub>2</sub>] units facilitates stabilization of <i>S</i> = 1 magnetic subunits that mutually cancel via antiferromagnetic coupling as mediated by the O···Na<sup>+</sup>···O bridges.