X-ray Structure and Variable Temperature NMR Spectra of [<i>m</i><i>eso</i>-Triarylcorrolato]copper(III)

The diamagnetic square planar d<sup>8</sup> complexes [<i>meso</i>-arylcorrolato]copper(III) become paramagnetic upon warming, indicative of the equilibrium between the [corrolato]copper(III) and the [corrolato]<sup>+•</sup> copper(II) forms of the complex. [<i>meso</i>-Triphenylcorrolato]copper(III) was structurally characterized and found to be saddled.