The 1H-nmr spectra of mixed valence complexes of copper with derivatives of 1-amino-2,2-dimethyl-2-mercaptoethane

Paramagnetic cluster ions of the type Cu(II)₆Cu(I)₈L₁₂Cl^z, where z is charge and L a derivative of 1-amino-2,2-dimethyl-2-mercaptoethane, have been shown to produce detectable ¹H-nmr absorptions. Linewidths are narrow enough to permit the use of high resolution instruments. Downfield shifting of all detectable resonances is indicative of S → Cu²⁺ charge transfer, which results in a positive spin density at sulfur. Exchange measurements with ⁶⁷Cu indicate relatively static structures.