Possible structures for H-Cu-CH3 molecules

EPR spectra for H-Cu-CH3 molecules in glasses at 77 K show Cu-63 hyperfine splitting that accords with a d(x2-y2)(1) orbital for the semi-occupied mol ecular orbital (SOMO) rather than a d(z2)(1) SOMO. The g-values also strong ly imply a d(x2-y2)(1) configuration. The estimated spin densities on the H - and -CH3 ligands are small. It is argued that the molecule must be strong ly bent in order to favour this SOMO and that this bending may be induced b y weak solvation.