The hyperfine coupling tensors of muonated radicals in single-crystal benzophenone

The hyperfine coupling tensors of muonated radicals in a large single crystal of benzophenone have been determined by measuring the hyperfine couplings of the radicals as the crystal was rotated about three orthogonal axes. Signals from four radicals were observed, corresponding to the four molecules per unit cell in the crystal. Due to an ambiguity in the data we are unable to discriminate between two similar hyperfine coupling tensors. Both lead to an isotropic hyperfine coupling of similar to 32 MHz, contrasting with the solution value of 42 MHz obtained earlier in diethyl ether. The anisotropic components of the tensor are relatively large, at approximately -15 MHz, -6 MHz and 21 MHz, respectively.