High-resoln. 31 P solid-state NMR spectra of Ph3P Cu(I) complexes, obtained by combining proton dipolar decoupling, proton-P cross polarization, and magic-angle sample spinning, often reveal asym. quartets rather than single resonance lines. These splittings arise from coupling with the nuclear spin 3/2 of the quadrupolar Cu nucleus. Theor. NMR spectra of spins I = 1/2 coupled to spins S > 1/2 are presented for powders spinning at the magic angle. Scalar and dipolar interactions are considered for the S = 1 and S = 3/2 cases. The magnetic field dependence of the obsd. asym. quartets in (Ph3P)2Cu(I)NO3 can be accounted for by assuming a combination of scalar and dipolar coupling between P and Cu. The spectra allow the detn. of the scalar coupling const., dipolar coupling const., and Cu quadrupole const. Also, their signs can be established.