Selective proton decoupling was used to remove one of the homonuclear splittings in heteronuclear 2-dimensional NMR. The addnl. effort required to adjust the decoupler frequency to one of the proton shifts is easily offset by the increased simplicity of the spectra. In the expt., continuous weak irradn. is applied at the chem. shift of one of the distant protons which is not directly coupled to the P nuclei. The carrier frequency of both proton pulses and selective irradn. is chosen to be one and the same. [on SciFinder (R)]