A combination of NMR experiments was employed to obtain structural information from small numbers of monomer fragments which are at the junctions of the polyisobutylene-polybutadiene diblocks (PIB-b-PBD) and to confirm the main chain resonance assignments. The multiplicities of the C-13 resonances were determined using a DEFT experiment, and the one-bond and long-range H-1/C-13 Shift correlations were determined using the indirect detection experiments, HMQC and HMBC, respectively. Previous resonance assignments were based on comparisons with model compounds, correlation of systematic shifts with structural differences, and the APT spectra. The BD-NMR experiments performed in this work provide definitive proof of the preparation of PIB-b-PBD by correlation of resonances of PIE and PBD chain ends with a common structural unit. The chain end resonances of several other structural fragments present in the polymer mixture are also identified.