Primary alcohols show a prominent Debye process in the dielectric relaxation located at a timescale longer than the main structural relaxation. Böhmer and co-workers studied dilution effects of the hydrogen bonding network of n-butanol (BuOH) with n-bromobutane (BuBr) to better understand the origin of this process. Interestingly, this work has evidenced a crossover in Debye relaxation time (τ D ) for a critical concentration in BuBr x c = 0.5. By using molecular dynamics simulations and NMR experiments we propose here to explore further dilution effects on the dipolar and translational dynamics. Moreover, we discuss the relation between structural and dynamical properties in the context of a detailed study of the microstructure and the H-bond network. The overall results are consistent with the existence of a topological change in the liquid structure occurring at about x c = 0.5 from a hypernetted percolating network to independent nanodomains of n-butanol molecules embedded in the n-bromobutane phase.