Laser spectroscopy of the X 1Σ+ and B 1Πstates of the LiRb molecule

► We studied the X 1Σ+→ B 1Π band system of the 7Li85Rb molecule. ► We derived the molecular constants for the X 1Σ+ and B 1Π states. ► We observe Laser Induced Fluorescence up to v″ = 45 of the X 1Σ+ state. ► We observe rotational perturbations in the B 1Π state due to the C 1Σ+ state. ► B 1Π (v′ = 3) level is a promising intermediate for formation of ultracold LiRb.