Many of the facilities and missions that Canada is or will be involved in as well as the diverse science programs that drive these missions rely on the astronomical detection and characterization of atomic and molecular gas as well as dust grains across the electromagnetic spectrum. Molecular bands and dust features have been observed in almost all astrophysical environments—from exoplanet atmospheres to interstellar clouds and star forming regions to AGN winds. Indeed, to date, over 200 molecules and a handful of minerals have been identified in space, and the Universe is aglow with the widespread and abundant emission of Polycyclic Aromatic Hydrocarbons (PAHs). Molecules and dust grains can be powerful probes for the physical conditions in the environment in which they reside, and their presence can help elucidate chemical evolution. However, the vast majority of the known molecular spectral features remain unidentified, and for many identified species, we do not have enough information to turn their spectral appearance into diagnostic probes. Support from laboratory experiments, theoretical calculations and detailed observational data analysis will be crucial to fully exploit astronomical observations in the next decade. This white paper describes the current expertise in Canada in the fields of molecular astrophysics and astrochemistry, detail the key science questions to address within the next decade, and describe the expected needs from laboratory astrophysics and computational chemistry to establish a unique Canadian expertise center in molecular astrophysics and astrochemistry to support upcoming astronomical missions and facilities.

White paper identifier W056