Metal complexes bearing linked beta-diketonates and ancillary Lewis ligands have found wide interest as precursors. The relationships involving molecular architectures and mass transport properties of alkaline-, rare-earth and transition metal precursors are discussed. The effects due to the nature of the β-diketonate moiety as well as of the ancillary ligand on mentioned properties have been addressed. The perspectives of applications to MOCVD processes of complex oxide systems are commented, reporting on the in-situ growth of the La1-xSrxMnO3 phase, as a case study. Application of a transition metal precursor to the deposition of NiO films is commented as well.