We investigate the interactions between alkali metal atoms (M = Li,Na,K) and carbon quantum dot models (CQDs) by density functional theory. For systems where Li and Na metal atoms are initially placed between two nearly planar CQDs, the interaction with the metal species induces a significant reorganization of the carbon network with the formation of macrocycles, which keep some similarity with fragments of carbon nanotubes. Binding energies of metal atoms to CQDs are significantly stronger than what is observed in pristine graphene and also in graphene nanoribbons. CQDs are characterized by high electron affinities. For a model with 32 carbon atoms [CQD32] the first and second electron affinities are 4.3 and 2.1 eV, respectively. Time dependent density functional (TDDFT) calculations for the electronic spectra of [CQD-M] complexes are compared with experimental information for similar carbon based structures. The results relying on TDDFT for [CQD-M] indicate that the enhancement of the absorption in the visible region in comparison with isolated [CQD] is related to excitations with a significant charge-transfer character.