Using computer simulations we study linear oligomers end functionalized with ligands that can form trans- or cis-2:1 complexes with metal ions in a salt-screened good solvent. We show that trans-cis isomerization of ligand-metal complexes can significantly increase the average molecular weight as well as trigger formation of reversible metallosupramolecular network based on 3:1 ligand-metal complexes acting as cross-linkers. We predict the conditions under which the most dramatic changes in the properties of metallosupramolecular polymers, such as network formation or increase in elastic plateau modulus of the network, occur upon isomerization.