The two families of Ru-chromene and -chromone complexes isolated in this work represent the first examples of metalated chromene and chromone complexes synthesized through transition-metal-mediated cyclization of phenol-tethered ynone. These unprecedented metalated heterocyclic compounds exhibit remarkable features, such as pH-switchable metal–carbon bonding interactions, photo-triggerable release of organic chromone upon visible-light irradiation, and superior antioxidative property to their organic analogue (1,4-benzopyrone). These findings not only offer mechanistic insights into metal-induced activation of functionalized alkynes, but also add a new dimension to rational design of antioxidants and photo-responsive drug delivery systems.