Photoactivatable Pt^IV antitumour agents are widely studied as prodrug candidates and have a relevant role in preclinical practice. They undergo photoreduction into cytotoxic PtII species (e.g. cisplatin) when irradiated with UV light, potentially reducing side-effects of systemic chemotherapies. Nevertheless, two intimately related photochemical features for this class of compounds need to be improved for advancing their use towards application. On the one hand, tissue penetration needs to be enhanced by red-shifting excitation wavelengths, while on the other, photochemical efficiency has to be optimized to reduce irradiation time.