An unprecedented high-nuclearity metallamacrocycle-based 3D silver framework with formula {[Ag-2(C25H27N6O)(2)](CH3OH)(H2O)(0.17)}(n) (1), built on the basis of dodecanuclear silver building blocks, has been synthesized and characterized, and it shows strong phosphorescence emission at 10 K, which is a consequence of the presence of intersystem crossing from singlet to triplet caused by the heavy-atom effect of silver ions.