  We use ab initio spin-polarized density functional theory to study the
magnetic order in a Kagom\'e-like 2D metamaterial consisting of pristine or
substitutionally doped phenalenyl radicals polymerized into a nanoporous,
graphene-like structure. In this and in a larger class of related structures,
the constituent polyaromatic hydrocarbon molecules can be considered as quantum
dots that may carry a net magnetic moment. The structure of this porous system
and the coupling between the quantum dots may be changed significantly by
applying moderate strain, thus allowing to control the magnetic order and the
underlying electronic structure.
