Abstract The on-surface synthesis of porphyrin-nanographene (Por-NG) hybrids enables systematic control of π-electron magnetism in organic materials, yet the spin behavior of these systems remains difficult to predict because the porphyrin core perturbs the graphene lattice. We report the fabrication and electronic characterization of ZnPors fused with two and four 3triangulene units (i.e., ZnPorT2 and ZnPorT4, respectively) on Au(111). Rapid thermal annealing maximizes the yield of discrete hybrids by suppressing surface diffusion and unwanted lateral fusion. Scanning tunnelling microscopy and spectroscopy, supported by theory, show that both ZnPorT2 and ZnPorT4 exhibit diradical character with an antiferromagnetically coupled ground state. The hybrids undergo interfacial charge transfer to the metallic substrate: ZnPorT2 donates one electron forming open-shell ZnPorT2•+, while ZnPorT4 donates two electrons affording closed-shell ZnPorT42+. Despite this charge transfer, the multireference character of the frontier orbitals remains in ZnPorT2•+. The results establish an efficient route to complex Por-NG hybrids and clarify how molecular design and interfacial charge transfer shape their magnetic properties, an essential step toward functional magnetic nanoarchitectures.
García et al. (Tue,) studied this question.