Detailed information can be gathered using images acquired from multi-scale imaging at the molecular and macroscopic levels. However, the technical difficulties in combining separate functional units and the impermeability to biological barriers remain two of the biggest challenges in the development of such imaging systems. Herein, we report two manganese(II) compounds (MnFM1 and MnFM2) which showed enhanced stable fluorescence including a two-photon signal and magnetic contrast. These metal complexes were rationally constructed using terpyridine-based ligands and manganese(II) ions with small molecular weights. In particular, MnFM1 demonstrated multi-modal imaging effectiveness based on a d⁵ electron configuration: the compound displayed not only good penetration into thick tissue with an enhanced magnetic signal but also the capability of two-photon imaging and stimulated emission depletion (STED) super-resolution imaging. Compared to nano-based cross-platform systems, this candidate might open up the possibility of a revolutionised multi-modal imaging technique using metallic probes.

Four novel Zn^II coordination polymers, [(ZnCl₂)₂(L)₂]_n (1), [(ZnBr₂)₂(L)₂]_n (2), and [(ZnI₂)₂(L)₂]_n (3) and {[Zn(SCN)₂]_1.5(L)₃}_n (4), have been synthesized based on 4′-ferrocenyl-3,2′:6′,3′′-terpyridine with Zn^II ions and different coordination anions under similar ambient conditions. Their structures have been confirmed using single crystal X-ray diffraction analysis, showing that complexes 1–3 are one-dimensional (1D) double-stranded metal ion helical polymer chains and complex 4 is of a two-dimensional (2D) network. The structural transformations of them from a 1D polymer chain to a 2D network under the influence of the coordination anions has been systematic investigated. Furthermore, the optical band gaps have been measured by optical diffuse reflectance spectroscopy, revealing that the ligand and the complexes should have semiconductor properties.