Fig. 1.

Structure and electronic properties of Pt-pincer complexes. a Structure of general Pt-polypyridine pincer complexes with N^C^N (left), N^N^C (centre) and C^N^C (right) pincer ligands. b The valence Pt $d_{xy}$ and $d_{xz}$ orbitals interact strongly with π-type molecular orbitals on the monodentate ancillary ligand (left), while the $d_{z^2}$ orbitals of adjacent molecules can interact in the stacked geometry typically adopted in the solid state (right). c By adjusting the ancillary ligand, the energy of the $d_{z^2}$ orbital relative to the highest-occupied molecular orbital (HOMO) can be manipulated, making the optical properties more sensitive to the solid-state stacking