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Facile non-radiative decay of low-lying metal-centered (MC) dd excited states has been well documented to pose a significant obstacle to the development of phosphorescent Ni II complexes due to substantial structural distortions between the dd excited state and the ground state. Herein, we prepared a series of dinuclear Ni 2 II,II complexes by using strong σ-donating carbene-phenyl-carbene (C NHC  C phenyl  C NHC ) pincer ligands, and prepared their dinuclear Pt 2 II,II and Pd 2 II,II analogues. Dinuclear Ni 2 II,II complexes bridged by formamidinate/α-carbolinato ligand exhibit short Ni-Ni distances of 2.947-3.054 Å and singlet metal-metal-to-ligand charge transfer ( 1 MMLCT) transitions at 500-550 nm. Their 1 MMLCT absorption energies are red-shifted relative to the Pt 2 II,II and Pd 2 II,II analogues at ~450 nm and ≤420 nm respectively. One-electron oxidation of these Ni 2 II,II complexes produces valence-trapped dinuclear Ni 2 II,III species, which are characterized by EPR spectroscopy. Upon photoexcitation, these Ni 2 II,II complexes display phosphorescence (τ=2.6-8.6 μs) in the NIR (800-1400 nm) spectral region in 2-MeTHF and in the solid state at 77 K, which is insensitive to π-conjugation of the coordinated [C NHC  C phenyl  C NHC ] ligand. Combined with DFT calculations, the NIR emission is assigned to originate from the 3 dd excited state. Studies have found that the dinuclear Ni 2 II,II complex can sensitize the formation of singlet oxygen and catalyze the oxidation of cyclo-dienes under light irradiation., (© 2024 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)