Luminescent ZnII clusters [Zn4L4(μ3‐OMe)2X2] (X=SCN (1), Cl (2), Br (3)) and [Zn7L6(μ3‐OMe)2(μ3‐OH)4]Y2 (Y=I− (4), ClO4− (5)), HL=methyl‐3‐methoxysalicylate, exhibiting blue fluorescence at room temperature (λmax=416≈429 nm, Φem=0.09–0.36) have been synthesised and investigated in detail. In one case the external heavy‐atom effect (EHE) arising the presence of iodide counter anions yielded phosphorescence with a long emission lifetime (λmax=520 nm, τ=95.3 ms) at 77 K. Single‐crystal X‐ray structural analysis and time‐dependent density‐functional theory (TD‐DFT) calculations revealed that their emission origin was attributed to the fluorescence from the singlet ligand‐centred (1LC) excited state, and the phosphorescence observed in 4 was caused by the EHE of counter anions having strong CH−I interactions.

Two ferromagnetic multinuclear Ni(ii) clusters, [NiL(μ-OMe)(CHOH)] (1) and [Ni(HL)(μ-OMe)]Cl (2), and a mononuclear complex [NiL]·2HO (3) (HL = benzyl 2-hydroxy-3-methoxybenzoate; HL = 1-(2-hydroxy-3-methoxybenzamido)-2-(benzylideneamino)ethane; HL = 1-(2-hydroxy-3-methoxybenzamido)-2-(pyridylmethyleneamino)ethane) were synthesised, and their structures and magnetic behaviours were investigated in detail. 1 has a [NiO] cubane structure while 2 has a wheel-like [Ni@Ni] arrangement. The temperature-dependent magnetic susceptibilities for 1 and 2 are in accord with the presence of dominating intra-cluster ferromagnetic interactions between Ni(ii) ions. The best fits for their behaviours gave the following parameters: J = 11.06 cm, J = 1.43 cm, g = 2.29 for 1, and J = 6.87 cm, J = -3.41 cm, g = 2.24 for 2.

Zinc(II) complexes have a significant hurdle to overcome to exhibit phosphorescence because of the absence of spin‐orbital coupling (SOC) in the ZnII ion. The present manuscript reports the phosphorescent behaviour of a ZnII cluster [Zn7L6(μ3‐OMe)2(μ3‐OH)4]I2 (HL=methyl‐3‐methoxysalicylate) promoted by the external heavy‐atom effect (EHE) associated with the presence of iodide counter anions that act to introduce SOC into the system. This heptanuclear ZnII cluster with I− counter anions shows phosphorescence (λmax=520 nm) with an extremely long emission lifetime (τ=95.3 ms) at 77 K. More information can be found in the Communication by S. Hayami, M. Nakamura, et al. on page 5875.