To explore structure–activity relationships with respect to light-harvesting behavior, a family of neutral iridium complexes [Ir­(ppy)2(LR)] 1–4 (where ppy = 2-phenylpyridine, and N̂N = 2-(1H-pyrrol-2-yl)­pyridine and its functionalized derivatives) were designed and synthesized. The structural modifications in metal complexes are accomplished through the attributions of electron-donating CH3 in 2, OCH3 in 3, and electron-withdrawing CF3 in 4. The structural analysis displays that the pyridylpyrrole acts as one-negative charged bidentated ligand to chelate the iridium center. The electrochemical and photophysical properties of these complexes were systematically studied. The neutral 1–4 as well as the ionic structurally analogous [Ir­(ppy)2(bpy)]­(PF6) (5) were utilized as PSs in photocatalytic hydrogen generation from water with [Co­(bpy)3]­(PF6)2 as catalyst and triethanolamine (TEOA) as electron sacrificial agent in the presence of salt LiCl. Complex 1 maintains activity for more than 144 h under irradiation, and the total turnover number is up to 1768. The electrochemical properties and the quenching reaction indicate the H2 generation by neutral complexes 1–4 is involved exclusively in the oxidative quenching process.

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Pyridyl‐pyrrole ligands usually mimic the polypyridine ligand, and their metal complexes are interesting due to their rich coordination chemistry and their use in molecular devices, biological therapeutics, and catalytic transformations. Cs‐symmetric HL3 ligand Br‐substituted on one of the pyridyl rings was designed and synthesized by Paal–Knorr pyrrole condensation. Ligand HL4 was synthesized by Suzuki‐coupling reaction between HL3 and 2‐thiopheneboronic acid in the presence of K2CO3 and Pd(PPh3)4 in degassed THF/H2O solution. Zinc complexes 1–5 with HL1 to HL5 were prepared by treatment of the corresponding pyridyl‐pyrrole ligands with diethylzinc in toluene at 0 °C in high yield. Ligand HL3 and all zinc complexes are characterized by X‐ray diffraction analysis. The structure of free HL3 is planar. The geometries at Zn in 1, 2, and 5 are compressed octahedra, while in 3 and 4 they are perhaps best described as being between cis‐divacant octahedral and distorted tetrahedral. In these zinc complexes, shorter Zn–Npyrrole [1.878(5)‐1.950(4) Å] and longer Zn–Npyridine [2.108(5)‐2.509(3) Å], Zn‐Npendant pyridine [2.802(2)‐3.039(3) Å] bond lengths are observed. Complexes 2 and 3 were used as catalysts to promote the coupling reaction of CO2 and various epoxides under solvent‐free conditions, and the catalytic mechanism was investigated by 1H NMR spectroscopy.

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