Four new lead(II)–iridium(III) heterobimetallic coordination frameworks, i.e., [Pb2(L)4(DMF)2]·ClO4·2DMF·13H2O (1·DMF), [Pb(L)2·H2O]·ClO4·3C3H6O·3H2O (1·Acetone), [Pb(L)2·H2O]·3C3H6O·3H2O·CH3CN (2·Acetone), and [Pb4(L)4I4·(DMF)2]·10H2O (3·DMF), where is L-H2 = Ir(ppy)2(H2dcbpy)PF6, ppy = 2-phenylpyridine, and H2dcbpy = 4,4′-dicarboxy-2,2′-bipyridine, have been synthesized and structurally characterized using elemental analyses, IR spectroscopy, optical spectroscopy, and single-crystal X-ray diffraction. Heavy atoms, i.e. lead(II) atoms, were introduced to the frameworks and coordinated with the chromophore to promote an efficient intersystem crossing from the singlet to the triplet 3MLCT excited state and further promote sensitivity to oxygen. The emissions of 1·DMF, 1·Acetone, 2·Acetone and 3·DMF (referred to hereafter as 1·DMF–3·DMF) were ascribed to metal-to-ligand charge transfer transitions (MLCTs). These four compounds, using phosphorescence based detection, were able to detect oxygen sensitively in real gas, and their noteworthy oxygen-sensing properties were also evaluated. The quenching constants, or KSV values, between 1·DMF–3·DMF and oxygen, can be deduced to be 1.44, 1.60, 2.85, and 5.11, respectively. The minimum detectable concentrations (LODs) of oxygen for 1·DMF–3·DMF were calculated to be 0.65%, 0.70%, 0.61%, and 0.52%, respectively, from three times the signal to noise ratio. Moreover, taking 3·DMF as an example, short response (50 s) and recovery times (24 s) toward oxygen have been measured. It should be noted that the evaluated recovery time for 3·DMF is even shorter than those reported for rare-earth MOF films. The gas sensing properties, including sensitivity, sensing linearity, reproducibility, matrix effect, cross-sensitivity effect, temperature effect, and long-term stability, were investigated. Finally, in order to spark a broad spectrum of interest in terms of an application, 3·DMF was mixed with a commercial dye, Coumarin 480 (C480), to form a ratiometric oxygen sensor for the analysis of real gas in air.

https://www.rsc.org/suppdata/ce/c4/c4ce02457e/c4ce02457e1.pdf

Four new lead(II)–iridium(III) heterobimetallic coordination frameworks: synthesis, structures, luminescence and oxygen-sensing properties

A photocatalytic system that consists of an Ir-based photosensitizer and a RuII bipyridine catalyst was developed for the selective reduction of CO2 to formic acid using triethanolamine as the electron donor. Catalyst turnover numbers up to 526 and a selectivity of 80 % towards formic acid were observed if the photocatalytic reaction was performed with [Ir(ppy)2(bpy)]PF6 (ppy=2-(pyridine-2-yl)benzene-1-ide, bpy=2,2′-bipyridine) as the photosensitizer and [Ru(bpy)2(Cl)(CO)]PF6 as the catalyst under visible-light irradiation (λ=400–700 nm). Interestingly, this photocatalytic system showed activity for the photoreduction of Na2CO3 to formic acid as well. The investigation of different ruthenium(II) catalysts revealed the positive influence of carbonyl ligands coordinated to the metal center. The enhancement of the catalytic activity is explained by a more favorable electron transfer from the photosensitizer to the catalyst, which is supported by the redox potentials of the complexes.

Photochemical Reduction of Carbon Dioxide to Formic Acid using Ruthenium(II)-Based Catalysts and Visible Light

Coordination chemistry of mononuclear ruthenium complexes bearing versatile 1,8-naphthyridine units: Utilization of specific reaction sites constructed by the secondary coordination sphere

Herein we report the synthesis and characterization of trans-[RuIICl2(PPh3)3] with potentially tridentate Schiff bases derived from 5,6-diamino-1,3-dimethyl uracil (H2ddd) and two 2-substituted aromatic aldehydes. In the diamagnetic ruthenium(II) complexes, trans-[RuCl(PPh3)2(Htdp)] (1) {H2tdp = 5-((thiophen-3-yl)methyleneamino)-6-amino-1,3-dimethyluracil} and trans-[RuCl(PPh3)2(Hsdp)] (2) {H2sdp = 5-(2-(methylthio)benzylideneamino)-6-amino-1,3-dimethyluracil}, the Schiff base ligands (i.e. Htdp and Hsdp) act as mono-anionic tridentate chelators. Upon reacting 5-(2-hydroxybenzylideneamino)-6-amino-1,3-dimethyluracil (H3hdp) with the metal precursor, the paramagnetic complex, trans-[RuIVCl2(ddd)(PPh3)2] (3), was isolated, in which the bidentate dianionic ddd co-ligand was formed by hydrolysis. The metal complexes were fully characterized via multinuclear NMR-, IR-, and UV–Vis spectroscopy, single crystal XRD analysis and conductivity measurements. The redox properties were probed via cyclic voltammetry wit...

Ruthenium(II/IV) complexes with potentially tridentate Schiff base chelates containing the uracil moiety

A new water-soluble ruthenium(II) carbonyl complex: cis-[Ru(bpy)2(SO3)(CO)]

The reaction of Bronsted acids with cis-[Ru(bpy)2(CO3)] (bpy = 2,2′-bipyridine) under CO results in cleavage of the carbonato ligand and formation of cationic cis-[Ru(bpy)2(CO)L] n + complexes [L = ONO2 (1 +), OH2 (2 2+), Cl (3 +), OCOH (4 +), and OCOCH3 (5 +)]. The structures of 1 + and 2 2+ were confirmed by single-crystal X-ray diffraction. Crystal data for 1(PF6): monoclinic, P21/c, a = 10.5242(3), b = 15.4727(3), c = 14.6571(3) A, β = 92.3219(9)°, V = 2384.77(9) A3, Z = 4, D calcd = 1.806 g cm−3, 5460 unique reflections (R int = 0.032), R 1 = 0.0540 [I > 2σ(I)], wR 2 = 0.1642 (all reflections); crystal data for 2(ClO4)2 · H2O: monoclinic, C2/c, a = 20.4247(7), b = 10.0777(3), c = 15.6039(5) A, β = 127.7569(8)°, V = 2539.31(14) A3, Z = 4, D calcd = 1.769 g cm−3, 2895 unique reflections (R int = 0.036), R 1 = 0.0343 [I > 2σ(I)], wR 2 = 0.0907 (all reflections). Except for 2(PF6)2 the complexes exhibit oxidation at 1.02–1.30 V versus Fc+/Fc in acetonitrile. Bipyridine-centered reductions are also observ...

One-pot synthesis of cis-bis(2,2′-bipyridine)carbonylruthenium(II) complexes from a carbonato precursor: X-ray crystal structures and electron transfer processes of the series complexes

It is extremely important for synthetic chemists to control the structure of new compounds We have constructed ruthenium-based mononuclear complexes with the tridentate 2,6-di(1,8-naphthyridin-2-yl)pyridine (dnp) ligand to investigate a new synthetic approach using a specific coordination space The synthesis of a family of new ruthenium complexes containing both the dnp and triphenylphosphine (PPh3) ligands, [Ru(dnp)(PPh3)(X)(L)]n+ (X = PPh3, NO2−, Cl−, Br−; L = OH2, CH3CN, C6H5CN, SCN−), has been described All complexes have been spectroscopically characterized in solution, and the nitrile complexes have also been characterized in the solid state through single-crystal X-ray diffraction analysis Dnp in the present complex system behaves like a “molecular sieve” in ligand replacement reactions Both experimental data and density functional theory (DFT) calculations suggest that dnp plays a crucial role in the selectivity observed in this study The results provide useful information toward elucidating this facile and selective synthetic approach to new transition metal complexes

https://www.mdpi.com/2304-6740/1/1/32/pdf

Facile and Selective Synthetic Approach for Ruthenium Complexes Utilizing a Molecular Sieve Effect in the Supporting Ligand

Ruthenium complexes bearing a tridentate polypyridyl ligand with non-coordinating donor atoms: Construction of a specific coordination environment involving noncovalent interactions

Takashi Yamanaka

Papers

One-pot synthesis of cis-bis(2,2′-bipyridine)carbonylruthenium(II) complexes from a carbonato precursor: X-ray crystal structures and electron transfer processes of the series complexes

Facile and Selective Synthetic Approach for Ruthenium Complexes Utilizing a Molecular Sieve Effect in the Supporting Ligand

Ruthenium complexes bearing a tridentate polypyridyl ligand with non-coordinating donor atoms: Construction of a specific coordination environment involving noncovalent interactions