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Here we have achieved accurate ligand tailoring at specific sites on calixarene-protected Cu(ii)-based metallamacrocycles.

Here, we systematically studied the self-assembly behavior of chiral polyoxytitanium clusters for the first time. Through the cooperative assembly of ferrocenecarboxylic acid and ketoxime ligands, we successfully incorporated the planar chirality of ferrocene (Fc) into the layered {Ti

The first Ti(iv)-based metallocalixarene nanocage cluster was obtained using t-butylcalix[4]arene as the ligand, which has extraordinary chemical stability and can act as a stable photocatalyst to catalyze the oxidation of ammonia to imine.

The first family of tunable metallocalixarene coordination cages of Ti(iv) with a framework formula [Ti12(iOPr)12(TBC[4])6L6] have been assembled from six {Ti2(iOPr)2(TBC[4])}2+ nodes and six pyridinedicarboxylic ligands through [6+6] condensation.

Incorporating heterometal and chromogenic groups into the titanium oxo cluster (TOC) nanomaterials is one of the effective strategies for the development of new high-performance photoelectrically active materials. In this Article, we report the structures and photoelectrochemical (PEC) performances of a family of TOCs, including pure [Ti12O8(OEt)16L8] ({Me-Ti12}) and six Cd-doped clusters formulated as [H4Cd2Ti10O8(OEt)16(L)8(H2O)2] ({Cd2Ti10}; L = salicylic acid and their derivatives). The six Cd-doped clusters are isostructural, containing the same {Cd2Ti10O8} core, but are protected by salicylic ligands modified with different functional groups. The compositions, structures, and solution stability of these clusters have been studied in detail by single-crystal X-ray diffraction and electrospray ionization mass spectrometry measurements. The embedding of heterometallic Cd(II) and chemical modification of organic protective shells can effectively regulate the PEC water oxidation activity of those clusters, with {F-Cd2Ti10} having the highest turnover number of 518.55 and the highest turnover frequency of 172.85 h-1. Our work highlights the potential of using TOCs that do not contain noble metals as water oxidation catalysts, and their catalytic activity can be regulated by structural modification.

Interconversion between CO2 + H2 and FA/formate is the most promising strategy for the fixation of carbon dioxide and reversible hydrogen storage; however, FA dehydrogenation and CO2 hydrogenation are usually studied separately using different catalysts for each reaction. This report describes of the catalysis of [Cp*Ir(N∧N)(X)]n+ (Cp* = 1,2,3,4,5-pentamethylcyclopentadienyl; X = Cl, n = 0; X = H2O, n = 1) bearing a proton-responsive N∧N pyridylpyrrole ligand for both reactions. Complex 2-H2O catalyzes FA dehydrogenation at 90 °C with a TOFmax of 45 900 h-1. Its catalysis is more active in aqueous solution than in neat solution under base-free conditions. These complexes also catalyze CO2 hydrogenation in the presence of base to formate under atmospheric pressure (CO2/H2 = 0.05 MPa/0.05 MPa) at 25 °C with a TOF value of 4.5 h-1 in aqueous solution and with a TOF value of 29 h-1 in a methanol/H2O mixture solvent. The possible mechanism is proposed by intermediate characterization and KIE experiments. The extraordinary activity of these complexes are mainly attributed to the metal-ligand cooperative effect of the the pyrrole group to accept a proton in the dehydrogenation of formic acid and assist cooperative heterolytic H-H bond cleavage in CO2 hydrogenation.

Spurred by the rapid growth of Ru-based complexes as molecular water oxidation catalysts (WOCs), we propose novel ruthenium(II) complexes bearing pyridylpyrrole-carboxylate (H2ppc) ligands as members of the WOC family. The structure of these complexes has 4-picoline (pic)/dimethyl sulfoxide (DMSO) in [Ru(ppc)(pic)2(dmso)] and pic/pic in [Ru(ppc)(pic)3] as axial ligands. Another ppc2- ligand and one pic ligand are located at the equatorial positions. [Ru(ppc)(pic)2(dmso)] behaves as a WOC as determined by electrochemical measurement and has an ultrahigh electrocatalytic current density of 8.17 mA cm-2 at 1.55 V (vs NHE) with a low onset potential of 0.352 V (vs NHE), a turnover number of 241, a turnover frequency of 203.39 s-1, and kcat of 16.34 s-1 under neutral conditions. The H2O/pic exchange of the complexes accompanied by oxidation of a ruthenium center is the initial step in the catalytic cycle. The cyclic voltametric measurements of [Ru(ppc)(pic)2(dmso)] at various scan rates, Pourbaix diagrams (plots of E vs pH), and kinetic studies suggested a water nucleophilic attack mechanism. HPO42- in a phosphate buffer solution is invoked in water oxidation as the proton acceptor.

Exploiting noble-metal-free systems for high-performance photocatalytic CO

Seven three dimensional (3D) uranyl organic frameworks (UOFs), formulated as [NH4 ][(UO2 )3 (HTTDS)(H2 O)] (1), [(UO2 )4 (HTTDS)2 ](HIM)6 (2, IM=imidazole), [(UO2 )4 (TTDS)(H2 O)2 (Phen)2 ] (3, Phen=1,10-phenanthroline), [Zn(H2 O)4 ]0.5 [(UO2 )3 (HTTDS)(H2 O)4 ] (4), and {(UO2 )2 [Zn(H2 O)3 ]2 (TTDS)} (5), {Zn(UO2 )2 (H2 O)(Dib)0.5 (HDib)(HTTDS)} (6, Dib=1,4-di(1H-imidazol-1-yl)benzene) and [Na]{(UO2 )4 [Cu3 (u3 -OH)(H2 O)7 ](TTDS)2 } (7) have been hydrothermally prepared using a rigid octadentate carboxylate ligand, tetrakis(3,5-dicarboxyphenyl)silicon(H8 TTDS). These UOFs have different 3D self-assembled structures as a function of co-ligands, structure-directing agents and transition metals. The structure of 1 has an infinite ribbon formed by the UO7 pentagonal bipyramid bridged by carboxylate groups. With further introduction of auxiliary N-donor ligands, different structure of 2 and 3 are formed, in 2 the imidazole serves as space filler, while in 3 the Phen are bound to [UO2 ]2+ units as co-ligands. The second metal centers were introduced in the syntheses of 4-7, and in all cases, they are part of the final structures, either as a counterion (4) or as a component of framework (5-7). Interesting, in 7, a rare polyoxometalate [Cu3 (μ3 -OH)O7 (O2 CR)4 ] cluster was found in the structure. It acts as an inorganic building unit together with the dimer [(UO2 )2 (O2 CR)4 ] unit. Those uranyl carboxylates were sufficiently determined by single crystal X-ray diffraction, and their topological structures and luminescence properties were analyzed in detail.

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 NN = 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.

Unlike [Ru2(μ-O2CCH3)4], the structurally analogous water-soluble RuII,III2 diphosphonato complex K3[Ru2(hedp)2(H2O)2] (K3·1) is only involved in stoichiometric water oxidation with a maximum 67% O2 yield under CAN/HNO3 solution (pH 1.0) for 2.5 h. The water oxidation mechanism and intermediate products were ascertained by UV-vis, ESI-MS and DFT calculation.

Energetic metal–organic frameworks (EMOFs) have witnessed increasing development and been proved as promising candidates for new high energy density materials (HEDMs). Here, three metal energetic complexes based on 3,4-diaminofurazan (DAF) and 3-amino-1H-1,2,4-triazole (Hatz) ligands have been synthesized via a routine method and fully characterized by IR, 1H NMR, 13C NMR spectroscopy, X-ray single-crystal diffraction and DSC-TG techniques. The standard heats of combustion were obtained by an oxygen bomb calorimeter, and the detonation performance was calculated using the EXPLO5 program. Crystal structure determinations reveal that 1 shows a one-dimensional zigzag chain structure consisting of Zn(II) and bidentate DAF, ultimately producing a 2D MOF through extensive hydrogen bond interactions. The crystal densities of these complexes are up to 1.9 g cm−3 at 298 K. The thermal analyses from the DSC-TG test show that most of them have good thermal stability with the highest decomposition temperature of 241 °C. The as-synthesized compounds possess highly positive heats of formation with values for 2 and 3 of 2329.30 kJ mol−1 and 3261.57 kJ mol−1, respectively, and high heats of detonation with value for 2 of 10231 kJ kg−1, superior to that of HMX and RDX, which are most powerful organic explosives in use today. Expectedly, they exhibit excellent detonation performance, of which 2 has the best detonation velocity (9405 m s−1) and detonation pressure (46.64 GPa), and thus shows a great promise for potential applications as a high-energy density material. In addition, DFT calculations were performed in order to investigate the electronic properties based on the structures. This study highlights the great potential of nitrogen-rich group containing EMOFs (or complexes) for new eco-friendly energetic materials.

Incorporating heterometal into titanium-oxygen clusters (TOCs) is an effective way to improve its catalytic activity. Herein, we synthesize three novel heterometallic TOCs with the formula of [Ti

Treatment of [Ir(PPh3)3Cl] with 2-[5-(pyridin-2-yl)-1H-pyrrol-2-yl]pyridine (Hdpp) in refluxing toluene affords an unexpected pyrrole-metalated iridium(III) hydride complex, [Ir(K2C,N-dpp)(H)(Cl)(PPh3)2] (1), via Cpyrrole-H activation, while the presence of the base KOtBu as the deprotonation reagent produces a pyridine-metalated iridium(III) hydride complex, [Ir(K3C,N,N-dpp)(H)(PPh3)2] (2), via Cpyridine-H activation. Treatment of [Ir(PPh3)3Cl] prepared by a convenient method with Hdpp in the presence of KOtBu under the refluxing mixture solvent toluene/methanol (2:1, v/v) generates the N,N-chelating complex [Ir(K2N,N-dpp)(H)(Cl)(PPh3)2] (3) together with 1 and the N,N-chelating dihydride complex [Ir(K2N,N-dpp)(H)2(PPh3)2] (4). Complex 4 is also readily produced by the reaction of [Ir(PPh3)3Cl] and Hdpp in the presence of KOtBu under refluxing methanol or by the reaction of IrCl3 and PPh3 in refluxing 2-ethoxyethanol. Complexes 1-4 are fully characterized by NMR, IR, and UV-vis spectroscopy and X-ray diffraction analysis. The dpp-/dpp2- ligand shows rich coordination capability, of which pyridine- and pyrrole-cyclometalated coordination modes are first reported. The formation of structural isomers 1 and 3 involved the selective activation of the C-H and N-H bonds of Hdpp is rationalized by theoretical calculations.

New dipyridylpyrrole N-oxide ligands HL1 and HL2 are designed and synthesized via oxidation of 2-(5-(pyridin-2-yl)-1H-pyrrol-2-yl)pyridine (Hdpp) by using 3-chloroperbenzoic acid (m-CPBA) in CH2Cl2. The treatment of ZnEt2 with two equiv. of HL1 and HL2 affords [Zn(L1)2] and [Zn(L2)2] in medium yield, respectively. These ligands and zinc complexes are fully characterized by NMR, IR, UV-vis and ESI-MS spectroscopy and X-ray diffraction analysis. The structure of HL1 and HL2 shows a planar geometry. The intramolecular hydrogen-bond interactions between the imino hydrogen and N-oxide oxygen atom are observed. In [Zn(L1)2] and [Zn(L2)2], two ligands chelate to the zinc metal with a cross perpendicular geometry. The zinc complexes were employed as a highly efficient catalyst for the thiol-Michael addition of thiols to α,β-unsaturated ketones in EtOH at room temperature. The loading of the catalyst is lowered to 0.01 mol%. The catalytic mechanism was proposed based on NMR and ESI-MS experiments.

A family of Ru2dimers, [Ru2(μ-κ2N,N′:κ2N′,N′′-dpp)2(μ-X)(X)2]q+(X = Cl, Br,q= 0 and X = I,q= 1) is synthesized from a [Ru2(OAc)4Cl] paddlewheel starting material. The neutral products are mixed-valence Ru25+dimers with a Ru–Ru bond order of 0.5, while the cationic iodide is a Ru26+dimer with formal bond order of 1.0. The Ru–Ru distance is strikingly independent of the identity of the halide and the oxidation state of ruthenium, most likely a consequence of the small bridging nitrogen which constrains the geometry. The spectroscopic properties (EPR, UV/Vis) of the Br complex are consistent with a large σ–σ* splitting in [Ru2(μ-κ2N,N′:κ2N′,N′′-dpp)2(μ-Br)(Br)2].

Four novel polyoxouranium-based uranyl carboxylates have been constructed by using a combination of three silicon-centered carboxylate ligands and polyoxouranium building blocks. Interesting oligomerization of the uranyl groups from three types of tetrameric units in 1 and 2 to octameric [(UO2)8(μ3-OH)6(μ2-OH)2(H2O)4]8+ in 3 and ultimately infinite polyoxouranium chains in 4 was observed. The 3D structure of 2 contains two different linear tetramers, whose structures are totally different from seven types of tetranuclear motifs previously observed in uranyl carboxylates. Compound 3 displays a rare octanuclear polyoxouranium brick; it is fabricated by the association of eight uranyl units in pentagonal-bipyramidal geometry that involves the edge-sharing polyhedral connection mode, which are further linked by four isolated UO7 pentagonal bipyramids to create a complicated 3D framework. These newly synthesized hybrid materials were extensively characterized by single crystal analysis, thermogravimetric analysis (TG) and different spectroscopic techniques (IR, UV-vis, and luminescence spectroscopy), which show well-resolved characteristic "five-finger" emission of the uranyl ions under excitation at 420 nm. Relativistic density functional theory (DFT) was used to explore five model compounds that theoretically simulate experimental real compounds. Experimental spectroscopy was rationalized by electronic-structure analysis.

Treatment of [Ru 3 (CO) 12 ] with 2,5-di(2-pyridyl)pyrrole (HL1) and 2,5-di(2-(5-bromopyridyl)pyrrole (HL2) in refluxing toluene afforded the dinuclear Ru(I) carbonyl complexes [Ru 2 (CO) 4 (L)] (L = L1 ( 1 ), L2 ( 3 ), respectively). Alternatively, 1 along with a minor mononuclear product [Ru(CO) 2 (L1) 2 ] ( 2 ) was synthesized from reaction of [Ru(CO) 2 Cl 2 ] n with HL1 in methanol in the presence of triethylamine. Complexes 1 – 3 have been fully characterized by NMR, IR, UV–vis, ESI-MS, and elementary analysis. Single-crystal X-ray diffraction indicates that both 1 and 3 feature a Ru–Ru single bond and the di(pyridyl)pyrrolide ligands bind to the two Ru(I) centers in a μ-κ 2 N,N’ :κ 1 N” chelating-bridging mode. Complex 2 is mononuclear Ru(II) complex with two κ 2 N , N ’ di(pyridyl)pyrrolide ligand. The spectroscopic and electrochemical properties of 1 and 3 were also explored.

The treatment of 2-(5-(pyridin-2-yl)-1H-pyrrol-2-yl)pyridine (HL1) and PhICl2 as halogenation reagent generated monochloro-pyrrole HL2, dichloro-pyrrole HL3 and penta-chloro L4. The reaction of HL3 with [Ru(CO)2Cl2]n gave diruthenium(I) complex [Ru2(μ-κ2N,N′:κ1N″-L3)2(CO)4] (1) and monoruthenium(II) complex [Ru(κ3N,N′,N‴-L3)(κ2N,N′-L3)(CO)] (2). All these newly synthesized compounds were fully characterized by 1H NMR, IR, UV–Vis spectra, elemental analyses and X-ray diffraction study. The structural analysis shows that dichloro-pyrrole L3− acts as chelating and bridging ligand to coordinate two ruthenium atoms in 1, and acts as bidentated and tridentated ligand in 2.

Image-guided photodynamic therapy (PDT) has received growing attention due to its non-invasiveness and precise controllability. However, the PDT efficiency of most photosensitizers are decreased in living system due to the aggregation-caused singlet oxygen (1 O2 ) generation decreasing. Herein, we present an Iridium (III) pyridylpyrrole complex (Ir-1) featuring of aggregation-induced emission (AIE) and 1 O2 generation characteristics for image-guided PDT of cancer. Ir-1 aqueous solution exhibits bright red phosphorescence peaked at 630 nm, large Stokes shift of 227 nm, and good 1 O2 generation ability. The 1 O2 generating rate of Ir-1 in EtOH/water mixture solution is 2.3 times higher than that of Rose Bengal. In vitro experimental results revealed that Ir-1 has better biocompatibility and higher phototoxicity compared with clinically used photosensitizers (Rose Bengal and Ce6), suggesting that Ir-1 can serve as a photosensitizer for image-guided PDT of cancer.

Unlike [Ru2(μ-O2CCH3)4], the structurally analogous water-soluble RuII,III2 diphosphonato complex K3[Ru2(hedp)2(H2O)2] (K3·1) is only involved in stoichiometric water oxidation with a maximum 67% O2 yield under CAN/HNO3 solution (pH 1.0) for 2.5 h. The water oxidation mechanism and intermediate products were ascertained by UV-vis, ESI-MS and DFT calculation.

The diethylphosphonate ligand HL 1 substituted pyridylpyrrole was synthesized by treatment of 2-bromo-6-(1H'-pyrrol-2-yl)pyridine and diethylphosphite in presence of base triethylamine and catalyst Pd(PPh 3 ) 4 under refluxing toluene conditions. The HL 1 ligand was treated with bromotrimethylsilane and followed hydrolysis by methanol to afford diphosphonic acid ligand H 3 L 2 . Treatment of H 3 L 2 with [Ru(NO)Cl 3 ] in presence of triethylamine in refluxing thf was generated diruthenium nitrosyl complex [Ru(L 2 )(NO)(Cl)] 2 ·(Et 3 NH) 2 ([ 1 ]·(Et 3 NH) 2 ), which is water soluble. The ligands and metal complex were fully characterized by NMR, IR, ESI-MS and single crystal X-ray diffraction technology. The solid state structure analysis displays 1 2- is dinuclear species, of which two ruthenium atoms are linked by two PO 3 2- groups. Photorelease of nitric oxide from 1 2- was monitored by UV-Vis spectra and the amount of the NO was determined by Griess reaction and DPPH radical scavenging reaction.

A carboxylate-driven assembly strategy has been developed for the first time to build calix[n]arene-based polyoxotitanate clusters with tuneable nuclearity and structures. Photocatalytic studies revealed that these clusters exhibit structural-dependent H2 evolution ability with a maximum rate up to 415.11 μmol h−1 g−1, which is almost the highest recorded in polyoxotitanate clusters.

New dipyridylpyrrole N-oxide ligands HL1 and HL2 are designed and synthesized via oxidation of 2-(5-(pyridin-2-yl)-1H-pyrrol-2-yl)pyridine (Hdpp) by using 3-chloroperbenzoic acid (m-CPBA) in CH2Cl2. The treatment of ZnEt2 with two equiv. of HL1 and HL2 affords [Zn(L1)2] and [Zn(L2)2] in medium yield, respectively. These ligands and zinc complexes are fully characterized by NMR, IR, UV-vis and ESI-MS spectroscopy and X-ray diffraction analysis. The structure of HL1 and HL2 shows a planar geometry. The intramolecular hydrogen-bond interactions between the imino hydrogen and N-oxide oxygen atom are observed. In [Zn(L1)2] and [Zn(L2)2], two ligands chelate to the zinc metal with a cross perpendicular geometry. The zinc complexes were employed as a highly efficient catalyst for the thiol-Michael addition of thiols to α,β-unsaturated ketones in EtOH at room temperature. The loading of the catalyst is lowered to 0.01 mol%. The catalytic mechanism was proposed based on NMR and ESI-MS experiments.

A family of Ru2 dimers, [Ru2(μ-κ2N,N':κ2N',N''-dpp)2(μ-X)(X)2]q+ (X = Cl, Br, q = 0 and X = I, q = 1) is synthesized from a [Ru2(OAc)4Cl] paddlewheel starting material. The neutral products are mixed-valence Ru25+ dimers with a Ru-Ru bond order of 0.5, while the cationic iodide is a Ru26+ dimer with formal bond order of 1.0. The Ru-Ru distance is strikingly independent of the identity of the halide and the oxidation state of ruthenium, most likely a consequence of the small bridging nitrogen which constrains the geometry. The spectroscopic properties (EPR, UV/Vis) of the Br complex are consistent with a large σ-σ* splitting in [Ru2(μ-κ2N,N':κ2N',N''-dpp)2(μ-Br)(Br)2].

With use of a macrocyclic polyphenol, tert-butylcalix[8]arene (TBC[8]), as ligands, a series of TBC[8]-stabilized {Ti4O2}clusters, containing penta- and hexacoordinated Ti centers, were synthesized. Such complexes are "core-shell" shaped containing a {Ti4O2} core arranged in a zigzag fashion. While outer walls of the clusters are decorated by deprotonated TBC[8], their upper and lower surfaces can be modified by various O- or N-donor ligands, and the ratio of the penta- and hexacoordinated Ti(IV) centers in the {Ti4O2} core can be precisely regulated from 4:0, to 3:1, to 2:2, to 1:3, and finally to 0:4. The combined coordination of different ligands in the axial direction shows significant influence on the adsorption of the TBC[8]-Ti4 system in the visible-light region, and their absorption edge can be precisely regulated from 600 to 700 nm. The above structural functionalization in the TBC[8]-Ti4 system also tunes their photocatalytic H2 production activities and oxidative desulfurization ability. Thus, for the first time, by confining the polyoxotitanium cluster in macrocyclic molecules, we provide an example of understanding the structure-property relationship of titanium-oxygen materials by ligand modification.

A well structure-defined dinuclear silver complex [Ag2(PDP)]OTf, where HPDP—bispyridylpyrrole ligand, OTf−—triflato, was used as catalyst for coupling of CO2 with epoxides to generate exclusive cyclic carbonates. Yield up to 87% was obtained for various substrates at a low loading of 0.1 mol%, at ambient temperature and pressure under solvent-free condition. The catalytic reusability of 1·OTf was also studied. Although coupling reaction of CO2 with epoxides can be catalyzed by dinuclear silver complexes with low catalyst loading at ambient temperature and pressure, the experiment of reusability of catalyst displays the dinuclear silver complex is decomposed due to the excess Br− in co-catalyst TBAB. The formed silver triphenylphosphine complex or inorganic silver materials provide real catalytic reactivity to the coupling reaction.

Nanoprobes are advantageous over small molecular probes in sensitivity but most luminescence molecules used to construct nanoprobes often suffer from an aggregation-caused quenching effect. Herein, we rationally designed a small molecular probe Cys(StBu)-Lys(Ru(bpy)32+)-CBT (1) which “smartly” self-assembled into nanoparticles 1-NPs inside cells with non-quenched, persistent phosphorescence. Employing this property, we successfully applied 1 for long-term sensing of biothiol activity in living HepG2 cells and tumors. We envision that, by modifying the amino group with an enzyme substrate, our probe 1 could be further developed for sensing intracellular enzyme activity with non-quenched, persistent phosphorescence.

N,N′-diisobutyloxycarbonyl-N″,N‴-(1,3-propylene)-bisthiourea ( L ) and its silver(I) and gold(I) complexes were designed and synthesized. Treatment of 1,3-propanediamine with the isothiocyanate i PrCH 2 OC(O)NCS yielded bisthiourea L with over 90% yield. Treatment of L with AgNO 3 in CH 3 CN afforded coordination polymer {[Ag( L )(NO 3 )·CH 3 CN]} n ( 1 ) with layer structure, while with HAuCl 4 in CH 3 CN resulted in reduction of Au 3+ to Au + to yield molecular [Au( L )Cl] ( 2 ). Ligand L and complexes 1 and 2 were fully characterized by IR, 1 H NMR, UV–Vis, cyclic voltammetry and element analysis. The X-ray diffraction analysis displays that the bisthiourea L behaves as sulfur donor to coordinate to Ag and Au atom with μ 3- (S, μ 2 -S′,S′) and μ 2 -S, S′ coordination mode in 1 and 2 , respectively.

Nitrogen donor ligands HL1, HL3, HL4 and their silver complexes 1·OTf–4·OTf are prepared and fully characterized. Treatment of HL1-HL4 with AgOTf (OTf− = triflato) in presence of base Et3N and co-ligand PPh3 affords dinuclear Ag(I) complexes [Ag2(L)(PPh3)2]·OTf (L = L1−, 1·OTf; L = L2−, 2·OTf; L = L3−, 3·OTf; L = L4−, 4·OTf), respectively. The solid structure displays L acts as bis(bidentate) ligand, bridging between two Ag(I) centres. The Ag⋯Ag interaction as well as other weak interactions, such as Ag⋯Brintermolecular for 1+, Ag⋯Brintramolecular for 2+, Ag⋯S for 3+ are observed. These complexes are applied in the A3-coupling reaction of aldehydes, alkynes and amines under mild conditions, and showed excellent catalytic efficiency and recyclability. 1 mol% catalyst loading gives 99% yield of propargylamines product in 0.15 h at 35 °C in open air atmosphere. 1·OTf can be recycled six times without noticeable less of the catalyst activity.

The synthesis of four low symmetry A2B type Cu(III)triarylcorroles with meso-aryl substituents that provide electron donating (push) and withdrawing (pull) properties is reported, along with their structural characterization by NMR spectroscopy and X-ray crystallography. An analysis of the structure–property relationships in the optical and redox properties has been carried out by comparing their optical spectroscopy, electrochemistry, and spectroelectrochemistry to trends predicted in DFT and TD-DFT calculations. The results demonstrate that A2B type Cu(III)triarylcorroles are highly efficient catalysts for electrocatalyzed hydrogen evolution reactions (HERs) and that their reactivity can be modulated by changing the nature of the B-position meso-substituent.

Treatment of [Ir(PPh3)3Cl] with the 2-(1H-pyrrol-2-yl)pyridine (Hpp) ligand under refluxing toluene affords the iridium(III) hydride complex [Ir(H)Cl(pp)(PPh3)2] (1), whereas in the simultaneous presence of KOtBu the reaction gives iridium(III) hydride isomers, namely ortho-metallated triphenylphosphine cis-(P,P)-[Ir(H)(pp)(PPh3){K2C,P-PPh2(C6H4)}] (2) and trans-(P,P)-[Ir(H)(pp)(PPh3){K2C,P-PPh2(C6H4)}] (3). Complexes 1–3 are fully characterized by 1H NMR, 31P NMR, IR and UV–vis spectroscopy, together with single crystal X-ray diffraction analysis.

Five mononuclear copper(I) complexes and one dinuclear silver(I) phosphine complex containing the bispyridylpyrrole ligand were synthesized and structurally characterized. Treatment of CuCl and the deprotonated bispyridylpyrrole ligand with bis(phosphine) ligands afforded the copper(I) complexes [(PDPH)Cu(XANTPhos)] (1), [(PDPH)Cu(DPEPhos)] (2), [(PDPBr)Cu(XANTPhos)] (3) and [(PDPBr)Cu(DPEPhos)] (4), while addition of two equivalences of PPh3 gave [(PDPBr)Cu(PPh3)2] (5), where PDPH− = 2,5-bis(2-pyridyl)pyrrole, PDPBr− = 2,5-bis(6′-bromo-2′-pyridyl)-pyrrole, XANTPhos = 9,9-di-methyl-4,5-bis(diphenylphosphino)xanthene, DPEPhos = oxydi-2,1-phenylene)bis-diphenylphosphine. Reaction of PDPBr− with AgOTf and DPEPhos yielded the dinuclear silver(I) complex [(PDPBr)Ag2(DPEPhos)](OTf) (6). All of these complexes were fully characterized on the basis of IR spectra, 1H and 31P NMR spectra, elements analysis, UV–Vis spectra and X-ray single crystal diffraction analysis. The photophysical properties of these complexes were also studied.

A new class of neutral dicopper(I)–halide complexes with {Cu2(μ-X)} (X = Cl, Br and I) core supported by bispyridylpyrrole ligand have been synthesized and characterized. Replacements of chloride ligand in [Cu2(μ-X)2(PPh3)3] (X = Cl, Br, I) by the anionic PDPH− (PDPH− = 2,5-bis(2′-pyridyl)pyrrole) or PDPBr− (PDPBr− = 2,5-bis(6′-bromo-2′-pyridyl)-pyrrole) ligand gives complexes 1–6. They are [(PDPH)Cu2(μ-X)(PPh3)2] (X = Cl (1); Br (2); I (3)) and [(PDPBr)Cu2(μ-X)(PPh3)2] (X = Cl (4); Br (5); I (6)). The X-ray crystallographic studies reveal these complexes are isostructural. Two phosphine–copper(I) units are linked by one halogen atom and one nitrogen atom from bridging bispyridylpyrrole ligand to form 4-membered Cu2XN core. Each copper atom is located in the center of distorted tetrahedral geometry. The PDPH− and PDPBr− ligands display μ2-κ2(N,N′), κ2(N′,N″) bonding mode. The separation of Cu⋯Cu in 1–6 is in the range of 2.6708(15)–2.7959(6) A. The photophysical properties of 1–6 are described.

A copper-bispyridylpyrrolide complex [Cu(PDPH)Cl] (PDPH = 2,5-bis(2′-pyridyl)pyrrole) was synthesized and characterized. The complex crystallizes in the orthorhombic system with space group Pccn, a = 0.9016(3) nm, b = 1.0931(4) nm, c = 2.5319(8) nm, and V = 2.4951(15) nm3. The copper center is situated in a square planar geometry. The interaction of the copper(II) complex with calf thymus DNA (CT-DNA) was investigated by electronic absorption, circular dichroism (CD) and fluorescence spectra. It is proposed that the complex binds to CT-DNA through groove binding mode. Nuclease activity of the complex was also studied by gel electrophoresis method. The complex can efficiently cleave supercoiled pBR322 DNA in the presence of ascorbate (H2A) via oxidative pathway. The preliminary mechanism of DNA cleavage by the complex with different inhibiting reagents indicates that the hydroxyl radicals were involved as the active species in the DNA cleavage process.