Using Rigidity and Conjugation of Subunits to Modulate Supramolecular Topologies Constructed by Half-Sandwich Fragments.

The synthesis of supramolecular compounds with a high degree of controllability and the targeted modulation of their topological transitions pose significant challenges in situ. In this study, we have successfully constructed an array of discrete structures based on a series of bidentate pyridyl ligands (L1, L2, and L3), which were subsequently ligated with half-sandwiched (Cp*Ir fragments) building blocks. Our further investigations elucidate a strategy for coordinating the relative lengths of the bidentate ligands with the building blocks, achieving specific concentrations that drive the transformation of tetranuclear metal macrocycles into Borromean rings.

Design of Highly Electrophilic and Stable Metal Nitrido Complexes.

ConspectusMetal oxo (M═O) and nitrido (M≡N) complexes are two important classes of high-valent transition metal complexes. The use of M═O as oxidants in chemical and biological systems has been extensively investigated. Nature makes use of M═O in enzymes such as cytochrome to oxidize a variety of substrates.

Cytotoxic -ruthenium(III) bis(amidine) complexes.

In chemotherapy, the search for ruthenium compounds as alternatives to platinum compounds is proposed because of their unique properties. However, the geometry effect of ruthenium complexes is sparely investigated. In this paper, we report the synthesis of a series of bis(acetylacetonato)ruthenium(III) complexes bearing two amidines (1-) in a configuration.

Synergistic effects of CHCOH and Ca on C-H bond activation by MnO.

The activation of metal-oxo species with Lewis acids is of current interest. In this work, the effects of a weak Brønsted acid such as CHCOH and a weak Lewis acid such as Ca on C-H bond activation by KMnO have been investigated. Although MnO is rather non-basic (p of MnO(OH) = -2.

Structure and Reactivity of One- and Two-Electron Oxidized Manganese(V) Nitrido Complexes Bearing a Bulky Corrole Ligand.

As a strategy to design stable but highly reactive metal nitrido species, we have synthesized a manganese(V) nitrido complex bearing a bulky corrole ligand, [Mn(N)(TTPPC)] (, TTPPC is the trianion of 5,10,15-Tris(2,4,6-triphenylphenyl)corrole). Complex is readily oxidized by 1 equiv of CpFe to give the neutral complex , which can be further oxidized by 1 equiv of [(-Br-CH)N][B(CF)] to afford the cationic complex . All three complexes are stable in the solid state and in CHCl solution, and their molecular structures have been determined by X-ray crystallography.

Molecular surface modification of silver chalcogenolate clusters.

This study presents a molecular surface modification approach to synthesizing a family of silver chalcogenolate clusters (SCCs) containing the same [AgS] core and different surface-bonded organic ligands (DMAc or pyridines; DMAc = dimethylacetamide), with the aim of tuning the luminescence properties and increasing the structural stability of the SCCs. The SCCs displayed strong and tuneable luminescence emissions at 77 K (from green to orange to red) as influenced by the peripheral pyridine ligands. In addition, SCC 5 protected by pyridine molecules was stable in ambient air, humid air and even liquid water for a long time (up to 1 week), and it was more structurally stable than SCC 1 bonded with DMAc molecules under the same conditions.

Structure and Reactivity of a Manganese(VI) Nitrido Complex Bearing a Tetraamido Macrocyclic Ligand.

Manganese complexes in +6 oxidation state are rare. Although a number of Mn(VI) nitrido complexes have been generated in solution via one-electron oxidation of the corresponding Mn(V) nitrido species, they are too unstable to isolate. Herein we report the isolation and the X-ray structure of a Mn(VI) nitrido complex, [Mn(N)(TAML)] (), which was obtained by one-electron oxidation of [Mn(N)(TAML)] ().

Room Temperature Aerobic Peroxidation of Organic Substrates Catalyzed by Cobalt(III) Alkylperoxo Complexes.

Room temperature aerobic oxidation of hydrocarbons is highly desirable and remains a great challenge. Here we report a series of highly electrophilic cobalt(III) alkylperoxo complexes, Co(qpy)OOR supported by a planar tetradentate quaterpyridine ligand that can directly abstract H atoms from hydrocarbons (R'H) at ambient conditions (Co(qpy)OOR + R'H → Co(qpy) + R' + ROOH). The resulting alkyl radical (R') reacts rapidly with O to form alkylperoxy radical (R'OO), which is efficiently scavenged by Co(qpy) to give Co(qpy)OOR' (Co(qpy) + R'OO → Co(qpy)OOR').

Cr(V)-Cr(III) in-situ transition promotes ROS generation to achieve efficient cancer therapy.

The development of metal-based anticancer drugs is of considerable interest and significance in inorganic medicine. In contrast to noble metal-based small molecules, the anticancer property of earth abundant metal-based small molecules is much less explored which are usually essential trace element for the human body. Among earth abundant metals, chromium (Cr) in the +3 valent is an essential trace element for the human body to low down the blood lipids and maintain the blood sugar; on the other hand, Cr(VI) are known to be highly toxic due to their oxidation power.

Self-assembly and guest-induced disassembly of triply interlocked [2]catenanes.

Two fascinating triply interlocked [2]catenanes and one simple triangular prism metallacage were constructed by tuning the widths of the organometallic dinuclear building blocks. Notably, the interlocked architectures were disassembled in the presence of large aromatic molecules to form their corresponding monomeric host-guest complexes.

A new supramolecular catalytic system: the self-assembly of Rh8 cage host anthracene molecules for [4 + 4] cycloaddition induced by UV irradiation.

The supramolecular assembly, used as a molecular reactor, is of great significance in host-guest chemistry. In this work, we used a tetratopic pyridyl ligand as a building block to hierarchically combine a slightly twisted cuboid with half-sandwich rhodium fragments. The cuboid directionally self-assembled hydrophobic pockets that can encapsulate conjugated molecules like anthracene (ANT) as guests in solutions, by supramolecular interactions including hydrogen bonding and hydrophobic interactions.

Assembly of Discrete Chalcogenolate Clusters into a One-Dimensional Coordination Polymer with Enhanced Photocatalytic Activity and Stability.

Interlinking discrete supertetrahedral chalcogenolate clusters with conjugated bipyridine linkers form a one-dimensional coordination polymer, [CdAg(SPh)(DMF)(HO)(bpe)] (), displaying a broader visible-light absorption and a narrower band gap than those of the discrete cluster. More importantly, the coordination polymer demonstrates enhanced activity and stability for the photocatalytic degradation of organic dye in water.

Generation and Reactivity of a One-Electron-Oxidized Manganese(V) Imido Complex with a Tetraamido Macrocyclic Ligand.

The synthesis and X-ray structure of a new manganese(V) mesitylimido complex with a tetraamido macrocyclic ligand (TAML), [Mn (TAML)(N-Mes)] (1), are reported. Compound 1 is oxidized by [(p-BrC H ) N] [SbCl ] and the resulting Mn species readily undergoes H-atom transfer and nitrene transfer reactions.

Interlinking supertetrahedral chalcogenolate clusters with bipyridines to form two-dimensional coordination polymers for photocatalytic degradation of organic dye.

Chalcogenolate clusters Cd6Ag4(EPh)16(DMF)3(CH3OH) (E = S, Se) with supertetrahedral structures are isolated. Further interlinking the clusters with organic linker 4,4'-trimethylenedipiperidine in the stepwise assembly approach forms two-dimensional coordination polymers. The clusters and the coordination polymers show tunable band gaps and efficient photocatalytic activities for the degradation of aqueous dye solution.

High efficiency green OLEDs based on homoleptic iridium complexes with steric phenylpyridazine ligands.

A series of steric phenylpyridazine based homoleptic iridium(iii) complexes (1-3) have been synthesized with novel one-pot methods. Single X-ray structural analyses are conducted on complexes 1 and 2 to reveal their coordination arrangement. These complexes exhibit a very strong green phosphorescence emission with high quantum yields of over 64%.

Electrocatalytic oxygen evolution with a cobalt complex.

The development of an earth-abundant, first-row water oxidation catalyst that operates at a high TOF and a low overpotential remains a fundamental chemical challenge. Cobalt complexes are important members of water oxidation catalysts. Herein, we report a cobalt-based robust homogeneous water oxidation catalyst, which can electrocatalyze water oxidation at a high pH and a low overpotential (η = 520 mV) in phosphate buffer.

Photodimerization behaviour of 1D-3D Zn(II) coordination polymers with tetrazolyl styrylpyridine.

The [2 + 2] photodimerization of tetrazolyl styrylpyridine leads to single-crystal-to-single-crystal transformations of four Zn(II) coordination polymers with 1D-3D structures, exhibiting controllable reaction extent, luminescence decrease or blue shift, and a two-step reaction process with a phase transition point.

Stepwise assembly of a semiconducting coordination polymer [Cd8S(SPh)14(DMF)(bpy)]n and its photodegradation of organic dyes.

Chalcogenolate clusters can be interlinked with organic linkers into semiconducting coordination polymers with photocatalytic properties. Here, discrete clusters of Cd8S(SPh)14(DMF)3 were interlinked with 4,4'-bipyridine into a one dimensional coordination polymer of [Cd8S(SPh)14(DMF)(bpy)]n with helical chains. A stepwise mechanism for the assembly of the coordination polymer in DMF was revealed by an ex situ dynamic light scattering study.

A new copper species based on an azo-compound utilized as a homogeneous catalyst for water oxidation.

A new azo-complex [(L)Cu(II)(NO3)] [L = (E)-3-(pyridin-2-yldiazenyl)naphthalen-2-ol (HL)], was prepared via a one-pot synthetic method at 60 °C and was structurally characterized by IR, EA, PXRD and single crystal X-ray diffraction. In addition, TGA studies indicated that the complex was stable in air. The redox properties were determined by cyclic voltammetry, which revealed that the complex could be utilized as a catalyst for water oxidation under mild conditions.

Anion-directed self-assembly of two half-sandwich ruthenium-based metallamacrocycles as catalysts for water oxidation.

The binuclear [η(6) -(cymene)Ru(L)]2 (OTf)2 (TfO(-) =trifluoromethanesulfonate) and tetranuclear [η(6) -(cymene)Ru(L)]4 (NO3 )4 metallacycles were prepared by treating the pyridyl-substituted 8-hydroxyquinoline ligand (E)-2-[2-(pyridin-3-yl)vinyl]quinolin-8-ol (HL) with [(p-cymene)Ru(μ-Cl)Cl]2 in the presence of AgOTf or AgNO3 . The molecular structures of these complexes were confirmed by single-crystal X-ray diffraction, which revealed that both complexes have macrocycle frameworks induced by the TfO(-) and NO3 (-) counteranions, respectively. The electrochemical properties of the two metallacycles were investigated by cyclic voltammetry, which showed that they have great potential as catalysts for water oxidation.

Pyrolytic cavitation, selective adsorption and molecular recognition of a porous Eu(III) MOF.

A channel-equipped metal-organic framework (1-pyr), resulting from the pyrolysis of [(CH3)2NH2]@[Eu2L3(HCOO)] (1) (L(2-) = isophthalate), showed the preferable absorption of CO2 and the Eu(III)-based emission quenched by aromatics.

Immobilization of volatile and corrosive iodine monochloride (ICl) and I(2) reagents in a stable metal-organic framework.

The major discovery here is a robust and water-stable metal-organic framework (MOF) material capable of reversible binding of the volatile and reactive molecules of ICl and I2. The immobilization of I2 and ICl, as well as their controllable release thus achieved, is to facilitate the wide-ranging applications of these volatile species as catalysts and reagents in chemical and industrial processes. The framework material TMBP·CuI (hereafter TCuI) can be conveniently prepared in quantitative yields by heating CuI and the organic linker TMBP (3,3',5,5'-tetramethyl-4,4'-bipyrazol) in acetonitrile.

Water oxidation catalysts and pH sensors based on azo-conjugated iridium/rhodium motifs.

Herein we report the molecular structures and electronic properties of ionic, hydrophobic half-sandwich complexes with formula [η(5)-Cp*Ir(L)(Cl)](OTf) (), [η(5)-Cp*Rh(L)(Cl)](OTf) (), [η(5)-Cp*Ir(L)(H2O)](OTf)2 () and [η(5)-Cp*Rh(L)(H2O)](OTf)2 (), where L is 1-(2-pyridylazo)-2-naphthol. The electrochemical properties of these complexes have been investigated, and they displayed good electronic properties for use as water oxidation catalysts. Interestingly, the color of their solutions is unambiguously transformed from brown to green at pH = 12; the color changes of , and are especially apparent.

Azo-conjugated half-sandwich Rh/Ru complexes for homogeneous water-oxidation catalysis.

Herein we report the molecular structures and electronic properties of ionic, hydrophobic, half-sandwich complexes of the formula [η(5)-Cp*Rh(L)(MeOH)] (1) and [η(6)-CyRu(L)(H2O)] (2), where L is azo-dye compound of (p-(2-hydroxy-1-naphthylazo)benzenesulfonic acid sodium salt). Both these complexes have been investigated electrochemically and found to display good electronic properties for use as water-oxidation catalysts potentially.