Microwave-Assisted Fabrication of Copper Oxide/N-Doped Carbon Nanocatalyst for Efficient Electrochemical CO Conversion to Liquid Fuels.

Electrochemical CO reduction reaction (CORR), which is driven by electricity generated from renewable energy sources, is a promising technology for sustainably producing carbon-based chemicals or fuels. Several CORR catalysts have been explored to date, among which copper-based electrocatalysts are the most widely known for electrochemical CORR and are extensively studied for their ability to generate an array of products. Their low selectivity, however, hinders their possibility of being used for practical purposes.

Deuteration and Tritiation of Pharmaceuticals by Non-Directed Palladium-Catalyzed C-H Activation in Heavy and Super-Heavy Water.

Deuterated and tritiated analogs of drugs are valuable compounds for pharmaceutical and medicinal chemistry. In this work, we present a novel hydrogen isotope exchange reaction of drugs using non-directed homogeneous Pd-catalysis. Aromatic C-H activation is achieved by a commercially available pyridine ligand.

Diverse Coordination Modes and Bidirectional Noninnocence of Pyridyl-β-diketonate on Ruthenium Platforms as a Function of Coligands.

The article demonstrated diverse binding modes of deprotonated 1,3-di(2-pyridinyl)-1,3-propanedione (HL) (κ-[O,O], κ-[N,O], and μ-bis-κ-[N,O]) on selective ruthenium platforms: Ru(acac) (dimeric []ClO), Ru(bpy) (monomeric []ClO), Ru(pap) (isomeric monomeric []ClO/[]ClO, dimeric [](ClO)), and Ru(PPh)(CO) (monomeric , isomeric dimeric []ClO/[]ClO) (acac = acetylacetonate, bpy = 2,2-bipyridine, pap = 2-phenylazopyridine). Structural authentication of the complexes revealed (i) diverse binding mode of L including its unprecedented bridging mode in []ClO, (ii) varying degrees of nonplanarity of L, and (iii) development of 1D polymeric chains or dimeric/tetrameric forms via intermolecular π-π interactions. The preferential binding feature of L in the complexes could also be corroborated by their calculated relative energies.

Fine Tuning between Radical versus Nonradical States of Azoheteroarenes on Selective Osmium Platforms.

The article highlights the cooperative impact of azoheteroarenes [abbt: 2,2'-azobis(benzothiazole), L1-L3; bmpd: ()-1,2-bis(1-methyl-1-pyrazole-3-yl) diazene, L4] and coligands [bpy: 2,2'-bipyridine; pap: 2-phenylazopyridine] in tuning radical (N-N) versus nonradical (N═N) states of L on selective Os-platforms in structurally/spectroscopically characterized monomeric []ClO-[]ClO and [](ClO)-[](ClO)/[](ClO)-[](ClO), respectively. The preferred -configuration of L in the complexes prevented obtaining ligand bridged dimeric species. It revealed that {Os(bpy)} facilitated the stabilization of both nonradical ([](ClO)-[](ClO)) and radical ([]ClO-[]ClO) states of L1/L2, while it delivered exclusively the radical form for L3 in []ClO.

Sequential Oxygenation of Bis(β-diketiminate) on a Selective Diruthenium Platform.

This article demonstrated the redox-noninnocent phenylene-linked bis(β-diketiminate) (L)-bridged first example of isomeric diruthenium(III)-acac species (acac = acetylacetonate) and its ability to activate dioxygen. The coordination of deprotonated L to the {Ru(acac)} in bis(bidentate) mode led to isomeric {(acac)Ru}(μ-L) ( = 1, -/- ). displayed Ru(III)-based anisotropic EPR in CHCN but without the resolution of the forbidden (Δ = 2) signal at 77 K.

Superior electrocatalytic hydrogen evolution activity of a triply bridged diruthenium(II) complex on a carbon cloth support.

This article describes the structural authentication of a unique triply bridged [1](ClO) and monomeric [2]ClO/[3]ClO. Electrochemical HER on a carbon cloth support demonstrated the superior performance of [1](ClO) with high TON (>10) and its long-term stability. The primary kinetic isotope effect of [1](ClO) revealed the involvement of PCET in the rate-determining step.

Metal-ligand synergy driven functionalisation of alkylene linked bis(aldimine) on a diruthenium(II) platform. Cyclisation oxygenation.

This article addresses the impact of metal-ligand redox cooperativity on the functionalisation of coordinated ligands. It demonstrates the structure-reactivity correlation of bis(aldimine) derived bis-bidentate L (Py-CHN-(CH)-NCH-Py, with = 2 (L1), 3 (L2), 4 (L3)) as a function of the conformation (/) of its alkylene linker as well as the overall structural form (/) of (acac)Ru(μ-L)Ru(acac) complex moieties (1-5) possessing an electron-rich acetylacetonate (acac) co-ligand. A systematic variation of the bridging alkylene unit of L in Ru/Ru-derived 1-5 led to the following reactivity/redox events, which were validated through structural, spectroscopic, electrochemical and theoretical evaluations: (i) Cyclisation of the ethylene linked ( conformation) bis-aldimine unit of L1 C-C coupling yielded pyrazine bridged (acac)Ru(μ-L1')Ru(acac), 1a, while the corresponding -form (ethylene linker) of the metal-bound L1 in 2 ((acac)Ru(μ-L1)Ru(acac)) led to oxygenation at the ligand backbone (bis-aldimine (L) → bis(carboxamido) (L'')) O activation to generate RuRu-derived (acac)Ru(μ-L1'')Ru(acac) (2a).

The isomer-sensitive electrochemical HER of ruthenium(II)-hydrido complexes involving redox-active azoheteroaromatics.

The article deals with the development of isomeric ruthenium(II)-hydrido complexes [Ru(H)(L1)(PPh)(CO)]ClO ([1a]ClO-[1b]ClO)/[Ru(H)(L2)(PPh)(CO)]ClO ([2a]ClO-[2b]ClO) involving azo coupled L1 [L1: ()-1,2-bis(1-methyl-1-pyrazol-3-yl)diazene]/L2 [L2: ()-1,2-bis(4-iodo-1-methyl-1-pyrazol-3-yl)diazene], respectively. Structural evaluation of the complexes affirmed the conformation of the coordinated/uncoordinated pyrazole groups of L and its unperturbed neutral azo (NN) state. Isomeric forms in [1a]ClO/[1b]ClO or [2a]ClO/[2b]ClO differed with respect to the and orientations of the coordinated CO and N(azo) donor of L, respectively.

Energy-efficient CO/CO interconversion by homogeneous copper-based molecular catalysts.

Facile conversion of CO to commercially viable carbon feedstocks offer a unique way to adopt a net-zero carbon scenario. Synthetic CO-reducing catalysts have rarely exhibited energy-efficient and selective CO conversion. Here, the carbon monoxide dehydrogenase (CODH) enzyme blueprint is imitated by a molecular copper complex coordinated by redox-active ligands.

Tetracoordinated 15-Electron Ruthenium(I) in a Discrete Triruthenium Framework.

This paper highlights the unique case of a tetracoordinated Ru(I) (15-electron) component in a structurally characterized discrete triruthenium setup, [(acac)RuL(μ-Ru)LRu (acac)](ClO) ([](ClO), where acac = acetylacetonate; = 1), which was formed along with the monomeric [(acac)Ru(L)] ([]ClO; = /) and dimeric [{(acac)Ru}(μ-L)](ClO) ([](ClO); = 1) counterparts upon interaction of {Ru(acac)} and L = 3,3'-dipyridin-2-yl-1,1'-bis(imidazo[1,5-]pyridinyl).

Donor-acceptor bridge 2,5-bis(2-oxido-phenyl)thiazolo-[5,4-]thiazole derived diruthenium and diosmium systems. Structural and competitive electronic events as a function of metal ion, bridge and ancillary ligand.

The article deals with the structural and electronic forms of hitherto unexplored L (HL = 2,5-bis(2-hydroxyphenyl)thiazolo-[5,4-]thiazole) bridged analogous diruthenium [{(AL1/AL2) Ru}(μ-L)] [1](ClO)/[2](ClO) and diosmium [{(AL1/AL2)Os}(μ-L)] [3](PF)/[4](ClO) complexes as a function of moderate-to-strongly π-accepting ancillary ligands: AL1 = 2,2'-bipyridine (bpy) and AL2 = 2-phenylazopyridine (pap). Structural elucidation of the complexes established an -oriented bridge (L) linked to the metal units through its N,O/O,N-donor sets, which led to two six-membered chelates in each case. It also highlighted the twisting of the phenolato functions of L with respect to the central thiazolothiazole (TzTz) unit and the unreduced state of the azo function of AL2 and multiple non-covalent π⋯π/CH⋯π interactions within the molecules in the nearby asymmetric units.

Unique Metal-Ligand Interplay in Directing Discrete and Polymeric Derivatives of Isomeric Azole-Carboxylate. Varying Electronic Form, C-C Coupling, and Receptor Feature.

This article dealt with the ruthenium and osmium derivatives of isomeric 1-indazole-3-carboxylic acid/2-indazole-3-carboxylic acid (HL1) and 1-benzimidazole-2-carboxylic acid (HL2) along with the π-acidic bpy (bpy = 2,2'-bipyridine) and pap (pap = 2-phenylazopyridine) co-ligands. It thus extended structurally authenticated monomeric ([(bpy)Ru(HL1)]ClO []ClO, (pap)Ru(L1) , (bpy)Os(L1) , (pap)Os(L1) , (bpy)Ru(L2) , (bpy)Os(L2) , and (pap)Os(L2) ) and dimeric ([(bpy)Ru(μ-L2)Ru(bpy)](ClO) [](ClO)) complexes. It also described modified L2' (L2' = 2,2'-bisbenzimidazolate)-bridged [(pap)Ru(μ-L2')Ru(pap)](ClO) [](ClO), where L2' was developed selectively with the {Ru(pap)} metal fragment via in situ intermolecular C-C coupling of the two units of decarboxylated benzimidazolate.

Nitrogen substitution induced lattice contraction in nickel nanoparticles for electrochemical hydrogen evolution from simulated seawater.

Herein, we demonstrate a facile method for the introduction of nitrogen in the lattices of nickel nanoparticles to form NiN ( = 0.13, 0.20, 0.

Ruthenium Azobis(benzothiazole): Electronic Structure and Impact of Substituents on the Electrocatalytic Single-Site Water Oxidation Process.

The present article deals with the structurally and spectroelectrochemically characterized newer class of ruthenium-azoheteroarenes [Ru(Ph-trpy)(Cl)(L)]ClO, []ClO-[]ClO (Ph-trpy: 4'-phenyl-2,2':6',2″-terpyridine; L1: 2,2-azobis(benzothiazole) ([]ClO); L2: 2,2'-azobis(6-methylbenzothiazole) ([]ClO); L3: 2,2'-azobis(6-chlorobenzothiazole) ([]ClO)). A collective consideration of experimental (i.e.

Azo Appended Modified Lawsone Derived Ru-Systems with Multi-Redox Entities. Competitive Electronic Form and the Question of Azo Reduction.

The article dealt with the ruthenium complexes of redox active azo appended modified lawsone L (HL : (E)-2-hydroxy-3-(p-tolyldiazenyl)naphthalene-1,4-dione))/L (HL :5-hydroxy-6-p-tolylazobenzo[a]phenazine) derived [Ru (acac) (L )]/[Ru (acac) (L )] 1/5, [Ru (bpy) (L )]ClO /[Ru (bpy) (L )]ClO [2]ClO /[6]ClO , ctc-[Ru (pap) (L )]ClO /ctc-[Ru (pap) (L )]ClO [3]ClO /[7]ClO and [Ru (CO)(H)(PPh ) (L )]/[Ru (CO)(Cl)(PPh ) (L )] 4/8 (acac=acetylacetonate, bpy=2,2'-bipyridine, pap=2-phenylazopyridine). The ligands L and L differed with respect to the para-quinone versus phenazine moieties linked to the azo function. Structural analysis of the complexes established unreduced state of the azo (N=N) group of coordinated L /L or pap as well as unprecedented para-quinone form of L .

Indazole-Derived Mono-/Diruthenium and Heterotrinuclear Complexes: Switchable Binding Mode, Electronic Form, and Anion Sensing Events.

The article deals with the newer classes of mononuclear: [(acac)Ru(H-Iz)(Iz)] , [(acac)Ru(H-Iz)]ClO []ClO/[]ClO, and [(bpy)Ru(H-Iz)(Iz)]ClO []ClO, mixed-valent unsymmetric dinuclear: [(acac)Ru(μ-Iz)Ru(bpy)]ClO []ClO, and heterotrinuclear: [(acac)Ru(μ-Iz)M(μ-Iz)Ru(acac)] (M = Co:, Ni:, Cu:, and Zn:) complexes (H-Iz = indazole, Iz = indazolate, acac = acetylacetonate, and bpy = 2,2'-bipyridine). Structural characterization of all the aforestated complexes established their molecular identities including varying binding modes (N and N donors and 1-indazole versus 2-indazole) of the heterocyclic H-Iz/Iz in the complexes. Unlike []ClO containing two NH protons at the backface of H-Iz units, the corresponding []ClO was found to be unstable due to the deprotonation of its positively charged quaternary nitrogen center, and this resulted in the eventual formation of the parent complex .

Inner-Sphere Electron Transfer Induced Reversible Electron Reservoir Feature of Azoheteroarene Bridged Diruthenium Frameworks.

This article demonstrates the stabilization of ground- and redox-induced metal-to-ligand charge transfer excited states on coordination of azo-coupled bmpd(L4) [bmpd = ()-1,2-bis(1-methyl-1-pyrazol-3-yl)diazene; L4 = -N═N-] to the electron-rich {Ru(acac)} (acac = acetylacetonate) unit in mononuclear Ru(acac)(L4) () and diastereomeric dinuclear (acac)Ru(μ-L4)Ru(acac) [, ΔΔ/ΛΛ ()/, ΔΛ ()] complexes, respectively. It also develops further one-step intramolecular electron transfer induced L4 bridged isovalent higher analogue [(acac)Ru(μ-L4)Ru(acac)]ClO in diastereomeric forms, -[]ClO-[]ClO. On the contrary, under identical reaction conditions electronically and sterically permuted bimpd [L5, ()-1,2-bis(4-iodo-1-methyl-1-pyrazol-3-yl)diazene)] delivered mononuclear Ru(acac)(L5) () as an exclusive product.

On the Question of S-S Bond Cleavage of 2,2'-Dithiodipyridine on Selective Ru and Os Platforms. MLCT or Hydride or Solvent Mediated Event.

This article deals with the S-S bond scission of the model substrate 2,2'-dithiodipyridine (DTDP) in the presence of a selective set of metal precursors: Ru(acac), [RuCl(PPh)], [RuHCl(CO)(PPh)], [Ru(H)(CO)(PPh)], [Ru(bpy)Cl], [Ru(pap)Cl], [Os(bpy)Cl], and [Os(pap)Cl] (acac, acetylacetonate; bpy, 2,2'-bipyridine; pap, 2-phenylazopyridine). This led to the eventual formation of the corresponding mononuclear complexes containing the cleaved pyridine-2-thiolate unit in -/[]ClO-[]ClO. The formation of the complexes was ascertained by their single-crystal X-ray structures, which also established sterically constrained four-membered chelate (average N1-M-S1 angle of 67.

Dioxygen Activation by Redox-Active Bis(aldimine) Ligand Bridged Diruthenium Complex Possessing Singlet Ground State.

The unexplored 'actor' behavior of redox-active bis(aldimine) congener, p-phenylene-bis(picoline)aldimine (L1), towards dioxygen activation and subsequent functionalization of its backbone was demonstrated on coordination with {Ru(acac) } (acac= acetylacetonate). Reaction under aerobic condition led to the one-pot generation of dinuclear complexes with unperturbed L1, imino-carboxamido (L2 ), and bis(carboxamido) (L3 )-bridged isovalent {Ru (μ-L1)Ru }, 1/ {Ru (μ-L3 )Ru }, 3 and mixed-valent {Ru (μ-L2 )Ru }, 2. Authentication of the complexes along with the redox non-innocence behavior of their bridge have been validated through structure, spectroelectrochemistry and DFT calculations.

Expanding chemical space by para-C-H arylation of arenes.

Biaryl scaffolds are privileged templates used in the discovery and design of therapeutics with high affinity and specificity for a broad range of protein targets. Biaryls are found in the structures of therapeutics, including antibiotics, anti-inflammatory, analgesic, neurological and antihypertensive drugs. However, existing synthetic routes to biphenyls rely on traditional coupling approaches that require both arenes to be prefunctionalized with halides or pseudohalides with the desired regiochemistry.

Bidirectional noninnocence of hinge-like deprotonated bis-lawsone on selective ruthenium platform: a function of varying ancillary ligands.

The present work aimed to obtain discrete heavier metal complexes of unperturbed deprotonated bis-lawsone (hinge-like HL = 2,2'-bis(3-hydroxy-1,4-napthoquinone). This is primarily due to its limited examples with lighter metal ions (Co, Zn, and Ga) and the fact that our earlier approach with the osmium ion facilitated its functionalisation. Herein, we demonstrated the successful synthesis and structural characterisation of L-derived diruthenium [(bpy)Ru(μ-L)Ru(bpy)](ClO) [1](ClO) ( = 0), (acac)Ru(μ-L)Ru(acac)2 ( = 1) and monoruthenium (pap)Ru(L) 3 ( = 0) derivatives (bpy = 2,2'-bipyridine, acac = acetylacetonate, and pap = 2-phenylazopyridine).

Directing group assisted rhodium catalyzed -C-H alkynylation of arenes.

Site-selective C-H alkynylation of arenes to produce aryl alkynes is a highly desirable transformation due to the prevalence of aryl alkynes in various natural products, drug molecules and in materials. To ensure site-selective C-H functionalization, directing group (DG) assisted C-H activation has been evolved as a useful synthetic tool. In contrast to DG-assisted -C-H activation, distal -C-H activation is highly challenging and has attracted significant attention in recent years.

Recent developments in first-row transition metal complex-catalyzed CO hydrogenation.

Our modern civilization is currently standing at a crossroads due to excessive emission of anthropogenic CO leading to adverse climate change effects. Hence, a proper CO management strategy, including appropriate CO capture, utilization, and storage (CCUS), has become a prime concern globally. On the other hand, C chemicals such as methanol (CHOH) and formic acid (HCOOH) have emerged as leading materials for a wide range of applications in various industries, including chemical, biochemical, pharmaceutical, agrochemical, and even energy sectors.

Diruthenium and triruthenium compounds of the potential redox active non-chelated η-N,η-N-benzothiadiazole bridge.

In the present study, a series of non-chelated BTD (2,1,3-benzothiadiazole)-bridged diruthenium(II) ([{(CHCN)(acac)Ru}(μ-BTD)] 1, [{CHCN(acac)Ru}(μ-BTD){Ru(acac)(η-N-BTD)}] 2, [{(η-N-BTD)(acac)Ru}(μ-BTD)] 3), and triruthenium ([{(acac)Ru}(μ-BTD)(η-N-BTD)] 4) complexes with varying ratios of η-N and μ-bis-η-N,η-N modes of BTD were studied. Complexes 1-4 ( = 0) were obtained the one-pot reaction of electron-rich Ru(acac)(CHCN) and electron-deficient BTD in refluxing acetone. The relatively low Ru(II)/Ru(III) potential of 1-4 (0.