Coligands Controlled Reactivities of Ruthenium(II) Precursors: Antiferromagnetically Coupled Ruthenium(III)-Phenoxyl versus Ruthenium(II)-Phenoxyl Forms.

The study disclosed that the reactivities of [Ru (PPh)Cl] and [Ru(PPh)(CO)(H)Cl] precursors toward a trimethoxyarylimino-phenol derivative are sensibly different. The former promotes methoxy demethylation reaction affording a [Phenolato-Ru-Phenolato] unit, while the latter containing π-acidic CO and hydride as coligands leads to C-H activation reaction, generating a [Phenolato-Ru-Aryl] unit. Notably, the oxidized analogues of these two forms produce antiferromagnetically coupled [Ru-phenoxyl] and paramagnetic [Ru-phenoxyl] forms, which exhibit diverse reactivities.

Correlation in Structural Architecture toward Fabrication of Schottky Device with a Series of Pyrazine Appended Coordination Polymers.

Energy is the center of importance for the survivability of civilization. Use of fossil fuel is going to be suspended, and renewable energy is technologically costlier. In the quest for new energy sources and to minimize fuel expenditure, the design of energy efficient devices is one of the solutions.

Aminoisophthalate Bridged Cd(II)-2D Coordination Polymer: Structure Description, Selective Detection of Pd in Aqueous Medium, and Fabrication of Schottky Diode.

Photoluminescence activity of coordination polymers (CPs) has evoked intricate applications in the field of materials science, especially sensing of ions/molecules. In the present study, 2,3,5,6-tetrakis(2-pyridyl)pyrazine (tppz) and 5-aminoisophthalate (HAIPA) coordinated to Cd(II) to architect a coordination polymer, {[Cd(HAIPA)(tppz)(OH)]·3HO} (CP) which unveils blue emission in an aqueous acetonitrile (98% aqueous) suspension. The emission is selectively quenched by Pd only without interference in the presence of as many as 16 other cations.

Carbazole Integrated Tetrakis-(1 H-pyrrole-2-carbaldehyde): A Highly Selective Fluorescent Probe for HPO.

A new carbazole-coupled tetrakis-(1 H-pyrrole-2-carbaldehyde) anion receptor 1 has been designed and synthesized. Anion binding studies in organic media using fluorescence and UV-vis spectroscopy revealed that receptor 1 is capable of sensing HPO with high selectivity. Addition of HPO to THF solution of 1 resulted in the emergence of a new broad band at longer wavelength along with quenching of the original emission band forming a ratiometric response.

Two pillared-layer metal-organic frameworks based on the pinwheel trinuclear carboxylate-clusters of Zn(II) and Co(II): synthesis, crystal structures, magnetic study, and Lewis acid catalysis.

Using a dicarboxylic acid, [1,1'-biphenyl]-4,4'-dicarboxylic acid (HL1) and an exobidentate ligand, (1,1')-,'-(1,4-phenylene)bis(1-(pyridin-4-yl)methanimine) (L2), two 3D interpenetrated networks, {[Zn(L1)(L2)]·9HO} (Zn-MOF) and {[Co(L1)(L2)(DMF)]·0.5DMF} (Co-MOF), have been prepared in good yields. The crystal structure analysis of Zn-MOF and Co-MOF revealed that both have a 3D pillared-layer structure based on pinwheel trinuclear metal-carboxylate clusters as secondary building units (SBUs).

Rational synthesis of a pyridyl-imidazoquinazoline based multifunctional 3D Zn(II)-MOF: structure, luminescence, selective and sensitive detection of Al and TNP, and its semiconducting device application.

In the age of sustainable development, the exploration of multifunctional materials is of high priority due to their economic benefits and environmental suitability. A stable luminescent coordination polymer, [Zn(tdc)(pdiq)] (1), (pdiq = pyridyl-imidazoquinazoline; Htdc = 2,5-thiophenedicarboxylic acid) has been prepared and structurally confirmed by single-crystal X-ray diffraction analysis. The 3D framework consists of a distorted octahedral geometry with a ZnON coordination sphere where four carboxylato-O donations come from two tdc as bridging ligands and two pyridyl-Ns come from two pdiq.

Diastereo- and regioselective petasis aryl and allyl boration of ninhydrins towards synthesis of functionalized indene-diones and dihydrobenzoindeno-oxazin-ones.

Petasis aryl and allyl borations were accomplished using substituted ninhydrins, boronic acids or 2-allyl-4,4,5,5-tetramethyl-1,3,2-dioxaborolane and 1,2-aminophenols in Hexafluoroisopropanol (HFIP) without any catalysts to synthesize different aryl and allyl derivatives of ninhydrins. The nature of substitution in the boronic acids and 1,2-amino phenols was the key factor in determining the diastereo-regioselectivity and the type of product distributions. The products were isolated and characterized by HMBC, HSQC, H, C NMR experiments and X-ray single crystallographic analysis.

Green synthesis of C5-C6-unsubstituted 1,4-DHP scaffolds using an efficient Ni-chitosan nanocatalyst under ultrasonic conditions.

A heterogeneous and magnetically recyclable Ni-chitosan nanocatalyst was synthesized and thoroughly characterized by powder Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray (EDX) spectroscopy, etc. It was effectively utilized in the eco-friendly synthesis of new C5-C6-unsubstituted 1,4-DHPs under ultrasonic irradiation. The important focus of the methodology was to develop an environmentally friendly protocol with a short reaction time and a simple reaction procedure.

Idiosyncatic recognition of Zn and CN using pyrazolyl-hydroxy-coumarin scaffold and live cell imaging: depiction of luminescent Zn(II)-metallocryptand.

Multi-responsive and selective sensor design is one of the stimulating research areas in the sensors field. We have designed a pyrazolyl-hydroxy-coumarin scaffold, 7-hydroxy-4-methyl-8-(((5-phenyl-1-pyrazol-3-yl)imino)methyl)-2-chromen-2-one (HL) and characterized it by spectroscopic techniques (H NMR, C NMR, ESI-MS, IR). The single crystal X-ray diffraction measurement confirms the molecular structure of the probe.

Activation of O across a C(sp)-C(sp) bond.

The activation of atmospheric molecular dioxygen (O) is reported, which occurred across a C(sp)-C(sp) bond of a piperazine derivative without any catalyst at ambient conditions under the formation of 1,2,4,7-dioxadiazoctane, an 8-membered (larger-ring) cyclic organic peroxide.

A Reusable Efficient Green Catalyst of 2D Cu-MOF for the Click and Knoevenagel Reaction.

[Cu(CPA)(BDC)] (CPA = 4-(Chloro-phenyl)-pyridin-4-ylmethylene-amine; BDC = 1,4-benzenedicarboxylate) has been synthesized and structurally characterized by single crystal X-Ray diffraction measurement. The structural studies establish the copper (II) containing 2D sheet with (4,4) square grid structure. The square grid lengths are 10.

A combined experimental and theoretical study on a single, unsupported oxo-bridged Mn(III,III) dimer coordinated to two iminobenzosemiquinone π-radical anions.

Ligand H2LAP comprises a non-innocent 2-aminophenol unit and an innocent bis(pyridin-2-ylmethyl)amine unit. The ligand, upon reaction with an equivalent amount of Mn(ClO4)2·6H2O in the presence of Et3N under air in MeOH, provided a mono(oxo)-bridged dinuclear Mn2 complex ({[(LISQ)MnIII-O-MnIII(LISQ)][(ClO4)]2}; 1). X-ray crystal structure analysis of complex 1 revealed that in the dicationic unit, the physical oxidation state of each Mn ion was +III and the 2-aminophenol unit of ligand H2LAP was in its one-electron oxidized iminobenzosemiquinone form.

Sunlight assisted SCSC dimerization of a 1D coordination polymer impacts the selectivity of Pd(II) sensing in water.

A one-dimensional coordination polymer (1D CP) [Cd(4-nvp)2(5-ssa)]·(4-nvp) (1) [4-nvp = 4-(1-naphthylvinyl)pyridine and 5-ssa = 5-sulfosalicylic acid] undergoes topochemical [2+2] cycloaddition by sunlight irradiation to generate a two-dimensional (2D) CP [Cd(rctt-4-pncb)0.5(4-nvp)(5-ssa)]·(4-nvp) (1') [rctt-4-pncb = 1,3-bis(4'-pyridyl)-2,4-bis(naphthyl)cyclobutane] in a single-crystal to single-crystal manner. Interestingly, 1' can be reverted back to 1 by heating and both the CPs selectively recognize Pd2+ in aqueous medium; however, the limit of detection is improved after photodimerization.

Mixed-valence di-ruthenium(II,III) complexes of redox non-innocent -aryl--phenylenediamine derivatives.

A mononuclear ruthenium(ii), [(L1IQ)Ru2+(PPh3)2Cl2]·CHCl3 (1·CHCl3), a di-ruthenium(ii,ii), [(L2IQ)2Ru24+Cl4(PPh3)2] (2) and a mixed-valence di-ruthenium(ii,iii), [(L3IQ)Ru25+Cl5(PPh3)2]·MeOH (3·MeOH) complex, where L1IQ, L2IQ and L3IQ are, respectively, o-diiminobenzoquinone forms of redox non-innocent N-(5-nitropyridyl)-o-phenylenediamine (L1H2), N-(2,4-dinitrophenyl)-o-phenylenediamine (L2H2) and N-(3-nitropyridyl)-o-phenylenediamine (L3H2) derivatives, were successfully isolated. The molecular and electronic structures of 1·CHCl3, 2 and 3·MeOH were confirmed by single-crystal X-ray crystallography, EPR, UV-Vis-NIR spectroscopies and density functional theory (DFT) calculations. Both 1·CHCl3 and 2 exhibited reversible anodic waves due to the Ru(iii)/Ru(ii) redox couple, while the cyclic voltammogram of 3·MeOH displayed two successive cathodic waves due to ruthenium(iii)/ruthenium(ii) and (L3IQ/L3ISQ) redox couples.

Electrically conductive Cu(II)-based 1D coordination polymer with theoretical insight.

A nitro-functionalized Cu(ii)-based one-dimensional coordination polymer (1D CP) [Cu(nip)(4-phpy)2]n (1) (H2nip = 5-nitroisophthalic acid and 4-phpy = 4-phenylpyridine) was synthesized and characterized by elemental analysis, powder X-ray diffraction (PXRD) and single crystal X-ray diffraction (SCXRD). In the solid-state self-assembly of 1, two sets of weak intermolecular forces, CHπ interaction among the axially bound 4-phpy ligands and ππ interaction among bridging nip ligands from adjacent 1D coordination polymeric chains led to 3D supramolecular packing. Interestingly compound 1 exhibited electrical conductivity in the semiconducting regime and behaved as a Schottky barrier diode.

X-ray structure of two Schiff bases: TURN-ON sensing of Fe and Al in the HepG2 cell line.

The efficiency of the fluorescence sensitivity of a sensor may be tuned by the modulation of the steric and electronic parameters in the structure. In this study, the thiophenyl Schiff base (E)-N-(phenyl(pyridin-2-yl)methyl)-N-(thiophen-2-ylmethylene)benzene-1,2-diamine (HL') exhibited very high selectivity and a sensitive fluorescence enhancement towards Fe with violet emission (λ, 385 nm; LOD, 3.8 nM).

Coordination polymers of Ag(i) and Hg(i) ions with 2,2'-azobispyridine: synthesis, characterization and enhancement of conductivity in the presence of Cu(ii) ions.

The cationic coordination polymers (CPs) of the types [Hg(abpy)][PF] (1) and [Ag(abpy)][PF] (2) (abpy = 2,2'-azobispyridine) were synthesized and characterized. Experimentation using the crystals confirmed that 1 and 2 are conductors of electricity. The relative conductivity of 1 is 62 times greater than that of 2.

A Chemodosimetric Approach for Fluorimetric Detection of Hg Ions by Trinuclear Zn(II)/Cd(II) Schiff Base Complex: First Case of Intermediate Trapping in a Chemodosimetric Approach.

The present work discloses the application of two fluorescent zinc and cadmium complexes ( and ) for sensing of Hg(II) ions through a chemodosimetric approach. The ligand under consideration in this work is a NO donor Schiff base ligand ()-4-bromo-2-(((2-morpholinoethyl)imino)methyl)phenol (), which has been harnessed to generate complexes [ZnL(OAc)] () and [CdL(OAc)] (). X-ray single crystal diffraction studies unveil the trinuclear skeleton of complexes and .

Biporous Cd(II) Coordination Polymer via Disulfide Bond Formation: Self-Healing and Application to Photosensitive Optoelectronic Device.

A heteroporous metal-organic framework, [Cd(2,2'-DSB)(INH)(HO)] (), is fabricated by the reaction of CdI, 2-mercaptobenzoic acid (2-MBAH), and isoniazid (INH). The X-ray structure of the compound shows the bridging INH and 2,2'-disulfanediyldibenzoic acid (H2,2'-DSBA) around the Cd(II) ion center. 2-MBAH has been dimerized to the formation of 2,2'-DSB (S-S-bonded dianion), which has further extended to form the 2D network.

Designing of Pb(II)-Based Novel Coordination Polymers (CPs): Structural Elucidation and Optoelectronic Application.

[Pb(bdc)(aiz)] () and [Pb(bdc)(aiz)(MeOH)] () (Hbdc = 1,4-benzene dicarboxylic acid, aiz = ()-'-(thiophen-2-ylmethylene)isonicotinohydrazide) have been synthesized, and structural characterization has been established by X-ray analysis and thermogravimetric analysis (TGA). Here, bdc links two Pb(II) centers and the aiz ligand binds the metal centers in two different manners: chelating and monodonating. Thus, polymerizations have taken place from the combination of mixed ligand system.

The oxidative dehydrogenation of a coumarinyl scaffold with copper ion and metal ion detection in human liver cancer cells (HepG2).

An unsymmetrical o-phenylenediamine derivative, L (7-hydroxy-4-methyl-8-(1-(phenyl- (pyridin-2-yl)methyl)-1H-benzo[d]imidazol-2-yl)-2H-chromen-2-one), has been synthesized from (E)-N-(phenyl(pyridine-2-yl)methylene)benzene-1,2-diamine with 7-hydroxy-4-methyl-2-oxo-2H-chromene-8-carbaldehyde and characterized by X-ray, IR, H NMR and ESI-MS spectral analyses. The X-ray structure shows L as a cyclic benzimidazole derivative, but it undergoes ring-opening upon reaction with transition metal ions. L is non-emissive in 9 : 1 (v/v) EtOH/HO (HEPES buffer, pH 7.

Exploration of catecholase-like activity of a series of magnetically coupled transition metal complexes of Mn, Co and Ni: new insights into the solution state behavior of Mn complexes.

A series of tri-nuclear complexes of general formula [ML(OAc)], where M = Mn (1), Co (2) and Ni (3), (HL = (E)-4-bromo-2-(((2-morpholinoethyl)imino)methyl)phenol), have been synthesized. Single crystal X-ray crystallography reveals that each molecule contains three metal ions which are bridged by four acetate moieties. In the solution phase, the complexes are present as mononuclear species.

Supramolecular Assembly of a Zn(II)-Based 1D Coordination Polymer through Hydrogen Bonding and π···π Interactions: Crystal Structure and Device Applications.

A new mixed-ligand divalent one-dimensional coordination polymer (1D CP) [Zn(adc)(4-nvp)(HO)] , () [Hadc = acetylenedicarboxylic acid and 4-nvp = 4-(1-naphthylvinyl)pyridine] has been synthesized and well characterized by elemental analysis, infrared spectrum, single-crystal X-ray crystallography, powder X-ray diffraction pattern, and thermogravimetric analysis. The compound constructs a 3D supramolecular network by the combination of hydrogen bonding, C-H···π, and π···π interactions. Interestingly, the material shows Schottky behavior which is exclusively analyzed with the help of thermionic emission and space charge-limited current theory.

Orthometalated -(Benzophenoxazine)--aminophenol: Phenolato versus Phenoxyl States.

The molecular and electronic structures of the orthometalated ruthenium(III) and osmium(III) complexes of -(benzophenoxazine)--aminophenol (LH) that exhibits versatile redox activities are reported. The redox chemistry of LH is remarkably different from that of -(aryl)--aminophenol (LH). The study established that LH is redox noninnocent and is a precursor of a phenoxyl radical.

Pseudo five component reaction towards densely functionalized spiro[indole-3,2'-pyrrole] by picric acid, an efficient syn-diastereoselective catalyst: insight into the diastereoselection on C(sp)-C(sp) axial conformation.

A new series of highly-functionalized spiro compounds of pyrrole were synthesized by a one pot, step-economic condensation of isatin, arylamine and β-keto ester catalyzed by wet picric acid. Initially, the reaction was proposed with an expectation of the formation of a multi-spiro heterocyclic framework of highly-substituted piperidine. However, the isomeric compound was characterized to be a five-membered pyrrole derivative with a diverse scope of variations having different types of substituents in the three components respectively.