Functionalizing Thiosemicarbazones for Covalent Conjugation.

Thiosemicarbazones (TSCs) with their modular character (thiosemicarbazides + carbonyl compound) allow broad variation of up to four substituents on the main RRC=N(1)-NH-C(S)-N(4)RR core and are thus interesting tools for the formation of conjugates or the functionalization of nanoparticles (NPs). In this work, di-2-pyridyl ketone was introduced for the coordination of metals and 9-anthraldehyde for luminescence as R and R to TSCs. R and R substituents were varied for the formation of conjugates.

Assessing the Character of the CF Ligand from the Electrochemical and Photophysical Properties of [Ni(CF)(NN)] Complexes.

Organonickel complexes containing α-diimine ligands [Ni(CF)(NN)] (NN = 2,2'-bipyridine (bpy), 2,9-dimethyl-1,10-phenanthroline (dmphen), 3,4,7,8-tetramethyl-1,10-phenanthroline (tmphen), dipyrido[3,2-:2',3'-]phenazine (dppz), 1,4-bis(isopropyl)-1,4-diazabutadiene (Pr-DAB), and 1,4-bis(2,6-dimethylphenyl)-1,4-diazabutadiene (Xyl-DAB) were prepared and studied structurally, spectroscopically, and electrochemically. Their molecular structures from single-crystal X-ray diffraction show near-perfect square planar Ni(II) coordination except in the case of dmphen. Primary reversible electrochemical reductions in the range from -1 to -2 V vs ferrocene/ferrocenium couple lead to mainly diimine-localized radical anion complexes, while secondary reductions in the range from -2 to -2.

Nickel Perfluoroalkyl Complexes Supported by Simple Acetate Coligands.

The interaction of tetramethylammonium acetate with [(MeCN)Ni(CF)], [(MeCN)Ni(CF)], and [NMe][(MeCN)Ni(CF)] was explored by F NMR spectroscopy. We show that depending on the nature of the nickel complex, one or two acetate ligands can add to the metal center and replace the nickel-bound MeCN ligands, depending on the acetate concentration. The number of acetates that could bind to nickel, and whether the resulting complex exists as a monomer or dimer, was determined to be dependent on the nature of the fluoroalkyl ligand.

Multi-Component Syntheses of Spiro[furan-2,3'-indoline]-3-carboxylate Derivatives Using Ionic Liquid Catalysts.

Two previously described Brønsted acidic ionic liquids, 3,3'-(1,6-hexanediyl)bis(1-methyl)-1-imidazolium hydrogen sulfate () and 1,1'-(1,6-hexanediyl)bis(pyridinium) hydrogen sulfate (), were used as catalysts for the preparation of spiro[furan-2,3'-indoline]-3-carboxylate derivatives via a three-component reaction of anilines, isatins (-alkyl-indoline-2,3-diones), and diethyl acetylenedicarboxylate, in high yields. The use of ultrasonic (US) irradiation led to the targeted products (-) in high yields ranging from 80% to 98%. Under the same conditions, the use of sulfuric acid and acetic acid as a Brønstedt catalyst did not yield the desired benchmark product .

Cyanido-bridged diplatinum(ii) complexes: ligand and solvent effect on aggregation and luminescence.

The association of platinum(ii)-based luminophores, which is caused by metal⋯metal and π-π stacking interactions, has been actively exploited in supramolecular construction of photofunctional molecular materials. Herein, we describe a series of bimetallic complexes [{Pt(C^N^*N)}(CN)][BAr], containing cyanido-bridged cyclometalated Pt(ii) chromophore fragments (HC^N^N = 6-phenyl-2,2'-bipyridine, (benzyltriazolyl)-phenylpyridine, and pyrazolyl-phenylpyridine; HC^N*N = -pentyl-6-phenyl--(pyridin-2-yl)pyridin-2-amine; ^/* denote five/six-membered metallocycles). These compounds are intensely phosphorescent at room temperature showing quantum yields up to 0.

Polyethylenimine Grafted onto Nano-NiFeO@SiO for the Removal of CrO, Ni, and Pb Ions from Aqueous Solutions.

Polyethyleneimine (PEI) has been reported to have good potential for the adsorption of metal ions. In this work, PEI was covalently bound to NiFeO@SiO nanoparticles to form the new adsorbent NiFeO@SiO-PEI. The material allowed for magnetic separation and was characterized via powder X-ray diffraction (PXRD), showing the pattern of the NiFeO core and an amorphous shell.

Enhanced luminescence properties through heavy ancillary ligands in [Pt(C^N^C)(L)] complexes, L = AsPh and SbPh.

In the frame of our research aiming to develop efficient triplet-emitting materials, we are exploring the concept of introducing additional heavy atoms into cyclometalated transition metal complexes to enhance intersystem-crossing (ISC) and thus triplet emission through increased spin-orbit coupling (SOC). In an in-depth proof-of-principle study we investigated the double cyclometalated Pt(II) complexes [Pt(C^N^C)(PnPh)] (HC^N^CH = 2,6-diphenyl-pyridine (Hdpp) or dibenzoacridine (Hdba); Pn = pnictogen atoms P, As, Sb, or Bi) through a combined experimental and theoretical approach. The derivatives containing Pn = P, As, and Sb were synthesised and characterised comprehensively using single crystal X-ray diffraction (scXRD), UV-vis absorption and emission spectroscopy, transient absorption (TA) spectroscopy and cyclic voltammetry (CV).

A Sulfonic Acid Polyvinyl Pyridinium Ionic Liquid Catalyzes the Multi-Component Synthesis of Spiro-indoline-3,5'-pyrano[2,3-]-pyrimidines and -Pyrazines.

A sulfonated poly-4-vinyl pyridinium (PVPy-IL-B-SOH) containing an acidic pyridinium/HSO ionic liquid moiety was prepared and used as a catalyst for the three-component reaction of malononitrile with 1-alkylindoline-2,3-diones and 1,3-dimethylpyrimidine-2,4,6(1,3,5)-trione or methyl 5-hydroxy-1-pyrazole-3-carboxylate, leading to methyl 6'-amino-5'-cyano-2-oxo-2'-spiro[indoline-3,4'-pyrano[2,3-]pyrazole]-3'-carboxylates or -3,4'-pyrano[2,3-]pyrimidine]-6'-carbonitrile derivatives under ultrasonic irradiation conditions. The solid catalyst allows easy separation, is cheap, produces high yields under mild conditions, and does not require column chromatography for product isolation and purification.

Structure, Optical and Magnetic Properties of Two Isomeric 2-Bromomethylpyridine Cu(II) Complexes [Cu(CHNBr)(NO)] with Very Different Binding Motives.

Two isomeric 2-bromomethylpyridine Cu(II) complexes [Cu(CHNBr)(NO)] with 2-bromo-5-methylpyridine (L) and 2-bromo-4-methylpyridine (L) were synthesized as air-stable blue materials in good yields. The crystal structures were different with [Cu(L)(NO)] () crystallizing in the monoclinic space group 2/c, while the 4-methyl derivative was solved and refined in triclinic 1¯. The orientation of the Br substituents in the molecular structure ( () vs.

Structural insight into halide-coordinated [FeSXY] clusters (X, Y = Cl, Br, I) by XRD and Mössbauer spectroscopy.

Iron sulphur halide clusters [FeSBr] and [FeSXY] (X, Y = Cl, Br, I) were obtained in excellent yields (77 to 78%) and purity from [Fe(CO)], elemental sulphur, I and benzyltrimethylammonium (BTMA) iodide, bromide and chloride. Single crystals of (BTMA)[FeSBr] (1), (BTMA)[FeSBrCl] (2), (BTMA)[FeSClI] (3), and (BTMA)[FeSBrI] (4) were isostructural to the previously reported (BTMA)[FeSI] (5) (monoclinic, ). Instead of the chloride cubane cluster [FeSCl], we found the prismane-shaped cluster (BTMA)[FeSCl] (6) (1̄).

Rhenium Tricarbonyl Complexes of Azodicarboxylate Ligands.

The excellent π-accepting azodicarboxylic esters adcOR (R = Et, Pr, Bu, Bn (CH-CH) and Ph) and the piperidinyl amide derivative adcpip were used as bridging chelate ligands in dinuclear Re(CO) complexes [{Re(CO)Cl}(µ-adcOR)] and [{Re(CO)Cl}(µ-adcpip)]. From the adcpip ligand the mononuclear derivatives [Re(CO)Cl(adcpip)] and [Re(CO)(PPh)(µ-adcpip)]Cl were also obtained. Optimised geometries from density functional theory (DFT) calculations show and isomers for the dinuclear -Re(CO) complexes at slightly different energies but they were not distinguishable from experimental IR or UV-Vis absorption spectroscopy.

Triplet Emitting C^N^C Cyclometalated Dibenzo[c,h]Acridine Pt(II) Complexes.

In a series of Pt(II) complexes [Pt(dba)(L)] containing the very rigid, dianionic, bis-cyclometalating, tridentate C^N^C2− heterocyclic ligand dba2− (H2dba = dibenzo[c,h]acridine), the coligand (ancillary ligand) L = dmso, PPh3, CNtBu and Me2Imd (N,N’-dimethylimidazolydene) was varied in order to improve its luminescence properties. Beginning with the previously reported dmso complex, we synthesized the PPh3, CNtBu and Me2Imd derivatives and characterized them by elemental analysis, 1H (and 31P) NMR spectroscopy and MS. Cyclic voltammetry showed partially reversible reduction waves ranging between −1.

From energy to electron transfer photocatalysis (PenT → PET): oxidative cyclobutane cleavage alters the product composition.

Photocatalytic [2+2]-cycloadditions between cyclic enones and electron-rich cyclic enol ethers are initiated by triplet-triplet energy transfer from an excited iridium photocatalyst to the enone acceptor. The composition of the resulting cycloadduct mixture shows a surprising time dependency of the cyclobutane stereoisomeric ratio which indicates that the products are not photostable under the reaction conditions. The isomerisation of the cycloadducts 3 by a photoinduced redox process points to a switch from triplet energy transfer (PenT) to photoinduced electron transfer (PET) catalysis.

Photophysical Study on the Rigid Pt(II) Complex [Pt(naphen)(Cl)] (Hnaphen = Naphtho[1,2-][1,10]Phenanthroline and Derivatives.

The electrochemistry and photophysics of the Pt(II) complexes [Pt(naphen)(X)] (Hnaphen = naphtho[1,2-][1,10]phenanthroline, X = Cl or C≡CPh) containing the rigid tridentate -coordinating pericyclic naphen ligand was studied alongside the complexes of the tetrahydro-derivative [Pt(thnaphen)(X)] (Hthnaphen = 5,6,8,9-tetrahydro-naphtho[1,2-][1,10]phenanthroline) and the -coordinated complex [Pt(bdq)(Cl)] (Hbdq = benzo[1,2-:5,4-']diquinoline. The cyclic voltammetry showed reversible reductions for the complexes, with markedly fewer negative potentials (around -1.6 V vs.

Next Generation Copper Mediators for the Efficient Production of F-Labeled Aromatics.

Cu-mediated radiofluorination is a versatile tool for the preparation of F-labeled (hetero)aromatics. In this work, we systematically evaluated a series of complexes and identified several generally applicable mediators for highly efficient radiofluorination of aryl boronic and stannyl substrates. Utilization of these mediators in nBuOH/DMI or DMI significantly improved F-labeling yields despite use of lower precursor amounts.

Isoelectronic Pt(II) complexes of cyclometalating C^N^N ligands with phenyl/(benzo)thiophenyl and pyridyl/(benzo)thiazolyl moieties.

A series of cyclometalated Pt(II) complexes [Pt(C^N^N)X] (X = Cl, CCPh, CCCF) was synthesised from the protoligands HC^N^N containing either phenyl (ph), naphthyl (na) or (benzo)thiophenyl (b(th)) functions and either pyridyl (py) or (benzo)thiazolyl ((b)tz) units, alongside the central 4-phenyl-pyridyl (ppy) or Bu-phenyl-pyridyl (tbppy) group. Depending on the combination of the or building blocks, these square planar complexes reveal very different electrochemical, UV-vis absorption and emission behaviour. The reversible reductions shift anodically along the series th/py < ph/tz ≈ th/tz < ph/btz while the irreversible oxidations shift cathodically along the series Cl ≈ CCCF < CCPh.

Awakening a Molecular Mummy: The Inter-and Intramolecular Photochemistry of Pyromellitic Diimides with Alkyl Carboxylates.

Pyromellitic acid diimides are not as chemically unreactive as conjecturable (and presupposed) from their numerous applications as electron acceptor units or electron carriers in molecular donor-acceptor dyads or triads. Similar to the corresponding phthalimides, electronically excited pyromellitic diimides oxidize alkyl carboxylates in aqueous solution via intermolecular electron transfer (PET) processes, which eventually results in radical-radical combination products, e.g.

Synthesis, structure, and electrochemical properties of [LNi(R)(CF)] and [LNi(R)] complexes.

The new anionic nickelate complexes [(MeCN)Ni(CF)(CF)], [(MeCN)Ni(CF)(CF)], [(IMes)Ni(CF)(CF)], [(IMes)Ni(CF)] (IMes = 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene), and [(F-NHC)Ni(R)] (F-NHC = 1,3-bis(2,4-FPh), 2,4,6-FPh- or 3,4,5-FPh)imidazol-2-ylidene; (R = CF or CF) were synthesized and structurally characterized. The electrochemical properties of all new compounds were revealed by cyclic voltammetry studies and compared to the known CF analogue [(MeCN)Ni(CF)]. The IMes-coordinated complexes exhibited initial oxidation events that were well-separated from a second oxidation process in the cyclic voltammograms.

CO to CO Electroreduction, Electrocatalytic H Evolution, and Catalytic Degradation of Organic Dyes Using a Co(II) -Tetraarylporphyrin.

The -tetrakis(4-(trifluoromethyl)phenyl)porphyrinato cobalt(II) complex [Co(TMFPP)] was synthesised in 93% yield. The compound was studied by H NMR, UV-visible absorption, and photoluminescence spectroscopy. The optical band gap g was calculated to 2.

Heterobimetallic uranyl(VI) alkoxides of lanthanoids: formation through simple ligand exchange.

Lanthanoid and actinoid silylamides are versatile starting materials. Herein we show how a simple ligand exchange with -butanol leads to the formation of the first trimeric heterobimetallic uranyl(VI)-lanthanoid(III) alkoxide complexes. The coordination of the endogenous uranyl oxo atom results in a significant elongation of the bond length and a significant deviation from the linear uranyl arrangement.

Ammonium Pertechnetate in Mixtures of Trifluoromethanesulfonic Acid and Trifluoromethanesulfonic Anhydride.

Ammonium pertechnetate reacts in mixtures of trifluoromethanesulfonic anhydride and trifluoromethanesulfonic acid under final formation of ammonium pentakis(trifluoromethanesulfonato)oxidotechnetate(V), (NH ) [TcO(OTf) ]. The reaction proceeds only at exact concentrations and under the exclusion of air and moisture via pertechnetyl trifluoromethanesulfonate, [TcO (OTf)], and intermediate Tc species. Tc nuclear magnetic resonance (NMR) has been used to study the Tc compound and electron paramagnetic resonance (EPR), Tc NMR and X-ray absorption near-edge structure (XANES) experiments indicate the presence of the reduced technetium species.

Photoluminescence of Ni(II), Pd(II), and Pt(II) Complexes [M(Medpb)Cl] Obtained from C‒H Activation of 1,5-Di(2-pyridyl)-2,4-dimethylbenzene (MedpbH).

The three complexes [M(Medpb)Cl] (M = Ni, Pd, Pt) containing the tridentate ,,-cyclometalating 3,5-dimethyl-1,5-dipyridyl-phenide ligand (Medpb) were synthesised using a base-assisted C‒H activation method. Oxidation potentials from cyclic voltammetry increased along the series Pt < Ni < Pd from 0.15 to 0.

Encapsulation and Release of Doxorubicin from TiO Nanotubes: Experiment, Density Functional Theory Calculations, and Molecular Dynamics Simulation.

Titanium dioxide (TiO) nanotubes are attractive materials for drug-delivery systems because of their biocompatibility, chemical stability, and simple preparation. In this study, we loaded TiO nanotubes with anticancer drug doxorubicin (DOX) experimentally and in all-atom molecular dynamics (MD) simulations. The release of doxorubicin from the nanotubes was studied by high-performance liquid chromatography (HPLC) and confocal Raman spectroscopy, and drug-release profiles were evaluated under various conditions.

25th Anniversary of Molecules-Recent Advances in Inorganic Chemistry.

Celebrating the "25th Anniversary of Molecules" with a Special Issue dedicated to "Recent Advances in Inorganic Chemistry" strengthens the renewed role that inorganic chemistry, one of the oldest chemistry divisions, has lately earned thanks to cutting-edge perspectives and interdisciplinary applications, eventually receiving the veneration and respect which its age might require [...