Copper-Mediated -CF(OCF)(CFH) Transfer to Organic Electrophiles.

The integration of fluorine into medicinal compounds has become a widely used strategy to improve the biochemical and therapeutic properties of drugs. Inclusion of -CFH and -OCF fluoroalkyl groups has garnered attention due to their bioisosteric properties, enhanced lipophilicity, and potential hydrogen-bonding capability in bioactive substances. In this study, we prepared a series of stable Cu[CF(OCF)(CFH)]L complexes by insertion of commercially available perfluoro(methyl vinyl ether), CF=CF(OCF), into Cu-H bonds derived from Stryker's reagent, [CuH(PPh)], using ancillary ligands L.

Distortion Engineering: A Strategy to Modulate Molecular Upconversion with Molecular Cluster-Aggregates.

The rational engineering of molecules is a powerful chemistry tool of pivotal importance in the fields of molecular magnetism and luminescence. Hence, systems that can be modulated via molecular engineering and composition control are expected to present extra versatility regarding the tunability of their properties. This is the case with molecular cluster aggregates (MCAs), high nuclearity molecular compounds.

Electrostatic Surface Potentials and Chalcogen-Bonding Motifs of Substituted 2,1,3-Benzoselenadiazoles Probed via Se Solid-State NMR Spectroscopy.

Chalcogen bonds (ChB) are moderately strong, directional, and specific non-covalent interactions that have garnered substantial interest over the last decades. Specifically, the presence of two σ-holes offers great potential for crystal engineering, catalysis, biochemistry, and molecular sensing. However, ChB applications are currently hampered by a lack of methods to characterize and control chalcogen bonds.

Electron-Triggered Imine Coupling: Synthesis and Characterization of Three Redox States (0,-1,-2) of a Ni(N S ) Complex.

Metal imine-thiolate complexes, M(NS) are known to undergo imine C-C bond formation to give M(N S ) complexes (M=Co, Ni) containing a redox-active ligand. Although these transfor-mations are not typically quantitative, we demonstrate here that the one-electron reduction of a related Ni bis(imine-thiolate) complex affords the corresponding paramagnetic [Ni(N S )] anion (2⋅ ) exclusively; subsequent oxidation with [Cp Fe]BF then affords a high yield of neutral 2 (Cp=η -cyclopentadienyl). Moreover, electrochemical studies indicate that a second one-electron reduction affords the diamagnetic dianion.

Tetrel bond in the triphenyltin(IV) chloride-cyclo-hexyl-diphenyl-phosphane oxide (1/1) cocrystal.

The single-crystal X-ray diffraction structure of the title compound, [SnCl(CH)]·CHOP, is reported. The 1:1 cocrystal features a short and directional tetrel bond between tin and oxygen. The tin-oxygen distance is 2.

P and P Ions Supported by BZIMPY Ligands.

We report a class of compounds in which both P -X and P forms featuring the same ligand are stable and readily cycled with each other. A series of P -X (X=Cl, Br, I) dicationic triflate salts supported by benzyl- and allyl-substituted 2,6-bis(benzimidazole-2-yl)pyridine (BZIMPY) ligands is synthesized. Surprisingly, treatment of these with R PO (R=Et, Oct) results in reduction to BZIMPY-ligated P monocationic triflate salts while treatment with Ph P reduces but also substitutes the compound to produce Ph P-BZIMPY-ligated P dicationic triflate salts.

Tuneable tetrel bonds between tin and heavy pnictogens.

The first example of a binary cocrystal, comprised of SnPhCl and PPh, whose components are organized short and directional tetrel bonds (TtB) between tin and phosphorus, is described. DFT elucidates, for the first time, the factors influencing the strength of TtBs involving heavy pnictogens. A CSD survey reveals that such TtBs are also present and determinative in single component molecular systems, highlighting their significant potential as tuneable structure-directing elements.

Anticooperativity and Competition in Some Cocrystals Featuring Iodine-Nitrogen Halogen Bonds.

Phenomena such as anticooperativity and competition among non-covalent bond donors and acceptors are key considerations when exploring the polymorphic and stoichiomorphic landscapes of binary and higher-order cocrystalline architectures. We describe the preparation of four cocrystals of 1,3,5-trifluoro-2,4,6-triiodobenzene with N-heterocyclic compounds, namely acridine, 3-aminopyridine, 4-methylaminopyridine, and 1,2-di(4-pyridyl)ethane. The cocrystals, which are characterized by single-crystal and powder X-ray diffraction experiments, all show moderately strong and directional iodine⋅⋅⋅nitrogen halogen bonds with reduced distance parameters ranging from 0.

Nickel-Catalyzed Homologation of Vinylidene Difluoride (CH═CF): Selective β-F β-H Elimination.

Hydrofluoroolefins (HFOs) constitute the newest generation of fluorocarbon refrigerants and foam-blowing agents due to their reduced global warming potential their saturated analogues. To identify new synthetic routes to HFOs, we show that reactions of bulky Ni(0) phosphine and -NHC complexes with vinylidene difluoride (VF2) afford μ-fluoro-1,1,3-trifluorobut-3-enyl Ni complexes. Moreover, addition of triisopropylsilane allows for reductive elimination of the reduced product─2,4,4-trifluoro-1-butene─demonstrating the Ni-catalyzed hydrodefluorodimerization of VF2.

1,3,5-Tri-fluoro-2,4,6-tri-iodo-benzene-piperazine (2/1).

The single-crystal structure of the title compound, CHN·2CFI, features a moderately strong halogen bond between one of the three crystallographically distinct iodine atoms and the nitro-gen atom. The iodine-nitro-gen distance is 2.820 (3) Å, corresponding to 80% of the sum of their van der Waals radii.

A cationic -lanthanide MOF enhances the uptake of iodine vapour at room temperature.

The first example of a cationic cluster-based -lanthanide metal-organic framework (MOF) bearing an asymmetric linker, herein named UOTT-4, has been designed and fully characterized. Compared to its rare-earth (RE) anionic counterpart (RE-UiO-66), UOTT-4 was found to significantly improve the performance towards adsorption of iodine vapour at room temperature, opening avenues for the design of the next-generation cationic porous materials for the beneficial uptake and confinement of target molecules.

Se and Te solid-state NMR and X-ray diffraction structural study of chalcogen-bonded 3,4-dicyano-1,2,5-chalcogenodiazole cocrystals.

Three novel chalcogen-bonded cocrystals featuring 3,4-dicyano-1,2,5-selenodiazole (CNSe) or 3,4-dicyano-1,2,5-tellurodiazole (CNTe) as chalcogen-bond donors and hydroquinone (CHO), tetraphenylphosphonium chloride (CHP·Cl) or tetraethylphosphonium chloride (CHP·Cl) as chalcogen-bond acceptors have been prepared and characterized by single-crystal X-ray diffraction (XRD), powder X-ray diffraction and Se/Te magic-angle spinning solid-state NMR spectroscopy. The single-crystal XRD results show that the chalcogenodiazole molecules interact with the electron donors through two σ-holes on each of the chalcogen atoms, which results in highly directional and moderately strong chalcogen bonds. Powder XRD confirms that the crystalline phases are preserved upon moderate grinding of the samples for solid-state NMR experiments.

Reductive 1,2-Arylation of Isatins.

We report an intermolecular Ni-catalyzed reductive coupling of aryl iodides and isatins to form 3-hydroxyoxindoles. In contrast to common metal-mediated methods, -butanol is used as a mild stoichiometric reductant resulting in benign waste products. This formal 1,2-addition reaction is facilitated by a 1,5-diaza-3,7-diphosphacyclooctane (PN) ligand.

Solvent-free Zn (NSNO) complex-catalysed dihydroboration of nitriles.

N-donors are the most commonly employed Lewis bases in ligand-assisted catalysis. A dimeric zinc complex (Zn-1) employing a tetradentate pyridine-thioether-anilido-aryloxide NSNO ligand (L) effects the quantitative conversion of nitriles to the corresponding double hydroborated products at 1 mol% catalyst loading. Variable Time Normalization Analysis kinetic studies showed a first-order dependence with respect to the nitrile, pinacolborane and zinc and clear evidence for catalyst deactivation.

Solid-state multinuclear magnetic resonance and X-ray crystallographic investigation of the phosphorus...iodine halogen bond in a bis(dicyclohexylphenylphosphine)(1,6-diiodoperfluorohexane) cocrystal.

Halogen bonding to phosphorus atoms remains uncommon, with relatively few examples reported in the literature. Here, the preparation and investigation of the cocrystal bis(dicyclohexylphenylphosphine)(1,6-diiodoperfluorohexane) by X-ray crystallography and solid-state multinuclear magnetic resonance spectroscopy is described. The crystal structure features two crystallographically unique C-I.

SNS ligand-assisted catalyst activation in Zn-catalysed carbonyl hydroboration.

Ligands that include Lewis acid/base functionality have extensive applications in bifunctional catalysis using first row metals. In this work, zinc bis(amido), bis(thiolate) and amido-thiolate SNS complexes were prepared and compared as precatalysts for carbonyl hydroboration using pinacolborane. Mechanistic studies revealed two different ligand-assisted precatalyst activation pathways, both leading to an active and robust zinc alkoxide catalyst.

Elucidating Two Distinct Pathways for Electrocatalytic Hydrogen Production Using Co Pincer Complexes.

Hydrogen gas is a sustainable energy source with water as the sole combustion product. As a result, efforts to catalyze H production are pertinent and widespread. The electrocatalytic H generating capabilities of two Co complexes, [Co(κ -2,6-{Ph PNR} (NC H ))Br ] with R=H (I) or R=Me (II), were presented for a variety of proton sources including trifluoroacetic acid (TFA), acetic acid (AA), and trifluoroethanol (TFE).

Electrocatalytic H Generation from Water Relying on Cooperative Ligand Electron Transfer in "PN P" Pincer-Supported Ni Complexes.

Water is the most sustainable source for H production, and the efficient electrocatalytic production of H from mixed water/acetonitrile solutions by using two new air-stable nickel(II) pincer complexes, [Ni(κ -2,6-{Ph PNR} (NC H )Br ] (R=H I, Me II) is reported. Hydrogen generation from H O/CH CN solutions is initiated at -2 V against Fc , and bulk electrocatalysis studies showed that the catalyst functions with an excellent Faradaic efficiency and a turnover frequency of 160 s . A DFT computational investigation of the reduction behavior of I and II revealed a correlation of H formation with charge donation from electrons originating in a reduced ligand-localized orbital.

Nickel(II)-SNS Thiolate Complexes: Reactivity and Solution Dynamics.

Nickel coordination chemistry with a biomimetic thiolate-imine-thioether SNS ligand is accompanied by diverse reactivity and multidentate ligand dynamics. Reaction of Ni(acac) with 2 equiv of 2-(methylthio)-phenyl-benzothiazolidine (MPB) affords the bis(arylimino-phenylene-thiolate) complex Ni(κ-SNS) (; acac = acetylacetonate). Thermolysis of in refluxing toluene is accompanied by imine C-C bond formation, yielding [Ni(NS)] () with a redox-active ligand.

Room-Temperature Upconversion in a Nanosized {Ln} Molecular Cluster-Aggregate.

The successive absorption of low-energy photons to the accumulation of the intermediate excited states leading to higher energy emission is still a challenge in molecular architectures. Contrary to low-phonon solids and nanoparticles, the rational construction of molecular systems containing an excess of donor atoms in relation to acceptor ones is far from trivial. Moreover, the vibrations caused by high-energy oscillators commonly present on coordination compounds result in serious drawbacks on molecular upconversion.

Lanthanide-Based Molecular Cluster-Aggregates: Optical Barcoding and White-Light Emission with Nanosized {Ln } Compounds.

Counterfeit goods represent a major problem to companies, governments, and customers, affecting the global economy. In order to protect the authenticity of products and documents, optical anti-counterfeit technologies have widely been employed via the use of discrete molecular species, extended metal-organic frameworks (MOFs), and nanoparticles. Herein, for the first time we demonstrate the potential use of molecular cluster-aggregates (MCA) as optical barcodes via composition and energy transfer control.

Characterization of Commercial Metal Oxide Nanomaterials: Crystalline Phase, Particle Size and Specific Surface Area.

Physical chemical characterization of nanomaterials is critical to assessing quality control during production, evaluating the impact of material properties on human health and the environment, and developing regulatory frameworks for their use. We have investigated a set of 29 nanomaterials from four metal oxide families (aluminum, copper, titanium and zinc) with a focus on the measurands that are important for the basic characterization of dry nanomaterials and the determination of the dose metrics for nanotoxicology. These include crystalline phase and crystallite size, measured by powder X-ray diffraction, particle shape and size distributions from transmission electron microscopy, and specific surface area, measured by gas adsorption.

Asymmetric Ring Opening in a Tetrazine-Based Ligand Affords a Tetranuclear Opto-Magnetic Ytterbium Complex.

We report the formation of a tetranuclear lanthanide cluster, [Yb (bpzch) (fod) ] (1), which occurs from a serendipitous ring opening of the functionalised tetrazine bridging ligand, bpztz (3,6-dipyrazin-2-yl-1,2,4,5-tetrazine) upon reacting with Yb(fod) (fod =6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octandionate). Compound 1 was structurally elucidated via single-crystal X-ray crystallography and subsequently magnetically and spectroscopically characterised to analyse its magnetisation dynamics and its luminescence behaviour. Computational studies validate the observed M energy levels attained by spectroscopy and provides a clearer picture of the slow relaxation of the magnetisation dynamics and relaxation pathways.

A Barrel-Shaped Metal-Organic Blue-Box Analogue with Photo-/Redox-Switchable Behavior.

Donor-acceptor interactions are ubiquitous in the design and understanding of host-guest complexes. Despite their non-covalent nature, they can readily dictate the self-assembly of complex architectures. Here, a photo-/redox-switchable metal-organic nanocapsule is presented, which was assembled by using lanthanide ions and viologen building blocks, by relying on such donor-acceptor interactions.

Incorporation of a nitrogen-rich energetic ligand in a {Yb} complex exhibiting slow relaxation of the magnetisation under an applied field.

Though often used as the precursor in energetic materials research and organic synthesis, 3,6-dihydrazinyl-1,2,4,5-tetrazine (dhtz) has not been previously explored in coordination chemistry. Herein, we present the first crystalline coordination compound with dhtz, [Yb(dhtz)(fod)] (fod = 6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionate). This compound exhibits Single-Molecule Magnet behaviour under an applied magnetic field, and m states were resolved through luminescence studies.