Here we present the first synthetic route to bis(η 5 :η 1 -pentafulvene)zirconium complexes as well as investigations of several consecutive reactions. Sodium amalgam reduction of ZrCl 4 in the presence of a bulky substituted pentafulvene in THF leads to the formation of [η 5 :η 1 -C 5 H 4  CR 2 ] 2 Zr(THF) (2a, R = p-tol; 2b, R = Ph). The molecular structure of 2a has been determined by single-crystal X-ray diffraction and exhibits an unusually large Zr−C exo distance (2.708(2) Å) caused by the bulky substituents at the exocyclic carbon, which allows THF coordination. The reaction of 2a with H-acidic compounds such as hydrogen chloride, amines, and water were examined: addition of HCl leads to the dichloride complex [η 5 -C 5 H 4 -CH(p-tol) 2 ] 2 ZrCl 2 (3) and treatment of 2a with p-methylaniline forms the bis-amide complex [η 5 -C 5 H 4 -CH(p-tol) 2 ] 2 Zr(NH-p-tol) 2 (4), whereas addition of the sterically more demanding dicyclohexylamine furnishes the monoamide complex [η 5 :η 1 -C 5 H 4 C(p-tol) 2 ][η 5 -C 5 H 4 -CH(p-tol) 2 ]Zr(NCy 2 ) (5). The cyclotrimeric compound {[η 5 -C 5 H 4 -CH(p-tol) 2 ] 2 Zr(μ-O)} 3 (6) is obtained by reaction of 2a with water. Moreover, insertion reactions of CX multiple bonds (X = N, O) into the Zr−C exo (Fv) bond of 2a result in the formation of the zirconacycles [η 5 :η 1 -C 5 H 4 -C(p-tol) 2 -C(C 6 H 4 Cl)N−] 2 Zr (7), [η 5 :η 1 -C 5 H 4 -C(p-tol) 2 -MeC 4 H 6 N−] 2 Zr (8), and [η 5 :η 1 -C 5 H 4 -C(p-tol) 2 -C(Ph) 2 O−] 2 Zr (9). Finally, 2a is a valuable agent for the activation of molecular hydrogen under ambient conditions. In this regard, only one pentafulvene ligand per zirconium atom is protonated and the dinuclear zirconium hydride complex {[η 5 :η 1 -C 5 H 4 C(p-tol) 2 ][η 5 -C 5 H 4 -CH(p-tol) 2 ]Zr(μ-H)} 2 (10) is isolated. All compounds were confirmed by single-crystal X-ray diffraction and NMR spectroscopic measurements.

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It was previously shown that water distributes heterogeneously in deep eutectic solvents (DESs). The aim of this study was to see whether this behavior was common to other hydrogen bonding compounds and determine when a solute formed an emulsion or a homogeneous solution. Pulsed field gradient (PFG) and nuclear Overhauser effect (NOE) NMR, and dynamic light scattering (DLS) are employed to probe the phase behavior of glucose, 1-pentanol and phenol in Ethaline (ethylene glycol: choline chloride, 2:1). By comparing the measured values of self-diffusivities to those calculated assuming Stokesian behavior, it was discovered that glucose forms a homogeneous solution, whereas 1-pentanol forms a heterogeneous mixture. A change in aggregates size of 10 wt% phenol in Ethaline is observed at 313 K. Above 313 K aggregation is enhanced and larger aggregates are formed, suggesting a melting of phenol affects the phase behavior. { 1 H, 1 H}-NOESY NMR showed that glucose interacts strongly with Ethaline whilst with 1-pentanol and phenol this interaction is weaker. DLS experiments further indicated the heterogeneity and homogeneity. Results suggest that solid solutes that are capable of strong hydrogen bonding are soluble in DESs whereas liquid solutes form heterogeneous nanophases due to the weaker solute-solvent interactions and density difference.

Herein we report the reactivity of the proligand tris(2-pyridylthio)methane (HTptm) with various Alkaline Earth (AE) reagents: 1) dialkylmagnesium reagents and 2) AE bis-amides (AE = Mg-Ba). Heteroleptic complexes of general...

There is a need for new conductive, scalable sensors with piezoresistive and thermoresistive properties for applications in bioengineering. For example, the demand for real-time sensory feedback in upper-limb prosthetics requires sensors that are low-cost, scalable, and sensitive to temperature, pressure, and movement. It is possible to manufacture low-cost conductive sensors by directly mixing a low-cost filler such as graphite into fillers such as polyorganosiloxane, although they can have poor electrical and mechanical homogeneity. In this paper, an alternative approach is outlined to form these sensors: ethylene was polymerized using a nickel catalyst to form a polymer with up to 93 branches per 1000 carbon atoms. This branched polyethylene was fibrous and had a greater volume than high-density polyethylene. After hot pressing with a graphite filler to form a conductive, flexible sensor, the polyethylene samples had electrical resistivity down to ≈0.067 𝛀m, a thermal coefficient of resistance ≈−7.5 𝛀 • C −1 at 27 • C, and a electrical resistance sensitive to forces down to 0.1 N. The process is scalable, and provides a route to homogeneous, low-cost sensors for future prosthetics applications.