Upcycling Polyolefin Blends into High-Performance Materials by Exploiting Azidotriazine Chemistry Using Reactive Extrusion.

The revalorization of incompatible polymer blends is a key obstacle in realizing a circular economy in the plastics industry. Polyolefin waste is particularly challenging because it is difficult to sort into its constituent components. Untreated blends of polyethylene and polypropylene typically exhibit poor mechanical properties that are suitable only for low-value applications.

Rational Design of Mono- and Bi-Nuclear Cyclometalated Ir(III) Complexes Containing Di-Pyridylamine Motifs: Synthesis, Structure, and Luminescent Properties.

Heteroleptic cyclometalated iridium (III) complexes (-) containing di-pyridylamine motifs were prepared in a stepwise fashion. The presence of the di-pyridylamine ligands tunes their electronic and optical properties, generating blue phosphorescent emitters at room temperature. Herein we describe the synthesis of the mononuclear iridium complexes [Ir(ppy)(DPA)][OTf] (), (ppy = phenylpyridine; DPA = Dipyridylamine) and [Ir(ppy)(DPA-PhI)][OTf] (), (DPA-PhI = Dipyridylamino-phenyliodide).

Synthesis of Benzo[][2,7]naphthyridinones and Benzo[][2,6]naphthyridinones via Ruthenium-Catalyzed [2+2+2] Cycloaddition between 1,7-Diynes and Cyanamides.

A convenient method for the ruthenium-catalyzed synthesis of benzo[]naphthyridinone derivatives is reported. The [2+2+2] cycloaddition from various mono- and disubstituted 1,7-diynes and cyanamides provided benzo[][2,7]naphthyridinones as major products and benzo[][2,6]naphthyridinones as minor ones in yields of ≤79% and regioselectivities of ≤99:1. This method is amenable to internal and terminal diynes and a number of cyanamides with diverse functional group tolerance.

Cyclometalated Rhodium and Iridium Complexes Containing Masked Catecholates: Synthesis, Structure, Electrochemistry, and Luminescence Properties.

Two neutral cyclometalated rhodium and iridium coordination assemblies [(F2ppy)M(η-Cat)], M = Rh, () and M = Ir, () (F2ppy: 2,4-difluorophenylpyridine), displaying a masked catecholate (η-Cat = η-O∧O) are described. The catecholate ligand is π-bonded to an organometallic Cp*Ru(II) moiety. The latter brings stability to the whole system in solution and suppresses the formation of the related paramagnetic semiquinone complex.

Enantiopure, luminescent, cyclometalated Ir(III) complexes with N-heterocyclic carbene-naphthalimide chromophore: design, vibrational circular dichroism and TD-DFT calculations.

A series of chiral cyclometalated iridium complexes of the type [Ir(C^N)(C^C:)], {(C^N) = ppy (2); dfppy (3)} featuring a naphthalimide N-heterocyclic carbene ligand (C^C:) = (Naphthalimide-NHC) are described and fully characterized. The racemic complexes -2 and -3 were resolved chiral column chromatography techniques into their corresponding enantiopure species -2, -2, -3, -3 as confirmed by their CD curves. This unique class of molecules containing organic and inorganic chromophores might be used as a platform to probe the stereochemical effect on the photophysical properties.

Highly Efficient Synthesis of Poly(silylether)s: Access to Degradable Polymers from Renewable Resources.

The design of new materials with tunable properties and intrinsic recyclability, derived from biomass under mild conditions, stands as a gold standard in polymer chemistry. Reported herein are platinum complexes which catalyze the formation of poly(silylether)s (PSEs) at low catalyst loadings. These polymers are directly obtained from dual-functional biobased building blocks such as 5-hydroxymethylfurfural (HMF) or vanillin, coupled with various dihydrosilanes.

Silver(I) Oxide-/DBU-Promoted Synthesis of Dihydrofuran Units through Allenyl Silver Formation.

A formal [3+2] cyclization mediated by silver(I) oxide and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) is described herein.

Unique Class of Enantiopure N-Heterocyclic Carbene Half-Sandwich Iridium(III) Complexes with Stable Configurations: Probing Five-Membered versus Six-Membered Iridacycles.

A unique class of enantiopure N-heterocyclic carbene half-sandwich iridium complexes is reported. These compounds display stable configurations at the metal center, as demonstrated by their chiroptical properties. Remarkably, because of the nature of the naphthalimide molecule, two regioisomers containing five-membered [( R)-2a and ( S)-2a] and six-membered [( R)-2b and ( S)-2b] iridacycles were obtained.

Capturing a Square Planar Gold(III) Complex Inside a Platinum Nanocage: A Combined Experimental and Theoretical Study.

A novel synthetic procedure was set up to gain access to platinum coordination cages PtL, which are less investigated compared to their palladium counterparts. This PtL nanocage exhibits an adequate cavity for guest encapsulation. Indeed, the Au(III) metal complex [Au(bdt)] (bdt = benzene-1,2-dithiolate) was successfully captured inside the cavity, in contrast to the analogous palladium cage which failed to host the gold complex.

Cyclometalated N-heterocyclic carbene iridium(iii) complexes with naphthalimide chromophores: a novel class of phosphorescent heteroleptic compounds.

A series of cyclometalated N-heterocyclic carbene complexes of the general formula [Ir(C^N)(C^C:)] has been prepared. Two sets of compounds were designed, those where (C^C:) represents a bidentate naphthalimide-substituted imidazolylidene ligand and (C^N) = ppy (3a), F2ppy (4a), bzq (5a) and those where (C^C:) represents a naphthalimide-substituted benzimidazolylidene ligand and (C^N) = ppy (3b), F2ppy (4b), bzq (5b). The naphthalimide-imidazole and naphthalimide-benzimidazole ligands 1a,b and the related imidazolium and benzimidazolium salts 2a,b were also prepared and fully characterized.

Mechanistic Aspects of the Polymerization of Lactide Using a Highly Efficient Aluminum(III) Catalytic System.

We report here a unique example of an in situ generated aluminum initiator stabilized by a C-symmetric salen ligand which shows a hitherto unknown high activity for the ROP of rac-lactide at room temperature. Using a simple and robust catalyst system, which is prepared from a salen complex and an onium salt, this convenient route employs readily available reagents that afford polylactide in good yields with narrow polydispersity indices, without the need for time-consuming and expensive processes that are typically required for catalyst preparation and purification. In line with the experimental evidence, DFT studies reveal that initiation and propagation proceed via an external alkoxide attack on the coordinated monomer.

Encapsulation of a metal complex within a self-assembled nanocage: synergy effects, molecular structures, and density functional theory calculations.

A novel palladium-based metallacage was self-assembled. This nanocage displayed two complementary effects that operate in synergy for guest encapsulation. Indeed, a metal complex, [Pt(NO2)4](2-), was hosted inside the cavity, as demonstrated by solution NMR studies.

Zinc and cobalt complexes based on tripodal ligands: synthesis, structure and reactivity toward lactide.

The coordination chemistry of a series of pro-ligands ([L¹]-[L⁶]) with cobalt and zinc derivatives has been studied. All complexes have been characterized by multinuclear NMR, elemental analysis, and by single-crystal X-ray diffraction studies. Polymerization of rac-lactide takes place at 130 °C in the presence of cobalt and zinc complexes to yield polymers under solvent free conditions with controlled molecular masses and narrow polydispersities.

Self-Assembled M₂L₄ Nanocapsules: Synthesis, Structure and Host-Guest Recognition Toward Square Planar Metal Complexes.

Metallosupramolecular cages of the general formulas [M₂(L)₄][X]₄ can be self-assembled in good yields, where M = Pd, X = NO₃, L = (); M = Pd, X = OTf, L = (); M = Pt, X = OTf, L = (); M = Pd, X = OTf, L = (); = 1,3-bis(pyridin-3-ylethynyl)-5-methoxybenzene; and = 2,6-(pyridin-3-ylethynyl)- 4-methoxyaniline, respectively. These cages have been fully characterized using ¹H, C NMR, elemental analysis, IR spectroscopy, and electrospray mass spectrometry. Additionally the molecular structure of [Pd₂()₄][OTf]₄ () was confirmed using single crystal X-ray diffraction.

Near-infrared room temperature emission from a novel class of Ru(II) heteroleptic complexes with quinonoid organometallic linker.

A novel class of luminescent octahedral ruthenium complexes 2-4 displaying a π-bonded quinonoid ligand is described. Remarkably, the presence of this organometallic ligand affects their UV-vis properties and transforms them into panchromatic absorbers. Furthermore, it turns on room temperature NIR emissions.

Polymersomes with PEG corona: structural changes and controlled release induced by temperature variation.

Thermoresponsive behavior of different kinds of polymersomes was studied using small angle neutron scattering (SANS), transmission electron microscopy (TEM), and proton nuclear magnetic resonance ((1)H NMR). The polymersomes were made of block copolymers containing a 2000 Da polyethylene glycol (PEG) as a hydrophilic block and either a liquidlike polymer (e.g.

The design, synthesis and photochemical study of a biomimetic cyclodextrin model of photoactive yellow protein (PYP).

The design, synthesis and study of the photophysical and photochemical properties of the first biomimetic cyclodextrin (CD) model of photoactive yellow protein (PYP) are described. This model bears a deprotonated trans-p-coumaric acid chromophore, covalently linked via a cysteine moiety to a permethylated 6-monoamino β-CD. NMR and UV/Visible spectroscopy studies showed the formation of strong self-inclusion complexes in water at basic pH.

Synthetic and mechanistic pathways of cis and trans-hydroxytamoxifen drug derivatives reacting with Cp*Rh complexes that involve η1-N, η2-N,O, η1-O, and η6 bonding modes, via a novel N-π rearrangement; relative binding affinities and computer docking studies of cis and trans-η6-Cp*Rh-hydroxytamoxifen complexes at the estrogen, ERα and ERβ receptors, and growth inhibition to breast cancer cells.

The reactions of the breast cancer drug metabolite derivatives of tamoxifen, cis and trans-hydroxytamoxifen, cis-1 and trans-2, with [Cp*Rh(L)(3)](2+) complexes (L = H(2)O or MeOH), in CH(2)Cl(2) and CH(3)OH solvents, initially provided the kinetic η(1)-N complexes, cis-4 (OTf(-), CH(3)OH) and trans-5 (OTf(-), CH(3)OH), which underwent a novel, regioselective, intramolecular N-π rearrangement to give the cis and trans-η(6)-phenol substituted complexes, cis-6 and trans-7, via η(2)-N,O, η(1)-O, and ether aromatic ring η(6) intermediates. Recent density functional theory (DFT) calculations showed a preferred ground state for η(1)-N; η(2)-N,O; η(1)-O; and the η(6) complexes, including the prominent roles of the triflate anion (OTf(-)), and solvent molecules (CH(2)Cl(2) and CH(3)OH), and provided further steric, electronic, and thermodynamic data on the mechanism of the N-π rearrangement. The η(6) complex, cis-6, was shown to be an antagonist for ERα estrogen receptor binding, in a competition experiment with the female hormone, estradiol; therefore, computer docking studies of this biologically active complex at the estrogen receptors, ERα and ERβ, also provided information on the binding modes and thermodynamic parameters, while bioassay results provided growth inhibition data on both hormone dependent and independent breast cancer cell lines.

Chiral octahedral bimetallic assemblies with Δ-TRISPHAT as counter anion: design, anion metathesis, and Cp*Ir as a probe for chiral recognition.

The chiral octahedral bimetallic assemblies [(bpy)(2)Ru(o-L(Ir))][CF(3)SO(3)](2) (2), [(ppy)(2)Rh(o-L(Ir))][NO(3)] (7) and [(ppy)(2)Ir(o-L(Ir))][NO(3)] (8) featuring chelating organometallic linker [Cp*Ir(η(4)-o-benzoquinone)] (o-L(Ir)) have been prepared and fully characterized. Anion metathesis following a convenient procedure allowed the preparation of the related diastereomers [Δ-(bpy)(2)Ru(o-L(Ir))][Δ-TRISPHAT](2) (2a) and [Λ-(bpy)(2)Ru(o-L(Ir))][Δ-TRISPHAT](2) (2b) as well as the octahedral rhodium [(Δ, Λ)-(ppy)(2)Rh(o-L(Ir))][Δ-TRISPHAT] (7a, 7b) and iridium [(Δ, Λ)-(ppy)(2)Ir(o-L(Ir))][Δ-TRISPHAT] (8a, 8b) bimetallic assemblies. (1)H NMR studies in solution carried out on these compounds showed different behavior.

Multimodal study of secondary interactions in Cp*Ir complexes of imidazolylphosphines bearing an NH group.

Hydrogen bonding phenomena are explored using a combination of X-ray diffraction, NMR and IR spectroscopy, and DFT calculations. Three imidazolylphosphines R(2)PImH (ImH = imidazol-2-yl, R = t-butyl, i-propyl, phenyl, 1a-1c) and control phosphine (i-Pr)(2)PhP (1d) lacking an imidazole were used to make a series of complexes of the form Cp*Ir(L(1))(L(2))(phosphine). In addition, in order to suppress intermolecular interactions with either imidazole nitrogen, 1e, a di(isopropyl)imidazolyl analogue of 1b was made along with its doubly (15)N-labeled isotopomer to explore bonding interactions at each imidazole nitrogen.

Muscle transfection and permeabilization induced by electrotransfer or pluronic L64: Paired study by optical imaging and MRI.

Background: Muscle transfection by electrotranfer is an efficient currently used procedure. Recently, the block copolymer pluronic L64 has been reported to improve muscle transfection. Both procedures are known to permeabilize muscle fibres.

Braunicetals: acetals from condensation of macrocyclic aldehydes and terpene diols in Botryococcus braunii.

Two series of braunicetals were isolated from the green microalga Botryococcus braunii. Based on spectroscopic and chemical evidence, their structures were determined to be acetals formed by the condensation of C32 and C34 macrocyclic aldehydes with C33 and C34 methylated squalene diols (series I), or a C40 lycopaene diol (series II).

Supramolecular cobalt cages and coordination polymers templated by anion guests: self-assembly, structures, and magnetic properties.

We report the anion-templated syntheses of a variety of supramolecular assemblies of Co(II). Remarkably in the presence of a weakly coordinating ion such as BF(4) (-), a discrete three-dimensional cage [BF(4) subset(BF(4))(2)Co(2)(L(1))(4)][BF(4)] (2) is formed with three coordinated BF(4) (-) ions, a rare example in supramolecular chemistry (L(1)=di(benzimidazole)-1,4-phenylene). Switching to stronger coordinating ions, such as NO(3) (-) or Cl(-), a one-dimensional coordination polymer [[Co(L(1))(NO(3))(2)](n)] (3) and a metallomacrocycle [Co(2)(L(1))(2)(Cl)(4)] (5) were formed, respectively.

Insights into the binding properties of a cuprous ion embedded in the tren cap of a calix[6]arene and supramolecular trapping of an intermediate.

Coordination of Cu(I) to a tren unit that is covalently linked to a calix[6]arene has been explored. The resulting complex revealed itself very stable in solution under an inert atmosphere, but extremely sensitive to O2 in solution as well as in the solid state. Therefore, its binding properties towards non-redox ligands have been studied in detail.