Synthesis and characterisation of group 8 tris(1-benzyl-1,2,3-triazol-4-yl)-p-anisolylmethane complexes

The tris(1,2,3-triazol-4-yl)methane framework offers a highly versatile architecture for ligand design, yet the coordination chemistry of this class of ligand remains largely unexplored. We report here the synthesis and characterisation of the homoleptic complexes [M(ttzm)₂](PF₆)₂ (ttzm = tris(1-benzyl-1,2,3-triazol-4-yl)-p-anisolylmethane; M = Fe (Fe), Ru (Ru), Os (Os)). Initial attempts to prepare Ru by reaction of [Ru(p-cymene)Cl₂]₂ and ttzm also led to the isolation of the heteroleptic complex [Ru(p-cymene)(ttzm)](PF₆)₂. The structures of [Ru(p-cymene)(ttzm)](PF₆)₂, [Fe(ttzm)₂]²⁺ (as its BPh₄^- salt) and Os were solved by X-ray diffraction. The homoleptic Fe(II) and Os(II) containing cations adopt distorted octahedral geometries due to the steric interactions between the ansiole and triazole rings of the ttzm ligands. The homoleptic complexes all adopt a low-spin d⁶ configuration and exhibit reversible M(II)/M(III) processes (+0.35 to +0.72 V vs. Fc/Fc⁺). These oxidation processes are cathodically shifted relative to those of related hexatriazole donor based complexes with density functional theory (DFT) calculations showing the metal d-orbitals are destabilised through a π-donor contribution from the triazole rings. The complexes all show prominent UV-visible absorption bands between 350 and 450 nm assigned to transitions of ¹MLCT character. Whilst none of the homoleptic complexes are emissive in room temperature fluid solutions, Os is emissive at 77 K in an EtOH/MeOH glass (λ_max 472 nm).

Monodisperse-porous cerium oxide microspheres as a new support with appreciable catalytic activity for a composite catalyst in benzyl alcohol oxidation

Monodisperse porous ceria microspheres as a support with individual catalytic activity, facile post-functionalization and high surface area for heterogeneous catalysis.

Copper-Mediated Synthesis of (E)-1-Azido and (Z)-1,2-Diazido Alkenes from 1-Alkene-1,2-diboronic Esters: An Approach to Mono- and 1,2-Di-(1,2,3-Triazolyl)-Alkenes and Fused Bis-(1,2,3-Triazolo)-Pyrazines

A stereoselective and convenient route has been demonstrated to access (Z)-1,2-diazido alkenes from the corresponding 1,2-diboronic esters via a copper-mediated reaction with sodium azide. Alternately, mono-functionalization was regioselectively carried out with trimethylsilyl azide as an azidation reactant. The in situ conversion of bis-azides to the corresponding bis-triazoles can be readily achieved in the presence of copper sulfate and sodium ascorbate, while the modification of the catalytic system opened a new convenient route to bis-triazolo-pyrazines, a new class of fused heterocycles.

Anion-templated assembly of multinuclear copper(ii)–triazole complexes

Anions were used as templates to construct copper(ii) clusters with different architectures.