From Terminal to Spiro-Phosphonium Acceptors, Remarkable Moieties to Develop Polyaromatic NIR Dyes.

Phosphonium-based compounds gain attention as promising photofunctional materials. As a contribution to the emerging field, we present a series of donor-acceptor ionic dyes, which were constructed by tailoring phosphonium (A) and extended π-NR (D) fragments to an anthracene framework. The alteration of the π-spacer of electron-donating substituents in species with terminal - PPh Me groups exhibits a long absorption wavelength up to λ =527 nm in dichloromethane and shifted the emission to the near-infrared (NIR) region (λ=805 nm for thienyl aniline donor), although at low quantum yield (Φ<0.

Improved synthetic routes to -heterocyclic carbene-metal-diketonato complexes of gold and copper.

In our search for simple synthetic routes to -heterocyclic carbene (NHC)-metal complexes and their derivatives, we herein report an operationally simple, expedient and scalable method to obtain the widely used NHC-metal-diketonates. The reported complexes are synthesized for the first time under mild, aerobic conditions and in excellent yields in a sustainable manner. The protocol is general with regards to the anionic co-ligand and the ancillary carbene ligands.

Synthesis of Carbene-Metal-Amido (CMA) Complexes and Their Use as Precatalysts for the Activator-Free, Gold-Catalyzed Addition of Carboxylic Acids to Alkynes.

A straightforward synthetic protocol leading to carbene-metal-amido (CMA) complexes (metal=Au, Cu) using a mild base and an environmentally desirable solvent (EtOH) has been explored, with a focus on complexes bearing backbone-substituted N-heterocyclic carbene (NHC) ligands, including BIAN-NHCs (BIAN=bis(imino)acenaphthene). The novel CMAs were structurally characterized, and gold-based CMAs bearing diverse NHCs were screened as simple, Brønsted-basic precatalysts. The readily accessible complexes display high catalytic activity in the intermolecular and intramolecular hydrocarboxylation of internal alkynes and alkynoic acids respectively, while the screening reveals the ancillary ligand effect of NHCs in these catalytic systems.

A green route to platinum N-heterocyclic carbene complexes: mechanism and expanded scope.

A sustainable and facile weak-base synthetic route to platinum N-heterocyclic carbene (NHC) complexes is disclosed. The mechanism of this reaction is also elucidated experimental and computational investigations. This straightforward protocol is then used for the synthesis of novel Pt(II)-NHC complexes and its utility is further explored to access key Pt(0)-NHC precatalysts.