Enhanced cytotoxicity of silver complexes bearing bidentate N-heterocyclic carbene ligands

A diverse library of cationic silver complexes bearing bis(N-heterocyclic carbene) ligands have been prepared which exhibit cytotoxicity comparable to cisplatin against the adenocarcinomas MCF7 and DLD1. Bidentate ligands show enhanced cytotoxicity over monodentate and macrocyclic ligands

Correction: Metal complexes as a promising source for new antibiotics

Correction for ‘Metal complexes as a promising source for new antibiotics’ by Angelo Frei et al., Chem. Sci., 2020, 11, 2627–2639

Mechanistic Elucidation of the Arylation of Non-Spectator N-Heterocyclic Carbenes at Copper Using a Combined Experimental and Computational Approach

CuI(NHC)Br complexes (NHC = N-heterocyclic carbene) undergo a direct reaction with iodobenzene to give 2-arylated benzimidazolium products. The nature of the N-substituent on the NHC ligand influences the reactivity of the CuI(NHC)Br complex toward arylation. N-Benzyl or N-phenyl substituents facilitate arylation, whereas N-mesityl substituents hinder arylation. Density functional theory calculations show that an oxidative addition/reductive elimination pathway involving CuIII species is energetically feasible. A less hindered CuI(NHC)Br complex with N-benzyl groups is susceptible to oxidation reactions to give 1,3-dibenzylbenzimidazolium cations containing a CuIBr anion (various polymorphs). The results described herein are of relevance to C–H functionalization of (benz)azoles

Mechanistic Elucidation of the Arylation of Non-Spectator N-Heterocyclic Carbenes at Copper using a Combined Experimental and Computational Approach

CuI(NHC)Br complexes (NHC = N-heterocyclic carbene) undergo a direct reaction with iodobenzene to give 2-arylated benzimidazolium products. The nature of the Nsubstituent on the NHC ligand influences the reactivity of the CuI(NHC)Br complex towards arylation. N-Benzyl or Nphenyl substituents facilitate arylation, whereas N-mesityl substituents hinder arylation. Density functional theory calculations show that an oxidative addition/reductive elimination pathway, involving CuIII species, is energetically feasible. A less hindered CuI(NHC)Br complex, with N-benzyl groups, is susceptible to oxidation reactions to give 1,3- dibenzylbenzimidazolium cations containing a CuIBrx anion (various polymorphs). The results described herein are of relevance to C-H functionalization of benz(azoles)

XSED - XML-Based Description of Status - Event Components and Systems

Most user interfaces and ubiquitous systems are built around event-based paradigms. Previous work has argued that interfaces, especially those heavily depending on context or continuous data from sensors, should also give attention to status phenomena – that is continuously available signals and state. Focusing on both status and event phenomena has advantages in terms of adequacy of description and efficiency of execution. This paper describes a collection of XML-based specification notations (called XSED) for describing, implementing and optimising systems that take account of this dual status–event nature of the real world. These notations cover individual components, system configuration, and separated temporal annotations. Our work also presents a implementation to generate Status-Event Components that can run in a stand-alone test environment. They can also be wrapped into a Java Bean to interoperate with other software infrastructure, particularly the ECT platform

Electrochemical Synthesis of a Tetradentate Copper N-Heterocyclic Carbene Calix[4]arene and Its Transmetalation to Palladium: Activity of the Palladium Complex in Suzuki–Miyaura Cross-Coupling

A novel N-heterocyclic carbene 1,3-alternate calix[4]arene complex bearing four palladium(II) centers per ligand has been prepared. Electrochemical synthetic methods were used to prepare the corresponding copper(I) complex, followed by transmetalation onto palladium(II). The activity of the palladium complex was probed in the Suzuki-Miyaura cross-coupling reaction. An inverse correlation between palladium concentration and activity was observed, with the results indicating that calix[4]arenes in the cone conformation may reduce the aggregation of palladium(0) nanoclusters, whereas our 1,3-alternate calix[4]arene does not provide any supramolecular stabilizing effect.</p