ABSTRACT
A new generation of N-heterocyclic carbene palladium(II) complexes containing vinyl groups in different positions in the backbone of the N-heterocycle have been developed. The fully characterised monomers were copolymerised with divinylbenzene to fabricate robust polymer supported NHC-PdII complexes and these polymers were applied as heterogeneous catalysts in directed C-H halogenation of arenes with a pyridine-type directing group. The catalysts demonstrated medium-high catalytic activity with up to 90 % conversion and 100 % selectivity in chlorination. They are heterogeneous and recyclable (at least six times) with no significant leaching of palladium in batch mode catalysis. The best catalyst was also applied under continuous flow conditions where it disclosed an exceptional activity (90 % conversion) and 100 % selectivity for the mono-halogenated product for at least six days, with no leaching of palladium, no loss of activity and an ability to maintain the original oxidation state of PdII .
ABSTRACT
Rapid development of new microscopy techniques exposed the need for genetically encoded fluorescent tags with special properties. Recent works demonstrated the potential of fluorescent proteins with tryptophan-based chromophores. We applied rational design and random mutagenesis to the monomeric red fluorescent protein FusionRed and found two groups of mutants carrying a tryptophan-based chromophore: with yellow (535 nm) or orange (565 nm) emission. On the basis of the properties of proteins, a model synthetic chromophore, and a computational modeling, we concluded that the presence of a ketone-containing chromophore in different isomeric forms can explain the observed yellow and orange phenotypes.
Subject(s)
Fluorescent Dyes/chemistry , Luminescent Proteins/chemistry , Luminescent Proteins/genetics , Staining and Labeling/methods , Tryptophan/chemistry , Color , Computer Simulation , Fluorescent Dyes/chemical synthesis , Hydrogen-Ion Concentration , Ketones/chemistry , Molecular Structure , Protein Isoforms/chemistry , Red Fluorescent ProteinABSTRACT
The title compound, [Pd(C11H8N)(C6H10NS2)], crystallizes with three similar and discrete mol-ecules in the asymmetric unit. The CNS2 donor set defines a distorted square-planar geometry around the Pd(II) atom, with very small deviations from planarity. The bidentate nature of the ligands gives fairly large deviations from the ideal 90° angles; the C-Pd-N angles are all around 81° and the S-Pd-S angles are around 75°. Mol-ecules pack via dispersion inter-actions.
