The surprisingly facile formation of Pd(i)-phosphido complexes from ortho-biphenylphosphines and palladium acetate.

The widely-used ortho-biphenylphosphine ligands SPhos and RuPhos not only undergo facile orthometallation with palladium acetate, yielding strained, four-membered dimeric palladacycles but more surprisingly, in the presence of alcoholic solvents, along with the less encumbered analogue MePhos, yield unusual dinuclear Pd(i) complexes, in which the Pd-centers are bridged by both a phosphide ligand and by the arene of a coordinated phosphine donor.

Ligand-Free Iron-Catalyzed C-F Amination of Diarylamines: A One-Pot Regioselective Synthesis of Diaryl Dihydrophenazines.

A one-pot synthesis of various 5,10-diaryl-5,10-dihydrophenazines (DADHPs) from diarylamines has been achieved by using an iron-catalyzed C-F amination. Homodimerization of magnesium diarylamides, followed by defluorinative intramolecular cyclization (double ortho C-F amination) in the presence of catalytic FeCl and stoichiometric 1,2-dibromoethane, affords the corresponding DADHPs with complete regiocontrol. The unique high reactivity of fluorine over other halogens indicates that amination proceeds via an SAr mechanism facilitated by iron.

Gateway state-mediated, long-range tunnelling in molecular wires.

If the factors controlling the decay in single-molecule electrical conductance G with molecular length L could be understood and controlled, then this would be a significant step forward in the design of high-conductance molecular wires. For a wide variety of molecules conducting by phase coherent tunnelling, conductance G decays with length following the relationship G = Ae. It is widely accepted that the attenuation coefficient β is determined by the position of the Fermi energy of the electrodes relative to the energy of frontier orbitals of the molecular bridge, whereas the terminal anchor groups which bind to the molecule to the electrodes contribute to the pre-exponential factor A.