Electronic and magnetic communication in mixed-valent and homovalent ruthenium complexes containing phenylcyanamide type bridging ligands.

Four new phenylcyanamido-bridge dinuclear ruthenium complexes [{Ru(tpy)(thd)}2(mu-L)] with tpy = 2,2':6',2' '-terpyridine, thd = 2,2,6,6-tetramethyl-3,5-heptanedione and L = dcbp = 4,4'-dicyanamidobiphenyl; bcpa = bis(4-cyanamidophenyl)acetylene; bcpda = bis(4-cyanamidophenyl)diacetylene; bcpea = 9,10,-bis(4-cyanamidophenylethynyl)anthracene have been prepared and fully characterized. The mixed valent Ru(II)Ru(III) and homovalent paramagnetic Ru(III)Ru(III) forms of all the complexes were electrochemically generated and studied by UV-vis-NIR and EPR spectroscopy. Electronic communication was quantified by the electronic coupling parameter V(ab) extracted from intervalence measurements in the near IR area, and magnetic communication was quantified in terms of the exchange coupling constant J, accessible from the intensity of the EPR signal when varying the temperature.

On the role of the bridging dicyanamidobenzene ligand in a new binuclear ruthenium complex: [{Ru(tpy)(thd)}2(mu-dicyd)][PF6] with tpy = 2,2':6',2' '-terpyridine and thd = 2,2,6,6-tetramethyl-3,5-heptanedione.

The dicyanamidobenzene-bridge diruthenium complex [{Ru(tpy)(thd)}(2)(mu-dicyd)][PF(6)] ([3][PF(6)]) (dicyd = 1,4-dicyanamidobenzene, tpy = 2,2':6',2' '-terpyridine, thd = 2,2,6,6-tetramethyl-3,5-heptanedione) and its mononuclear counterpart [Ru(tpy)(thd)(Ipcyd)] (2) [Ipcyd = 4-iodophenylcyanamide anion (Ipcyd(-))] were synthesized and fully characterized. Cyclic voltammetry of 3 showed the presence of four reversible one-electron redox couples. UV-vis-NIR spectroelectrochemistry and EPR spectroscopy of the electrogenerated paramagnetic intermediates were used to ascertain the oxidation-state distribution.

Pyridinium CH...anion and pi-stacking interactions in modular tripodal anion binding hosts: ATP binding and solid-state chiral induction.

The preparation of two new tripodal "pinwheel" type anion hosts based on a triethylbenzene core and bipyridinium or ethylnicotinium arms is reported. The new materials bind anions via CH..

Anion sensing 'venus flytrap' hosts: a modular approach.

A series of podands based on three hydrogen bonding 'arms' have been prepared and their affinities for simple inorganic anions measured.