Tridentate phosphine ligands bearing aza-crown ether lariats

Cationic ruthenium alkylidene catalysts bearing phosphine ligands

The discovery of highly active catalysts and the success of ionic liquid immobilized systems have accelerated attention to a new class of cationic metathesis catalysts. We herein report the facile syntheses of cationic ruthenium catalysts bearing bulky phosphine ligands. Simple ligand exchange using silver(I) salts of non-coordinating or weakly coordinating anions provided either PPh3 or chelat...

Dithiolene complexes as metallo-ligands: a crown-ether approach

Synthesis and coordination chemistry of tridentate (PNN) amine enamido phosphine ligands with ruthenium.

Tridentate amine-imine-phosphine ligands, R2PC5H7NC2H4NEt2 [(R)PNN(H)], where R = Pr(i) or Bu(t) are synthesized using a straightforward protocol of condensation, deprotonation, and addition of a chlorodialkylphosphine. Multinuclear NMR spectroscopy shows the ligands exist exclusively in the enamine tautomeric form in solution. Treating these ligands with RuHCl(PPr(i)3)2(CO) forms the desired c...

Stability constants of aza-oxa-crown ether complexes with silver(I) in nonaqueous polar solvents

Complex formation between the silver(I) ion and monoazaand diaza-crown ethers has been studied in five polar, nonaqueous solvents using potentiometric techniques. The stability constants are spread over seven orders of magnitude, and the major contributor to this variation is the solvation of the silver(I) cation. The ring-size dependence of the stability constants is determined both by the cor...

Synthesis, characterization and cation-induced dimerization of new aza-crown ether-appended metalloporphyrins.

New metalloporphyrins bearing one or two aryl-aza-crown ether moieties at meso-positions have been synthesized using a palladium catalyzed amination reaction and fully characterized by spectral techniques. X-Ray structural data have been presented for the zinc and copper complexes of mono-substituted aza-crown ether appended metalloporphyrins. UV-Vis and (1)H NMR spectroscopic studies showed th...