Search

Tris(bipyridyl)ruthenium(II) complexes modified such that one of the bipyridines is appended with a crown ether display luminescence that is responsive to complexation with metal ions. The syntheses and steady-state and time-resolved luminescence measurements in addition to other supporting spectroscopic characterization is reported.

The design, synthesis and characterization of new (dioxo)Mo(VI) epoxidation catalysts based on monoanionic tridentate ligands are presented. It is suggested that direct oxygen atom transfer from coordinated alkyl peroxide to olefin is the most straightforward mechanism in line with the available data.

A detailed analysis of electronic effects on enantioselectivity in the (salen)Mn(III)-catalyzed asymmetric epoxidation reaction is presented. Experimental data support the proposal that the electronic character of chiral (salen)Mn catalysts influence the enantioselectivity of the catalytic epoxidation by changing the position of the transition state in the first C-O bond-forming stage. Observations may be the basis for general implications for the design of asymmetric catalysts, especially those that stimulate reactions without substrate precoordination.

The visual fluorescent assay is used for the detection of triacetone triperoxide (TATP). Aryl sulfoxides have application in the detection of species beyond oxidants and the titration of a pyrene derivative with metal ions such as [Li.sup.+] and [Zn.sup.2+] has led to the enhancement of fluorescence.

The bicyclic core of octosyl acid A is prepared using a diastereoselective acetylide addition and 6-endo selenoetherification as key steps. A detailed study of the reaction and difficulties encountered in the conversion of a phenyl group to a carboxylic acid are discussed.

Chitin synthase (CS) polymerizes UDP-GlcNAc to form chitin (poly-beta(1,4)-GlcNAc), a key component of fungal cell wall biosynthesis. The synthesis of two fluorescent UDP-GlcNAc analogues and their evaluation as chitin synthase substrates is described.

A new approach to aminoglycosides based on the formation of triazolines from a readily available glycal precursor followed by efficient formation and ring-opening of the corresponding aziridine is described. The operation is operationally simple, with no purification required after the initial cyclization and mild conditions for the formation of the aminoglycoside product.

The first direct evaluation of the two-active site mechanism for chitin synthase, a glycosyltransferase essential for fungal cell wall biosynthesis is reported. The results suggest that polymerizing transferases such as chitin synthase are mechanistically distinct from the comparatively well-understood single-sugar transferases.

The control of excited dynamics can modulate both of the fundamental nonradiative decay pathways, S1->T1 intersystem crossing (ISC) and internal conversion (IC), in simple fluorophores is proved. This approach should be generally applicable to the development of polyaryl fluorescent chemosensors.

The synthesis of a proof-of-principle library based on a core biarylpyridine fluorophore and the discovery of novel visibly emissive Hg(super 2+)-responsive from this library is described. This approach reverses the reigning discovery paradigm, which requires a preestablished building event.

A mechanism for fluorescent chemosensor action is described.

The identification and study of ligand-receptor interactions can be facilitated by the synthesis and screening of combinatorial libraries. The advantages of combinatorial systems include their ability to simultaneously examine structural changes, thus allowing synergistic effects in ligand binding to be evaluated. For this same reason, combinatorial chemistry provides an excellent approach for discovering new types of coordination compounds. The use of ligands prepared through solid-phase combinatorial synthesis in selective transition metal binding is reported.