Tina M. Trnka

Increased ring closing metathesis activity of ruthenium-based olefin metathesis catalysts coordinated with imidazolin-2-ylidene ligands

The novel air and water tolerant, imidazolinylidene-substituted ruthenium-based complex 3, has been prepared starting from RuCl2(CHPh)(PCy3)2 2 and shown to exhibit increased ring-closing metathesis activity at elevated temperature compared to that of the parent complex 2. Di-, tri-, and even tetra-substituted cycloolefins were successfully prepared from corresponding diene precursors using catalytic amounts of 3 in moderate to excellent yields.

Terminal ruthenium carbido complexes as ??-donor ligandsElectronic supplementary information (ESI) available: additional crystallographic information. See http://www.rsc.org/suppdata/cc/b2/b207903h/

The terminal carbido ligand of (PCy3)2(Cl)2RuC coordinates to other metal centers in a σ-donor fashion, as in (PCy3)2(Cl)2RuC–Pd(Cl)2(SMe2) and (PCy3)2(Cl)2RuC–Mo(CO)5.

Design of a doubly-hydrophilic block copolypeptide that directs the formation of calcium carbonate microspheres

The crystallization of calcium carbonate into microspheres has been accomplished using the rationally-designed, doubly-hydrophilic block copolypeptide poly(Nepsilon-2[2-(2-methoxyethoxy)ethoxy]acetyl-L-lysine)(100)-b-poly(L-aspartate sodium salt)30 as a structure-directing agent.