Stereochemistry can have a profound impact on polymer and materials properties. Unfortunately, straightforward methods for realizing high levels of stereocontrolled polymerizations are often challenging to achieve. In departure from traditional metal-mediated ring-opening metathesis polymerization (ROMP), we discovered remarkably simple method controlling alkene stereochemistry in photoredox me...

Glycosaminoglycans are sulfated polysaccharides that play important roles in fundamental biological processes, such as cell division, viral invasion, cancer and neuroregeneration. The multivalent presentation of multiple glycosaminoglycan chains on proteoglycan scaffolds may profoundly influence their interactions with proteins and subsequent biological activity. However, the importance of this...

S Chapter 1 Study of Chiral Arylimido Molybdenum ROMP Catalysts. Molybdenum ROMP catalysts with a chiral ortho-(phenethyl)phenylimido ligand have been prepared. Mo(CHCMe2Ph)(N-2-C 6H4-CHMePh)(O-2,6-C 6H3-Ph2)2 (1la) and Mo(CHMe 2Ph)(N2-C6H4-CHMePh)[BIPHENO(Me) 2(t-Bu) 4] (11b) were isolated and shown to effect the polymerization of 2,3-dicarbomethoxynorbonadienes. Highly-trans syndiotactic poly...

Linear hybrid block copolymers with well controlled molecular weights and narrow polydispersities were synthesized via ring-opening metathesis polymerization (ROMP) followed by ring-opening polymerization of amino acid N-carboxyanhydrides.

Herein we demonstrate the effect that structure of olefinic end-group ( i.e. oxanorbornenyl vs norbornenyl) has upon outcome both macromonomer preparation by RAFT polymerization and subsequent bottlebrush polymer synthesis ROMP.

Brittle and Ductile Deformational Structures in Tectonic Zones: The Research Trends in India N MANDAL1*, A CHATTOPADHAYAY2, H B SRIVASTAVA3, T K BISWAL4 and S BOSE5 1Department of Geological Sciences, Jadavpur University, Kolkata 700 032, India 2Department of Geology, University of Delhi, Delhi 110 007, India 3Department of Geology, Banaras Hindu University, Varanasi 221 005, India 4Department ...

We consider the arithmetics of Collatz cycles in Q(2)]. In particular , we prove optimal estimates for the length of a cycle in terms of its minimum. As an application, we derive an improved version of Eliahou's criterion , and we show that the length of (integer) Collatz cycles which do not contain 1, is at least 102 225 496 provided the Collatz conjecture is veriied for all initial values x 0...

Highly thermally stable N-aryl,N-alkyl N-heterocyclic carbene (NHC) ruthenium catalysts were designed and synthesized for latent olefin metathesis. These catalysts showed excellent latent behavior toward metathesis reactions, whereby the complexes were inactive at ambient temperature and initiated at elevated temperatures, a challenging property to achieve with second generation catalysts. A st...