Accession Number:
ADA272647
Title:
Rotational Isomers of Mo(VI) Alkylidene Complexes and Cis/Trans Polymer Structure: Investigations in Ring-Opening Metathesis Polymerization
Descriptive Note:
Technical rept.,
Corporate Author:
MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF CHEMISTRY
Personal Author(s):
Report Date:
1993-10-20
Pagination or Media Count:
49.0
Abstract:
In the last few years well-defined metathesis catalysts of the general type MNRCHROR2 MMo or W have proven useful in a variety of olefin metathesis studies, in part because the activity of catalysts can be varied systematically by altering the electron-withdrawing ability of the alkoxides. Complexes containing t-butoxides OCMe3 and OCMeCf32 in particular , an arylimido ligand often NAr, where Ar 2,6-i-Pr2C6H3, and molybdenum have been the most versatile. In the area of ring-opening metathesis polymerization ROMPmolybdenum complexes have been employed most often to prepare polymers from a variety of norbornenes and norbornadienes. Molybdenum complexes appear to tolerate a wide range of functionalities, are stable and active in a variety of solvents,and have been shown to produce polymers that are virtually all trans and highly tactic or all cis with a tactic bias of approx. 75. Alkylidene rotational isomers or rotamers eq 1 are found for many high-oxidation state alkylidene complexes
Descriptors:
Subject Categories:
- Inorganic Chemistry
- Physical Chemistry
- Polymer Chemistry
- Atomic and Molecular Physics and Spectroscopy