Chemistry 367L/392N

Macromolecular ChemistryMacromolecular Chemistry

Lecture 23Lecture 23

Yves ChauvinYves ChauvinInstitutInstitut FranFranççaisais du du PPéétroletroleRueilRueil--Malmaison, France Malmaison, France

Robert GrubbsRobert GrubbsCalifornia Institute of Technology California Institute of Technology

(Caltech) Pasadena, CA, USA (Caltech) Pasadena, CA, USA

Richard SchrockRichard SchrockMassachusetts Institute Massachusetts Institute

of Technology (MIT) of Technology (MIT) Cambridge, MA, USACambridge, MA, USA

Transition metal catalysis of polymerizationTransition metal catalysis of polymerization

Chemistry 367L/392N

HomeworkHomework

Assignment 11Assignment 11Due May 4Due May 4thth before 5PMbefore 5PM

DO: Submit a corrected copy of your midterm DO: Submit a corrected copy of your midterm examexam

Chemistry 318N

MetathesisMetathesisFrom From Dictionary.comDictionary.com

1. the transposition of letters, syllables, or sounds in a word, as in the pronunciation aksor ask.

2. In chemistry, reaction whose result is the interchange of two parts of two substances to form two new substances, as

AgNO3 + NaCl→ AgCl + NaNO3.

Chemistry 318N

Olefin MetathesisOlefin Metathesis

Chemistry 318N

Ring opening metathesis Ring opening metathesis polymerization ROMPpolymerization ROMP

* *

catalyst

Chemistry 318N

Ring strain driving forceRing strain driving force

Living!!!

Chemistry 318N

Olefin Metathesis CatalystsOlefin Metathesis Catalysts�� Schrock and GrubbsSchrock and Grubbs

–– Air sensitiveAir sensitive

–– Initially were molybdenum and ruthenium based, respectivelyInitially were molybdenum and ruthenium based, respectively

–– Shared 2005 Nobel Prize with ChauvinShared 2005 Nobel Prize with Chauvin

Images from Images from PappenfusPappenfus, T. M. Synthesis and Catalytic Activity of Ruthenium, T. M. Synthesis and Catalytic Activity of Ruthenium--IndenylideneIndenylidene Complexes for Olefin Complexes for Olefin Metathesis, Metathesis, J. Chem. Ed.J. Chem. Ed. 2007,2007, 84 (12), 199884 (12), 1998--2000.2000.

Span of Olefin Metathesis

Types of Metathesis

R1R 2 R1

R 2+

**

n

**

n

R 2

R1

+

R2

R1

cross metathesis (CM) ring closing metathesis (RCM)

ring opening cross metathesis (ROCM)

acyclic diene metathesis (ADMET)ring opening metathesis polymerization (ROMP)

C.W. Bielawski, R.H. Grubbs Prog. Polym. Sci. 32 (2007) 1.

Chemistry 318N

ADMET is step growth ADMET is step growth polymerization chemistrypolymerization chemistry

� High strength polymers can be made by ADMET

Symmetrical Diene

Symmetrical Repeat Unit

Ken Wagener

George and Josephine Butler Polymer Research Laboratory - Department of Chemistry University of Florida

Animation of ADMET MechanismThe ADMET Reaction

R

R

x

+ Gaseous Ethylene

Room Temp.

ADMET PolymerDiene Monomer

MetathesisCatalyst

+

Professor Ken Wagener, University of Florida

Chemistry 318N

Lets Practice ADMETLets Practice ADMET

Catalyst

Vacuum

* *

H2C CH2

Catalyst, BIG pressure

Chemistry 318N

Tuesday LectureTuesday LecturePolymer separation membranesPolymer separation membranes

Prof. . Benny Freeman