How Close Is Too Close? Polymerization Behavior and Monomer-Dependent Reorganization of a Bimetallic Salphen Organotitanium Catalyst

Anna M. Invergo; Shaofeng Liu; Rachel D. Dicken; Aidan R. Mouat; Massimiliano Delferro; Tracy L. Lohr; Tobin J. Marks

doi:10.1021/acs.organomet.8b00220

How Close Is Too Close? Polymerization Behavior and Monomer-Dependent Reorganization of a Bimetallic Salphen Organotitanium Catalyst

Anna M. Invergo, Shaofeng Liu, Rachel D. Dicken, Aidan R. Mouat, Massimiliano Delferro, Tracy L. Lohr^*, Tobin J. Marks

^*Corresponding author for this work

Chemistry

Research output: Contribution to journal › Article › peer-review

20 Scopus citations

Abstract

The binuclear salphen Ti polymerization catalyst N,N′-1,2-phenylene[(salicylideneaminato)Ti(Cp∗)Me₂)]₂ (2) is synthesized by reaction of salphen-H₂ with Cp∗TiMe₃. Mononuclear [N-(2,6-diisopropyl)phenyl(salicylideneaminato)]Ti(Cp∗)Me₂ (1) serves as a control. Activation studies of 2 with cocatalyst Ph₃C⁺B(C₆F₅)₄ ^- yield the cationic polymerization-inactive complex [N,N′-1,2-phenylene(salicylideneaminato)Ti(Cp∗)]⁺B(C₆F₅)₄ ^- (4) and polymerization-active Cp∗TiMe₂ ⁺B(C₆F₅)₄ ^-. Polymerization studies comparing 2 with Cp∗TiMe₃ suggest that, within the catalytic time frame, while 2 retains bimetallic character under an ethylene atmosphere, it rapidly decomposes to 4 and Cp∗TiMe₂ ⁺ in the presence of 1-hexene. These monomer-dependent reorganization results highlight the importance of olefin polymerization activation mechanistic studies while providing insight for improved bimetallic catalyst design.

Original language	English (US)
Pages (from-to)	2429-2436
Number of pages	8
Journal	Organometallics
Volume	37
Issue number	15
DOIs	https://doi.org/10.1021/acs.organomet.8b00220
State	Published - Aug 13 2018

Funding

Financial support by DOE (Grant 86ER13511, supported catalysts and models thereof; S.L.), NSF (Grant CHE-1464488, cooperative effects in multimetallic homogeneous catalysis; T.L.L., M.D., and R.D.D.), and the Chemical Sciences, Geosciences and Biosciences Division, U.S. Department of Energy, through grant DEFG02-03ER15457 to the Institute of Catalysis in Energy Processes (ICEP; supported catalysts and models thereof; A.M.I. and A.R.M.) at North-western University is gratefully acknowledged. Purchase of the NMR instrumentation at the IMSERC at Northwestern University was supported by NSF (Grant CHE-1048773). We also thank Boulder Scientific Company for a generous gift of Ph3C+B(C6F5)4−.

ASJC Scopus subject areas

Physical and Theoretical Chemistry
Organic Chemistry
Inorganic Chemistry

Access to Document

10.1021/acs.organomet.8b00220

Cite this

@article{85c71f37ac4e4adca96aa52dcfd07127,

title = "How Close Is Too Close? Polymerization Behavior and Monomer-Dependent Reorganization of a Bimetallic Salphen Organotitanium Catalyst",

abstract = "The binuclear salphen Ti polymerization catalyst N,N′-1,2-phenylene[(salicylideneaminato)Ti(Cp∗)Me2)]2 (2) is synthesized by reaction of salphen-H2 with Cp∗TiMe3. Mononuclear [N-(2,6-diisopropyl)phenyl(salicylideneaminato)]Ti(Cp∗)Me2 (1) serves as a control. Activation studies of 2 with cocatalyst Ph3C+B(C6F5)4 - yield the cationic polymerization-inactive complex [N,N′-1,2-phenylene(salicylideneaminato)Ti(Cp∗)]+B(C6F5)4 - (4) and polymerization-active Cp∗TiMe2 +B(C6F5)4 -. Polymerization studies comparing 2 with Cp∗TiMe3 suggest that, within the catalytic time frame, while 2 retains bimetallic character under an ethylene atmosphere, it rapidly decomposes to 4 and Cp∗TiMe2 + in the presence of 1-hexene. These monomer-dependent reorganization results highlight the importance of olefin polymerization activation mechanistic studies while providing insight for improved bimetallic catalyst design.",

author = "Invergo, {Anna M.} and Shaofeng Liu and Dicken, {Rachel D.} and Mouat, {Aidan R.} and Massimiliano Delferro and Lohr, {Tracy L.} and Marks, {Tobin J.}",

note = "Funding Information: Financial support by DOE (Grant 86ER13511, supported catalysts and models thereof; S.L.), NSF (Grant CHE-1464488, cooperative effects in multimetallic homogeneous catalysis; T.L.L., M.D., and R.D.D.), and the Chemical Sciences, Geosciences and Biosciences Division, U.S. Department of Energy, through grant DEFG02-03ER15457 to the Institute of Catalysis in Energy Processes (ICEP; supported catalysts and models thereof; A.M.I. and A.R.M.) at North-western University is gratefully acknowledged. Purchase of the NMR instrumentation at the IMSERC at Northwestern University was supported by NSF (Grant CHE-1048773). We also thank Boulder Scientific Company for a generous gift of Ph3C+B(C6F5)4−. Publisher Copyright: {\textcopyright} 2018 American Chemical Society.",

year = "2018",

month = aug,

day = "13",

doi = "10.1021/acs.organomet.8b00220",

language = "English (US)",

volume = "37",

pages = "2429--2436",

journal = "Organometallics",

issn = "0276-7333",

publisher = "American Chemical Society",

number = "15",

}

TY - JOUR

T1 - How Close Is Too Close? Polymerization Behavior and Monomer-Dependent Reorganization of a Bimetallic Salphen Organotitanium Catalyst

AU - Invergo, Anna M.

AU - Liu, Shaofeng

AU - Dicken, Rachel D.

AU - Mouat, Aidan R.

AU - Delferro, Massimiliano

AU - Lohr, Tracy L.

AU - Marks, Tobin J.

N1 - Funding Information: Financial support by DOE (Grant 86ER13511, supported catalysts and models thereof; S.L.), NSF (Grant CHE-1464488, cooperative effects in multimetallic homogeneous catalysis; T.L.L., M.D., and R.D.D.), and the Chemical Sciences, Geosciences and Biosciences Division, U.S. Department of Energy, through grant DEFG02-03ER15457 to the Institute of Catalysis in Energy Processes (ICEP; supported catalysts and models thereof; A.M.I. and A.R.M.) at North-western University is gratefully acknowledged. Purchase of the NMR instrumentation at the IMSERC at Northwestern University was supported by NSF (Grant CHE-1048773). We also thank Boulder Scientific Company for a generous gift of Ph3C+B(C6F5)4−. Publisher Copyright: © 2018 American Chemical Society.

PY - 2018/8/13

Y1 - 2018/8/13

N2 - The binuclear salphen Ti polymerization catalyst N,N′-1,2-phenylene[(salicylideneaminato)Ti(Cp∗)Me2)]2 (2) is synthesized by reaction of salphen-H2 with Cp∗TiMe3. Mononuclear [N-(2,6-diisopropyl)phenyl(salicylideneaminato)]Ti(Cp∗)Me2 (1) serves as a control. Activation studies of 2 with cocatalyst Ph3C+B(C6F5)4 - yield the cationic polymerization-inactive complex [N,N′-1,2-phenylene(salicylideneaminato)Ti(Cp∗)]+B(C6F5)4 - (4) and polymerization-active Cp∗TiMe2 +B(C6F5)4 -. Polymerization studies comparing 2 with Cp∗TiMe3 suggest that, within the catalytic time frame, while 2 retains bimetallic character under an ethylene atmosphere, it rapidly decomposes to 4 and Cp∗TiMe2 + in the presence of 1-hexene. These monomer-dependent reorganization results highlight the importance of olefin polymerization activation mechanistic studies while providing insight for improved bimetallic catalyst design.

AB - The binuclear salphen Ti polymerization catalyst N,N′-1,2-phenylene[(salicylideneaminato)Ti(Cp∗)Me2)]2 (2) is synthesized by reaction of salphen-H2 with Cp∗TiMe3. Mononuclear [N-(2,6-diisopropyl)phenyl(salicylideneaminato)]Ti(Cp∗)Me2 (1) serves as a control. Activation studies of 2 with cocatalyst Ph3C+B(C6F5)4 - yield the cationic polymerization-inactive complex [N,N′-1,2-phenylene(salicylideneaminato)Ti(Cp∗)]+B(C6F5)4 - (4) and polymerization-active Cp∗TiMe2 +B(C6F5)4 -. Polymerization studies comparing 2 with Cp∗TiMe3 suggest that, within the catalytic time frame, while 2 retains bimetallic character under an ethylene atmosphere, it rapidly decomposes to 4 and Cp∗TiMe2 + in the presence of 1-hexene. These monomer-dependent reorganization results highlight the importance of olefin polymerization activation mechanistic studies while providing insight for improved bimetallic catalyst design.

UR - http://www.scopus.com/inward/record.url?scp=85051415217&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85051415217&partnerID=8YFLogxK

U2 - 10.1021/acs.organomet.8b00220

DO - 10.1021/acs.organomet.8b00220

M3 - Article

AN - SCOPUS:85051415217

SN - 0276-7333

VL - 37

SP - 2429

EP - 2436

JO - Organometallics

JF - Organometallics

IS - 15

ER -

How Close Is Too Close? Polymerization Behavior and Monomer-Dependent Reorganization of a Bimetallic Salphen Organotitanium Catalyst

Abstract

Funding

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

CCDC 1836726: Experimental Crystal Structure Determination

CCDC 1836727: Experimental Crystal Structure Determination

Cite this

How Close Is Too Close? Polymerization Behavior and Monomer-Dependent Reorganization of a Bimetallic Salphen Organotitanium Catalyst

Abstract

Funding

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Datasets

CCDC 1836726: Experimental Crystal Structure Determination

CCDC 1836727: Experimental Crystal Structure Determination

Cite this