TY - JOUR
T1 - A Robust, Divalent, Phosphaza-bicyclo[2.2.2]octane Connector Provides Access to Cage-Dense Inorganic Polymers and Networks
AU - Bedard, Joseph
AU - Linford-Wood, Thomas G
AU - Thompson, Benedict C
AU - Werner-Zwanziger, Ulrike
AU - Marczenko, Katherine M
AU - Musgrave, Rebecca A
AU - Chitnis, Saurabh S
N1 - Funding Information:
The authors acknowledge Prof. Joe B. Gilroy and Alexander Eugene Rosario Watson at Western University for providing the TGA and DSC data. The authors acknowledge Prof. Jan Rainey for valuable discussions on the use of DOSY NMR for the determination of molecular weights. This work was supported in part by NSERC Grant RGPIN-2018-05574. Acknowledgment is made to the donors of the American Chemical Society Petroleum Research Fund for support (or partial support) of this research.
Funding Information:
This work was supported in part by NSERC Grant RGPIN-2018-05574. Acknowledgment is made to the donors of the American Chemical Society Petroleum Research Fund for support (or partial support) of this research.
Publisher Copyright:
© 2023 American Chemical Society.
PY - 2023/4/5
Y1 - 2023/4/5
N2 - While polymers containing chain or ring motifs in their backbone are ubiquitous, those containing well-defined molecular cages are very rare and essentially unknown for the inorganic elements. We report that a rigid and dinucleophilic cage (PNSiMe3)2(NMe)6, which is chemically robust and accessible on a multi-gram scale from commercial precursors, serves as a linear and divalent connector that forms cage-dense inorganic materials. Reaction of the cage with various ditopic P(III) dihalide comonomers proceeded via Me3SiCl elimination to give high molecular weight (30 000-70 000 g mol-1), solution-processable polymers that form free-standing films. The end groups of the polymers could be tuned to engender orthogonal reactivity and form block copolymers. Networked cage-dense materials could be accessed by using PCl3 as a tritopic P(III) linker. Detailed mechanistic studies implicate a stepwise polycondensation that proceeds via phosphino-phosphonium ion intermediates, prior to Me3SiCl loss. Thus, metathesis between the dinucleophilic cage and polyhalides represents a general strategy to making cage-dense polymers, setting the stage for systematically understanding the consequences of the three-dimensional microstructure on macroscopic material properties.
AB - While polymers containing chain or ring motifs in their backbone are ubiquitous, those containing well-defined molecular cages are very rare and essentially unknown for the inorganic elements. We report that a rigid and dinucleophilic cage (PNSiMe3)2(NMe)6, which is chemically robust and accessible on a multi-gram scale from commercial precursors, serves as a linear and divalent connector that forms cage-dense inorganic materials. Reaction of the cage with various ditopic P(III) dihalide comonomers proceeded via Me3SiCl elimination to give high molecular weight (30 000-70 000 g mol-1), solution-processable polymers that form free-standing films. The end groups of the polymers could be tuned to engender orthogonal reactivity and form block copolymers. Networked cage-dense materials could be accessed by using PCl3 as a tritopic P(III) linker. Detailed mechanistic studies implicate a stepwise polycondensation that proceeds via phosphino-phosphonium ion intermediates, prior to Me3SiCl loss. Thus, metathesis between the dinucleophilic cage and polyhalides represents a general strategy to making cage-dense polymers, setting the stage for systematically understanding the consequences of the three-dimensional microstructure on macroscopic material properties.
UR - http://www.scopus.com/inward/record.url?scp=85151157608&partnerID=8YFLogxK
U2 - 10.1021/jacs.3c00882
DO - 10.1021/jacs.3c00882
M3 - Article
C2 - 36961918
SN - 0002-7863
VL - 145
SP - 7569
EP - 7579
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 13
ER -