A Robust, Divalent, Phosphaza-bicyclo[2.2.2]octane Connector Provides Access to Cage-Dense Inorganic Polymers and Networks

Joseph Bedard, Thomas G. Linford-Wood, Benedict C. Thompson, Ulrike Werner-Zwanziger, Katherine M. Marczenko, Rebecca A. Musgrave, Saurabh S. Chitnis

Research output: Contribution to journalArticlepeer-review

6 Citations (SciVal)


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.

Original languageEnglish
Pages (from-to)7569-7579
Number of pages11
JournalJournal of the American Chemical Society
Issue number13
Early online date24 Mar 2023
Publication statusPublished - 5 Apr 2023

Bibliographical note

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.

Accession Codes
CCDC 2237461–2237462 contain the supplementary crystallographic data for this paper. These data can be obtained free of charge via www.ccdc.cam.ac.uk/data_request/cif, or by emailing data_request@ccdc.cam.ac.uk, or by contacting The Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: +44 1223 336033.

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry


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