We have developed F-functionalized chelating σ-aryl Group 4 complexes as catalysts for olefin polymerization and synthetic models of ‘weak attractive ligand–polymer interactions’ (WALPI). For the first time, the elusive and controversial C–H···F–C interaction was manifested as NMR-discernible 1H-19F coupling in solution and characterized by a neutron diffraction study.1 These observations carry important implications for catalyst design, since they substantiate the practical feasibility of the ortho-F···H(β) ligand–polymer contacts proposed for living Group 4 fluorinated phenoxyimine catalysts.2 Multinuclear NMR experiments have revealed a substantial scalar component for the observed 1H-19F coupling, thus confirming that such C–H···F–C interactions are genuine and occur with chemical connectivity.3 Significantly, reports on late transition metal systems have appeared that point to the generality of the WALPI concept for modulating polymerization reactions.4 We have also investigated and rationalized the surprising effects of substituents that are remote from the active site upon the olefin polymerization reactivity of chelating σ-aryl Ti(IV) catalysts.5 Recent results concerning unusual reaction pathways and the impact of rotating elements upon polymerization behavior will be presented. (1) (a) Kui, S. C. F.; Zhu, N.; Chan, M. C. W. Angew. Chem. Int. Ed. 2003, 42, 1628. (b) Chan, M. C. W.; Kui, S. C. F.; Cole, J. M.; McIntyre, G. J.; Matsui, S.; Zhu, N.; Tam, K.-H. Chem. Eur. J. 2006, 12, 2607. (2) Mitani, M.; Mohri, J.; Yoshida, Y.; Saito, J.; Ishii, S.; Tsuru, K.; Matsui, S.; Furuyama, R.; Nakano, T.; Tanaka, H.; Kojoh, S; Matsugi, T.; Kashiwa, N.; Fujita, T. J. Am. Chem. Soc. 2002, 124, 3327. (3) (a) So, L.-C.; Liu, C.-C.; Chan, M. C. W.; Lo, J. C. Y.; Sze, K.-H.; Zhu, Chem. Eur. J. 2012, 18, 565. (b) Liu, C.-C.; So, L.-C.; Lo, J. C. Y.; Chan, M. C. W.; Kaneyoshi, H. Makio, H. Organometallics 2012, 31, 5274. (4) (a) Weberski Jr., M. P.; Chen, C.; Delferro, M.; Zuccaccia, C.; Macchioni, A.; Marks, T. J. Organometallics 2012, 31, 3773. (b) Iwashita, A.; Chan, M. C. W.; Makio, H.; Fujita, T. Catal. Sci. Technol. 2014, 4, 599. (5) Lo, J. C. Y.; Chan, M. C. W.; Lo, P.-K.; Lau, K.-C.; Ochiai, T.; Makio, H. Organometallics 2013, 32, 449.

Chelating σ-aryl post-metallocenes: Unusual reaction pathways and synthetic models of weak attractive ligand–polymer interactions

249th National Meeting (2015)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.