Photocontrolled Living Anionic Polymerization of Phosphorus‐Bridged [1]Ferrocenophanes: A Route to Well‐Defined Polyferrocenylphosphine (PFP) Homopolymers and Block Copolymers |
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Authors: | Sanjib?K Patra Dr George?R Whittell Dr Simone Nagiah Cheuk‐Lam Ho Wai‐Yeung Wong Prof Ian Manners Prof |
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Institution: | 1. School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS (UK), Fax: (+44)?117‐929‐0509;2. Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong (P. R. China), Fax: (+852)?3411‐7348 |
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Abstract: | Phosphorus‐bridged strained 1]ferrocenophanes Fe{(η‐C5H4)2P(CH2CMe3)}] ( 2 ) and Fe{(η‐C5H4)2P(CH2SiMe3)}] ( 3 ) with neopentyl and (trimethylsilyl)methyl substituents on phosphorus, respectively, have been synthesized and characterized. Photocontrolled living anionic ring‐opening polymerization (ROP) of the known phosphorus‐bridged 1]ferrocenophane Fe{(η‐C5H4)2P(CMe3)}] ( 1 ) and the new monomers 2 and 3 , initiated by NaC5H5] in THF at 5 °C, yielded well‐defined polyferrocenylphosphines (PFPs), Fe{(η‐C5H4)2PR}]n (R=CMe3 ( 4 ), CH2CMe3 ( 5 ), and CH2SiMe3 ( 6 )), with controlled molecular weights (up to ca. 60×103 Da) and narrow molecular weight distributions. The PFPs 4 – 6 were characterized by multinuclear NMR spectroscopy, DSC, and by GPC analysis of the corresponding poly(ferrocenylphosphine sulfides) obtained by sulfurization of the phosphorus(III) centers. The living nature of the photocontrolled anionic ROP allowed the synthesis of well‐defined all‐organometallic PFP‐b‐PFSF ( 7 a and 7 b ) (PFSF=polyferrocenylmethyl(3,3,3,‐trifluoropropyl)silane) diblock copolymers through sequential monomer addition. TEM studies of the thin films of the diblock copolymer 7 b showed microphase separation to form cylindrical PFSF domains in a PFP matrix. |
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Keywords: | block copolymers metallopolymers phosphanes photolysis self‐assembly |
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