Organic-metalloblock copolymers via photocontrolled living anionic ring-opening polymerization

A new method for the preparation of organic-organometallic diblock copolymers including a polyferrocenylsilane (PFS) metalloblock through photocontrolled ring-opening polymerization (ROP) is reported. Polystyrene (PS) homopolymers end-capped with a cyclopentadienyl group (1) were used as macroinitiators for the photocontrolled ROP of sila[1]ferrocenophanes [Fe(eta-C5H4)(2)Si {C CtBu}(2)] 3a and [Fe(eta-C5H4)(2)Si(Me)(C CSiMe3)] 3b to afford diblock copolymers with controlled molecular weights and block ratios, as well as low polydispersities (PDI < 1.2). Block copolymer PSm-b-[Fe(eta-C5H4)(2)Si{C C(t-Bu)}(2)](n) 4 was clusterized with [Co-2(CO)(8)], forming the highly metallized PSm-b-[Fe(eta-C5H4)(2)Si{Co-2(CO)(6)C-2(t-Bu)}(2)](n) (PS-b-(Co-PFS), 7). The diblock PSm-b-[Fe(eta-C5H4)(2)Si(Me)(C CH)](n) 6 was prepared by selective desilylation of PSm-b-[Fe(eta-C5H4)(2)Si (Me)(C CSiMe3)](n) 5 was then reacted with ClAuP(n-Bu)(3) in the presence of an amine as HCl acceptor to afford PSm-b-[Fe(eta-C5H4)(2)Si(Me){C CAuP(n-Bu)(3)}](n) (PS-b-(Au-PFS), 8). Preliminary studies on the self-assembly of these materials in thin films showed phase separation with metal-rich nanodomains within an organic matrix.