Polyferrocenylsilanes: synthesis, properties, and applications

Abstract

This in-depth review covers progress in the area of polyferrocenylsilanes (PFS), a well-established, readily accessible class of main chain organosilicon metallopolymer consisting of alternating ferrocene and organosilane units. Soluble, high molar mass samples of these materials were first prepared in the early 1990s by ring-opening polymerisation (ROP) of silicon-bridged [1]ferrocenophanes (sila[1]ferrocenophanes). Thermal, transition metal-catalysed, and also two different living anionic ROP methodologies have been developed: the latter permit access to controlled polymer architectures, such as monodisperse PFS homopolymers and block copolymers. Depending on the substituents, PFS homopolymers can be amorphous or crystalline, and soluble in organic solvents or aqueous media. PFS materials have attracted widespread attention as high refractive index materials, electroactuated redox-active gels, fibres, films, and nanoporous membranes, as precursors to nanostructured magnetic ceramics, and as etch resists to plasmas and other radiation. PFS block copolymers form phase-separated iron-rich, redox-active and preceramic nanodomains in the solid state with applications in nanolithography, nanotemplating, and nanocatalysis. In selective solvents functional micelles with core-shell structures are formed. Block copolymers with a crystallisable PFS core-forming block were the first to be found to undergo "living crystallisation-driven self-assembly" in solution, a controlled method of assembling block copolymers into 1D or 2D structures that resembles a living covalent polymerisation, but on a longer length scale of 10 nm-10 μm.

Two-dimensional assemblies from crystallizable homopolymers with charged termini

“…12,13 In a further advance, nanosheets formed by the crystallization of precursors containing silsesquioxane clusters bound to hyperbranched polymers can be fragmented into seeds using sonication which can be used to control the growth of 2D platelets on subsequent precursor addition. 14 We have shown that addition of a BCP with a crystallizable poly(ferrocenyldimethylsilane) (PFS) core-forming block 15 and a short complementary corona-forming block to seeds derived from the sonication of 1D cylindrical PFS BCP micelles allows access to lenticular platelet micelles. 16 Sequential addition of different PFS BCPs to seeds yields lenticular platelet block comicelles with concentric regions of different coronal chemistry.…”

Funktionelle polymere Materialien auf der Basis von Hauptgruppen‐Elementen

“…Der Einbau von Pn III -Zentren zwischen Vinylen-, Alkinylen-oder Arylenbausteinen führt zu Polymeren, die nicht nur eine Verlängerung der Konjugation durch s-p-Konjugation aufweisen, sondern auch potenziell auf Lewis-Säure-Bindung oder Oxidation zur formalen Pn V -Oxidationsstufe reagieren. [136] Ein eindrucksvolles Beispiel ist die Herstellung farbcodierter lumineszierender Nanostrukturen durch Keimwachstum von zylindrischen Blockcopolymer-Micellen 69 (Abbildung 19, unten). [131] In jüngerer Zeit berichteten Gates et al über die ersten Beispiele von Poly(phenylendiethinylenphosphanen) 64;s ie sind nicht emittierend, werden aber in Lçsung durch Einwirken von Luft oder gezielte Oxidation mit wässrigem Wasserstoffperoxid blau fluoreszierend unter Bildung des Polymers 65.…”

Unique Bora[1]ferrocenophanes with Sterically Protected Boron: A Potential Gateway to Helical Polyferrocenes

“…[1][2][3][4][5][6][7][8][9][10][11] Out of many methodologies to prepare metallopolymers,r ing-opening polymerization (ROP)o fs trained ferrocenophanes (FCPs) had been extensively applied in the past. [1][2][3][4][5][6][7][8][9][10][11] Out of many methodologies to prepare metallopolymers,r ing-opening polymerization (ROP)o fs trained ferrocenophanes (FCPs) had been extensively applied in the past.…”

“…[2,9] Unambiguously, sila [1]ferrocenophanes (A,F igure 1) are the most intensively studied strained compounds amongst the plethora of [n]FCPs reported since the discovery of the first FCP,acarbon-bridged [3]FCP,i n1 957. [9] Among am ultitude of applications of PFS materials,t he most notable discovery is their ability to form block copolymers which can produce micelles with rod-like core-shell structures in block-selective solvents that further undergo crystallization-driven self-assembly (CDSA) to form materials with well-defined architectures. [9] Among am ultitude of applications of PFS materials,t he most notable discovery is their ability to form block copolymers which can produce micelles with rod-like core-shell structures in block-selective solvents that further undergo crystallization-driven self-assembly (CDSA) to form materials with well-defined architectures.…”