Charged Metallopolymers as Universal Precursors for Versatile Cobalt Materials

Abstract

Inorganic metal-based materials have been widely utilized in catalytic chemistry, life sciences, and engineering. [1] Cobaltrelated materials, including metallic cobalt, [2] cobalt oxide, [3] cobalt alloy, [4] and cobalt phosphide, [5] have been used in magnetic materials, aerospace engineering, and energy storage. With the development of modern nanoelectronic technology and the increasing demand for nanostructured materials, [6] the preparation of nanostructured inorganic cobaltcontaining materials has become a crucial technological challenge. Various methods have been developed to prepare nanoscale inorganic cobalt-containing materials, including electrodeposition, [7] polymeric precursor synthesis, [8] solvothermal/hydrothermal methods, [5b, 9] and sol-gel precipitation. [10] Among them, the utilization of metal-containing polymer precursors to prepare nanostructured cobalt-based materials has been used in particular, for such reasons as controlled molecular weight and architectures offered by well-established controlled/living synthetic methods, various morphologies from polymer self-assembly, [11] and facile manipulation of polymers. [12] As a result, a myriad of metalcontaining polymer precursors in the form of thin films, micelles, or fibers have been designed and utilized for preparation of functional inorganic materials. [8] However, metal-containing polyelectrolytes or charged metallopolymers have been much less studied as precursors to prepare inorganic metal-based materials. [13] Compared with neutral metal-containing polymers, the existence of counterions in charged metallopolymers has several advantages as novel precursors, such as ion-dependent solubility [14] and ioninduced self-assembly. [15] Thus these polyelectrolytes could be universal precursors for access to multifunctional inorganic materials. Unfortunately, it is challenging to perform facile exchange of counterions for charged metallopolymers. Most studies have been limited to specific systems (usually small molecules [16] or super-macromolecules [17] ), thus severely restricting the diversity of charged metallopolymers.Phase transfer has been applied in various organic reactions [18] and utilized in applications such as ionic selfassembly, [19] heterogeneous catalysts, [18,20] and ionic liquids. [21] However, the utilization of phase transfer to tune metalassociated counterions for charged metallopolymers is much less explored. [15, 19b] We have recently demonstrated ion exchange between hexafluorophosphate (PF 6 À ) and tetraphenyl borate (BPh 4 À ) ions in cationic cobaltocenium-containing monomers/polymers, which was clearly a phase transfer-driven reaction. [14b, 22] But this specific reaction was only limited for BPh 4 À anions. It is still challenging to apply a powerful technique to access other types of counterions for cobaltocenium-containing polymers.Herein, we report a facile phase-transfer ion-exchange method to prepare cationic cobaltocenium-containing polyelectrolytes with diverse counterions by the use of tetrabutylam...

Charged Metallopolymer-Grafted Silica Nanoparticles for Antimicrobial Applications

“…51 Thus, nanoparticles with PF 6 − anions were subjected to anion exchange with TBACl to result in hydrophilic chloride-based particles. The complete conversion from PF 6 − to Cl − was confirmed by running 19 F NMR of the resultant nanoparticles (Figure S5).…”

“…Ion-exchange to Cl − was performed according to a previous report using tetrabutylammonium chloride salt (TBACl). 51 A typical procedure was as follows: 1 mL of PF 6 − -paired CsNP (30 mg/mL in acetonitrile) was slowly dropped into 5 mL of TBACl solution (in acetonitrile) under vigorous stirring. After stirring for 5 min, the precipitated Cl − -paired CsNP was collected and washed by acetonitrile three times to remove PF 6 − anions and excess TBACl.…”

Side-Chain Cobaltocenium-Containing Polymers: Controlled Polymerization and Applications

“…These polymers could be utilized as universal precursors to prepare diverse advanced cobalt materials such as cobalt metal, cobalt phosphide, cobalt monoxide, cobalt-iron alloy and cobalt ferrite with different nanostructures (Figure 3) (32).…”

Metal-containing and related polymers for biomedical applications

“…123 The gels were prepared via free radical polymerization of methacrylate cobaltocenium monomers and dimethacrylate functionalized PEO crosslinkers. Based on the unique anion-dependent solubility of cobaltocenium moieties, 117, 124 these gels showed a transition between organogels and hydrogels. Such a transition could be easily achieved by using tetrabutylammonium salts (Fig.…”