Ligand Induced Steric Crowding in Rare Earth Metal-Mediated Group Transfer Polymerization of Vinylphosphonates: Does Enthalpy Matter?

Design, Synthesis and Actual Applications of the Polymers Containing Acidic P-OH Fragments: Part 2-Sidechain Phosphorus-Containing Polyacids

Macromolecules containing acidic fragments in side-groups—polyacids—occupy a special place among synthetic polymers. Properties and applications of polyacids are directly related to the chemical structure of macromolecules: the nature of the acidic groups, polymer backbone, and spacers between the main chain and acidic groups. The chemical nature of the phosphorus results in the diversity of acidic >P(O)OH fragments in sidechain phosphorus-containing polyacids (PCPAs) that can be derivatives of phosphoric or phosphinic acids. Sidechain PCPAs have many similarities with other polyacids. However, due to the relatively high acidity of −P(O)(OH)2 fragment, bone and mineral affinity, and biocompatibility, sidechain PCPAs have immense potential for diverse applications. Synthetic approaches to sidechain PCPAs also have their own specifics. All these issues are discussed in the present review.

Metal-Catalyzed Group-Transfer Polymerization: A Versatile Tool for Tailor-Made Functional (Co)Polymers

Accommodating the increasing demand for tailor-made polymers is a major goal in polymer chemistry. Therefore, the investigation of polymerization techniques, which allow the precise synthesis of macromolecules is of exceptional interest. Ionic or controlled radical polymerization are capable living-type methods for the generation of uniform polymers. However, even these approaches reach their limits in certain issues. In the last decades, group-transfer polymerization (GTP) and especially metal-catalyzed GTP have proven to give access to a plethora of tailor-made homo- and copolymers based on α,β-unsaturated monomers. Thereby, GTP has established its potential in the development of functional and smart polymers. This concept article highlights the most significant progress in metal-catalyzed GTP with a focus on functional (co)polymers including different polymeric architectures and microstructures.

Small-Scale Metal-Based Syntheses of Lanthanide Iodide, Amide, and Cyclopentadienyl Complexes as Analogues for Transuranic Reactions

Small-scale reactions of the Pu analogues La, Ce, and Nd have been explored in order to optimize reaction conditions for milligram scale reactions of radioactive plutonium starting from the metal. Oxidation of these lanthanide metals with iodine in ether and pyridine has been studied, and LnI₃(Et₂O)_x (1-Ln; x = 0.75-1.9) and LnI₃(py)₄ (2-Ln; py = pyridine, NC₅H₅) have been synthesized on scales ranging from 15 mg to 2 g. The THF adducts LnI₃(THF)₄ (3-Ln) were synthesized by dissolving 1-Ln in THF. The viability of these small-scale samples as starting materials for amide and cyclopentadienyl f-element complexes was tested by reacting KN(SiMe₃)₂, KCp' (Cp' = C₅H₄SiMe₃), KCp'' (Cp'' = C₅H₃(SiMe₃)₂-1,3), and KC₅Me₄H with 1-Ln generated in situ. These reactions produced Ln[N(SiMe₃)₂]₃ (4-Ln), Cp'₃Ln (5-Ln), Cp″₃Ln (6-Ln), and (C₅Me₄H)₃Ln (7-Ln), respectively. Small-scale samples of Cp'₃Ce (5-Ce) and Cp'₃Nd (5-Nd) were reduced with potassium graphite (KC₈) in the presence of 2.2.2-cryptand to check the viability of generating the crystallographically characterizable Ln²⁺ complexes [K(2.2.2-cryptand)][Cp'₃Ln] (8-Ln; Ln = Ce, Nd).

Multiresponsive micellar block copolymers from 2-vinylpyridine and dialkylvinylphosphonates with a tunable lower critical solution temperature

Tailor-made, multi-responsive micellar AB and ABB′ block copolymers show a pH-sensitivity and a tunable LCST within an expanded temperature range.