The physical properties, including the solid state arrangement, photophysics, solubility, and electrochemical behavior of a series of halo-BsubPcs (halo = F, Cl, Br) have been measured (IUPAC name halo-(7,12:14,19-diimino-21,5-nitrilo-5H-tribenzo(c,h,m)(1,6,11)triazacyclopentadecinato)-boron(III)). We have found that across the series all are relatively similar in most regards. Exceptions include that F-BsubPc can be 5 to 25 times more soluble than Cl-BsubPc in common organic solvents. F-BsubPc was also found to be hydrolytically stable under the conditions tested, whereas Cl-BsubPc and Br-BsubPc readily hydrolyzed to form HO-BsubPc. The relative rates of reaction for the series of halo-BsubPcs under standard phenoxylation conditions have also been measured. It was found that F-BsubPc does not undergo phenoxylation, whereas Br-BsubPc showed a markedly higher reaction rate relative to Cl-BsubPc. Based on these data some assumptions can be made as to the suitability of either F-BsubPc or Br-BsubPc to be used in place of the more common Cl-BsubPc. The data indicate that F-BsubPc is a potential replacement for Cl-BsubPc in organic electronic materials whereas Br-BsubPc might be more suitable as a chemical intermediate. Comments on the synthetic methods used to produce each halo-BsubPc are also made.

We report the synthesis and characterization of a series of boronsubphthalocyanine (BsubPc) dyes which have organic solubility >10 À2 M while being amenable to doping into polymeric films. To achieve high solubility we have placed the 3-pentadecylphenoxy molecular fragment in a variety of positions within the BsubPc chemical structure including around the periphery of the BsubPc ligand and in the axial position to the boron atom. We have found that placement of the 3-pentadecylphenoxy molecular fragment around the periphery adversely affects the photostability of the resulting BsubPc whereas placement in the axial position has little effect. We also confirm that the presence of fluorine atoms around the periphery improves the photostability. Overall we present a systematic study of the 3-pentadecylphenoxy fragment as a solubilizing moiety for BsubPc. The nature of the substituents and their position does not affect the nearly pure magenta color characteristic of BsubPc derivatives.

Reductive amination facilitates the protecting group free post-polymerization functionalisation of a temperature responsive, aldehyde-containing polymer with histidine.

Amino acids are the natural building blocks for the world around us. Highly functional, these small molecules have unique catalytic properties, chirality, and biocompatibility. Imparting these properties to surfaces and other macromolecules is highly sought after and represents a fast-growing field. Polymers functionalized with amino acids in the side chains have tunable optical properties, pH responsiveness, biocompatibility, structure and self-assembly properties. Herein, we review the synthesis of amino acid functional polymers, discuss manipulation of available strategies to achieve the desired responsive materials, and summarize some exciting applications in catalysis, chiral particles, and drug delivery.

The copolymerization of N-isopropylacrylamide (NiPAm) with aldehyde functional monomers facilitates postpolymerization functionalization with amino acids via reductive amination, negating the need for protecting groups. In reductive amination, the imine formed from the condensation reaction between an amine and an aldehyde is reduced to an amine. In this work, we categorize amino acids into four classes based on the functionality of their side chains (acidic, polar neutral, neutral, and basic) and use their amine groups in condensation reactions with aldehyde functional polymers. The dynamic nature of the imine as well as the versatility of reductive amination to functionalize a polymer with a range of amino acids is highlighted. In this manner, amino acid functional polymers are synthesized without the use of protecting groups with high yields, demonstrating the high functional group tolerance of carbonyl condensation chemistry and the subsequent reduction of the imine. Prior to the reduction of the imine bond, transimination reactions are used to demonstrate dynamic polymers that shuffle from a glycine- to a histidine-functional polymer.

The study of the mechanical behavior of cells is an active area of academic research and as such, is an increasingly important component of biomedical engineering education. However, in delivering engineering courses, practical experience with experimental cell mechanics is often challenging to provide for untrained undergraduate students, as the lab work involved is expensive, delicate and usually requires substantial experimental skill. This article reports the development of a novel lab experience for senior undergraduate students, for which a microfabricated system was designed and constructed to conduct micropipette aspiration of single cells. Application of the microfabricated system to measure the elastic modulus of primary heart valve fibroblasts produced results comparable to those made with a conventional micropipette aspiration system. The relative simplicity and affordability of the system made it accessible to undergraduate students in a laboratory course, who judged the lab as a strongly positive learning experience.

Histidine functional block copolymers are thermally self‐assembled into polymer micelles with poly‐N‐isopropylacrylamide in the core and the histidine functionality in the corona. The thermally induced self‐assemblies are reversible until treated with Cu2+ ions at 50 °C. Upon treatment with 0.5 equivalents of Cu2+ relative to the histidine moieties, metal‐ion coordination locks the self‐assemblies. The self‐assembly behavior of histidine functional block copolymers is explored at different values of pH using DLS and 1H NMR. Metal‐ion coordination locking of the histidine functional micelles is also explored at different pH values, with stable micelles forming at pH 9, observed by DLS and imaged by atomic force microscopy. The thermal self‐assembly of glycine functional block copolymers at pH 5, 7, and 9 is similar to the histidine functional materials; however, the self‐assemblies do not become stable after the addition of Cu2+, indicating that the imidazole plays a crucial role in metal‐ion coordination that locks the micelles. The reversibility of the histidine‐copper complex locking mechanism is demonstrated by the addition of acid to protonate the imidazole and destabilize the polymer self‐assemblies. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1964–1973

A highly efficient photoinitiated flocculation system formed through the trapping of a photogenerated thiobenzaldehyde with polyethylenimine was developed. This photoresponsive system provides spatial and temporal control over flocculation processes and has been applied to heavy metal flocculation.