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• 106-96-7 propargyl bromide 
• 75-50-3 trimethylamine 
• 6340-39-2 (2,3-dibromo-propyl)-trimethyl-ammonium; bromide 
• 100312-98-9 C₆H₁₁⁽³⁾HN⁽¹⁺⁾*Br^(1-) 

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• 75-50-3 trimethylamine 
• 880-09-1 di(N-piperidinyl)methane 

Relevant academic research and scientific papers

Polyelectrolyte-induced self-assembly of positively charged alkynylplatinum (II)-terpyridyl complexes in aqueous media

Polyelectrolytes carrying multiple negative charges were found to induce the aggregation and self-assembly of the positively charged platinum(II)- terpyridyl complexes in aqueous media. The aggregation and self-assembly of the complexes were driven by electrostatic interactions between the polymer and the complex, and by terpyridine ligand π-π stacking and platinum-platinum (metal-metal) interactions. As a result, remarkable UV/ Vis and emission spectral changes were observed. The spectroscopic property changes were related to the structural properties of the metal complexes as well as the polyelectrolytes. The induced self-assembly of the platinum complexes was also strongly affected by the solution properties of the aqueous media, for example, the solution pH, ionic strength, and the percentage of organic solvent added.

Creation of hierarchical carbon nanotube assemblies through alternative packing of complementary semi-artificial β-1,3-glucan/carbon nanotube composites

Much attention has been focused on exploiting novel strategies for the creation of hierarchical polymer assemblies by the control of the assembling number or the relative location among neighboring polymers. We here propose a novel strategy toward the creation of "hierarchical" single-walled carbon nanotube (SWNT) architectures by utilizing SWNT composites with cationic or anionic complementary semiartificial β-1,3-glucans as "building blocks". These β-1,3-glucans are known to wrap SWNTs helically, to create one-dimensional superstructural composites. If the cationic composite is neutralized by an anionic composite, a well ordered SWNT-based sheet structure was created. Transmission electron microscopy (TEM) observation revealed that this sheet structure is composed of highly-ordered fibrous assemblies of SWNTs. This suggests that the cationic and anionic composites are tightly packed through electrostatic interactions. Moreover, both of the final assembly structures are readily tunable by adjusting the cation/anion ratio. The self-assembling modulation of functional polymers is associated with the progress in ultimate nanotechnologies, thus enabling us to create numerous functional nanomaterials. We believe, therefore, that the present system will extend the frontier of SWNT research to assembly chemistry including "hierarchical" superstructures.

On-Nanoparticle Gating Units Render an Ordinary Catalyst Substrate- And Site-Selective

When an organometallic catalyst is tethered onto a nanoparticle and is embedded in a monolayer of longer ligands terminated in "gating"end-groups, these groups can control the access and orientation of the incoming substrates. In this way, a nonspecific catalyst can become enzyme-like: it can select only certain substrates from substrate mixtures and, quite remarkably, can also preorganize these substrates such that only some of their otherwise equivalent sites react. For a simple, copper-based click reaction catalyst and for gating ligands terminated in charged groups, both substrate- and site-selectivities are on the order of 100, which is all the more notable given the relative simplicity of the on-particle monolayers compared to the intricacy of enzymes' active sites. The strategy of self-assembling macromolecular, on-nanoparticle environments to enhance selectivities of "ordinary"catalysts presented here is extendable to other types of catalysts and gating based on electrostatics, hydrophobicity, and chirality, or the combinations of these effects. Rational design of such systems should be guided by theoretical models we also describe.

Enzyme-like Click Catalysis by a Copper-Containing Single-Chain Nanoparticle

A major challenge in performing reactions in biological systems is the requirement for low substrate concentrations, often in the micromolar range. We report that copper cross-linked single-chain nanoparticles (SCNPs) are able to significantly increase the efficiency of copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC) reactions at low substrate concentration in aqueous buffer by promoting substrate binding. Using a fluorogenic click reaction and dye uptake experiments, a structure-activity study is performed with SCNPs of different size and copper content and substrates of varying charge and hydrophobicity. The high catalytic efficiency and selectivity are attributed to a mechanism that involves an enzyme-like substrate binding process. Saturation-transfer difference (STD) NMR spectroscopy, 2D-NOESY NMR, kinetic analyses with varying substrate concentrations, and computational simulations are consistent with a Michaelis-Menten, two-substrate, random-sequential enzyme-like kinetic profile. This general approach may prove useful for developing more-sustainable catalysts and agents for biomedicine and chemical biology.

Efficient synthesis of water-soluble calixarenes using click chemistry

(Chemical Equation Presented) Several water-soluble calix[4]arenes were synthesized via Huisgen 1,3-dipolar cycloaddition between azides and alkynes. Cationic, anionic, and nonionic calixarenes were prepared from a common azidocalixarene intermediate. Azidocalixarenes performed better than alkynylcalixarenes as precursors. The aggregation behavior of the water-soluble calixarenes was studied by 1H NMR spectroscopy.

Rates of Base-Catalyzed Hydrogen Exchange of Terminal Acetylenes in Aqueous Solution. Absence of Resonance Interaction

Rates of detritiation of 13 monosubstituted acetylenes labeled at the acetylenic hydrogen position were measured in aqueous amine buffer solution at 25 deg C, and hydroxide ion catalytic coefficients were evaluated.These rate constants, plus a few additional values from the literature, give a good correlation against inductive or field substituent constants: log(kHO-/M-1s-1) = 1.46+/-0.12 + (8.00+/-0.50)?I.This correlation is not improved by addition of resonance substituted constants, and the coefficients of the resonance term in two different dual parameter (resonance plus field) treatments of the data are in fact zero.