Small molecules bifunctional

Craig and coworkers also used metallopincer complexes to form supramolecular polymer networks [143, 144]. In their work, poly(4-vinylpyridine)s were synthesized and subsequently cross-linked by addition of small-molecule bifunctional palladium(II) or platinum(II) N,C,N-pincevs in dimethyl sulfoxide. With this approach, the authors were able to control the dynamic mechanical properties of the gels, as discussed in detail in the Sect. 2.3. 

Separation media, with bimodal chemistry, are generally designed for the complete separation of complex samples, such as blood plasma serum, that typically contain molecules differing in properties such as size, charge, and polarity. The major principle of bifunctional separation relies on the pore size and functional difference in the media. For example, a polymer bead with hydrophilic large pores and hydrophobic small pores will not interact with and retain large molecules such as proteins, but will interact with and retain small molecules such as drugs and metabolites. 

Liu S (2005) 6-Hydrazinonicotinamide Derivatives as Bifunctional Coupling Agents for "mTc-Labeling of Small Biomolecules. 252 117-153 Liu S, Robinson SP, Edwards DS (2005) Radiolabeled Integrin avp Antagonists as Radio-pharmaceuticals for Tumor Radiotherapy. 252 193-216 Liu XY (2005) Gelation with Small Molecules from Formation Mechanism to Nanostructure Architecture. 256 1-37... 

Roth, K.M., Zhou, Y., Yang, W. and Morse, D.E. (2005) Bifunctional small molecules are biomimetic catalysts for silica synthesis at neutral pH. Journal of the American Chemical Society, 127, 325-330. 

Condensation polymerizations (polycondensations) are stepwise reactions between bifunctional or polyfunctional components, with elimination of small molecules such as water, alcohol, or hydrogen and the formation of macromo-lecular substances. For the preparation of linear condensation polymers from bifunctional compounds (the same considerations apply to polyfunctional compounds which then lead to branched, hyperbranched, or crosslinked condensation polymers) there are basically two possibilities. One either starts from a monomer which has two unlike groups suitable for polycondensation (AB type), or one starts from two different monomers, each possessing a pair of identical reactive groups that can react with each other (AABB type). An example of the AB type is the polycondensation of hydroxycarboxylic acids ... 

In a similar way as has been described for syntheses of type al, the majority of examples of type b involve polycondensation of a,ea bifunctional, small molecule reaction partners. Some examples are the reaction of AIBN or AIBN derivatives with 1,4-cyclohexane bismethyl diamine78), 1,2-ethylene diamine78), 1,6-hexamethylene diamine 78-80 , bisphenol A 78,81 and mono-, di- and tetraethylene glycol 55-64 . In almost all case using the AIBN derivative 4,4 -azobis(4-cyano valeryl chloride), an interfacial polymerization was employed. These polymeric azo compounds could be used as initiators for radical block copolymerizations. 

Unlike conventional steric exclusion sorbents, RAM sorbents exhibit bifunctional or dual-zone character, in that the inner and outer surfaces are different. The outer surface is designed to exclude macromolecules physically and is rendered chemically hydrophilic to discourage retention of biomolecules. Small molecules penetrate to an inner surface, where they are retained by any of the various other sorptive surface chemistries already discussed [92],... 

Domine and Gogos (88-90) considered a very long, very wide, and thin mold being fed by a constant temperature mixture of AA, BB molecules. Both types are bifunctional and the feed has a molecular weight Mq. The polymerization, assumed to be reversible, proceeds by the reaction of A-ends with B-ends, and follows idealized step polymerization (condensation) kinetics without the generation of a small molecule (91). Specifically, we have... 

Essentially, two types of unsaturated bifunctional compound display the capability of being condensed in high yield, via a transition metal-catalysed carbon-carbon coupling reaction, into their requisite generic high molecular weight polymers plus a small molecule non-conjugated acyclic dialkenes and haloaromatic derivatives. 

Huang, L. Yuan, X. Aiken, C. Chen, C. H. Bifunctional anti-human immunodeficiency virus t3fpe 1 small molecules with two novel mechanisms of action. Antimicrob. Agents Chemother, 2004, 48 663—665. 

Condensation polymerisation occurs when multifunctional monomers, which possess more than one chemically reactive group per molecule, react together with the elimination of small molecules, typically either water or HC1. With a bifunctional monomer the product is a linear polymer, e.g. the polyamide Nylon-6 is derived from e-amino caproic acid as follows ... 

Verdine utilized RCM as a key step in the synthesis of a library of bifunctional small molecules to screen for heterodimerizer (potential synthetic antitumor agents)... 

Figure 4 Architecture of three-hybrid screens, (a) The classic, small-molecule-based, three-hybrid platform is shown. The three components of this systems are a DNA-binding protein fused to a known drug-binding domain (X), a bifunctional small molecule that binds X on one end and displays a query "bait" on the other, and a library of possible "prey" proteins (V) expressed as fusions to transcriptional activation domains. Assembly of the ternary complex recruits the activation domain to the promoter and initiates reporter gene expression. A partial list of examples is shown in the inset boxes because of space constraints, some relevant systems are absent, (b) The RNA-based, three-hybrid is assembled in a similar fashion except that the bifunctional ligand is an RNA molecule. The complex between the MS2 RNA and the MS2-coat protein is typically used as the anchoring interaction.

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