- Heterocyclic derivatives of long-chain diacetylenic acids
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Acyl derivatives of 2-aminopyridine, 2-aminopyrimidine, 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl, and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl were obtained form long-chain diacetylenic acyl chlorides and the corresponding heterocyclic compounds.Spreading isotherms of monolayers on a water surface show that lengthening of the hydrocarbon chain and replacement of the pyridyl groups in these compounds by the more hydrophilic pyrimidyl groups render the films more condensed.Long-chain acyl derivatives of nitroxyl radicals form monolayers possesing a low collapse pressure.ESR spectra on Langmuir-Blodgett films of these radicals before and after photopolymerization were recorded. - Keywords: long-chain diacetylenic acids, N-pyridyl and N-pyrimidylamides of alkanediynic acids, long-chain derivatives of nitroxyl radicals, synthesis, monolayers, Langmuir-Blodgett films
- Usov, O. M.,Tret'yakov, E. V.,Sveshnikova, L. L.,Shvartsberg, M. S.
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- Plenty of Room at the Top: A Multi-Scale Understanding of nm-Resolution Polymer Patterning on 2D Materials
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Lamellar phases of alkyldiacetylenes in which the alkyl chains lie parallel to the substrate represent a straightforward means for scalable 1-nm-resolution interfacial patterning. This capability has the potential for substantial impacts in nanoscale electronics, energy conversion, and biomaterials design. Polymerization is required to set the 1-nm functional patterns embedded in the monolayer, making it important to understand structure–function relationships for these on-surface reactions. Polymerization can be observed for certain monomers at the single-polymer scale using scanning probe microscopy. However, substantial restrictions on the systems that can be effectively characterized have limited utility. Here, using a new multi-scale approach, we identify a large, previously unreported difference in polymerization efficiency between the two most widely used commercial diynoic acids. We further identify a core design principle for maximizing polymerization efficiency in these on-surface reactions, generating a new monomer that also exhibits enhanced polymerization efficiency.
- Brooks, Jacob T.,Claridge, Shelley A.,Davis, Tyson C.,Hayes, Tyler R.,Shi, Anni,Singh, Anamika,Villarreal, Terry A.
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supporting information
p. 25436 - 25444
(2021/10/29)
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- Polyacetylenic lipids, radiation-sensitive compositions, photographic elements and processes relating to same
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A photopolymerizable monomer comprising a lipid having at least one hydrophobic acyl chain containing at least two conjugated acetylenic linkages is useful in preparing radiation-sensitive compositions and photographic elements comprising a plurality of liposomes. Further, processes for photopolymerizing the radiation-sensitive compositions and for forming an image in the photographic elements comprise exposing the lipid to radiation, heating the lipid to a temperature equal to or above a first transition temperature of the lipid to render it insensitive to further exposure, and optionally cooling the lipid to a temperature equal to or below a seocnd phase transition temperature of the lipid to render it again sensitive to further exposure. The monomeric lipids, when photopolymerized, form polymeric lipids exhibiting decreased solubility and liposome wall permeability as compared to the unpolymerized monomeric lipids.
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