Molecular structure, supramolecular organization and thermotropic phase behavior of N -acylglycine alkyl esters with matched acyl and alkyl chains

2017 ◽  
Vol 208 ◽  
pp. 43-51 ◽  
Author(s):  
S.Thirupathi Reddy ◽  
Musti J. Swamy
Keyword(s):  
Molecular Structure ◽  
Phase Behavior ◽  
Supramolecular Organization ◽  
Alkyl Esters ◽  
Alkyl Chains

scholarly journals Thin-film materials based on phthalocyanine derivatives: structure and physico-chemical properties

2019 ◽  
Vol 30 ◽  
pp. 08006
Author(s):  
Alexandr Kazak ◽  
Margarita Marchenkova ◽  
Antonina Smirnova ◽  
Tatiana Dubinina ◽  
Alexey Seregin ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Thin Film ◽  
Water Surface ◽  
Chemical Properties ◽  
Lattice Parameter ◽  
Complexing Agent ◽  
Supramolecular Organization ◽  
Structure Parameters ◽  
Physico Chemical ◽  
Layer Packing

In order to establish the effect of the molecular structure of mix-substituted phthalocyanine derivatives on its supramolecular organization in thin-films, the floating layers of three A3B-type phthalocyanine derivatives were obtained. Their supramolecular organization was determined and it was found that the studied compounds form homogeneous stable floating layers on the water surface. Structure parameters of floating layers depend both on the length of aliphatic substituents (R = CnH2n+1) and the metal complexing agent. Ligands I and II form stable monolayer structures, which the layer packing periods increase with the elongation of aliphatic substituents: the lattice parameter (d) is 1.93 and 2.3 nm for ligands I (n = 6) and II (n = 8), correspondingly. During further compression of the formed monolayers, ligands I and II form stable bilayers, in which the arrangement of molecules remains similar to the structure of the previous monolayers. These bilayers contain minor inclusions of 3D aggregates. Metal complex III forms only stable monolayer (d = 2.06 nm), upon further compression of which 3D- aggregates included in the monolayer are formed.

Synthesis, Structures, and Conformations of Linked Bis-Glyoxylamides Derived from Bis-Acylisatins

2014 ◽  
Vol 67 (9) ◽  
pp. 1270 ◽  
Author(s):  
Venty Suryanti ◽  
Glenn C. Condie ◽  
Mohan Bhadbhade ◽  
Roger Bishop ◽  
David StC. Black ◽  
...  
Keyword(s):  
Amino Acid ◽  
Crystal Structures ◽  
Intermolecular Interactions ◽  
Ring Opening ◽  
Alkyl Esters ◽  
Alkyl Chains

A series of bis-glyoxylamides possessing hydrophobic alkyl chains was successfully synthesised by ring opening of bis-acylisatins with amines or amino acid alkyl esters. The crystal structures revealed the interplay of intra- and intermolecular interactions (NH···O and C=O···C=O interactions) and the conformations of these long molecules.

scholarly journals Molecular structure and melting: implications for phase change materials

2018 ◽  
Vol 96 (7) ◽  
pp. 722-729 ◽  
Author(s):  
John A. Noël ◽  
Samer Kahwaji ◽  
Mary Anne White
Keyword(s):  
Molecular Structure ◽  
Phase Change ◽  
Phase Change Materials ◽  
Alkyl Chains ◽  
Melting Temperatures ◽  
Enthalpy Changes ◽  
Melting Properties ◽  
Load Leveling ◽  
The Relationship ◽  
Selection Of

Phase change materials (PCMs) offer a promising technology for thermal energy storage, load leveling, and peak shifting applications. A desirable PCM has a melting temperature within the temperature boundaries of its application and a high change in enthalpy on melting. Knowledge of the relationships between these thermodynamic properties and molecular structure would advance informed selection of PCM candidates for a given application. In the present investigation, the relationship between structure (length of alkyl chains) and melting properties has been investigated for isomeric esters, showing that esters containing longer individual alkyl chains have higher melting temperatures and higher enthalpy changes on melting. The melting entropy changes, however, are relatively independent of the alkyl chain distribution.

scholarly journals Effect of Molecular Structure on Electrochemical Phase Behavior of Phospholipid Bilayers on Au(111)

Langmuir ◽  
2021 ◽  
Vol 37 (40) ◽  
pp. 11887-11899
Author(s):  
Philip N. Jemmett ◽  
David C. Milan ◽  
Richard J. Nichols ◽  
Liam R. Cox ◽  
Sarah L. Horswell
Keyword(s):  
Molecular Structure ◽  
Phase Behavior ◽  
Phospholipid Bilayers

scholarly journals Organic Phase Change Materials for Thermal Energy Storage: Influence of Molecular Structure on Properties

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6635
Author(s):  
Samer Kahwaji ◽  
Mary Anne White
Keyword(s):  
Molecular Structure ◽  
Phase Change ◽  
Thermal Energy ◽  
Phase Change Materials ◽  
Lower Cost ◽  
Alkyl Chains ◽  
Melting Temperatures ◽  
Wide Range ◽  
Efficient Packing ◽  
The Relationship

Materials that change phase (e.g., via melting) can store thermal energy with energy densities comparable to batteries. Phase change materials will play an increasing role in reduction of greenhouse gas emissions, by scavenging thermal energy for later use. Therefore, it is useful to have summaries of phase change properties over a wide range of materials. In the present work, we review the relationship between molecular structure and trends in relevant phase change properties (melting temperature, and gravimetric enthalpy of fusion) for about 200 organic compounds from several chemical families, namely alkanes (paraffins), fatty acids, fatty alcohols, esters, diamines, dinitriles, diols, dioic acids, and diamides. We also review availability and cost, chemical compatibility, and thermal and chemical stabilities, to provide practical information for PCM selection. Compounds with even chain alkyl lengths generally give higher melting temperatures, store more thermal energy per unit mass due to more efficient packing, and are of lower cost than the comparable compounds with odd alkyl chains.

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