Intrinsically heat-sealable polyimide films with atomic oxygen resistance: Synthesis and characterization

2020 ◽  
Vol 32 (8) ◽  
pp. 902-913 ◽  
Author(s):  
Hongjiang Ni ◽  
Yu Xing ◽  
Xiaoxiang Dai ◽  
Daijun Zhang ◽  
Jun Li ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Mechanical Property ◽  
Thermal Resistance ◽  
Mechanical Strength ◽  
Phosphine Oxide ◽  
Atomic Oxygen ◽  
Synthesis And Characterization ◽  
Polyimide Films ◽  
Diphenylphosphine Oxide ◽  
Oxide Group

Intrinsically heat-sealable polyimides with atomic oxygen (AO) resistance (ARPIs) were synthesized from 2,3,3′,4′-oxydiphthalic anhydride (aODPA), 2,5-bis[(4-aminophenoxy)phenyl]diphenylphosphine oxide (BADPO), and para-phenylenediamine (PDA). The effects of the molecular structure and diamine ratio were investigated on the properties of the ARPI, including mechanical property, thermal property, heat sealability, and AO resistance. Heat sealability and AO resistance were realized for the ARPI film by combining the asymmetry of the aODPA moiety and the passivated layer forming characteristic of diphenylphosphine phosphine oxide group. Meanwhile, the deficiency of low mechanical strength and thermal resistance, commonly existing in a completely BADPO-derived polyimide system, was remedied effectively by the higher reactivity and rigidity of PDA.

scholarly journals Theoretical Study of the Structures of 4-(2,3,5,6-Tetrafluoropyridyl)Diphenylphosphine Oxide and Tris(Pentafluorophenyl)Phosphine Oxide: Why Does the Crystal Structure of (Tetrafluoropyridyl)Diphenylphosphine Oxide Have Two Different P=O Bond Lengths?

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2778
Author(s):  
Joseph R. Lane ◽  
Graham C. Saunders
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Phosphine Oxide ◽  
Density Functional ◽  
Lone Pair ◽  
Diphenylphosphine Oxide ◽  
Functional Theory ◽  
Weak Hydrogen Bonding ◽  
Independent Molecules ◽  
The Difference

The crystal structure of 4-(2,3,5,6-tetrafluoropyridyl)diphenylphosphine oxide (1) contains two independent molecules in the asymmetric unit. Although the molecules are virtually identical in all other aspects, the P=O bond distances differ by ca. 0.02 Å. In contrast, although tris(pentafluorophenyl)phosphine oxide (2) has a similar crystal structure, the P=O bond distances of the two independent molecules are identical. To investigate the reason for the difference, a density functional theory study was undertaken. Both structures comprise chains of molecules. The attraction between molecules of 1, which comprises lone pair–π, weak hydrogen bonding and C–H∙∙∙arene interactions, has energies of 70 and 71 kJ mol−1. The attraction between molecules of 2 comprises two lone pair–π interactions, and has energies of 99 and 100 kJ mol−1. There is weak hydrogen bonding between molecules of adjacent chains involving the oxygen atom of 1. For one molecule, this interaction is with a symmetry independent molecule, whereas for the other, it also occurs with a symmetry related molecule. This provides a reason for the difference in P=O distance. This interaction is not possible for 2, and so there is no difference between the P=O distances of 2.

scholarly journals Arene Ruthenium Metalla-Assemblies with Anthracene Moieties for PDT Applications

Inorganics ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 97 ◽  
Author(s):  
Marie Gaschard ◽  
Farzaneh Nehzat ◽  
Thomas Cheminel ◽  
Bruno Therrien
Keyword(s):  
Molecular Structure ◽  
Single Crystal ◽  
General Formula ◽  
Structure Analysis ◽  
White Light ◽  
Light Irradiation ◽  
Synthesis And Characterization ◽  
X Ray

The synthesis and characterization of three metalla-rectangles of the general formula [Ru4(η6-p-cymene)4(μ4-clip)2(μ2-Lanthr)2][CF3SO3]4 (Lanthr: 9,10-bis(3,3’-ethynylpyridyl) anthracene; clip = oxa: oxalato; dobq: 2,5-dioxido-1,4-benzoquinonato; donq: 5,8-dioxido-1,4-naphthoquinonato) are presented. The molecular structure of the metalla-rectangle [Ru4(η6-p-cymene)4(μ4-oxa)2(μ2-Lanthr)2]4+ has been confirmed by the single-crystal X-ray structure analysis of [Ru4(η6-p-cymene)4(μ4-oxa)2(μ2-Lanthr)2][CF3SO3]4 · 4 acetone (A2 · 4 acetone), thus showing the anthracene moieties to be available for reaction with oxygen. While the formation of the endoperoxide form of Lanthr was observed in solution upon white light irradiation, the same reaction does not occur when Lanthr is part of the metalla-assemblies.

Sign in / Sign up

Export Citation Format

Share Document