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Strong Intermolecular Interaction (strong + intermolecular_interaction)

Distribution by Scientific Domains

Chemistry	80%

Selected Abstracts

The structure and dynamic properties of nitrile,butadiene rubber/poly(vinyl chloride)/hindered phenol crosslinked composites

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008
Ping Xiang
Abstract In this article, a new nitrile,butadiene rubber (NBR) crosslinked composites containing poly(viny chloride) (PVC) and hindered phenol (AO-80 and AO-60) was successfully prepared by melt-blending procedure. Microstruture and dynamic mechanical properties of the composites were investigated using SEM, DSC, XRD, and DMTA. Most of hindered phenol was dissolved in the NBR/PVC matrix and formed a much fine dispersion. The results of DSC and DMTA showed that strong intermolecular interaction was formed between the hindered phenol and NBR/PVC matrix. The NBR/PVC/AO-80 crosslinked composites showed only one transition with higher glass transition temperature and higher tan , value than the neat matrix, whereas for the NBR/PVC/AO-60 crosslinked composites, a new transition appeared above the glass transition temperature of matrix, which was associated with the intermolecular interaction between AO-60 and PVC component of the matrix. Both AO-80 and AO-60 in the crosslinked composites existed in amorphous form. Furthermore, the chemical crosslinking of composites resulted in better properties of the materials, e.g., considerable tensile strength and applied elastic reversion. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]

3,9-Bis(dicyanomethylene)-2,4,8,10-tetrathiaspiro[5.5]undecane

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2001
Zheng-Rong Zhou
The title compound, 2,2,-(2,4,8,10-tetrathiaspiro[5.5]undecane-3,9-diylidene)bis(propanedinitrile), C13H8N4S4, has been designed and synthesized for use as a potential new organic molecular electronic material. The spiro-annulated structure has twofold symmetry and is formed by two equal push,pull ethylene units, with the cycloalkylthio groups as electron donors and the cyano groups as electron acceptors. The intermolecular S,N non-bonded separation within a layer in the lattice is 3.296,(6),Å, indicating a strong intermolecular interaction between the cyano groups and the S atoms, while the S atoms in two neighbouring molecules have a shortest S,S contact of 3.449,(3),Å. In addition, attractive C,H,N and C,H,S interactions bridge adjacent molecules either within a layer or between layers. In short, these four types of intermolecular interactions combine to form an extended three-dimensional network in the lattice, resulting in a highly ordered array of molecular packing. [source]

,-Conjugated Dendrimers as Stable Pure-Blue Emissive Materials: Photophysical, Electrochemical, and Electroluminescent Properties

CHEMISTRY - AN ASIAN JOURNAL, Issue 4 2009
Yang Jiang
Abstract Bigger, stronger, better: A family of giant ,-conjugated dendrimers has been developed as pure-blue active materials for organic light-emitting diodes. The dendrimer-generation number has little effect on the photophysical, electrochemical, and EL properties, and device efficiency of G0 and G1. The preliminary OLED devices achieve pure-blue color with stable CIE chromaticity coordinates (0.16, 0.08) for both G0 and G1. A family of giant ,-conjugated dendrimers has been developed as pure-blue active materials for organic light-emitting diodes (OLEDs). The investigation of their photophysical properties indicates that G0 and G1 exhibit almost the same absorption and PL spectra in dilute solutions and in thin films. The steric hindrance of the bulky dendrimers effectively prevents strong intermolecular interaction in the solid state, which effectively improves the emission spectral stability. Preliminary OLEDs fabricated with the configuration of ITO/PEDOT:PSS/PVK/dendrimer/TPBI/Ba/Al achieve a pure-blue emission with stable CIE chromaticity coordinates (0.16, 0.08) for both G0 and G1. These results indicate that G0 and G1 are promising blue-light emitting materials with good stability. Such strategy provides us a platform to achieve pure-blue emitting dendrimer-like materials with high efficiency for use as OLEDs. [source]

Synthesis of Carrier-Transporting Dendrimers with Perylenebis(dicarboximide)s as a Luminescent Core

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 4 2006
Jianfeng Pan
Abstract Well-defined, modular dendrimers enable processing techniques and electronic properties to be tuned independently. Moreover, the dendritic topology can isolate the core chromophore, thus reducing or eliminating strong intermolecular interactions. This paper presents the synthesis of three series of flexible, dendron-functionalized dendrimers as red-light-emitting materials by a convergent approach: (1) carbazole (CZ) or oxadiazole (OXZ) terminated imide-type dendrimers, (2) cascade energy-transferring imide-type dendrimers, and (3) CZ-terminated perylene bay-type dendrimers. They all consist of the luminescent core of perylenebis(dicarboximide)s with specific functional groups of CZ or OXZ at the periphery and are constructed from flexible Fréchet-type poly(aryl ether) dendrons. The chemical structures of the dendrons and dendrimers were determined by standard spectroscopic techniques including 1H and 13C NMR spectroscopy and low/high-resolution mass spectrometry (ESI or MALDI-TOF). The dendrimers are designed on the basis of the following considerations: (1) dendron functionalization to incorporate CZ or OXZ units to realize the carrier-injection adjustment, (2) tuning or improving solubility, functionality, glass-transition temperature (Tg) with well-defined dendrons, and (3) avoiding luminescence quenching with the help of high site-isolation of dendrons to enhance core luminescence. DSC results indicate that the incorporation of Fréchet-type poly(aryl ether) dendrons can improve the amorphous properties and increase Tg. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source]

5-(4,5-Ethylenedithio-1,3-dithiol-2-ylidene)-1,3,4,6-tetrathiapentalen-2-one (EDTO,TTP) and 5-[4,5-(ethene-1,2-diyldithio)-1,3-dithiol-2-ylidene]-1,3,4,6-tetrathiapentalen-2-one (VDTO,TTP)

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 5 2009
Hong-Feng Chen
The title sulfur-rich organic molecular crystals, namely EDTO,TTP (C9H4OS8) and VDTO,TTP (C9H2OS8), are characterized by conjugated C,S bonds and S...S intermolecular short contacts. The planar EDTO,TTP molecules are parallel packed and exhibit strong intermolecular interactions, including side-by-side transverse S...S contacts, face-to-face longitudinal ,,, interactions and C,H...O hydrogen bonding. On cooling the EDTO,TTP crystal from 220 to 120,K, the cell dimensions and the intermolecular distances (such as S...S contacts and especially ,,, spacings) become shorter, while the intramolecular bonds become longer. The curved VDTO,TTP molecules are packed in such a way as to make the crystal fully depolarized. The intermolecular interactions of the VDTO,TTP crystal are relatively weak, because of the weak ,,, interactions and the lack of hydrogen bonding. [source]