107984-01-0Relevant articles and documents
Synthesis of nano-pore size Al(III)-imprinted polymer for the extraction and preconcentration of aluminum ions
Shakerian, Farid,Dadfarnia, Shayessteh,Shabani, Ali Mohammad Haji
, p. 669 - 676 (2013)
In this study, an ion imprinted polymer (IIP) was prepared for the selective separation and preconcentration of trace levels of aluminum. Al(III) IIP was synthesized in the presence of Al(III)-8-hydroxyquinoline (oxine) complex using styrene and ethylene glycol dimethacrylate as a monomer and crosslinker, respectively. The imprinted Al(III) ions were completely removed by leaching the IIP with HCl (50 % v/v) and were characterized by FTIR and scanning electron microscopy. The maximum sorption capacity for Al(III) ions was found to be 3.1 mg g-1 at pH 6.0. Variables affecting the IIP solid phase extraction were optimized by the univariable method. Under the optimized conditions, a sample volume of 400 mL resulted in an enhancement factor of 194. The detection limit (defined as 3 S b/m) was found to be 1.6 μg L-1. The method was successfully applied to the determination of aluminum in natural water, fruit juice and cow milk samples.
The effect of electron donating and withdrawing groups on the morphology and optical properties of Alq3
Duvenhage,Visser,Ntwaeaborwa,Swart
, p. 46 - 49 (2014)
By adding electron donating (EDG) and withdrawing groups (EWG) to the Tris-(8-hydroxyquinoline) aluminum (Alq3) molecule, the emission color can be tuned. In this study the effect of EDG and EWG on the morphology and optical properties of Alq3 were investigated. Alq3 powders was synthesized with an EDG (-CH3) substituted at positions 5 and 7 ((5,7-dimethyl-8-hydroxyquinoline) aluminum) and EWG (-Cl) at position 5 ((5-chloro-8-hydroxyquinoline) aluminum). A broad absorption band at ~380 nm was observed for Alq3. The bands of the substituted samples were red-shifted. The un-substituted Alq3 showed a high intensity emission peak at 500 nm. The -Cl and -CH3 samples showed a red-shift of 33 and 56 nm respectively. The morphology of the samples was studied using a scanning electron microscope. The photo degradation of the samples was also investigated and the dimethyl sample shows the least degradation to the UV irradiation over the 24 h of continuous irradiation.
Synthesis of reactive [Al(Et)(q′)2] (q′ = 2-methyl-8-quinolinolato) serving as a precursor of light emitting aluminum complexes: Reactivity, optical properties, and fluxional behavior of the aluminum complexes
Iijima, Takayuki,Yamamoto, Takakazu
, p. 5016 - 5023 (2006)
Reaction of AlEt3 with 2-methyl-8-quinolinol gave ethylbis(2-methyl-8-quinolinolato)aluminum complex [Al(Et)(q′)2] 1. The complex 1 provided photoluminescent Al complexes by reactions with phenols, carboxylic acid, and H2O. The α-CH2 hydrogens in the Et group of 1 was diastereotropic as revealed by 1H NMR spectroscopy because of the presence of a chiral center at Al. The chirality at Al was dynamically lost at elevated temperature in CDCl2CDCl2 and DMSO-d6, as indicated by temperature dependent 1H NMR spectroscopy. This dynamic or fluxional behavior of 1 is explained by rotation of the 2-methyl-8-quinolinolato ligand. The kinetic parameters of the dynamic process were estimated at ΔH?? = 135 kJ mol-1 and ΔS? = 159 J K-1 mol-1 in CDCl2CDCl2 and at ΔH? = 124 kJ mol-1 and ΔS? = 151 J K-1 mol-1 in DMSO-d6, respectively, at 350 K. Structures of some of the obtained Al complexes were confirmed by single-crystal X-ray crystallography. These Al complexes showed photoluminescence peaks at 492-507 nm in CHCl3 with quantum yields of 7-23%.
A theoretical and experimental study on meridional-facial isomerization of tris(quinolin-8-olate)aluminum (Alq3)
Iwakura,Ebina,Komori-Orisaku,Koide
, p. 12824 - 12827 (2014)
The rationale behind the stereospecific synthesis of a facial isomer of tris(quinolin-8-olate)aluminum (Alq3) is studied by density functional theory (DFT) calculations, which predict the favourable influence of an H3O+ ion on the distribution ratio between a meridional and a thermodynamically unstable facial isomer. This journal is the Partner Organisations 2014.
Surfactant-assisted hydrothermal route to organometallic tris(8-hydroxyquinoline)aluminum nanorod bundles
Ma, Dekun,Zhang, Junhao,Hu, Xiaokai,Zhou, Hongyang,Qian, Yitai
, p. 630 - 631 (2007)
A new surfactant-assisted hydrothermal route was presented to prepare organometallic tris(8-hydroxyquinoline)aluminum nanorod bundles on a large scale. In this hydrothermal system, sodium dodecylbenzenesulfonate (Chemical formula: C12H25-C6H4-SO 3Na, SDBS) played key roles in controlling the morphology and quality of the resultant products. The as-prepared nanorod bundles showed enhanced PL emission compared to submicron particles prepared by the same hydrothermal method. Copyright
Rational In Silico Design of an Organic Semiconductor with Improved Electron Mobility
Friederich, Pascal,Gómez, Verónica,Sprau, Christian,Meded, Velimir,Strunk, Timo,Jenne, Michael,Magri, Andrea,Symalla, Franz,Colsmann, Alexander,Ruben, Mario,Wenzel, Wolfgang
, (2017)
Organic semiconductors find a wide range of applications, such as in organic light emitting diodes, organic solar cells, and organic field effect transistors. One of their most striking disadvantages in comparison to crystalline inorganic semiconductors is their low charge-carrier mobility, which manifests itself in major device constraints such as limited photoactive layer thicknesses. Trial-and-error attempts to increase charge-carrier mobility are impeded by the complex interplay of the molecular and electronic structure of the material with its morphology. Here, the viability of a multiscale simulation approach to rationally design materials with improved electron mobility is demonstrated. Starting from one of the most widely used electron conducting materials (Alq3), novel organic semiconductors with tailored electronic properties are designed for which an improvement of the electron mobility by three orders of magnitude is predicted and experimentally confirmed.
Understanding M-ligand bonding and: Mer -/ fac -isomerism in tris(8-hydroxyquinolinate) metallic complexes
Lima, Carlos F.R.A.C.,Taveira, Ricardo J. S.,Costa, José C. S.,Fernandes, Ana M.,Melo, André,Silva, Artur M. S.,Santos, Luís M.N.B.F.
, p. 16555 - 16565 (2016)
Tris(8-hydroxyquinolinate) metallic complexes, Mq3, are one of the most important classes of organic semiconductor materials. Herein, the nature of the chemical bond in Mq3 complexes and its implications on their molecular properties were investigated by a combined experimental and computational approach. Various Mq3 complexes, resulting from the alteration of the metal and substitution of the 8-hydroxyquinoline ligand in different positions, were prepared. The mer-/fac-isomerism in Mq3 was explored by FTIR and NMR spectroscopy, evidencing that, irrespective of the substituent, mer- and fac-are the most stable molecular configurations of Al(iii) and In(iii) complexes, respectively. The relative M-ligand bond dissociation energies were evaluated experimentally by electrospray ionization tandem mass spectrometry (ESI-MS-MS), showing a non-monotonous variation along the group (Al > In > Ga). The results reveal a strong covalent character in M-ligand bonding, which allows for through-ligand electron delocalization, and explain the preferred molecular structures of Mq3 complexes as resulting from the interplay between bonding and steric factors. The mer-isomer reduces intraligand repulsions, being preferred for smaller metals, while the fac-isomer is favoured for larger metals where stronger covalent M-ligand bonds can be formed due to more extensive through-ligand conjugation mediated by metal d orbitals.
Improvement on the photorefractive performance of a monolithic molecular material by introducing electron traps
Zhang, Jie,Chen, Zhijian,Liu, Yihong,Huang, Maomao,Wei, Qun,Gong, Qihuang
, p. 1323 - 1325 (2004)
The ehancement in photorefractive performance was observed by introducing tris(8-hydroxyquinoline) aluminum (Alq3) as electron traps. A small amount of Alq3 formed quantum dots in (9-ethyl-9H-carbazol-3- ethylmetjylent)(4-nitrophenyl)-amine (ECYENPA), serving as electron traps. Alq3 prevented the the electron-hoe recombination and accelerate the electron-hole separation, benefiting the buildup of internal space-charge electric field. The analysis show that for a sample doped with 2 wt% of Alq 3 produced large two-beam coupling coefficient of 424 cm-1 in contrast to a value of 232 cm-1 for a sample without Alq 3.
Solid state preparation of the (8-hydroxyquinolinato)aluminum(III) complex from aluminum isopropoxide and 8-hydroxyquinoline
Saxena
, p. 1747 - 1767 (1999)
A new alternate method is described for the preparation of the (8-hydroxyquinolinato)aluminum(III) complex in the solid state from aluminum isopropoxide. The complex was characterised by IR spectra, elemental analyses and X-ray spectroscopy using a compact X-ray diffraction analyser. The light yellow complex prepared in the solid state has an identical structure with the one prepared by the wet method.
Highly selective and sensitive fluorescent paper sensor for nitroaromatic explosive detection
Ma, Yingxin,Li, Hao,Peng, Shan,Wang, Leyu
, p. 8415 - 8421 (2012)
Rapid, sensitive, and selective detection of explosives such as 2,4,6-trinitrotoluene (TNT) and 2,4,6-trinitrophenol (TNP), especially using a facile paper sensor, is in high demand for homeland security and public safety. Although many strategies have been successfully developed for the detection of TNT, it is not easy to differentiate the influence from TNP. Also, few methods were demonstrated for the selective detection of TNP. In this work, via a facile and versatile method, 8-hydroxyquinoline aluminum (Alq3)-based bluish green fluorescent composite nanospheres were successfully synthesized through self-assembly under vigorous stirring and ultrasonic treatment. These polymer-coated nanocomposites are not only water-stable but also highly luminescent. Based on the dramatic and selective fluorescence quenching of the nanocomposites via adding TNP into the aqueous solution, a sensitive and robust platform was developed for visual detection of TNP in the mixture of nitroaromatics including TNT, 2,4-dinitrotoluene (DNT), and nitrobenzene (NB). Meanwhile, the fluorescence intensity is proportional to the concentration of TNP in the range of 0.05-7.0 μg/mL with the 3σ limit of detection of 32.3 ng/mL. By handwriting or finger printing with TNP solution as ink on the filter paper soaked with the fluorescent nanocomposites, the bluish green fluorescence was instantly and dramatically quenched and the dark patterns were left on the paper. Therefore, a convenient and rapid paper sensor for TNP-selective detection was fabricated.
