Aluminium ions, interactions with

The strong interaction of polyvalent cations with polyions is well known to strongly alter the rheological properties of hydrolyzed polyacrylamide used in the tertiairy oil recovery process (1-4). The influence of divalent cations have already been studied(5-7) but the role played by the presence of small quantities of aluminium ions has never been investigated. 

This result shows that is reasonable to neglect other type of interactions between aluminium ions and the polymer for instance coordination binding with amide groups,... 

Humic acids and fulvic acids interact with a wide variety of cations. In addition to interacting with iron and aluminium, the species with which they are complexed in soils (57), they also form stable complexes with zirconium, thorium, the lanthanides and the uranyl ion. In the case of uranium it has been suggested that humic acids could be of considerable importance in the geological formation of secondary deposits of uranium (58). 

In these reactions (Scheme 3.1), the first electron addition is to the alkene giving a radical-anion. This interacts with the alkyl halide to transfer an electron, in a process driven by simultaneous cleavage of the carbon-halogen bond. The alkyl radical formed in this manner adds an alkene radical-anion [25]. Aluminium ions generated at the anode are essential to the overall process. They coordinate with the intermediate carbanion, which then interacts with the second halogen substituent in an Sn2 process to form the carbocycle. 

The Effects of Ions which Interact with Water. In the last section the premise was made that the counter-ions used for coagulation did not interact with water. However, it is well-known that many multivalent ions do react with water to form hydrolysed species which can sometimes be polymeric in nature. For example, in the case of aluminium, the Al3+ ion exists at pH values below ca. pH 3.3 as the hexa-aquo ion, with six water... 

On the other hand, the structure of Ca3Al2(OH)i2, formed via interaction of Al(OH)3 with Ca(OH)2, consists of Off ions packed with metal ions, which occupy the suitable size sites. Calcium cation is surrounded by eight Off ions, while aluminium cation is surrounded by six Off ions, corresponding distances being 0.250 and 0.192 nm, respectively. This means that the formation of stracture can proceed in a simpler manner than through the dissolution followed by crystallization. 

In addition it was found that molecules which only differ in one methyl group can be distinguished [48] and that there seemed to be a lower limit for a suitable template size in these systems since, e.g., dimethylaniline and diethylani-line exhibited the same adsorption power [37]. The most recent trend in imprinted silicas uses aluminium ions as dopants to introduce more specific interactions with the template. The silica gel is only surface-modified in the presence of e.g. phenanthrene by treatment with diazomethane. After removal of the template, the silica shows a stronger retention for all polycyclic aromatic compounds, but no particular affinity towards the template [52]. 

The participation of a monomeric form of the organoaluminium compound in the olefin addition may result in a preliminary interaction between the olefin and vacant p-orbitals of the aluminium ion with the formation of a 7t-coraplex before insertion of the olefin into the At—C bond. The first-order kinetics of this process with respect to monomer implies that the concentration of the n-complexes with respect to the monomer OAC form is low at elevated reaction temperatures these complexes were not identified by physical methods. 

However, in several special cases data on the possible formation of n-complexes with a monomeric form of OAC have been obtained. Thus, NMR studies have shown the formation of a n-complex by interaction of phenylacetylene with triethylaluminium. The heat of this reaction is 0.7 0.2 kcal/mol. Taking into account the heat of dissociation of an AljEtg molecule (17 kcal/mol the strength of the n-bond between phenylacetylene and aluminium ion is about 9 kcal/mol. The rate of phenylacetylene insertion into the aluminium-ethyl bond is first order with respect to the concentration of the -complex, according to reaction (18) ... 

The interaction of probe molecules with acidic OH groups is also studied, " even though the detail is not described in this report. Moreover, the spinning sidebands analysis in H MAS NMR offers the information on the distance between the bridging OH groups and aluminium ions in the zeolite framework. - ... 

Lovrecek, B., Bolanca, Z., and Korelic, O.. Surface charge and interaction with sulphate ions at the boehmitized aluminium. Surf. Coat. Technol., 31, 351, 1987. 

Acyl halide reacts with aluminium chloride to give rise to the acylium ion together with an anion i.e., AlClg.X. The aromatic hydrocarbon interacts with the generated acylium ion to yield the corresponding intermediate ion, which subsequently loses a proton to result into the formation of acyl benzene. 

The Equation (i) above clearly depicts the manner in which an acid chloride interacts with aluminium chloride to form an electrophilic complex (1). Further, it most probably involves the acylium ion (2) as the reactive electrophilic species, although an electrophilic complex (1) between the acid chloride and the aluminium chloride may also be engaged. 

Equation (i) shows the interaction between an alkyl halide and aluminium chloride to yield the alkyl ion and the aluminium chloride-halide anion. In Equation ii) the alkyl ion reacts with benzene to form the intermediate ion in a rather slow mode, which subsequently loses a proton to form the desired alkyl benzene. 

In ail cases both the formation of dication 506 and its interaction with nucleophiles seems to proceed with the intermediate formation of monocations of type B. Thus, the ion 506 react with lithium aluminium hydride or triethylamine to give the following tricyclic compounds ... 

Many phenols interact with aluminium halides to yield complexes in tautomeric ketoforms these complexes, as shown by the NMR spectra, are close analogues of hydroxyarenium ions (X = Cl or Br). 

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