摘要:
Onium salts having a complex anion are prepared by the reaction of (a) an electron donor compound of formula R1kHlkY, (b) a electron acceptor compound of formula MR11nX1mn and (c) an organic compound RX, wherein R, R1 and R11 are alkyl or aryl groups, X is halogen, pseudohalogen or an acid residue, X1 is halogen or hydrogen, Y is N, P, As, Sb, Bi, S, Se or Te, M is Be, Zn, Cd, B, Al, In, Ga, Tl, Si, Ge, Pb or Sn, l and m are integers representing the capacities of Y and M respectively to combine with hydrogen, and k and n are 0 or an integer from 1 to l or m respectively. The reaction in its simplest form may be represented by:-D + A + RX --> [DR]+[AX]-wherein D represents the electron donor and A the electron acceptor, but compounds formed by the reaction of two molecules of acceptor with one each of donor and RX ar also disclosed. The reaction may be carried out by first forming a co-ordination compound between donor and acceptor and reacting this with RX, or an adduct or mixture may be formed from the acceptor and RX which is then reacted with the donor, or the donor and RX may be first mixed and then reacted with the acceptor. Trimethylammonium triethylchloroaluminate obtained by first passing triethylamine gas into triethylaluminium to form a 1 : 1 complex and passing methyl chloride into the product. By passing further methyl chloride there is obtained the complex Triethylpropylstibonium triethylbromoindanate is prepared by reacting methylantimony and triethylindium under an inert gas and adding N :propyl bromide to the product. Further examples are indicated by the equations:- The complex onium salts may be degraded by such methods as solvolysis with methanol or water, oxidative cleavage or displacement with a stronger complexing agent for the acceptor compound to give the simple onium salt (DR)+X- where D represents the donor compound. For example, tetraethylstibonium triethyl bromoaluminate in solution in dichloromethane is added to methanol, ethane is evolved and aluminium methoxide removed by decantation, and the residue worked up to yield tetraethylstibonium bromide.
摘要:
The flow pattern of a fluid over a surface can be determined by treating the surface to form a reactive layer, entraining in the fluid a reagent compound which is capable of chemically changing the reactive layer, and then passing the fluid over the reactive layer which is to be examined. This method is illustrated by treating an aluminum surface of a blade member (such as that in a vacuum cleaner blower) or adjacent structural members to form a thin aluminum oxide film by anodic treatment. The microporous film which is formed is then impregnated with an organic dye. An air stream containing a reactive substance, such as acid vapors, is passed over the treated blade member. The acid vapors react with the dye and/or the oxide layer and produce a visible pattern upon the blade which is characteristic of the boundary layer flow of the air stream. An examination of the visible pattern is of assistance in determining the proper design and operating characteristics of the blade. The visible pattern may be formed or preserved by chemical post-treatment, such as etching to leach out dye from unreacted portions of the layer and to provide a more permanent record for subsequent use. Alternatively, the microporous aluminum oxide layer can be treated with a fluid stream containing a reactive substance to characteristically change the layer, followed by treatment with a dye to form the visible pattern of the boundary flow.