Kipping method

In contrast to growing interest with polysilanes, their preparation method is still limited. They have been traditionally prepared by the Wurtz-type condensation of dichlorosilanes with alkali metal (Kipping method). This method, however, requires drastic reaction conditions and, hence, is often limited in the type of substituents that are allowed to be located on the dichlorosilane monomer and also has a disadvantage in controlling the unit structure in the copolymerization. Several modified or alternative methods have been... 

The use of the Grignard reagents of the type RMgX for the production of alkyl-and aryl-chlorosilanes was pioneered by Kipping in 1904 and has been for a long time the favoured laboratory method for producing these materials. 

Combination of these various methods has led to a vast number of derivatives in which H is progressively replaced by one or more monofunctional group such as F, Cl, Br, I, CN, R, Ar, OR, SH, SR, NH2, NR2, etc. The cyclic silanes SisHm and Si6Hi2 were prepared in the late 1970s via (SiPh) which were themselves the first known homocyclic silane derivatives (F. S. Kipping, 1921) ... 

The sensitivity of invertase toward methyl mercury using the clean-up method can be improved using the low amount of invertase (0.05 pg/mL) with 10 min of incubation time and kipping the hydrolysis reaction time for more than 10 min. 

Tin tribenzyl chloride. — The first preparation of this compound was made by adding stannic chloride (1 moL) to ice-cold magnesium benzyl chloride (3 mols.) in dry ether, but the yield was poor. In Kipping s method the stannic chloride and magnesium are mixed in dry ether, prior to the addition of the benzyl chloride, this method giving a 60 per cent, yield- The crude product is recrystallised from acetone, and then from glacial acetic acid, until the melting-point is constant. It forms well-defined prisms, M.pt. 143 to 145 C., readily soluble in acetone, benzene, or chloroform, less so in ether or alcohol, and insoluble in water. With 1 mol. of iodine it reacts as follows —... 

Ruchti G, Dunn IJ Bourne JR (1981) Comparison of dynamic oxygen electrode methods for the measurement of Kip. Biotechnology and Bioengineering 23 277-290. 

As an internal A-electron basis X > we use genealogical spin eigenfunctions. The one-particle coupling coefficients yfj = are evaluated using well known group theoretical methods and stored on disc. We first consider the coefficients needed to calculate the a ijp, kip) and fiiijp, klq)... 

From the turn of the century on, the principal route for linking a carbon-silicon bond in synthesizing variously substituted silanes was the classical Grignard method , first introduced by Kipping and Dilthey Unfortunately, this reaction was mainly limited to obtain (organo-) saturated organosilanes. 

Independently of Carpenter, Jeffery and Kipping [86] proposed a method for determining carbonates in rocks. In contrast to Carpenter s method they proposed to use a dilute solution of orthophosphoric acid to decompose the carbonates. The same method of determining gaseous products by decomposing salt-like derivatives of phosphoric acid was also used for determining carbon dioxide and nitrogen oxide in aqueous solutions of monoethanolamine [87]. 

In general, detection limits with the KiP source are contparable to or better thait other atomic spectral procedures. Table lO-.f compares detection limits for Several of these methods. Note that more elements can be detected at levels of 10 ppb or less with plasma excitation than with other emission or absttrplion melhods. As we shall see in Chapter 11, the ICP coupled with mass spectrontetrie detection improves detection limits by two to live orders of magnitude for many elements and is thus strong competition for ICP optical emission spectroscopy. 

The first polysilanes were synthesized more than 75 years ago by Kipping through Wurtz-type reductive dehalogenation of dihalodiorganosilanes. This procedure, which is alkali metal intensive, has in the last decade been better understood and has consequently acquired a degree of control that was not previously considered possible. It remains the easiest and most widely used route to a polysilane and it will be discussed later in this section after consideration has been given to three other methods of synthesis that have been researched in recent years. 

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