Milling procedure, organic compounds

In theory, increased quantities of the organic compound finely ground with constant quantities of potassium bromide should give infrared spectra of increasing intensity. However, good quantitative results by this direct procedure are difficult to obtain due to problems associated with the non-quantitative transfer of powder from the small ball-mill grinder (or pestle and mortar) into the compression die. These are only partially overcome by using a micrometer to measure the final disc thickness. 

Bimolecular rate constants for oxidation by oxyradicals and singlet oxygen have been measured in numerous studies and have been compiled and used to develop reasonably accurate SARs for photooxidations. Atkinson (1987) developed an additivity SAR to estimate kHO(air) for many kinds of organic structures. Mill (1989) has summarized information on SARs for photooxidants in water and air. See Chapter 14 for a detailed discussion of the procedures used for estimating kHO(air) for most classes of organic compounds. 

A rapid, solvent-free and general synthesis of short- and long-chain substi-tnted zwitterionic meta- and para-amino benzoquinones was reported by Cuccia, Friscic et al. (Scheme 3.96) [64], Yields obtained by ball milling were compared with solution procedure, melt reactions, and mechanosynthesis in a cell lysis mill (Table 3.52). Authors demonstrated that cell lysis mill could be successfully employed to mechanosynthesis of organic compounds, and it is also suitable for coordination-based reactions. In transamination synthesis of meta-aminobenzo-quinones 350, an excess of amine was used, whereas para-aminobenzoquinones 352 are synthesized by condensation of 1,4-benzoquinone and an alkylamine in a 3 2 ratio. After chromatographic workup, it was determined that the yields were comparable for all four methods employed, while the solution reactions are the slowest. 

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