Chromatographic behaviour and chemical structure : I. Thin-layer chromatography of aliphatic acids

✍ Scribed by F. Gütlbauer

• Publisher: Elsevier Science
• Year: 1969
• Tongue: English
• Weight: 903 KB
• Volume: 45
• Category: Article
• ISSN: 1873-3778
• DOI: 10.1016/s0021-9673(01)86187-2

✦ Synopsis

acids and halogen adds; were separated on cellulose layers with the solvent mixture +&butanol-diethylamine-w'ater (85 :r : 14). The RM values so obttined illustrate in most 'cases the ,validity ,of MARTINIS 'the'ketical postulates for the relatipnship.between chemical: structure ,%ind RF value in partition 'chromatography.' Thus when 8~ is plotted against the number of,substituent groups of any one hind a'close approximation ,to linearity results,:except. in the c&e :of acids with vicinal hydrophilic groups. The ;,calculation of group consttints and binding increments was done by 'direct comparison of'the RN' values of, su,bstancesdiffering by only o.ne group or increment. These data facilitate :the .chromatographic 'elucidation of structural problems ; only very small amounts of the;'substancos' which do, nqt even need to 'be isolated in pure form are .' .' INTR,+&I~N .' ; , In-Vhe couke 'of our investi@ions of radiation induced carboxylation of organic acids. with 1% labelled. CO2 an an,alytical procedure was required to separate the_ organic acids fikmed'by this 'process. The method was also.required to indicate how m&ny:'COOH-groups were introduced into' the model 'substrate and in &hat' position relati&to other .functional groups, they were located.; 'A: chromatographic procedure appeared to be especially;suited, since there were already, a number of papers on the relatidnship between molecularstructure and'chromatdgraphic. behaviour2-18'. Bike& qk pr&ictioris of Cc&x+ ,et at? '. :,' and MARTIN~~;'~, linear relafionship b&ykkn'*h~' Rw ~ytluii 'and. the number. of., identical groups has been proved experimentally .by many' authors*-1*+-g@ :