Intercalation of Monoalkylamines and Aniline into Layered Aluminium Dihydrogentriphosphate

Abstract

Intercalation of monoalkylamines and aniline into layered aluminium dihydrogentriphosphate dihydrate, A1112133010H.2 0 (abbreviated to ADHP), was examined by using powder X-ray diffraction method, DTA-TG, and IR spectroscopy. A linear relationship was recognized b e tween carbon numbers of alkylamines and the interlayer spacings of intercalation compounds. The slope of the straight line was 2.1, sugge s ting the formation of bilayers such that alkylamines are intercalated into ADHP lay e r at a tilting angle 563. The interlayer spacing (d=7.9A) of ADHP was extended to 18.8A. by intercalation of aniline. When the facility of intercalation of alkylamines into ADHP w a s compared, alkylamines of relatively large carbon numbers such as octyl-(C8) and decylam i ne (C, o) were intercalated more readily into ADHP than those of small carbon number s (C1--C4)or of carbon numbers above C, 2. When intercalation compou n d s of methyl-, ethyl-, and propylamine were treated with 0.1moldm-3 phosphoric acid, these alkylamines in interlayer were removed to give the origin al ADHP. However, intercalation compounds of alkylamines of carbon numbers above C 6 and aniline showed stronger water-repellency and floated on water surface. Results of DTA a nd TG revealed that alkylamines and aniline were held firmly between ADHP layers and thu s, were stable at above their boiling points. Alkylamines intercalated in ADHP began to de c ompose at around 350°C.