Complex formation between naphthalene and dimethyl-β-cyclodextrin by heating in a sealed ampoule

Abstract

~~~~~ ~ ~~~An equ i molar mixture of naphthalene and am or p hous h e pta kis-( 2,6-d i a -m e t h y 1)-P-cyclodext r i n (DMPCD) has been heated in a sealed container at 70°C. The naphthaleneDMPCD complex was different from t h e inclusion complex obtained by coprecipitation. Two types of the complex were obtained by 'sealed-heating ' at different temperatures: heating t h e mixture at 60-80 "C gave a complex that showed excimer emission of naphthalene at 390 nm, whilst heating t h e mixture above 90°C gave a complex that exhibited monomer emission of naphthalene at 341 nm. It was also possible to differentiate between t h e two forms of the complex by powder X-ray diffraction and thermal analysis.