Asian Journal of Chemistry Vol. 22, No. 10 (2010), 7628-7640 Branching Structures of Alkali Metal Ion Responsive Supramolecules Based on Symmetric Structures of N,N-Bis(5-alkyl-2-hydroxybenzyl)methylamine ATTAPHON KAEWVILAI*, THITIPORN RUNGSIMANON†, NATTAMON KOONSAENG‡, SUWABUN CHIRACHANCHAI† and APIRAT LAOBUTHEE* Department of Materials Engineering, Faculty of Engineering, Kasetsart University, Ladyao, Chatuchak, Thailand E-mail: kaewvilai@hotmail.com; fengapl@ku.ac.th This work aimed to design and synthesize the alkali metal responsive supramolecules based on symmetric structures of N,N-bis(5-alkyl-2- hydroxybenzyl)methylamine. Novel branching structures of products, such as, N,N- bis -[5-methyl-2-(1’,3’-diethoxy-2’-propoxy) benzyl]methylamine (P-I), N,N-bis-[5-ethyl-2-(1’,3’-diethoxy-2’- propoxy)benzyl]methyl amine (P-II) and N,N-bis-[5-methoxy-2-(1’,3’- diethoxy-2’-propoxy)benzyl]methylamine (P-III) were successfully prepared. The alkali metal ion extraction efficiency of products was studied by Pedersen’s technique. The stoichiometric interaction ratios of host compounds (P-I to P-III) with alkali metal ion guests determined by UV-visible, 1 H NMR and ESI-MS spectroscopic techniques were found to be 2:1, 3:1 and 4:1, respectively. Key Words: Supramolecules, Pedersen’s technique, Stoichiometric interaction ratio. INTRODUCTION Supramolecules have received much attention owing to their unique property of molecular recognition at the molecular level which is never achieved in the simple individual molecules. The induced molecular interactions between supramolecules and guests to form host-guest compounds or inclusion compounds are known as noncovalent interactions or secondary forces, such as van der Waals, dipole-dipole interaction, hydrogen bonding, etc. 1-5 . Various novel supramolecules with specific functional groups have been, therefore, designed and proposed in both assembly and cyclic structures for the preferred properties 1-5 . For the past few years, our group has focused on the structure of benzoxazines that resemble repeating units of calixarenes (Scheme-I) 6-12 . Based on molecular design, the novel controlled structure †The Petroleum and Petrochemical College, Chulalongkorn University, Soi Chula 12, Phathumwan, Thailand. ‡Department of Chemistry, Faculty of Science, Kasetsart University, Ladyao, Chatuchak, Thailand.