The Origin of host-guest interaction in metal/benzoxazine systems

Abstract

A series of benzoxazine monomer derivatives, 3,4-dihydro-2H -l,3- benzoxazines, and ring opening of benzoxazine monomer derivatives (dimer derivatives), N,N-Bis (2-hydroxybenzyl) amine, with different functional groups at ortho and/or para positions on the phenol ring and amine groups were prepared. Ion interaction properties of the monomer derivatives for alkali metal were studied by using Pedersen’s technique and characterized by UV/Vis. Ion extraction percentage dependend on main factors; benzoxazine concentration and structure of benzoxazine. 3,4-dihydro-3,6,8-trimethyl-2H-1,3-benzoxazine, 1, and 3,4-dihydro-6-t-butyl-3-methyl-2H-l,3-benzoxazine, 4, gave the highest extraction comparing to the other monomers. Benzoxazine dimers formed the complex with CuCl2, CaCl2, and BaCl2 as confirmed by the ESIMS, FTIR and XRD. ESIMS clarified that benzoxazine dimers assembly as a series of clusters of 2-7 molecules. The peak shifting of OH group in FTIR implied that the molecular assembly of benzoxazine dimer was presented by inter and intramolecular hydrogen bonding. The XRD patterns implied after the change in the packing structure of benzoxazine complexation with metal guests.