Computational analysis for stable conformation of calcium complex of aromatic methacrylate car-boxylic acid monomers and the reactivity towards calcium ion were performed by molecular me-chanics (MM) and molecular orbital (MO) calculations. Six kinds of carboxylic acid monomers, 4-META, 4-MET, 4-AETA, 4-methacryloxy phthalic acid (4-MPA), 2-(N-methacryloyl ami-no)terephthalic acid (2-MATPA) and 5-(N-methacryloyl amino)isophthalic acid (5-MAIPA) were studied.
The three-dimensional structure with the lowest steric energy of carboxylic acid monomers and carboxylic acid monomer/Ca complexes were obtained by MM calculation. Steric energies of carboxylic acid monomer/Ca complexes were higher than those of carboxylic acid monomers.
The energies of highest occupied MO (HOMO) and lowest unoccupied MO (LUMO) were obtained by MO calculations. A energy differences between carboxylic acid monomer/Ca complex and carboxylic acid monomer (ΔE) and energy differences between LUMO of Ca ion and HOMO of carboxylic acid monomers (ΔE') were obtained. A liner correlation was found between ΔE and ΔE'.
It is suggested that computational MM and MO calculation will become one of the useful tools for the analysis of chemical substance and the understanding its biological role in nano bio-medical field.
Key words: aromatic carboxylic acid monomers, 4-META, molecular mechanics calculation, molecular orbital calculation