Synthesis, Structure and Properties of Tren-Schiff Base Compound and Its Manganese(III) Complex by Original Self-assembly Reaction

The new self-assembly tripodal hexadentate Schiff base compound, C27H30N4O3, derived from tris(2-aminoethyl)amine(tren) with salicylaldehyde and its manganese(III) complex [(C27H27N4O3)Mn]center dot CH3OH(1) were designed and synthesized by original self-assembly reaction at room temperature in the solution of methanol. Both the compounds were characterized by elemental analysis, IR spectrometry, UV-Vis spectroscopy and X-ray single crystal diffraction. It is noteworthy that the tripodal hexadentate Schiff base ligand effectively encapsulates the manganese(III) ion and enforces a six-coordinate geometry in complex 1 with the apical nitrogen atom of tren-Schiff base remaining unbound to the metal. It is found that there are several intra-molecular hydrogen bonds in them(C-H center dot center dot center dot O and O-H center dot center dot center dot N). In addition, quantum chemistry calculations were also performed and discussed in detail. These results are consistent with the structural analyses of them.