Synthesis And Characterization Of Novel Salen Complexes

Salen coordination compounds are important in the field of transition metal coordination chemistry and stereochemistry. In this thesis, according to the principle of crystal engineering and self-assembly, eleven coordination complexes from Salen are synthesized and characterized. Two of them are determined by X-ray structural analyses, and all complexes are measured by IR spectrum.5-hydroxysalicylidehyde reacted with ethylenediamine and o-phenylenediamine, gave two ligands L1 and L2. L1 coordinated with Cu(Ⅱ), Ni(Ⅱ) and Co(Ⅱ) ions, gave three single crystal complexes. L2 coordinated with Cu(Ⅱ), Ni(II), obtained two coordination single crystal compounds. The structure of [Cu(H2L1)]·2H2O and [Ni(H2L1)]·2H2O are characterized by IR, TG analysis along with single crystal X-ray diffraction. The single crystal X-ray diffraction analysis reveals that the two compounds including a mononuclear complex and two non-coordinated H2O molecules. Cu (Ⅱ) and Ni(Ⅱ) are four-coordinate by two imines N atoms and two phenol-0 atoms in a distorted square planer environment. There is a concurrence of hydrogen-bonding,π-πstacking and other intermolecular contacts, which leads to the formation of a 2-D supramolecule in the [Cu(H2L1)]·2H2O (1). In [Ni(H2L1)]·2H2O (2), the mononuclear molecules are connected by intermolecular hydrogen bonds resulting from free hydroxyl in the way of head to head to form a 1-D chain. There is a concurrence of hydrogen-bonding,π-πstacking and other intermolecular contacts, which leads to the formation of a 2-D supramolecule.1,3-dis(5-salicylidene)-propane diamino reacted with ethylenediamine, diaminocyclohex-ane, (1R,2R)-diaminocyclohexane and o-phenylenediamine, obtain four ligands L3, L4, L5 and L6 L3 coordinated with Cu(Ⅱ) and Ni(Ⅱ) ions, to give two single crystals. The structures did not determine by X-ray single crystal diffraction yet. The IR spectrum reveals that the metal ions coordinate with the ligand, the C=N bond and Ar-O bond shift to lower wave numbers.Salicylidehyde reacted with o-phenylenediamine obtain ligand L7 L7 coordinated with Cu(Ⅱ) and Ni(Ⅱ) ions, obtained two single crystals. But the structures did not determine by X-ray single crystal diffraction, because the crystal is thin needle. The IR spectrum reveals that the metal ions coordinate with the ligand, the C=N bond and Ar-O bond shift to lower wave numbers.5-carboxysalicylidene diamino reacted with diaminomaleonitrile and o-phenylenediamine, obtain two ligands L8 and L9 L8 coordinated with Cu(Ⅱ) ions, to give a single crystal and L9 coordinated with Mn(Ⅱ) ions, to give a single crystal. But the structures did not determine by X-ray single crystal diffraction. The IR spectrum reveals that the metal ions coordinate with the ligand, the C=N bond and Ar-O bond shift to lower wave numbers.