New Schiff Base Synthesis, Characterization, And Nature Study

Macrocyclic Schiff base complexes attract the people's extensive concern and researches because of its special spectrum, structure, thermodynamics and the dynamics stability, and its application involves to many fields such as biochemistry, medicine, coordination chemistry, supermolecular chemistry, catalysis and electrochemistry, etc. Therefore, it is of great important meaning to study the synthesis, structure, property and its application about macrocyclic Schiff base compound.This main content is shown as follows:1. Synthesis and characterization of chiral macrocyclic Schiff base (Salen)(1). Synthesis of chiral macrocyclic salen compound 4 with framework construction due to the two individual schiff base subunits linked covalently by methylene.a. Resolution of externally compensated diaminocyclohexaneChiral (R, R)-1,2-diaminocyclohexane was prepared from externally compensated 1,2-diaminocyclohexane mixation according to the literature.b. Synthesis of 5,5'-Methylene-bis-salicylaldehyde5,5'-Methylene-bis-salicylaldehyde was synthesized from salicylaldehyde according to the literature.c. Synthesis and characterization of the chiral macrocyclic Salen compound 4Salen 4 was synthesized directly by the reaction of 5,5'-Methylene-bis-salicylalde-hyde and (R, R)-1,2-diaminocyclohexane, and the compound was characterized by ¹HNMR, FT-IR, MS spectra and UV-vis.(2). Synthesis of chiral macrocyclic salen compound 5 with flexible frame construction due to the two individual Schiff base subunits linked covalently by flexible alkoxy chain.a. Synthesis of 2,4-dihydroxybenzaldehyde2,4-dihydroxybenzaldehyde was prepared from resorcinol according to the literature。b. Synthesis of the dialdehyde-1, 6-bis-(3'-hydroxy-4'-formylphenyloxy)alkane 1,6-bis-(3'-hydroxy-4'-formylphenyloxy)alkane was synthesized by the reaction of 2,4-dihydroxybenzaldehyde and dibromoalkyl in acetone according to the literature.c. Synthesis of the new chiral macrocyclic salen compound 5Salen 5 was synthesized from the above dialdehydes and (R, R)-1,2-diaminocyclo-hexane by using Ba²⁺ as template inons in the mixed solution of methanol and THEd. Spectral properties of the chiral macrocyclic salen compound 5The product obtained was characterized by ¹H NMR, FT-IR, UV-vis, Mass spectra, and the spectral properties of salen 4 and 5 were discussed. (3). Synthesis, characterization and spectral properties of new macrocyclic schiff bases containing hydroxyl functional group.New macrocyclic schiff bases containing hydroxyl functional group were synthesized from the hydroxy-bearing diamine compound, 5,5'-Methylene-bis-salicyl- aldehyde and the above dialdhyde by using Ca²⁺, Ba²⁺ as template inons. The product obtained was characterized by ¹H NMR, FT-IR, UV-vis spectroscopy, and Mass spectroscopy, and spectral properties of salen 4 and 5 were discussed.2. Synthesis, characterization and the crystal structure of new schiff base compounds containing hydroxyl functional group.(1). Synthesis of 1,3-bis- (2-aminophenoxy)-2-propanol.The diamine compound containing hydroxyl functional group was synthesized by etherization, reduction of nitro group from o-nitrophenol and epichlorohydrin.(2). The crystal structure of 1,3-bis(2-aminophenoxy)-2-propanolThe single crystal structure of 1,3-bis(2-aminophenoxy)-2-propanol was obtained firstly and discussed .The crystal structure exhibits a layer formation, and the two phenyl rings linked by ethereal chain form a non-coplanar structure. Layers are formed by the intermolecular hydrogen bonding, and the aryl rings in difference molecules are approximately parallel to each other.(3). Synthesis, characterization and spectral properties of new schiff base compounds containing hydroxyl functional group.The hydroxy-bearing Schiff base compound has obtained by the condensation of 1,3-bis-(2-aminophenoxy)-2-propanol and acetylacetone, and characterized by IR, ¹H NMR, MS and X-ray single crystal structural analysis. (4). The crystal structure of the hydroxy-bearing Schiff base compoundThe crystal structure data shows that a rare intramolecular ionic hydrogen bonding (N⁺-H…O^-) exists in the molecular. The intermolecular non-classical hydrogen bands C-H…O links the Schiff base molecular of non-coplanar S configuration into a helix chain structure along the a axis.3. Study on the crytal structure and interaction of cucurbituril with the hydroxy-bearing diamine compound.(1). The structure analysis of the crystalThe crystal structure of the inclusion complex with cucurbituril (Q[8]) and 1,3-bis (2-aminophenoxy)-2-propanol was determined by X-ray diffraction analysis. The results showed that the Q[8] bind guest to form an inclusion complex in a ratios of 1:2, and intermolecularÏ€-Ï€interations exist between the phenyl rings of two guest molecules in cavity of Q[8]. (2). The host-guest interaction study between the diamine compound and Cucurbit[8]uril.The structure and interaction of Q[8] with the guest were investigated by ¹H NMR techniques, UV spectroscopy and fluorescence spectrophotometry respectively, the results are in good agreement with the crystal structure of the host-guest complex.