Studies On The Synthesis, Characterization And Fluorescence Property Of The Novel Schiff Base Complexes

Metal coordination polymers, a new kind of molecule materials, have attracted much more attentions for their flexible tailoring,various topologies and promising application in ion-exchange, non-liner optics, molecular recognition. Schiff base and its complexes are widely used in the fields of analytical chemistry, biology, metal corroded and luminescent material. The study of them is focus of the study of coordination chemistry. So, prepare new Schiff base coordination polymer and study their properties and application are of important significance to the development of coordination chemistry.Four Schiff base ligands which are derived from 4,4ËŠ-diaminodiphenylmethane- 2-hydroxy-1-naphthaldehyde (H2DDMNA), 4,4ËŠ-diaminodiphenylether-2-hydroxy- 1-naphthaldehyde (H2DDENA), 2,7-diamino naphthalene -2-hydroxy- 1-naphthaldehyde (H2DNNA), 4,4ËŠ-diaminodiphenylether-2,4-dihydroxybenzaldehyde(H4DDEDB) have been prepared, and twenty nine coordination compounds of transition metal or lanthanide nitrates with these ligands and crystal of Schiff base 2-[[(2-aminophenyl)imino] phenyl- methyl]- 4-chlorophenol have been synthesized. In these complexes, there are six coord- ination polymer, ten low coordination polymer, one low coordination polymer of the ac- etate as a bridge, eight rare earth complexes and four dinuclear or multinuclear compl- exes. All these complexes are first reported by author. These ligands and complexes were characterized by elemental analysis, IR spectra, UV spectra , TG-DTG,X-ray crystal diffraction , molar conductance analysis, gel permeation chromatography(GPC) and assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometer. Fluorescence of schiff base ligands and their complexes of Cd2+, Zn2+ have been studied. The interaction between partial complexes and DNA has been studied, too.The transition metal complexes with Schiff base ligands from 4, 4ËŠ-diaminodiiphen- ylmethane-2-hydroxy-1-naphthaldehyde (H2DDMNA) are coordination polymers. The compositions of these complexes are confirmed to be [M(DDMNA)(L1)(H₂O)]n(M=Zn,Cu,Co,Ni,Mn,they are hexa-coordinated and quaternary coordination polymer ),[Cd(DDMNA)]n. The compositions of the metal complexes with Schiff base ligands from 4,4ËŠ-di- aminodiphenylether-2-hydroxy-1-naphthaldehyde(H2DDENA) are confirmed to be [M(DDENA)]n(M=Zn,Cu,Co,Ni,Mn,Cd),Ln(DDENA)(NO₃)(Ln=Sm,La,Gd,Dy ). The transition metal complexes of this ligand are low coordination polymers.The compositions of the metal complexes with Schiff base ligands from 2,7-diamino naphthalene-2-hydroxy-1-naphthaldehyde (H2DNNA) are confirmed to be [M (DNNA)]n M=Zn,Cu,Co,Ni),Ln (HDNNA)(NO₃)2(H₂O)(Ln=Sm,La,Gd,Dy). The transition metal complexes of this ligand are low coordination polymers.The compositions of the metal complexes with Schiff base ligands from 2,7-diamino naphthalene-2-hydroxy-1-naphthaldehyde(H2DNNA) are confirmed to be Cd2(DDEDB)L²(H₂O)5,Cu3(DDEDB)L²(L3)2(H₂O)2,Co5(DDEDB)(L3)6(H₂O)2,Ni4(DDEDB)(L3)4(H₂O)4 and Zn2(DDEDB)(H₂O)2. The Co5(DDEDB)(L3)6(H₂O)2 is low coordination polymers. The others are dinuclear or polynuclear complexes.The synthesis of ligands and complexes was in non-aqueous solvents. All of the complexes were stable and could be preserved in the air for a long time. The complexes were colored and powered substances. The properties of the Ln(â…¢) complex with theIn the complexes, the nitrogen atom of schiff base, oxygen atom of hydroxybenzene, and the oxygen atom in tetrahydrofuran are all coordinated to the metal ions. Water molecules are coordinated to the acceptor or exists as crystal water.The nitrate ions are within the coordination sphere, these are coordinated to the metal ions in the form of bidentate. The acetate tends to coordinate with the center ion as a bridge. Zn(II), Cu(II), Mn(II), Co(II), Ni(II) and Cd(II) atoms may be respectively hexa- or penta- coordinated.Combinating Achar differential and Coats-Redfern integral method which fits the thirty kinetic equations, the calculating program was designed. The kinetic equations of thermal decomposition for complexes and the corresponding kinetic parameters were gained. The kinetic parameters include E,A, order of reaction and correlation coefficient, etc. The activation entropyâ–³S≠and activation free-energyâ–³G≠for some thermal decomposition stage were also calculated.The thermal decomposition kinetic function of [Zn(DDMNA)(L1)(H₂O)]n in step 2 may be expressed as f(α)=(1-α)2, and the kinetic equation of thermal decomposition may be expressed as dα/dt = A·e-E/RT·f(α) = A·e-E/RT(1-α)2, E = 348.61kJ/mol, lnA =52.10, r = 0.9981,â–³S≠=180.96J/mol·K,â–³G≠=219.04 kJ/mol. The thermal decomposition kinetic function of[Cd(DDMNA)]n in step 1 may be expressed as f(α)=3/2(1-α)4/3[1/(1-α)1/3-1]-1, and the kinetic equation of thermal decom-position may be expressed as dα/dt = A·e-E/RT·f(α) = A·e-E/RT·3/2(1-α)4/3[1/(1-α)1/3-1]-1, E = 536.71kJ/mol, lnA =87.60, r = 0.9988,â–³S≠=476.66J/mol·K,â–³G≠=217.35 kJ/mol.The thermal decomposition kinetic function of [Zn(DDENA)]n may be expressed as f(α)=3/2(1-α)4/3[1/(1-α)1/3-1]-1, and the kinetic equation of thermal decomposition may be expressed as dα/dt = A·e-E/RT·f(α) = A·e-E/RT·3/2(1-α)4/3[1/(1-α)1/3-1]-1,E = 539.84kJ/mol,lnA =81.20, r = 0.9612,â–³S≠=422.56J/mol·K,â–³G≠=238.55 kJ/mol. The thermal decomposition kinetic function of Co5(DDEDB) (L3)6(H₂O)2 in step 2 may be expressed as f(α)=1/4(1-α)[-ln(1-α)]-3, and the kinetic equation of thermal decomposition may be expressed as dα/dt = A·e-E/RT·f(α) = A·e-E/RT·1/4(1-α)[-ln(1-α)]-3, E=312.54kJ/mol, lnA=43.65, r=0.9784,â–³S≠=110.05J/mol·K,â–³G≠= 227.25kJ/mol.The thermal decomposition kinetic function of Cd2(DDEDB )L²(H₂O)5 in step 2 may be expressed as f(α)=3/2(1-α)4/3[1/(1-α)1/3-1]-1, and the kinetic equation of thermal decomposition may be expressed as dα/dt=A·e-E/RT·f(α) =A·e-E/RT·3/2(1-α)4/3[1/(1-α)1/3-1]-1, E = 175.07kJ/mol, lnA =30.83, r = 0.9984,â–³S≠=6.53J/mol·K,â–³G≠=171.57 kJ/mol. The thermal decomposition kinetic function of [Zn(DNNA)]n may be expressed as f(α)=(1-α)2, and the kinetic equation of thermal decomposition may be expressed as dα/dt =A·e-E/RT·f(α)=A·e-E/RT(1-α)2, E=1789.21kJ/mol, lnA=260.92, r=0.9768,â–³S≠=1916.15 J/mol·K,â–³G≠=252.46 kJ/mol.The crystal of Schiff base 2-[[(2-aminophenyl)imino] phenylmethyl]-4-chlorophenol (C19H15ClN2O) was obtained and its crystal structure was determined by the single crystal X-ray diffraction. The compound crystallizes in the triclinic, space group P-1 with a =8.5630(17)?,α= 68.96(3)?, b = 9.4940(19)?,β= 84.84(3)?, c = 11.069(2)?,γ= 77.75(3)?, V = 820.7(3)?3, Z = 2, F(000) = 336, Dc = 1.306 g/cm3,μ= 0.24 mm-1, R1 = 0.0442, wR2 = 0.1186 (I>2sigma(I)), R1 = 0.0721, wR2 = 0.1339 (all data),w = 1/[σ2 (Fo2)+(0.0738P)2+0.1224P] and P=(Fo2+2Fc2)/3. The molecular structure of 2-[[(2-aminophenyl)imino]phenylmethyl]-4-chlorophenol is calculated using the density functional theory(DFT) with the gradient corrected B3LYP method. The standard 6-31G+ basis sets are applied for C,H,O,N and Cl atoms. Atom coordinates used in the calculation are from crystallographic data. The crystal structure of the compound is totally optimized. All data obtained from the calculations are consistent with those gained from the determination. All calculations are performed using the Gaussian03 program package. The formation of hydrogen bonding,, the relationship between fine micromechanism of the compound and its chemistry activities position are also expatiated according to the theory of molecular orbital (HOMO and LUMO) in this dissertation. It may direct to synthesize asymmetry schiff base ligand and complex etc.The excitation and emission peak wavelengths (λex/λem) of H2DDMNA, H2DDENA and H2DNNA are 491nm /510 nm; 494nm /515 nm and 290nm /505 nm, 352nm /505nm respectively in fluorescence spectra.The excitation and emission peak wavelengths(λex/λem) of the schiff base coordination polymer of [Zn(DDMNA)(L1)(H₂O)]n, [Cd(DDMNA)]n, [Zn(DDENA)]n, [Cd(DDENA)]n and [Zn(DNNA)]n are 281nm /505 nm, 348nm/505 nm, 430nm/505 nm; 290nm /515 nm, 349nm/515 nm, 430nm/515 nm, 456nm/515nm, 484nm/515 nm; 290nm /505 nm, 360nm/505nm; 290nm /410nm and 280nm/500 nm, 332nm/500 nm, 435nm/500 nm respectively in fluorescence spectra.The excitation and emission peak wavelengths(λex/λem) of Zn2(DDEDB )(H₂O)2 and Cd2(DDEDB)L²(H₂O)5 are 275nm/385nm and 300nm/375nm, 325nm/375nm respectively in fluorescence spectra.. The complexes of [Zn(DDMNA)(L1)(H₂O)]n, [Cd(DDMNA)]n, [Zn(DDENA)]n, [Cd(DDENA)]n , Cd2(DDEDB)L²(H₂O)5 , [Zn (DNNA)]n and Zn2(DDEDB )(H₂O)2 have good fluorescence. Compared with the ligands, the excitation peaks and the emission peakof their complexes have changed, and the fluorescence intensity increases.The interaction of the Cd2(DDEDB)L²(H₂O)5 and Dy(HDNNA)(NO₃)2(H₂O) complexes with DNA was studied by UVspectra and fluorescence spectra respectively. Experimental results show that on the incremental addition of DNA,the UV absorption bands of the complex of Cd2(DDEDB)L²(H₂O)5 enhance gradually and red-shifted while the fluorescence intensity of the complex weakens. The type of quenching of Cd2(DDEDB)L²(H₂O)5 and DNA is a static quenching process. The static quenching constant is KLB=2.2x104 L·mol-1. The binding site number n and the intrinsic binding constant were measured respectively, they were n=1.32, KA=2.63X105 L·mol-1.Experimental results show that on the incremental addition of DNA,the UV absorption bands of the complexe of Dy(HDNNA)(NO₃)2(H₂O) tiny enhance gradually. The fluorescence intensity of the EB-DNA complex weakens with increasing concentration of Dy(HDNNA)(NO₃)2(H₂O). It was confirmed that the combinations of DNA with Dy(HDNNA)(NO₃)2(H₂O) were not a single static or dynamic quenching process .they are joint action of the static and dynamic quenching process. It was confirmed that electrostatical and intercalation binding were the both modes of interaction between Dy(HDNNA)(NO₃)2(H₂O) complex and DNA..