of Kufa for Chemical Sciences

Anew Schiff base ligand . (HMPHM) 3-((4-chlorobenzylidene)amino)-4-((€-(3-hydroxy-5-(hydroxyl methyl)-2-Methyl)puridin-4-yl)methylene)amino)phenyl)(phenyl)methanon has been Prepared from reacting(3-amino-4-(((3-hydroxy-5-(hydroxylmethyl)-2-methylpyridin-4- yl)methylene)amino)phenyl)(phenyl)methanone with P -Chloro benzaldehyde Co(II), Ni(II), Cu(II), Zn(II), Cd(II), and Au(III) ions were used to create a new series of chelate complexes. The structures of the new Schiff base ligand and their transition metal complexes were characterized by using Fourier-transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance ( 1 H-NMR) technique, ultraviolet visible spectroscopy (UV-Vis), mass analysis, molar conductance, and magnetic susceptibility. [(M)(L) 2 ] where M = Co(II), Ni(II), Cu(II), Zn(II), and Cd(II), and [(M)(L)Cl]Cl where M = Au (III). The coordination sites of the Schiff base ligand were revealed by FTIR to be through oxygen of the hydroxyl group, and the nitrogen of azomethine groups. Based on data obtained, the octahedral geometry was suggested for all ligand complexes exception of the Au(III) complex, which had a square planar geometry.


Introduction
The organic compounds containing the azomethine group (-CH=N-) were named as an effective group in their composition with Schiff bases and that is through the condensation of aldehydes or ketones (alpha or aromatic) with primary amines (aliphatic or aromatic), in different solvents and in the presence of a catalyst through which the water molecules resulting from the reaction are with drawn (1,2) . Because of their vast range of biological applications, ease of preparation, chelating characteristics, and stability, Schiff bases are the most important and studied class. Schiff bases ligands have also played a key role in the creation of inorganic biochemistry and pharmacological activities such as antibacterial, antioxidant, anticancer, antifungal (3)(4)(5)(6)(7) .Many studies have been carried out to study the uses in various fields such as antimicrobial and molecular docking studies as well as thermodynamics studies of complexes formation with metal ions. Schiff bases ligand of 3,4-diamino benzophenone and their complexes have a variety of biological, analytical, and pharmacological applications (8)(9)(10) .In this paper, we report Synthesis, Identification and Spectral Studies of Some New Schiff base ligand Complexes Contained 3,4-Diaminobenzophenone and pyridoxal hydrochloride Compounds.

Materials and Methods
The electrothermal melting point model 9300 was used to measure the melting point of the ligand and its complexes. Elemental analyses were carried out by means of micro analytical unit of 1180 (C.H.N)elemental analyzer. Electronic spectra were recorded on Shimadzu spectrophotometer double beam model 1700 Uv-Vis spectrophotometer-FTIR spectra were recorded in KBr disc on FTIR Shimadzu spectrophotometer model 8400 at wave number(4000-400)cm-1. 1H-NMR -spectra in (ppm) unit were operating in DMSO-d 6 as solvent using (Bruker-Ultra Shield 3000 MHz Switzerland). Magnetic susceptibility were carried out on a balance magnetic(MSB-MKI)using faraday method. The diamagnetic corrections were made by Pascal's constants.
As for the second step, it included the preparation of a Schiff base ligand, where (3.47g,0.01mol) was reacted from resulting solution prepared in the first step and dissolved in (30 ml) of absolute methanol with a solution of (1.40g,0.01mol) p-chlorobenzaldehyde dissolved in (25 ml) of absolute methanol The mixture was was reflexed for (12hr) with continuous stirring and addition of (2-3) drops of glacial acetic acid, after that it was noticed that the color of the solution changed to a dark orange color, leaving the reaction mixture to settle to complete The precipitation process and obtaining more product, after that the precipitate was filtered, dried and recrystallized using hot absolute ethanol, the melting point was measured and it was (235C 0 ). Scheme 1. shows the course of chemical reactions of Schiff base ligand.

Results and Discussion:
All our complexes are Freely soluble in DMF, DMSO, Methanol and Ethanol. Also They are stable in air. The metal complexes were characterized by elemental analysis, molar conductivities, magnetic susceptibility, IR, UV-Vis, Mass and 1 H,MNR spectra. The analytical data of the complexes are in agreement with the experimental data. The value reveal that the metal to ligand ratio is(1:2), except the Au(III) complex (I:I) .The magnetic susceptibility of the chelate complexes at room temperature were consistent with octahedral geometry, except the Au(III) complex suggest a square planar geometry around the central metal ion. Most of chelate complexes prepared in this work showed conductivity values of the complexes. This proves that complexes have nonelectrolytic nature, except Au(III) complex has electrolytic nature

Micro analysis:
The elemental analysis data of 1:2 [M:L] ratio complexes showed that the theoretical values are in a good agreement with the found data ,as listed in table (1).The purity of Schiff base ligand were tested by TLC technique and C.H.N analysis.

Table.1: Physical properties and elemental analysis of Schiff base ligand and their metal complexes
Infrared spectra studies of the ligand and its complexes FTIR spectra the new Schiff base ligand and their metal complexes are shown in table (2). In The infrared spectrum of the ligand exhibit broad band at (3425) cm -1 were assigned to υ(OH) group in the free Schiff base ligand confirmed that hydroxyl group was presented in Schiff base ligand, which is absent in all metal complexes, revealed that it was coordinated to metal ions via deprotonation of phenolic υ(OH) (11)(12)(13) the Band at (1708) cm -1 due to carbonyl υ (C=O) of benzophenone group, this band unchanged in the spectra of complexes (14) The bands at (1653, 1566) cm-1 that were assigned to υ(CH=N) in the free Schiff base ligand, the azomethine peak in ligand is shifted, which indicated the coordination through υ (-C=N-) group (15,16 The appearance of new absorption bands at (511-574) cm-1 and (430-495) cm-1 refer to υ(M-N), υ(M-O) sequence in some complexes, confirmed that Oxygen and Nitrogen atoms of the ligand banded with the metal ions (17) . The spectra data of the new Schiff base ligand and the Cu(II) complex were shown in (Figure 1 and 2

Electronic spectra and magnetic susceptibility measurements
Ultravioletvisible spectra is one of on important methods used in the field of coordination chemistry, it is studied and compared metal complexes spectra with free ligand spectra .
The electronic absorption spectra of the new Schiff base ligand and its complexes were recorded in freshly ethanol solution (10 -3 ) at room temperature. The absorption region band assignment and the proposed geometry of the complexes Co(II), Ni(II), Cu(II), Zn(II),Cd(II) are octahedral except Au(III) complexes, which had square planar geometry. Their relevant data shown in Table. 3 .
The new Schiff base ligand shows two charge transfer (CT) absorption bands in the region Uv-Visible at (254)nm (39370)cm -1 , and (312)nm (23051) cm -1 which were allotted to (π -π*) and (n-π*) transition within molecule (18) . In the metal complexes, These absorption bands undergo of red-shifted indicating that the Schiff base ligand are coordinated to the metal ions (19) .
The band observed at 312 nm in the spectrum of the free ligand (HL) was red-shifted to 402-597 nm in the complexes due to ligand to metal charge transfer (LMCT) transition (20), suggesting an octahedral geometry around metal(II) in the complexes (21), except the Au(III) complexes, which had square planar geometry. The UV-Vis spectra of the new Schiff base ligand and Cu(II) complex are shown in (Figure 3).

Magnetic measurements
The magnetic moment value The Co(II) complex has 3.3 BM, which was in agreement with the reported value for octahedral Co(II) complexes (22) . The present Ni(II) complex showed a magnetic moment value of 2.4 within the range of 2.9-3.3 BM (23) , suggesting an octahedral environment. The Cu(II) complex showed a magnetic moment value of 1.78 BM, higher than the spin-only value 1.73 BM as expected for one unpaired electron, which was monomeric and consistent with a distorted octahedral geometry (24) . The Zn(II), Cd(II), Au(III) were diamagnetic and according to the empirical formulae of complexes (25) . An octahedral geometry was proposed , except the Au(III) complex suggested a square planar geometry around the central metal ion (26) . Based on the above results, we could deduce the probable structures of the complexes as shown in Fig.  6. Table(3):-Electronic spectra (nm, cm -1 ) magnetic moments, geometry, hybridization and conductivity.

Mass spectra
Mass spectra of new Schiff base ligand is shown in Figuer1,and the suggested mass spectral fragmentations of the ligand and its chelate complex is shown in schemes 2. The mass spectrum ligand displays abase peak at M/Z + =483 is attributed to the original molecular weight. which are in good agreement with their formula as expressed from micro analytical data .

HNMR spectra
The data of 1 H-NMR spectra of Schiff base ligand and Zn(II) complex are show in Figure 4,5 was measured in d 6 -DMSO solvent with TMS as an internal reference. The 1 HNMR spectrum of the ligand shows the following signals : phenyl multiples at (7.4-8.0)ppm, CH-methane at (8.9) ppm, CH 2 -pyridin ring at (4.7)ppm, CH 3 -pyridin ring at (3.5)ppm (27) . Methanolic-OH at (5.3)ppm, Phenolic-OH at (10.0)ppm (28) . This signal disappear in spectra of Zn(II) complex indicates to absence(OH) proton and contribute the oxygen atom in complexity. There is no appreciable change in all other signals in complex.

Molar conductivity measurements
The conductivity values (Ʌµ) of prepared complexes in DMSO solvent at a concentration of (10 -3 M) in room temperature are listed in Table (3). The result explained molar conductance in the range between (11 -19) S.cm 2 .mol -1 , indicating that the compounds are non-electrolytes (29) , except the molar conductance of Au(III) complexes are (33) S. cm 2 .mol -1 respectively suggesting that the electrolytic nature, indicate are present chloride ions outside the coordination sphere (30) .

The suggested structures of the metal complexes
According to the analytical data and spectroscopic studies of the prepared metal complexes are show in Fig. 2. The new Schiff base ligand behaves as a tridentate chelating agent coordination through the nitrogen atoms of azomethine group, and oxygen atom of (-OH) phenolic group.

Conclusion
In this study has reported the synthesis and characterization of new Schiff base ligand containing two (-C=N-)groups and its Co(II), Ni(II), Cu(II), Zn(II), Cd(II), and Au(III) complexes were synthesized and characterized by various spectroscopic techniques. The result show octahedral geometry around of the complexes with mole ratio (1:2) metal: ligand while the complex of Au(III) show a square planar geometry around the complex with mole ratio (1:1) metal : ligand.
According to elemental analysis, Uv-Vis, FT-IR,spectroscopy, melting point, conductivity, data Atomic absorption, 1 HNMR spectra magnetic moment measurements, and mass spectrum studies . The following structures are suggested for the synthesized metal complexes as shown in Fig.2.