Synthesis, Characterization and Bioactivity Evaluation for Some Metal Ions Complexes with New Ligand Derived from 2-hydroxy-1-napthaldehyed

The newly synthesized Schiff base ligand (E)-2-((2-phenylhydrazono)methyl)naphthalen-1-ol (phenyl hydrazine derivative), is allowed to react with each of the next mineral ion: Ni 2+ , Cu 2+ , Zn 2+ andCd 2+ successfully resulting to obtain new metal complexes with different geometric shape. The formation of Schiff base complexes and also the origin Schiff base is indicated using LC-Mass that manifest the obtained molar mass, FT-IR proved the occurrence of coordination through N of azobenzene and O of OH by observing the shifting in azomethines band and appearing of M-N and N-O bands. Moreover, we can also detect by such apparatus, the presence of aquatic water molecule inside the coordination sphere. UV-Vis spectra of all resultants revealed the creation of coordination by noticing the shifting in electronic transitions that happened in ligand at ultra violet region. TGA and DSC measurements for ligand and Ni-complex also prove the complexation and presence of coordinated water molecule inside the coordination sphere. In addition, molar accessibility and FAA results were closer to the counting results. The diagnoses return gave mononuclear complexes, bidentate dental behavior and tetrahedral geometry for all complexes. Depending on the antibiotic property of Schiff base and its complexes, we have tested such property on various types of microorganisms as detailed in the paper.


Introduction
Schiff bases are organic compounds that contain an azomethine group (-CH=N-), are named after the German scientist (Hugo Schiff) who synthesized them for the first time in 1864 by the condensation reaction of aldehydes or ketones with primary amines 1,2 .The general formula of which is [R1R2-C=N-R3] and the naming of these bases depending upon R1R2R3 groups either aliphatic or aromatic, and related with the aldehyde, ketone and amine that are derived from which.The Schiff bases complexes involving O, N donating atoms of chelates own an uncommon configuration.In these cases, the presence of donating atoms at complexes could enhance antibiotic reactivity such as (antitcancer, antifungal, antibacterial, etc.) 3 .Schiff bases are considered as (Imines), (Azomethines) and Published Online First: September, 2023 https://dx.doi.org/10.21123/bsj.2023.7918P-ISSN: 2078-8665 -E-ISSN: 2411-7986 Baghdad Science Journal (Anils) [4][5][6][7][8] .Generally, the Schiff bases derived from the condensation of aldehydes with primary amines, are referred to as (Aldimines), whereas the compounds that derived from the condensation of ketones with primary amines are referred to as (Ketimines).In the condensation of suitable acid hydrazines with ketones or aldehydes in the presence of suitable solvents, the result of this condensation is called (Hydrazones) 9,10 .These compounds are preferred to contain an aryl group attaches to either the nitrogen of amino group or the carbon of aldehyde or ketone molecule in order to increase their stability and keep them from decomposition or polymerization.This work investigates the synthesis and characterization of a new -Schiff base ligand (E)-2-((2-phenylhydrazono)methyl)naphthalen-1-ol and all complexes were formed and diagnosed by 1 H-NMR, Mass-spectroscopy, IR and UV Vis spectra and TGA.Also, we evaluated its vital reactivity.

Materials and Methods
The starting materials including (NH2-ph, 2hydroxy-1-naphthaldehyde, NiCl2.6H2O,CuCl2.2H2O,ZnCl2.2H2O,CdCl2.2H2O) were commercially abundant in addition to the employed catalysts including (dimethyl sulfoxide, abs.CH3CH2OH and diethyl-ether) that supplied from F-897ewluka, Sigma Aldrich.The employed FTIR apparatus operates in the range 4000-400 cm -1 Shimadzu-3800 model.Electronic spectral inform were accomplished depending on Shimadzu160meter.LC/MASS incomes are also established by Mass100P_Shimadzu contribution.Pyrolysis diagnosis were carried out depending on perkin_Elmer_pyris Diamond DSC/TG.Proton-NMR was published using Bruker 400-MHz-meter and elemental micro analysis were done on a perkin_Elmer_automatical instruments model 240B.mineralswere determinedobeying a Shimadzu (A-A) 680G AA_spectrometer.The Cl combination was estimated gravimetrically.Magnetic features were measured using balance magnetic susceptibility model MSR-MKi.

Preparation of the Ligand (E)-2-((2phenylhydrazono)methyl)naphthalen-1-ol
An ethanolic solution of 2-hydroxy-1naphthaldehyde (which formed by dissolving (0.5 g, 0.003 mol) of 2-hydroxy-1-naphthaldehyde in 10ml of ethanol with continuous stirring, then adding the hydrobromic acid HBr (about 3 drops as a catalyst) onto the extremely dissolved solution and adding 5 ml of ethanol (for dilution purposes because of its exothermic reaction), finally ,adding 5ml of phenyl hydrazine with continuous stirring (for about 5 min.),a yellow precipitate will be formed immediately, as shown in scheme 1.

Synthesis of Ni 2+ Complex
Nickle complex was synthesized as shown in scheme 1 by dissolving (0.1g, 0.0004 mol) NiCl2.6H2O as metal salt in 5ml of ethanol with continuous stirring at room conditions 25 o C. Then adding metal salt solution onto 5ml of ethanolic solution of (0.1 g, 0.0003 mol) from ligand.Light brown precipitate will be formed immediately for Ni 2 .The precipitate was filtered and washed by di ethyl ether and weighted, the weight was found 0.16 gm for 64% Ni 2+ and the organic complex was found to be 1:1.

Synthesis of Cu 2+ Complex
Copper complex was synthesized as shown in scheme 1 by dissolving (0.1g, 0.0004 mol) CuCl2.2H2O as metal salt in (5ml) of ethanol with continuous stirring at room conditions 25 o C. Then adding metal salt solution onto (5ml) of ethanolic solution of (0.1 g, 0.0003 mol) from ligand.dark green precipitate will be formed 6 hours of stirring.The precipitate was filtered and washed by di ethyl ether and weighted, the weight was found 0.06 gm for 44% Cu 2+ and the organic complex was found to be 1:1.

Synthesis of Cd 2+ Complex
Cadmium complex was synthesized as shown in scheme 1 by dissolving (0.1g, 0.0004 mol) CdCl2.2H2O as metal salt in 5ml of ethanol with continuous stirring at room conditions 25 o C. Then adding metal salt solution onto 5ml of ethanolic solution of (0.1 g, 0.0003 mol) from ligand.Green precipitate will be formed immediately.The precipitate was filtered and washed by di ethyl ether and weighted, the weight was found 0.05 gm for 55% Cd 2+ and the organic complex was found to be 1:1.

Synthesis of Zn 2+ Complex
Zinc complex was synthesized as shown in scheme 1 by dissolving (0.1g, 0.0004 mol) ZnCl2.2H2O as metal salt in 5ml of ethanol with continuous stirring at room conditions (25 o C).Then adding metal salt solution onto 5ml of ethanolic solution of (0.1 g, 0.0003 mol) from ligand.reddish-brown precipitate will be formed 6 hours of stirring.The precipitate was filtered and washed by di ethyl ether and weighted, the weight was found 0.03 gm for 46% Zn 2+ and the organic complex was found to be 1:1.

1-The Measurements of the Inhibitory Action on Bacteria
Bauer and his colleagues' method was followed in testing the activity of the synthesized ligand and its complexes on the bacteria by Well Diffusion Assay Method.The plates containing the agar middle were cultured in the bacterial suspension in 1×10 -3 M with 1.5×810 cell/ml by using glass diffuser, then bores with 6mm dimeter for each bore were carried out on the surface of the cultured middle by using sterile cork piercing, the synthesized extracted concentrations were carried to the bores of 50 mm in each bore, one bore contains the solvent as control.The activity of the extracted was detected by measuring the inhibition zone which formed around the bore after 24 hours incubation at 37 ˚C.

2-The Measurement of the Inhibitory Action of Fungi
Synthesis of the sabouraud dextrose agar or potato dextrose agar was with 1×10 -3 M in glass bottles with circular stirring so that the culture medium can be homogeneous and it is poured into Petri dishes with a diameter of 9 cm and then left to harden and using the spore suspension method, where a volume of 0.01 ml was taken from the spore suspension and the culture medium was received by stabbing method, it is the easiest and best method for most fungi, with a control sample free of extract for comparison, then the dishes were incubated in an inverted position at a temperature (28 ±2), then the fungal growth area and the spore density of the fungi were measured after three days.The results were taken by calculating the average of two perpendicular diameters for each colony.Each treatment was three replicated, and each replicate had one dish.

Results and Discussion
The 1 HNMR spectrum of ligand in DMSO-d6is shown in Fig. 1.The spectrum displayed a peak observed at δ (4.60) ppm which was assigned to chemical shifts of (N-H) amine 11 , the multiple peaks at δ (7.55) ppm are assigned to the aromatic protons of benzene groups.The singlet signal located at δ (9.74) ppm is attributed to the proton of C-H imine group (imine-C-H) 11 .The singlet signal observed at δ (9.16) ppm was attributed to chemical shifts of (OH-phenol) 12 .

Figure 1. 1 H-NMR Spectrum of Ligand
Micro elemental analysis manifest that, the practical incomes corresponded the theoretical incomes as illustrated in Table 1.The gained metallic complexes were found to be 1:1 M: L and metal salts, the conductance feature manifest that, the obtained complexes were nonelectrolytes.

FTIR Studies
FT-IR spectral data of obtained ligand demonstrates that, the absence of C=O vibrational, absence of asymmetric vibrational mode of NH2 group for starting materials and presence of unique vibrational mode at 1602 cm -1 13 .Attributed to C=N stretching vibrational mode which proves the formation of ligand through the mentioned groups.In addition to other vibrations that denoted in Table 3, C-H aldehydic 2555cm -1 , C-H aromatic 3020-3097 cm -1 , O-H phenolic 3461 cm -1 , C=N 1602 cm -1 , N-H 3228 cm -1 , C=C 1496 cm -1 .Moreover, in FT-IR data of our complexes, we can apparently notice the shifting in C=N vibrational mode, which manifest the creation of coordination through this group to be observed at (1620, 1610, 1625 and 1604) cm -1 for metal complexes Cu 2+ , Cd 2+ , Ni 2+ and Zn 2+ respectively.Moreover, some new bands appeared such as M-N observed at 550, 578, 582 and 570 cm -1 for the mentioned complexes respectively.Such vibrations attributed to the coordination with N of Schiff base group, M-O (the presence of this band results in absence of stretching vibrational mode of hydroxyl group) observed at 478, 495, 495 and 495 cm -1 for the mentioned complexes respectively.Such vibrations may be attributed to the coordination with O of OH group.Finally, aqua water molecule is presented inside the coordination sphere 14 .All spectral data are displayed in Table 2.

Mass Spectral Investigations
The mass spectral records of Schiff base ligand and its Cupper complex are demonstrated in Fig. 3 and Fig. 4, denoted a pack at m/z= 262 contributes to [M + ] and matching the molar mass of the ligand.In addition to other peaks that observed at 378, 373 and 427 m/z.which corresponds with its formula weight.
The suggested fractionation forms of the ligand, Ni, Cu and Cd complexes are illustrated in Schemes 2, 3, 4 and 5.

Ultra Violet-Visible for the Ligand and Its Complexes
The electronic spectrum of the ligand showed intense absorption at 260, 283 nm and 339, 354 nm which belong to ( π→π * ), (n→π * ) respectively.The electronic spectrum of Ni(II) complex showed four peaks at 280, 443, 616 and 678 nm assigned to (π→π * ), ʋ3( 3 T1→ 3 T1F), ʋ2( 3 T1→ 3 T1p) and ʋ1( 3 T1→ 3 A1 .respectively 16.The magnetic moment value 3.9 B.M supports the tetrahedral geometry for the complex.The theoretical value of magnetic moment is 2.98 describes only the spindle moment because of the presence of two single electrons.Whereas the experimental value 3.9 B.M, describes the spindle moment combined with orbital moment.Knowing that the molar conductivity was found to be 12 S.cm 2 mol -1.And according to the value of magnetic moment and the presence of two single electrons, the ligand can be considered as weak ligand with high spin.The ultra violet -visible spectrum of copper(II) complex illustrated three packs at 224, 292 and 887 nm attributed to (π→π * ), (n→π * ), ( 2 T2→ 2 E) respectively and the magnetic moment 1.63 B.M support tetrahedral geometry of the complex in addition to molar conductivity which https://dx.doi.org/10.21123/bsj.2023.7918P-ISSN: 2078-8665 -E-ISSN: 2411-7986 Baghdad Science Journal equal to 10 S.cm 2 mol -1 17 .And according to the value of magnetic moment and the presence of one single electron, the ligand can be considered as weak ligand with high spin.The electronic spectrum of Zn (II) (diamagnetic support tetrahedral geometry of the complex in addition to molar conductivity which equal to 17 S.cm 2 mol -1 .Cd (II) complex (diamagnetic support tetrahedral geometry of the complex in addition to molar conductivity which equals 19 S.cm 2 mol -1 .It showed three peaks at 261, 264 nm, 338,338 nm and 375, 379 nm assigned to (π→π * ), (n→π * ) and (C.T) respectively 18 , suggesting a tetrahedral geometry of all complexes .All the detected spectral incomes of the products are recorded in (Table 4).

Thermal Analysis
The thermogravimetric (TG) curve of ligand L shows relatively one step decomposition in the range 50-595 °C with four DSC peaks and estimated and calculated mass loss equal 97.47 and 98.36, respectively 19 .The TG curve of Ni complex shows four steps decomposition with four DSC peaks as shown in (Table 5) and Fig. 5 and 6.  on such organisms as demonstrated in Fig. 7. Additionally, we can also notice the variations in inhibitory radius between bacteria and fungi and according to these variations; we have detailed their action in Fig. 7 and Table 6.The ligand, copper and nickel complexes are more effective than other complexes in their inhibition toward both types of fungi because of the mutual effect between their corresponded metal salts and ligand 20 .

Conclusion
In this paper, the formation of Schiff-base (E)-2-((2phenylhydrazono)methyl)naphthalen-1-ol (phenyl hydrazine derivative) and their metal complexes including Ni 2+ ,Cu 2+ , Zn 2+ and Cd 2+ ions were prepared and proved successfully.Spectral combination using various apparatus could manifest the formation of the resultants including (FTIR, UV-VIS, LC/MSS, (TGA and DSC) and 1 H-NMR).Each apparatus can prove the results individually depending on its own features as detailed in the article.On the other hand, the bidentate behavior of ligand was detected spectrally.Finally, we could manifest successfully the biological activity of compounds toward several shapes of microorganisms.

Figure 3 .
Figure 3. Mass spectrum of Schiff-base Figure 4. Mass spectrum of Cucomplex