single synthesis and spectroscopic investigation of cu

G. Nageswara Reddy et al., IJSID 2011, 1 (2), 81--94

ISSN:2249-5347

IJSID International Journal of Science Innovations and Discoveries Research Article

An International peer Review Journal for Science

Available online through www.ijsidonline.info

SINGLE SYNTHESIS AND SPECTROSCOPIC INVESTIGATION OF CU (II) AND MN (II) NEW AZOMETHINE METAL COMPLEXES: BIOLOGICAL ACTIVITY G.Nageswara Reddy1, J.Sreeramulu1* 1Department

of Chemistry, SriKrishnadevarayaUniversity, Anantapur-515003,A.P, INDIA.

Received: 09.07.2011

ABSTRACT Modified: 21.09.2011 Published: 27.10.2011 Keywords: Synthesis, Characterization, Schiff Base (OVPTH), Biological activity

The synthesis and characterization of Schiff base and its solid metal complexes derived from Para-toluic hydrazide

and

2-hydroxy-3-methoxy

benzaldehyde

(OVPTH) by using modified Sand Mayer’s method. The derived colored complexes are Cu (II) & Mn (II) with

*Corresponding Author

OVPTH. The structures of the titled new azomethine were elucidated by Elemental analysis, IR, NMR, UV-Vis Spectrometry, ESR, Vibrational spin magnetometry, TG-DTA and Conductometric measurements. In addition the authors have been screened the compounds for biological activity. It Address: Name: G. Nageswara Reddy Place: Anantapur, Hyderabad E-mail:

[email protected]

was found that the compounds have shown activity against the organisms like Salmonella typhi, Enterococcus faecails and Escherichia coli. INTRODUCTION

International Journal of Science Innovations and Discoveries Vol 1, Issue 2, September-October 2011

81


INTRODUCTION Schiff base of various transition metal ions were investigated for their Coordinating capability, Pharmaceutical and biological activities [1-3] these complexes were used as catalysts for water photolysis [4]

and for oxygen reduction at modified carbon cathode [5]. Schiff base derivatives have been used in the

biological extraction of metals [6], paint industry and medicinal bioinorganic fields [7-9]. Some compounds have been used industry and catalytic hydrogenation of unsaturated hydrocarbons also used for analytical purpose

[11]

[10]

Schiff bases was

in the determination of metal ions. The applications of such

complexes depend to a large extent on their molecular structure. The author in the present study provides a new series of metal complexes of Cu (II) and Mn (II) with Schiff base ligand derived from Paratoluic hydrazide and 2-Hydroxy-3-methoxy benzaldehyde (OVPTH). These complexes were characterized by elemental analysis, IR, NMR, UV- Vis Spectrometer, ESR, VSM, TGA-DTA and Conductometric measurements to determine the mode of bonding and geometry, biological activities of the ligands and metal complexes were also carried out. MATERIALS AND METHODS Instrumentation: The percentage compositions of the elements (CHNO) for the compounds were determined using an element analyzer CHNO model Fison EA 1108.The Infra red spectra were recorded as potassium bromide (KBr) discs using a JASCO FT/IR-5300.The 1H (400Hz) nuclear magnetic resonanance spectra were recorded using the ACF200 Broker Germany Spectrometer. Uitraviolet Spectra were recorded using Prekin-Elmer lab India UV-Vis Spectrometer. The Electron spin reasonce spectra were recorded using the JES-FA Series and TG-DTA spectra were recorded using the SPTQ600 PA, Thermo gravimetric analyses of the metal complexes were carried out by using the Perkin Elmer system in thermal analysis centre Stickochin and ethyl alcohol were used as solvent. All chemicals used in the present investigation were pure Aldrich chemicals. Preparation of the ligand and its metal complexes: (Preparation of para-Toluichydrazide and 2-methyl-3-methoxybenzaldehyde Schiff base (OVPTH)): Para-toluic hydrazide 1.50g (1mole) 2-methyl-3-methoxy benzaldehyde 1.52g (1moles) were dissolved in 25ml of methanol were taken in 250ml borosil reflection flask and 1 ml of triethylamine . The mixture was refluxed for 3 hour on water bath and then cooled to room temperature, yellow colored sharp needles were separated out and washed with methanol and dried in vacuum desiccators over CaCl2 anhydrous. For the Preparation of Cu (II) and Mn (II) metal chloride salts were used. Dissolve 3.0g (2 Mole) of International Journal of Science Innovations and Discoveries Vol 1, Issue 2, September-October 2011

82


newly synthesized ligand in adequate of methanol. To this solution, aqueous solution of 6.655g (1 Mole) and 6.656g (1Mole) metal chlorides, and 1 ml of HCl. The mixture wad refiuxed for 6 hours in a water bath and then cooled to room temperature, black green and pale yellow colored sharp needles were separated out. The coloured metal complexes were washed with water and then methanol, and were recrystalised from ether and dried in vacuum dessicator over CaCl2 anhydrous. The elemental analysis was carried out for the newly synthesized ligand metal complexes. The prepared metal complexes were in 1:2 ratio. Synthesis of OVPTH has represented in figure-1. Ligands and metal complexes analytical data was tabulated in table-1 Figure-1: Synthesis of OVPTH

Table-1: Analytical data of the ligand and their metal complexes.

Molecular weight Co lour Yield M.P C% Calculated Found Elemental H% Calculated Analysis Found N% Calculated Found O% Calculated Found M% Calculated Found

OVPTH

Complex Cu(OVPTH)2X2

Mn(OVPTH)2X2

284.33 Yellow 75 184-186 67.52 67.48 5.62 5.92 9.84 9.73 16.88 16.32 -

665.54 Black Green 72 294-296 57.69 57.61 5.10 4.98 8.41 8.02 19.23 19.09 9.54 9.50

656.938 Pale Yellow 69 318-320 58.45 57.91 5.17 5.29 8.52 8.73 19.48 19.56 8.36 8.32

RESULTAND DISCUSSION Infrared spectral analysis:Infrared spectra were recorded with a JASCO FT/IR-5300 Spectrometer (4000-400 cm-1) using KBr pellets. By utilizing this spectroscopy, the presence of important functional groups in the compound International Journal of Science Innovations and Discoveries Vol 1, Issue 2, September-October 2011

83


can be identified.Table2 through light on the observation made in analyzing IR spectra of ligand and metal complexes. The typical IR spectra are presented in the Fig.1, 2 and 3. Table-2: The important IR bands of the Ligand and Their Metal Complexes Compound OVPTH Cu(OVPTH)2 Mn(OVPTH)2

OH(Water)

υOH (Phenolic)

3425 3381

3555 -

υ C=N

υ Ar-H

υ M-O

υ M-N

1647 1606 1620

3068 3032 3061

470 460

736 738

υ C-H 2844 2837 2843

Figure-1: IR Spectrum of OVPTH Ligand

Figure-2: IR Spectrum of Cu (OVPTH) 2 complex


84


Figure-3: IR spectrum of Mn (OVPTH) 2 Complex.

Interpretation of OVPTH and Cu (II), Mn(II) complexes: The Infrared spectrum of the ligand was compared with the spectra of Cu (II) and Mn (II) complexes. The data was summarized in table along their assignment. The typical IR spectrums are shown in Fig.1, 2 and 3. The IR spectrum of the ligand has shows broad band at 1647 cm-1 [14], which was assigned to due υC=N stretching of azomethine group. In complexes this band was shifted to lower regions ,1606 cm-1 and 1620 cm-1[15] for Cu(II) and Mn(II) complexes respectively, suggesting the involvement of azomethine group(>C=N) group in complexation .This was due to the reducation of electron densitry on Nitrogen.There by indicating the coordination of the metal in through the nitrogen atoms. The IR spectra of metal chelates shows the disappearance of the υ(OH)

[16]

bond at 3555 cm-1 . It

indicates the proton displacement from the phenolic (OH) group on complexation. Thus bonding of the metal ions to the ligands under investigation takes place through a covalent link with oxygen of the phenolic group. The IR spectra of Cu(II) and Mn(II) metal complexes exhibit a broad band

[17]

around

3425 cm-1-3380 cm-1 respectively, which can be assigned to υ(OH) of water molecules associated with complex formation. The two weaker bands at 812.50 cm-1-798.20 cm-1 were attributed to OH rocking and wagging vibrations of coordinated water molecules. New bands were observed in the complexes, which were not observed in ligand.The bands at 470 cm-1& 460 cm-1 were assigned to strentching frequenies of (M-O), the band at 736 cm-1and 738 cm-1 [18]were

assigned to the stretching frequencies (M-N) respectively[19-21]. International Journal of Science Innovations and Discoveries Vol 1, Issue 2, September-October 2011

85


NMR Spectrum of OVPTH Ligand and its Metal complexes:The 1H NMR spectra of ligand and metal complexes in DMSO-d6 as solvent were given in fig.4,5 and 6.The chemical shift values of the ligand and metal complexes were shown in Table-3. Ligand shows singlet at 2.3768 ppm

[21],

which is due to protons bonded to Azomethine group.On complexation this

band was shifted to low field regions 2.2646 ppm, 2.2939 ppm for Cu(II) and Mn(II) complexes respectively.This shifting indicates the shielding of azomethine.The aromatic ring protons forms a multiplet at 7.26 ppm, methoxy protons forms a singlet in the region 3.8358 ppm phenolic proton

[22]

shows singlet at 11.51 ppm, which was disappeared in the complexes. In the 1H NMR spectrum of the Cu(II) and Mn(II) complexes the signal due to azomethine protons were shifted 2.3768 ppm to 2.2646-2.2939 ppm respectively. This shifting indicates the shielding of the azomethine group. The aromatic ring protons that are seen in the 7.2-7.3 ppm[22] become broad and less intense compared with the corresponding Schiff base.In complexes the aromatic ring protons at 7.2-7.3 ppm become broad and less intense, compared with Schiffbase. The following complexation to the metal ion 2.82 ppm in the case of Cu(II) and Mn(II) complexes indicates the complexation of water molecules by coordination with metal ion. Table-3: 1H NMR Spectrum of the ligands and its metal complexes in DMSO-d6 in ppm Compound H-C=N CH3 OH OCH3 Ar-H O=C-NH OVPTH Cu(OVPTH) 2 Mn(OVPTH) 2

2.3768 2.2646 2.2939

1.1862 1.6693 1.6595

11.51 -

3.8358 3.6307 3.600

7.2613 7.2613 7.2662

7.7688 -

Figure-4: NMR Spectrum of OVPTH


86


Figure-5 : NMR Spectrum of Cu (OVPTH) 2 complex

Figure-6: NMR Spectrum of Mn (OVPTH) 2 complex

Conductivity measurements: The molar conductance of complexes in DMF(~10-3 M) was determined at 27+20C using Systronic 303 direct reading conductivity bridge. A known amount of solid complexes is transferred into 25ml standard flask and dissolved in dimethyl formamide (DMF). The contents are made up to the mark with DMF. The complex solution is transferred into a clean and dry 100ml beaker.The molar conductance of the complexes were less than 20 Ohm-1 cm2 mol-1 indicating the Non-electrolytic nature. These values suggest non-electrolytic nature of the present complexes. The molar conductance values of these metal International Journal of Science Innovations and Discoveries Vol 1, Issue 2, September-October 2011

87


complexes are given in the Table 4. Table-4: Conductance data for Metal-OVPTH Complexes: Cell constant: 1.00 S.No.

Metal Complex

Conductance Ohm-1

1.

Cu(OVPTH)2

2.

Mn(OVPTH)2

0.0056 x 10-3 0.0048 x 10-3

Specific Conductance Ohm-1 cm-1 0.0056 x 10-3

Molar Conductance Ohm-1 cm2 mol-1 5.60

0.0048 x 10-3

4.80

Electronic spectra: In UV-Visible electromagnetic radiation, the transitions are associated with the electronic energy levels of the compound under investigation. The electronic spectra were recorded on a Thermo Spectronic Heylos a spectrophotometer. The transition metal ions occur in a variety of structural environments. Because of this, the electronic structures are extremely varied. The electronic structures have been identified with UV-Visible spectroscopy OVPTH and its metal complexes: The electronic spectral of ligand and its metal complexes were given in the transitions were reported in the Table-5. Ligand shows signal band at 283 nm, assigned to ∏─∏* transistion. In complexes this band was shifted to higher wavelength regions. New bands were observed in the complexes at corresponding to the charge transfer transitions. In high concention spectra of complexes d-d transitions were observed in visible region. Table-5 : Electronic spectral data Complexes λmax of the complex in λmax of the ligand in nm nm Cu(OVPTH) 2 289.2 283 Mn(OVPTH) 2 285.5 283 Electronic spin resonance spectra: In the present study the X-band (~9.3GHz) ESR spectra of Cu (II) and Mn(II) complexes in DMF were recorded at room temperature and at liquid nitrogen temperature (LNT) on a JES-FA SERIES spectrometer. DPPH radical was used as a field maker. Analysis of OVPTH through ESR spectra of Cu(II) and Mn(II)complexes: The ESR spectra of the complex in poly crystalline state exhibit only one broad signal, which is attributed to dipolar broadening and enhanced spin lattice relaxation. Anisotropic spectra obtained for these complexes in DMF at LNT and representative ESR spectra of Cu (II) and Mn(II) complexes were presented in Fig.7 and 8. In this low temperature spectrum, four peaks of small intensity have been identified which are considered to originate from g║ component. The spin Hamiltonian, orbital reduction and bonding parameters of the Cu(II) and Mn(II) International Journal of Science Innovations and Discoveries Vol 1, Issue 2, September-October 2011

88


complexes were presented in Table 6. The g║ and g┴ are computed from the spectrum using DPPH free radical as g marker. Kvelson & Neiman[23] have reported that g║ value is less than 2.3 for covalent character and is greater than 2.3 for ionic character of the metal-ligand bond in complexes. Applying this criterion, the covalent bond character can be predicted to exist between the metal and the ligand complexes

[24].

The trend g║>gave> g┴> 2.0023 observed for the complex suggest that the unpaired

electron is localized in dx2- y2 and dz2 orbital of the copper (II) ions for the complex. It is observed that G value for these complexes are greater than four and suggest that there are no interactions between metal-metal centers in DMF medium. The ESR parameters g║, g┴, A║*and A┴* of the complexes and the energies of d-d transitions are used to evaluate the orbital reduction parameters (K║,K┴) the bonding parameters ( α 2), the dipolar interaction (P)[25].The observed K║ Cu(II). Figure-9: TG & DTA Spectrum of OVPTH-Cu

Figure-10: TG & DTA spectrum of OVPTH-Mn


91


Table 8 : Thermal analytical data of the Ligand and their metal complexes Weight of %of Temperature Molecular the fraction Range during weight in complex of weight Probable assignment weight loss in gms take in 0 C mgs

Complex X=H2O

[Cu.L2.X2] L=C16H15N2O3

[Mn.L2.X2] L=C16H15N2O3

665.54

656.938

13.8020

80-190 280-810 Above 810

9.0200

90-180 310-520 Above 520

5.4091 82.6396 11.95119 5.4799 83.7217 10.7982

Loss of 2H2O molecule. Loss of two L molecules. Remaining residue Corresponds to CuO. Loss of 2H2O molecule. Loss of two L molecules. Remaining residue Corresponds to MnO.

Biological activity The author in this present investigation attempted to find out antibacterial activity of ligand and their metal complexes against Salmonella typhi, Enterococcus faecails and Escherichia coli choosing serial paper disc method Table 9.The results of the biological activity of the metal complexes indicated the following facts. A comparative study of the ligand and their complexes indicates that the metal chelates exhibited higher antibacterial activity than that of the free ligand. The increase in the antibacterial activity of metal chelates was found due to the effect of metal ion on the metal chelates which could be explained on the basis of overtones concept and chelation theory. On chelation the polarity of the metal ion reduced to a greater extent due to the overlap of the ligand orbital and partial sharing of positive charges of metal ion with donor groups. It was further noted that the delocalization of electrons over the whole chelate ring enhanced the lipophillicity of thecomplexes.This increased lipophillicity[31] enhanced the penetration of the complexes into lipid membrane and blocking the metal sites on enzymes of microorganism.ssThe zones of inhibition of the ligand metal complexes were in the Table.9. Table 9 : Antibacterial Activity of the Metal complexes Total Area of Zone of clearance in mm S.No.

Compound

Salmonella Typhi

1 2 3

OVPTH Cu(OVPTH)2 Mn(OVPTH)2

12 18 16

Enterococcus Faecails 14 19 18

Escherichia coli 15 20 20

CONCLUSION The above study results reveals that, it can be concluded that Schiff base of O-Vanillin with alkalamine namely Para-Toulic hydrazide acts as a very good complexing agent towards many transition metal ions. By using above spectral studies these behave bidentate during complexation. All the metal International Journal of Science Innovations and Discoveries Vol 1, Issue 2, September-October 2011

92


complexes carry no charge and are thermally stable. As such no single technique is independent of predicting final structures of the complexes. ACKNOWLEDGEMENT The authors are thankful to the Director HCU, Hyderabad for the help rendered in obtaining IR and NMR graphs. They are thankful to IIT Madras for providing VSM. They are also thankful to Sri Krishnadevaraya Universtry, Anantapur for providing TG&DTA, UV and Biological activity. REFERENCES 1. Y.D.Kulkarni,A.Rowhani; J.Indian Chem.Soc., 67, 46 (1990). 2. D.X.West,A.E.Liberta,

S.B.Padhye,

P.B.Chilkate,

A.S.Sonawane,

O.Kumbhar,

R.G.Yerande;

Coord.Chem.Rev., 49, 123 (1993). 3. A.Singh, Lalita, R.Dhakarey, G.C.Sexena; J.Indian Chem.Soc., 73, 339 (1996). 4. R.H.Baker, J.Lilie, M.Gratzel; J.Am.Chem.Soc., 104, 422 (1982). 5. M.A.Ramadan, W.Sawdny, H.F.Y.El-Baradie, M.Gaber; J.TransitionMet.Chem., 22, 211 (1997). 6. W.H.Hegazy; Monatsh.Chem., 32, 639 (2001). 7. K.P.Deepa, K.K.Aravindakshan; Appl.Biochem. And Biotech., 118(1-3), 283 (2004). 8. Panchal, K.Pragnesh, M.N.Patel; Synthesis and Reactivity in J.Inorg.AndMetal-Org.Chem., 34(7), 1277 (2004). 9. W.Bair Kenneth, C.Andews, T.Webstery, Utile Richoand, L.Knick, Vincent, C.Cory Michael, Mckee, R.Bavid; J.Medicinal Chemistry., 34(7), (1991). 10. Chou,Chihyuch,Malcha,E.Robert,Nocito;Vincern DCT Int.Appl.Wo, 93(04), 136 (1993). 11. A.M.Ramadan, W.Sawdny, H.F.Y.El-Baradie, M.Gaber; J.B.Electrochem., 4, 959 (1988). 12. W.J.Geary; J.Coord.Chem.Rev., 7, 81 (1971). 13. M.N.Patel, S.H.Patel; J.Macromol.Sci.A, 16, 1420 (1981). 14. M.Lever; Anal.Chem.Acta, 65, 311 (1973). 15. W.J.Geary; J.Coord.Chem.Rev., 7, 81 (1971). 16. R.Sreenivasulu, J.Sreeramulu, K.Sudhakar Babu; J.Electro.chem.Soc., India, 54, 11 (2005). 17. M.E.Hossain, M.N.Alam, J.Begum, M.Akbar Ali, M.Nagimuddin, F.E.Smith, R.C.Hynes; Inorganic chimica Acta, 249, 207-213 (1996). 18. T.J.Mabrye, K.R.Markham; in the Flavonoids, edited by J.B.Harborne, T.J.Mabry, H.Mabry,Chapman and Hall, Landon p.78 (1975). 19. W.Heiber, P.John; J.Chem.Ber., 103, 2161 (1970). 20. Z.Jawarska, C.Jose, J.Urbanski; J.Spectrochim.Acta, 30a, 1161 (1974). International Journal of Science Innovations and Discoveries Vol 1, Issue 2, September-October 2011

93


21. B.Singh, R.D.Singh; Ind.J.Chem., 21, 648 (1982). 22. TarekM.A.Ismail; J.of Coordination Chem., 59(3), p. 255-270 (2006). 23. A.H.Maki, B.R.Mcgarvey; J.Chem.Phys., 29, 31- 35 (1958). 24. M.A.Halcrow, L.M.L.Chia, X.Liu, E.J.L.Mclnnes, J.E.Davies, et al.; Chem.Commun., 2465 (1998). 25. M.R.Wagnar, F.A.Walker; J.Inorg.Chem., 22, 3021 (1983). 26. J.Costa, R.Delgado, M.C.Figuera, R.T.Henriques, M.C.Teixeira; J.Chem., Soc., Dalton Trans., 65(1997). 27. J.M.Bret, P.Castan, G.Commeges, J.P.Laurent, D.Muller; J.Chem.Soc., Chem.Commun., 1273(1983). 28. Maurico Cavicchioli, P.P.Corbi, Petr Melnikov, Antonic C.Massabni; J.Coord.Chem., 55(8), pp.951- 959 (2002). 29. M.M.Abou-Sekkina, M.G.Abou El-Azm; Thermochim.Acta, 79, 47 (1984). 30. D.Broadbent, D.Dailimore, J.Dollimore; J.Chem.Soc.(A), 451 (1980). 31. K.P.Bslasubramanyam, R.Karvembu, V.Chinnuswamy, K.Natarajan; Ind.J.of Chem., 44A,

pp.2450-

2454(2005).


94