Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 135 (2015) 710–719

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Synthesis, characterization and antimicrobial activities of mixed ligand transition metal complexes with isatin monohydrazone Schiff base ligands and heterocyclic nitrogen base Jai Devi ⇑, Nisha Batra Department of Chemistry, Guru Jambheshwar University of Science and Technology, Hisar 125001, Haryana, India

h i g h l i g h t s

g r a p h i c a l a b s t r a c t

 Synthesis and characterization of

Schiff bases and their complexes.  In vitro antimicrobial activity of

compounds.  Biocidal activity of ligands increased

upon coordination with metal ions.  Compound Cu(LIV)(Q)H2O is found to

be most potent.

a r t i c l e

i n f o

Article history: Received 2 April 2014 Received in revised form 5 July 2014 Accepted 17 July 2014 Available online 1 August 2014 Keywords: Antimicrobial 8-Hydroxyquinoline Octahedral Tridentate

a b s t r a c t Mixed ligand complexes of Co(II), Ni(II), Cu(II) and Zn(II) with various uninegative tridentate ligands derived from isatin monohydrazone with 2-hydroxynapthaldehyde/substituted salicylaldehyde and heterocyclic nitrogen base 8-hydroxyquinoline have been synthesized and characterized by elemental analysis, conductometric studies, magnetic susceptibility and spectroscopic techniques (IR, UV–VIS, NMR, mass and ESR). On the basis of these characterizations, it was revealed that Schiff base ligands existed as monobasic tridentate ONO bonded to metal ion through oxygen of carbonyl group, azomethine nitrogen and deprotonated hydroxyl oxygen and heterocyclic nitrogen base 8-hydroxyquinoline existed as monobasic bidentate ON bonded through oxygen of hydroxyl group and nitrogen of quinoline ring with octahedral or distorted octahedral geometry around metal ion. All the compounds have been tested in vitro against various pathogenic Gram positive bacteria, Gram negative bacteria and fungi using different concentrations (25, 50, 100, 200 lg/mL) of ligands and their complexes. Comparative study of antimicrobial activity of ligands, and their mixed complexes indicated that complexes exhibit enhanced activity as compared to free ligands and copper(II) Cu(LIV)(Q)H2O complex was found to be most potent antimicrobial agent. Ó 2014 Published by Elsevier B.V.

Introduction The therapeutic and diagnostic properties of transition metal complexes have attracted attention leading to their application ⇑ Corresponding author. E-mail address: [email protected] (J. Devi). http://dx.doi.org/10.1016/j.saa.2014.07.041 1386-1425/Ó 2014 Published by Elsevier B.V.

in many areas of modern medicine. In this regard, mixed ligand metal complexes play an important role in the activation of enzymes and display good nucleolytic cleavage activity. Mixed ligand complexes are used for storage as well as for transport of active material through membrane [1]. Among the important pharmacophores responsible for biological activity, the isatin scaffold is viable lead structure for the synthesis of efficient

J. Devi, N. Batra / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 135 (2015) 710–719

chemotherapeutic agent [2]. Schiff bases derived from isatin exhibit many neurophysiological and neuropharmacological effects like antimicrobial, antiviral, anticonvulsant, anticancer, antimycobacterial, antimalarial, cysticidal, herbicidal and antiinflammatory activity [3–8]. They also have anti-HIV, antiprotozoal and antihelminthic activities [9–12]. Recently they have found application as enzyme inhibitors in the inhibition of cysteine and serine proteases [13]. Incited by this and as a part of our work on isatin derivatives, we reported the synthesis of novel mixed ligand transition metal complexes derived from isatin monohydrazone with 2-hydroxynapthaldehyde/substituted salicylaldehyde and heterocyclic nitrogen base 8-hydroxyquinoline. These compounds were characterized by elemental analysis, conductometric studies, magnetic susceptibility and spectroscopic techniques (IR, UV–VIS, NMR, Mass and ESR) and evaluated for antimicrobial activity with an expectation to find some novel and potential antimicrobial agent.

Experimental Materials and methods All the chemicals used in the present investigation were of Analytical grade. Metal salts as nitrates obtained from Aldrich and were used as such without any further purification. Elemental analysis (C, H and N) of samples was carried out by using Perkin Elmer 2400 instrument. Metal contents determined using standard gravimetric methods, cobalt as cobalt pyridine thiocyanate, nickel as nickel dimethylglyoximate, copper as cuperous thiocyanate and zinc as zinc ammonium phosphate [14]. IR spectra were recorded on Shimadzu IR affinity-I 8000 FT-IR spectrometer using KBr disc. 1 H NMR and 13C NMR were recorded on Bruker Avance II 300 MHz NMR spectrometer and all chemical shifts were reported in parts per million relative to TMS as internal standard in CDCl3. UV spectra were recorded on UV–VIS–NIR Varian Cary-5000

NNH2

O O + NH2NH2. H2O

EtOH

O

Reflux, 3h

N H

CHO OH

MeOH Reflux, 5h

N H

HLI = HLII = CH3 H HLIII = Br H HLIV = NO2 H

N

NH

N

HC

O OH

HLI-HLIV

OH N

NH

N

HC

M(NO3)2. xH2O +

N

+ O HQ

MeOH

HLI-HLIV

H N

Reflux, 4h

OH

O N

N

HC

711

O

+ (x-1)H2O+ 2HNO3

M N

O H2O

M = Co(II), Ni(II),Cu(II) and Zn(II) x = 1,6 Scheme 1.

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J. Devi, N. Batra / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 135 (2015) 710–719

M(NO3)2. xH2O + HLI-IV + HQ

M(LI-IV)(Q).H2O + (x-1) H2O + 2HNO3

Scheme 2. Reaction scheme for the synthesis of metal complexes.

spectrometer in DMF. Magnetic susceptibilities of complexes were measured by Gouy’s method, using Hg [Co(SCN)4] as the calibrant at room temperature. Mass spectra were recorded on a API 2000 (Applied Biosystems) mass spectrometer equipped with an electrospray source and a Shimadzu Prominence LC. Powder XRD of samples were carried out on Rigaku-miniflex-II with Cu Ka (1.54 Å), a source of radiation. Synthesis of Schiff base ligands Isatin monohydrazone was synthesized by reacting ethanolic solution (30 mL) of isatin (4.41 g, 30 mmol) with hydrazine hydrate (0.15 g, 30 mmol) in ethanol (10 mL). The mixture was refluxed for 3 h on water bath and allowed to cool at room temperature. The yellow compound formed was filtered, washed, dried and recrystallized from ethanol (mp. 225 °C, yield 90%). Schiff base ligands used in present investigation were prepared by reacting hot methanolic solution (20 mL) of 2-hydroxynapthaldehyde/5-substituted salicylaldehyde (10 mmol) with methanolic solution (10 mL) of isatin monohydrazone (10 mmol) with constant stirring. The resulting mixture was refluxed for 5 h with few drops of glacial acetic acid. The product obtained after the

evaporation of solvent was filtered, washed with methanol, recrystallized from same solvent and dried under vacuum (yield 70%). Synthesis of metal complexes Aqueous solution (15 mL) of metal salt, M(NO3)2xH2O (5 mmol) was added to hot methanolic solution (20 mL) of Schiff base ligands (HLI–IV) (5 mmol) with constant stirring and then added methanolic solution of 8-hydroxyquinoline (HQ) (0.72 g, 5 mmol). Sodium hydroxide was added to maintain the pH of solution. The resulting solution was refluxed for 4 h, separated complex was filtered, washed thoroughly with methanol followed by petroleum ether to remove unreacted metal nitrates or ligands and then dried in vacuum over fused calcium chloride (Scheme 1). Pharmacology Schiff base ligands HLI–IV, ligand HQ and their mixed ligand transition metal(II) complexes were assessed for antimicrobial activity against Gram positive bacteria viz. Bacillus subtilis (MTCC No. 1790), Micrococcus luteus (MTCC No. 4821); Gram negative bacteria viz. Pseudomonas aeruginosa (MTCC No. 9126), Pseudomonas

Table 1 Analytical data of ligands and their mixed transition metal(II) complexes. m/z

(XM)  103



316.2





279.9





344.8





310.6



11.54 (11.01) 11.02 (10.97) 11.56 (11.77) 12.43 (12.07) 12.04 (11.80) 11.95 (11.76) 12.94 (12.61) 13.04 (12.93) 10.67 (10.44) 10.74 (10.41) 11.24 (11.17) 11.67 (11.46) 11.45 (11.11) 11.43 (11.07) 12.04 (11.88) 12.43 (12.18)

535.8

8.4

535.6

6.3

539.2

4.7

541.5

6.9

499.8

8.4

499.6

5.6

504.6

7.2

505.1

7.6

564.8

8.5

564.9

7.8

568.2

6.4

571.3

6.9

530.9

9.2

530.7

11.0

535.4

9.3

537.2

6.5

Compounds

Mol. formula (mol.wt.)

Yield (%)

M.pt. (°C)

Color

Found (calcd) (%) C

H

N

M

HLI

C19H13N3O2 (315.33) C16H13N3O2 (279.29) C15H10N3O2Br (344.16) C15H10N4O4 (310.26) C28H20N4O4Co (535.42) C28H20N4O4Ni (535.18) C28H20N4O4Cu (540.03) C28H20N4O4Zn (541.87) C25H20N4O4Co (499.38) C25H20N4O4Ni (499.14) C25H20N4O4Cu (504.00) C25H20N4O4Zn (505.84) C24H17N4O4BrCo (564.25) C24H17N4O4BrNi (564.01) C24H17N4O4BrCu (568.87) C24H17N4O4BrZn (570.71) C24H17N5O6Co (530.35) C24H17N5O6Ni (530.12) C24H17N5O6Cu (534.97) C24H17N5O6Zn (536.81)

75

220

Red

78

185

Orange

73

168

Brown

79

215

Light yellow

58

>298d

Green

52

>300d

Brown

55

d

Green

d

Color-less

72.13 (72.37) 68.42 (68.81) 52.59 (52.35) 58.49 (58.07) 63.04 (62.81) 63.01 (62.84) 62.53 (62.27) 62.32 (62.06) 60.42 (60.13) 60.43 (60.16) 59.83 (59.58) 59.65 (59.36) 51.34 (51.09) 51.45 (51.11) 50.94 (50.67) 50.84 (50.51) 54.67 (54.35) 54.87 (54.38) 54.03 (53.88) 53.94 (53.70)

4.47 (4.16) 4.94 (4.69) 3.24 (2.93) 3.74 (3.25) 3.97 (3.77) 3.53 (3.77) 4.01 (3.73) 3.97 (3.72) 4.53 (4.04) 4.31 (4.04) 4.19 (4.00) 4.16 (3.99) 3.34 (3.04) 3.28 (3.04) 3.43 (3.01) 3.24 (3.00) 3.48 (3.23) 3.45 (3.23) 3.47 (3.20) 3.54 (3.19)

13.65 (13.33) 15.38 (15.05) 12.48 (12.21) 18.23 (18.06) 10.74 (10.46) 10.73 (10.47) 10.14 (10.37) 10.59 (10.34) 11.45 (11.22) 11.54 (11.22) 11.54 (11.12) 11.32 (11.08) 10.05 (9.93) 9.79 (9.93) 10.04 (9.85) 10.14 (9.82) 13.45 (13.21) 13.54 (13.21) 13.28 (13.09) 13.43 (13.05)

HLII HLIII HLIV Co(LI)(Q)H2O Ni(LI)(Q)H2O Cu(LI)(Q)H2O Zn(LI)(Q)H2O Co(LII)(Q)H2O Ni(LII)(Q)H2O Cu(LII)(Q)H2O Zn(LII)(Q)H2O Co(LIII)(Q)H2O Ni(LIII)(Q)H2O Cu(LIII)(Q)H2O Zn(LIII)(Q)H2O Co(LIV)(Q)H2O Ni(LIV)(Q)H2O Cu(LIV)(Q)H2O Zn(LIV)(Q)H2O

d = Decomposition temperature.

>287

60

>300

57

>294d

Green

55

>296d

Brown

60

>294

d

54

>300d

Color-less

55

>285d

Green

57

d

Brown

d

Green

>299

Green

59

>300

54

>300d

Color-less

55

>296d

Green

61

>297

d

53

>295d

Green

58

>294d

Color-less

Brown

J. Devi, N. Batra / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 135 (2015) 710–719

713

Table 2 H and 13C NMR spectral characteristics (d) of isatin monohydrazone Schiff base ligands and 8-hydroxyquinoline.

1

5

6

5' 4' 3'

8

9 6' 1'

N HC

N

3

NH 2

2''

5' 6' HLII= CH3 H

5'

O HLI =

2'

OH

OH

7

4

HLI-HLIV

HLIII = Br

6'

N

3''

H

HLIV = NO2 H

4'

9"

10"

8'' 7'' 6'' 5''

HQ

Ligands

1

13

HLI

13.95 (s, 1H, OH), 11.04 (s, 1H, CH), 9.81 (s, 1H, NH), 7.89 (d, 1H, C4AH, J = 7.92 Hz), 7.12 (t, 1H, C5AH), 7.60 (t, 1H, C6AH), 8.46 (d, 1H, C7AH, J = 8.28 Hz), 8.05 (d, 1H, C03 AH, J = 9.08 Hz), 7.18 (d, 1H, C04 AH, J = 9.08 Hz), 7.68 (d, 1H, C05 AH, J = 7.44 Hz), 7.46 (q, C06 AH, C07 AH), 6.94 (d, C08 AH, J = 7.76 Hz) 13.38 (s, 1H, OH), 10.95 (s, 1H, CH), 9.69 (s, 1H, NH), 7.83 (d, 1H, C4AH, J = 7.28 Hz), 7.15 (t, 1H, C5AH), 7.62 (t, 1H, C6AH), 8.38 (d, 1H, C7AH, J = 9.02 Hz), 7.43 (d, 1H, C03 AH, J = 7.26 Hz), 7.41 (d, 1H, C04 AH, J = 8.42 Hz), 7.52 (s, 1H, C06 AH) 13.52 (s, 1H, OH), 11.26 (s, 1H, CH), 9.70 (s, 1H, NH), 7.86 (d, 1H, C4AH, J = 6.84 Hz), 7.18 (t, 1H, C5AH), 7.61 (t, 1H, C6AH), 8.39 (d, 1H, C7AH, J = 7.02 Hz), 7.74 (d, 1H, C03 AH, J = 9.34 Hz), 8.30 (d, 1H, C04 AH, J = 7.18 Hz), 8.40 (s, 1H, C06 AH) 13.49 (s, 1H, OH), 11.13 (s, 1H, CH), 9.72 (s, 1H, NH), 7.82 (d, 1H, C4AH, J = 9.02 Hz), 7.23 (t, 1H, C5AH), 7.58 (t, 1H, C6AH), 8.48 (d, 1H, C7AH, J = 8.38 Hz), 7.82 (d, 1H, C03 AH, J = 9.02 Hz), 8.36 (d, 1H, C04 AH, J = 7.38 Hz), 7.68 (s, 1H, C06 AH) 12.92 (s, 1H, OH), 8.84 (d, 1H, C002 AH, J = 9.02 Hz), 7.28 (t, 1H, C00 3AH), 7.99 (d, 1H, C00 4AH, J = 8.04 Hz), 7.36 (d, 1H, C00 5AH, J = 8.28 Hz), 7.28 (t, 1H, C00 6AH), 7.01 (d, 1H, C00 7AH, J = 9.18 Hz)

164.97 (@N), 162.29 (CH@N), 159.57 (C@O), 110.80 (C4), 120.90 (C5), 120.38 (C6), 119.81(C7), 144.13(C8), 123.99(C9), 108.22 (C01 ), 148.34 (C02 ), 127.41 (C03 ), 133.36 (C04 ), 128.32 (C05 ), 132.61 (C06 ), 122.26 (C07 ), 122. 11 (C08 ), 136.78 (C09 ), 128.99 (C010 )

HLII

HLIII

HLIV

HQ

H NMR (CDCl3) d in ppm

C NMR (CDCl3) d in ppm

164.72 (C@N), 161.93 (CH@N), 159.05 (C@O), 111.09 (C4), 121.84 (C5), 120.27 (C6), 120.31 (C7), 144.01 (C8), 124.08 (C9), 109.42 (C01 ), 148.21 (C02 ), 127.30 (C03 ), 132.94 (C04 ), 130.04 (C05 ), 131.22 (C06 ), 20.09 (ACH3) 164.53 (C@N), 162.02 (CH@N), 159.24 (C@O), 111.78 (C4), 122.01 (C5), 120.78 (C6), 120.67 (C7), 144.19 (C8), 124.19 (C9), 109.43 (C01 ), 148.37 (C02 ), 127.63 (C03 ), 133.08 (C04 ), 129.12 (C05 ), 131.58 (C06 ) 164.95 (C@N), 162.31 (CH@N), 159.21 (C@O), 111.13 (C4), 122.06 (C5), 120.74 (C6), 120.62 (C7), 144.37 (C8), 124.85 (C9), 109.15 (C01 ), 148.47 (C02 ), 127.78 (C03 ), 133.25 (C04 ), 141.19 (C05 ), 132.08 (C06 ) 150.30 (C00 2), 125.64 (C00 3), 137.40 (C00 4), 120.42 (C00 5), 128.92 (C00 6), 116.40 (C00 7), 153.74 (C00 8), 138.81 (C00 9), 130.52 (C00 10)

Table 3 H and 13C NMR spectral characteristics (d) of zinc(II) complexes of isatin monohydrazone Schiff base ligands and 8-hydroxyquinoline.

1

Complexes

1

13

Zn(LI)(Q)H2O

11.22 (s, 1H, ACH), 9.80 (s, 1H, NH), 7.92 (d, 1H, C4AH, J = 6.34 Hz), 7.12 (t, 1H, C5AH), 7.60 (t, 1H, C6AH), 8.46 (d, 1H, C7AH, J = 7.04 Hz), 8.18 (d, 1H, C03 AH, J = 8.24 Hz), 7.20 (d, 1H, C04 AH, J = 7.10 Hz), 7.70 (d, 1H, C05 AH, J = 8.20 Hz), 7.46 (q, C06 AH, C07 AH), 6.93 (d, C08 AH, J = 7.42 Hz), 8.95 (d, 1H, C002 AH, J = 6.45 Hz), 7.30 (t, 1H, C003 AH), 7.99 (d, 1H, C004 AH, J = Hz), 7.36 (d, 1H, C005 AH, J = 6.04 Hz), 7.28 (t, 1H, C006 AH), 7.01(d, 1H, C007 AH, J = 8.04 Hz), 3.54 (s, 2H, H2O) 11.15 (s, 1H, ACH), 9.69 (s, 1H, NH), 7.83 (d, 1H, C4AH, J = 7.05 Hz), 7.15 (t, 1H, C5AH), 7.60 (t, 1H, C6AH), 8.42 (d, 1H, C7AH, J = 8.24 Hz), 7.52 (d, 1H, C03 AH, J = 6.40 Hz), 7.42 (d, 1H, C04 AH, J = 8.34 Hz), 7.52 (s, 1H, C06 AH), 8.92 (d, 1H, C002 AH, J = 8.03 Hz), 7.28 (t, 1H, C003 AH), 7.99 (d, 1H, C004 AH, J = 4.32 Hz), 7.54 (d, 1H, C005 AH, J = 8.28 Hz), 7.30 (t, 1H, C06 AH), 7.14 (d, 1H, C007 AH, J = 9.18 Hz), 3.52 (s, 2H, H2O) 11.45 (s, 1H, ACH), 9.70 (s, 1H, NH), 7.87 (d, 1H, C4AH, J = 6.93 Hz), 7.20 (t, 1H, C5AH), 7.61 (t, 1H,C6AH), 8.39 (d, 1H, C7AH, J = 8.14 Hz), 7.93 (d, 1H, C03 AH, J = 9.02 Hz), 8.31 (d, 1H, C04 AH, J = 8.02 Hz), 8.44 (s, 1H, C06 AH), 8.98 (d, 1H, C002 AH, J = 4.27 Hz), 7.29 (t, 1H, C003 AH), 7.97 (d, 1H, C004 AH, J = 8.04 Hz), 7.37 (d, 1H, C005 AH, J = 8.04 Hz), 7.28 (t, 1H, C006 AH), 7.03(d, 1H, C007 AH, J = 8.04 Hz), 3.54 (s, 2H, H2O) 11.34 (s, 1H, ACH), 9.71 (s, 1H, NH), 7.84 (d, 1H, C4AH, J = 6.38 Hz), 7.24 (t, 1H, C5AH), 7.60 (t, 1H, C6AH), 8.49 (d, 1H, C7AH, J = 9.02 Hz), 7.92 (d, 1H, C03 AH, J = 8.04 Hz), 8.35 (d, 1H, C04 AH, J = 4.14 Hz), 7.69(s, 1H, C06 AH), 8.97 (d, 1H, C002 AH, J = 4.44 Hz), 7.28 (t, 1H, C003 AH), 7.99 (d, 1H, C004 AH, J = 9.02 Hz), 7.35 (d, 1H, C005 AH, J = 9.03 Hz), 7.28 (t, 1H, C006 AH), 7.01 (d, 1H, C007 AH, J = 7.12 Hz), 3.52 (s, 2H, H2O)

166.84 (C@N), 164.40 (ACH@N), 161.89(C@O), 111.72(C4), 121.04 (C5), 120.54 (C6), 120.04(C7), 145.13(C8), 124.08 (C9), 109.21 (C01 ), 150.02 (C02 ), 128.04 (C003 ), 133.65 (C04 ), 128.32 (C05 ), 132.61 (C06 ), 122.26 (C07 ), 122. 11 (C08 ), 136.78 (C09 ), 128.99 (C10), 153.48 (C002 ), 125.93 (C003 ), 138.01 (C004 ), 120.98 (C005 ), 129.04 (C006 ), 117.65(C007 ), 155.01 (C008 ), 138.98 (C009 ), 131.04 (C0010 )

Zn(LII)(Q)H2O

Zn(LIII)(Q)H2O

Zn(LIV)(Q)H2O

H NMR (CDCl3) d in ppm

mendocina (MTCC No. 7094) and fungi Verticillum dahlia (MTCC No. 2063), Cladosporium herbarium (MTCC No. 351), Trichophyton soudanense (MTCC No.7859) by agar plate disc diffusion method. The bacteria and fungi were subcultured on Nutrient agar and sabouraud dextrose agar, respectively. The experimental values were compared with standard drugs i.e. Streptomycin for antibacterial activity and Fluconazole for antifungal activity.

C NMR (CDCl3) d in ppm

165.94 (C@N), 162.06 (ACH@N), 160.72 (C@O), 111.74 (C4), 122.03 (C5), 120.74 (C6), 120.31 (C7), 145.00 (C8), 124.82 (C9), 109.82 (C01 ), 150.04 (C02 ), 127.57 (C003 ), 133.01 (C04 ), 130.16 (C05 ), 132.04 (C06 ), 20.09 (ACH3), 152.48 (C002 ), 125.43 (C003 ), 137.83 (C004 ), 121.84 (C005 ), 129.02 (C006 ), 116.40 (C007 ), 154.83 (C008 ), 138.94 (C009 ), 130.86 (C0010 ) 165.84 (C@N), 163.48 (ACH@N), 161.08 (C@O), 111.93 (C4), 122.18 (C5), 120.78 (C6), 120.67 (C7), 145.04 (C8), 124.74 (C9), 109.43 (C01 ), 150.03 (C02 ), 127.92 (C03 ), 133.19 (C04 ), 129.84 (C05 ), 131.82 (C06 ), 151.07 (C002 ), 125.64 (C003 ), 137.58 (C004 ), 120.42 (C005 ), 128.92 (C006 ), 116.40 (C007 ), 154.32 (C008 ), 138.98 (C009 ), 130.23 (C0010 ) 167.08 (C@N), 164.01 (CH@N), 162.04 (C@O), 111.45 (C4), 122.83 (C5), 120.74 (C6), 120.62 (C7), 145.23 (C8), 125.01 (C9), 109.15 (C01 ), 150.01 (C02 ), 127.89 (C03 ), 133.53 (C04 ), 141.19 (C05 ), 132.08 (C06 ), 153.01 (C002 ), 125.93 (C003 ), 137.52 (C004 ), 120.42 (C005 ), 128.92 (C006 ), 116.40 (C007 ), 155.83 (C008 ), 138.81 (C009 ), 130.64 (C0010 )

Antibacterial activity assay For in vitro antibacterial activity, stock solution was prepared by dissolving compound in minimum amount of DMSO. Target microorganism cultures were prepared separately in 15 mL of liquid nutrient broth for activation. Inoculation was done with the help of micropipette with sterilized tips, 100 lL of activated strain was placed onto the surface of agar plate, spread over the whole

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J. Devi, N. Batra / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 135 (2015) 710–719

Table 4 Electronic absorption spectral data and magnetic moment (l) of mixed ligand transition metal(II) complexes of isatin monohydrazone Schiff base ligands and 8hydroxyquinoline. Complexes

Absorption (cm1)

Band assignment

B value

b value

t2/t1

Geometry

l (BM)

Co(LI)(Q) H2O

24,730 17,010 8820 24,820 15,324 9734 24,325 15,480 23,550 24,650 17,105 8846 24,730 15,448 9830 24,530 15,410 23,825 24,545 17,180 8835 24,310 15,430 9856 24,432 15,370 23,710 24,810 17,110 8830 24,535 15,370 9760 24,588 15,450 23,926

4

623 – – 729 – –

0.64 – – 0.70 – –

1.92 – – 1.57 – –

4.34 – – 3.06 – – 1.87

613 – – 712 – –

0.63 – – 0.69 – –

1.93 – – 1.57 – –

602 – – 678 – –

0.62 – – 0.65 – –

1.94 – – 1.56 – –

623 – – 708 – –

0.64 – – 0.68 – –

1.93 – – 1.57 – –







Octahedral – – Octahedral – – Distorted Octahedral Octahedral Octahedral – – Octahedral – – Distorted Octahedral Octahedral Octahedral – – Octahedral – – Distorted Octahedral Octahedral Octahedral – – Octahedral – – Distorted Octahedral Octahedral

Ni(LI)(Q)H2O

Cu(LI)(Q)H2O Zn(LI)(Q)H2O Co(LII)(Q) H2O

Ni(LII)(Q)H2O

Cu(LII)(Q)H2O Zn(LII)(Q)H2O Co(LIII)(Q) H2O

Ni(LIII)(Q)H2O

Cu(LIII)(Q)H2O Zn(LIII)(Q)H2O Co(LIV)(Q) H2O

Ni(LIV)(Q)H2O

Cu(LIV)(Q)H2O Zn(LIV)(Q)H2O

T1g(F) ? 4T1g(P) 4 T1g(F) ? 4A2g(F) 4 T1g(F) ? 4T2g(F) 3 A2g(F) ? 3T1g(P) 3 A2g(F) ? 3T1g(F) 3 A2g(F) ? 3T2g(F) p N ? Cu⁄ 2 Eg(D) ? 2T2g(D) LMCT 4 T1g(F) ? 4T1g(P) 4 T1g(F) ? 4A2g(F) 4 T1g(F) ? 4T2g(F) 3 A2g(F) ? 3T1g(P) 3 A2g(F) ? 3T1g(F) 3 A2g(F) ? 3T2g(F) p N ? Cu⁄ 2 Eg(D) ? 2T2g(D) LMCT 4 T1g(F) ? 4T1g(P) 4 T1g(F) ? 4A2g(F) 4 T1g(F) ? 4T2g(F) 3 A2g(F) ? 3T1g(P) 3 A2g(F) ? 3T1g(F) 3 A2g(F) ? 3T2g(F) p N ? Cu⁄ 2 Eg(D) ? 2T2g(D) LMCT 4 T1g(F) ? 4T1g(P) 4 T1g(F) ? 4A2g(F) 4 T1g(F) ? 4T2g(F) 3 A2g(F) ? 3T1g(P) 3 A2g(F) ? 3T1g(F) 3 A2g(F) ? 3T2g(F) p N ? Cu⁄ 2 Eg(D) ? 2T2g(D) LMCT

surface and then two wells having diameter of 10 mm were dug in media. In each well of inoculated agar plate, 100 lL of sterilized stock solution was poured and incubated at 37 °C for 48 h. Activity was determined by measuring the diameter of zone showing complete inhibition and has been expressed in mm. Antifungal activity assay For in vitro antifungal activity, the moulds were grown on sabouraud dextrose agar (SDA) at 25 °C for 7 days and used as inoculate. 15 mL of molten SDA (45 °C) was added to 100 lL volume of each compound having concentration of 100 lg/mL, reconstituted in the DMSO, poured into a sterile Petri plate and allowed to solidify at room temperature. The solidified poisoned agar plates were inoculated at the centre with fungal plugs 10 mm obtained from actively growing colony and incubated at 25 °C for 7 days. DMSO was used as negative control and Fluconazole was used as positive control to access antifungal activity. Diameters of the fungal colonies were measured and expressed as percent mycelial inhibition determined by the following formula.

Inhibition of mycelial growth % ¼ ðdc  dt Þ=dc  100 dc – average diameter of fungal colony in negative control; dt – average diameter of fungal colony in experimental plates. Determination of minimum inhibitory concentration (MIC) MIC is the lowest concentration of a compound that will inhibit the visible growth of microbes after overnight incubation. MIC of synthesized compounds were determined by means of two fold serial dilution technique. The stock solution of the test compound was prepared in dry dimethylsulfoxide to give a concentration of

4.21 – – 3.04 – – 1.75

4.38 – – 3.01 – – 1.86

4.43 – – 3.08 – – 1.92 –

100 lg/ml. The stock solution (0.1 mL) was added to 1.8 mL of sterile nutrient broth to form the first dilution (50 lg/mL). One mL of the solution from first dilution was diluted further with one mL of the sterile double strength nutrient broth to produce the second dilution. The process was repeated until a set of five dilutions with test compound concentrations of 50, 25, 12.5, 6.25 and 3.12 lg/mL was obtained. The MIC of standard drugs for antibacterial activity and antifungal activity were found to be Zn > HLI–IV > HQ. Conclusion Based on the various observations of elemental analysis, molar conductivity, spectroscopic techniques (IR, 1HNMR, 13C NMR, mass and ESR) and magnetic susceptibility measurements, it was observed that Schiff base ligands HLI–IV existed as monobasic tridentate ONO bonded to metal ion through oxygen of carbonyl group, azomethine nitrogen, deprotonated hydroxyl oxygen and HQ ligand existed as monobasic bidentate ON bonded through oxygen of hydroxyl group and nitrogen of quinoline ring. Mononuclear structure with octahedral or distorted octahedral geometry has been proposed for complexes. All the synthesized compounds showed promising antimicrobial activities against various microorganisms and their complexes showed better activity as

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compared to the parent ligands under identical experimental conditions. Among all compounds, Cu(LIV)(Q)H2O was found to be most potent antimicrobial agent and may be used in food and pharmaceutical industry after testing its toxicity in human beings. Appendix A. Supplementary material Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.saa.2014.07.041. References [1] M.N. Hughes, G. Wilkinson, R.D. Gillard, J.A. McCleverty, Comprehensive Coordination Chemistry, vol. 6, Pergamon Press, Oxford, UK, 1987. [2] J.R. Thakkar, N.V. Thakkar, Synth. React. Inorg. Met. Org. Chem. 30 (10) (2000) 1871. [3] S.K. Sridhar, S.N. Pandeya, J.P. Stables, A. Ramesh, Eur. J. Pharm. Sci. 16 (2002) 129. [4] N.R. Penthala, T.R. Yerramreddy, N.R. Madadi, P.A. Crooks, Bioorg. Med. Chem. Lett. 20 (15) (2010) 4468. [5] S.N. Pandeya, S. Smitha, M. Jyoti, S.K. Sridhar, Acta Pharm. 66 (2008) 43. [6] S.A. Imam, R.S. Varma, Experientia 31 (1975) 1287. [7] S.K. Bhattacharya, V. Glover, I. McIntyre, Neurosci. Lett. 92 (1992) 218. [8] K.S. Bhattacharya, K.M. Shankar, B.A. Satya, J. Psychopharmacol. 5 (1991) 202. [9] Z.H. Chohan, H. Pervez, A. Rauf, J. Enz. Inhib. Med. Chem. 19 (2004) 417. [10] S.N. Pandeya, S. Smitha, M. Jyoti, S.K. Sridhar, Acta Pharm. 55 (2005) 27. [11] R. Boon, Antiviral Chem. Chemother. 8 (1997) 5. [12] I. Chiyanzu, E. Hansell, J. Gut, Bioorg. Med. Chem. Lett. 13 (2003) 3527. [13] R.A. Lyer, P.E. Hanna, Bioorg. Med. Chem. Lett. 5 (1995) 89. [14] A.I. Vogel, Text book of Quantitative Chemical Analysis, fifth ed., Longmans, Edison, Wesley, London, 1999. [15] G. Cerchiaro, P.L. Saboya, A.M.C. Ferreira, D.M. Tomazela, M.N. Eberlin, Tran. Met. Chem. 29 (2004) 495. [16] P.K. Radhakrishnan, Inorg. Chim. Acta 110 (1985) 211. [17] J. Devi, N. Batra, Asian J. Res. Chem. 6 (10) (2013) 960. [18] A.A. Abou-Hussen, N.M. El-metwally, E.M. Saad, A.A. El-asmy, J. Coord. Chem. 58 (18) (2005) 1735. [19] G.G. Mohamed, M.M. Omar, A.M. Hindy, Turk J. Chem. 30 (2006) 361. [20] A.B.P. Lever, J.J. Lewis, Chem. Soc 2552 (1963). [21] R.L. Carlin, Transition Metal Chemistry, second ed., Marcel Decker, New York, 1965. [22] G.G. Mohammed, Spectrochim. Acta A 57 (2001) 1643. [23] T. M. Dunn, The visible and ultraviolet spectra of complex compounds in modern coordination chemistry (1960). [24] T.R. Reddy, R. Srinivasan, J. Chem. Phys. 43 (1965) 1404. [25] N. Raman, A. Selvan, S. Sudharsan, Spectrochim. Acta A 79 (2011) 873. [26] J. Devi, S. Kumari, R. Malhotra, Phosphorus Sulfur Silicon Relat. Elem. 187 (2012) 587. [27] J. Devi, N. Batra, R. Malhotra, Spectrochim. Acta A 97 (2012) 397.

Synthesis, characterization and antimicrobial activities of mixed ligand transition metal complexes with isatin monohydrazone Schiff base ligands and heterocyclic nitrogen base.

Mixed ligand complexes of Co(II), Ni(II), Cu(II) and Zn(II) with various uninegative tridentate ligands derived from isatin monohydrazone with 2-hydro...
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