Research Article Studies on Oligomer Metal Complexes ...downloads.hindawi.com/journals/isrn/2014/516274.pdf · Research Article Studies on Oligomer Metal Complexes Derived from Bisamic

Research ArticleStudies on Oligomer Metal Complexes Derived from BisamicAcid of Pyromellitic Dianhydride and 4-Bromoaniline

Yogesh S Patel

Chemistry Department Government Science College Gandhinagar Gujarat 382015 India

Correspondence should be addressed to Yogesh S Patel dryspatelgmailcom

Received 25 April 2014 Accepted 19 September 2014 Published 30 October 2014

Academic Editor Wen-Sheng Chen

Copyright copy 2014 Yogesh S Patel This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Novel oligomermetal complexes (2andashf) of the ligand 25-bis((4-bromophenyl)carbamoyl) terephthalic acid (1)were prepared usingtransitionmetal salts and characterized by various spectroscopic techniquesThe geometry of oligomermetal complexeswas carriedout by electronic spectral analysis andmagnetic measurement studies Polymeric properties have also been carried out Ligand wassynthesized using pyromellitic dianhydride and 4-bromoaniline It was duly characterized All novel synthesized compounds 1and 2andashf were evaluated for their antibacterial and antifungal activity The results showed significantly higher antibacterial andantifungal activity of oligomer metal complexes compared to the ligand

1 Introduction

The design and construction of polymeric metal complexeshave received great attention [1ndash6] The structures of metalcomplexes are depending upon the structure of the organicligands the coordinative geometry of metal ions metal-ligand ratio and other factors [7 8] Among various organicligands multicarboxylate ligands are often used to synthesizepolymer metal complexes for example 1245-benzene-tetracarboxylate 331015840441015840-biphenyl tetra carboxylic acid [9 10]111015840-biphenyl-231015840341015840-tetra carboxylic acid [11] and methy-lene diisophthalic acid [12] have been extensively used forthe synthesis of various polymer metal complexes On theother hand the use of auxiliary N-containing ligands is alsoan effective method for the framework formation of polymermetal complexes owing to the fact that they can satisfy andeven mediate the coordination needs of the metal centerand consequently generate more meaningful architectures[13 14] The oligomer metal complex based on bisamic acidof pyromellitic dianhydride has not attracted any attentionHence initial work in this direction has been reported by us[15ndash18] This prompted us to extend our work by using otherauxiliary ligand such as 25-bis((4-bromophenyl) carbamoyl)terephthalic acid With the aim of investigating the influenceof ligand containing carboxylic and amide group (ndashO and ndashN containing ligand) on the frameworks of metal complexes

we have carried out the study for the reaction of metal(II) salts with novel bisamic acid Scheme 1 summarizesour synthetic approach to the synthesis of oligomer metalcomplexes using various metal (II) acetates for exampleMn(II) Fe(II) Co(II) Ni(II) Cu(II) and Zn(II) metal ionsLigand when incorporated with transition metal ions wouldproduce a broad spectrum of antimicrobial property Thedetails of these procedures and the results obtained arediscussed below

2 Experimental

21 Materials and Measurements All common reagents andsolvents were used of analytical grade and were used withoutfurther purification Alumina supported precoated silicagel 60 F254 thin layer chromatography (TLC) plates werepurchased from the E Merck (India) Limited Mumbai andwere used to check purity of compounds and to study theprogress of the reaction whereby TLC plates were illuminatedunder ultraviolet light (254 nm) evaluated in I

2vapors and

visualized by spraying with Dragendorff rsquos reagent Infraredspectra (FT-IR) were obtained from KBr pellets in therange of 4000ndash400 cmminus1 with a Perkin Elmer spectrum GXspectrophotometer (FT-IR) instrument 1H NMR and 13CNMR spectra were acquired at 400MHz on a Bruker NMR

Hindawi Publishing CorporationInternational Scholarly Research NoticesVolume 2014 Article ID 516274 7 pageshttpdxdoiorg1011552014516274

2 International Scholarly Research Notices

Br

Br

Br

Br

HOOC

HNOC COOH

OOC CONH

COOHNOC

M M

n

H2O

H2O

Oligomer metal complexesM = Mn(II) Fe(II) Co(II) Ni(II) Cu(II) Zn(II)

25-Bis((4-bromophenyl)carbamoyl)terephthalic acid

Metalion

H2O

H2O

CONH

(2andashf)(1)

Scheme 1 Synthetic route for the oligomer metal complexes

spectrometer using DMSO-1198896(residual peak at 120575 sim25 or

sim395 ppm 300∘K) as a solvent as well as TMS an internal ref-erence standard Microanalytical (C N H) data was obtainedby using a Perkin Elmer 2400 CHN elemental analyzer Thesolid diffuse electronic spectra were recorded on a BeckmanDK-2A spectrophotometer with a solid reflectance attach-ment MgO was employed as a reference Magnetic moments[19] were determined by the Gouy method with mercurytetrathiocyanatocobaltate (II) [HgCo(NCS)

4] as calibrant

(119883119892 = 1644 times 10minus6 cgs units at 20∘C) by Citizen Balance(at room temperature) Molar susceptibilities were correctedusing Pascalrsquos constant [20] The thermogravimetric studieswere carried out with amodel Perkin Elmer thermogravimet-ric analyzer at a heating rate of 10∘Cminminus1 in the temperaturerange 50ndash700∘C The metal content of the oligomer metalcomplexes was carried by decomposing a weighed amountof each oligomer metal complexes with HClO

4 H2SO4 and

HNO3(1 15 25) mixture followed by standard EDTA titra-

tion method [21] Number average molecular weight (Mn)of oligomermetal complexes was determined by nonaqueousconductometric titration It was carried out in pyridine solu-tion against standard sodiummethoxide in pyridine solutionas titrant The number average molecular weight of eachsample was calculated according to method reported in theliterature [22]Themelting point was checked by the standardopen capillarymethod In order to facilitate the correct struc-tural assessment that is the coordination site we have trieda lot to generate a crystal for single crystal X-ray analysis butwe did not succeed Hasanzadeh et al [23] have reported thistype of acid amide metal complex So from the obtained dataand reference article interpretations become straightforward

22 Synthesis of Ligand 25-Bis((4-bromophenyl) carbamoyl)Terephthalic Acid (1) Adding a solution dropwise of 4-bromoaniline (2440 g 02mol) to a stirred solution of

pyromellitic dianhydride (21813 g 01mol) and keeping thetemperature of the medium close to 40ndash50∘C for an hour(Scheme 1) thus obtained ensuing solution was poured intoice water in which the reaction product precipitated Thefinal white precipitates were filtered washed and purified bycolumn chromatography Physicochemical parameters andFT-IR spectral data were mentioned in Tables 1 and 2 respec-tively 1H NMR (DMSO-119889

6 120575 ppm) 1087 (s 2HndashCOOH)

909 (s 2H ndashNHndash) 848 (s 2H ArndashH) 766 (d 4H ArndashH)and 749 (d 4H ArndashH) 13C NMR (DMSO-119889

6 120575 ppm) 1213

1227 1268 1309 1343 1352 1368 1679 and 1712

23 Synthesis of Oligomer Metal Complexes (2andashf) Alloligomer metal complexes were synthesized by using equim-olar amount of ligand and various metal (II) salts To awarm clear solution of ligand (5621 g 001mol) in 20mLof dimethylsulphoxide add 01M sodium hydroxide solu-tion and pH about 7-8 was maintained A pasty mass wasobserved It was diluted with water to make a solution clearTo the above solution metal (II) acetate solution (001mol)was added with constant stirring and the pH of the reactionmixture was adjusted to 6-7 for 2a 2b 2c 2d and 2f and 4-5for 2e Thus oligomer metal complexes were separated out inthe form of a suspension It was digested on a water bath for1 h filtered washed and dried in air at room temperatureThese oligomer metal complexes designated as 2andashf areinsoluble in common organic solvents likemethanol ethanolchloroform acetone and benzene

24 Biological Activity

241 Antibacterial Activity (In Vitro) Compounds (1 and2andashf) were screened for in vitro antibacterial activity againstGram-positive bacterial strains (Bacillus subtilis (BS) andStaphylococcus aureus (SA)) and Gram-negative bacterial

International Scholarly Research Notices 3

Table 1 Physicochemical parameters of the ligand and its oligomer metal complexes

Empirical formula ofcompound

Empiricalweight (gm) Color Yield MPa

(∘C)Elemental analysis calc (found )

120583eff BM 119872119899

DPC H N M

1 LC22H14Br2N2O6

56216 Light yellow 65 160b 4700(4689)

251(246)

498(492) mdash mdash mdash mdash

2a[MnndashLndash(H

2O)2]119899

C22H16Br2N2O8Mn 65112 White 45 gt250 4058(4050)

248(243)

430(425)

844(840) 554 3250 5

2b[FendashLndash(H

2O)2]119899

C22H16Br2N2O8Fe 65202 Light brown 58 gt250 4053(4045)

247(242)

430(423)

856(850) 498 3901 6

2c[CondashLndash(H

2O)2]119899

C22H16Br2N2O8Co65511 Light pink 55 gt250 4033

(4025)246(240)

428(421)

900(892) 425 3257 5

2d[NindashLndash(H

2O)2]119899

C22H16Br2N2O8Ni65487 Light green 63 gt250 4035

(4030)246(241)

428(426)

896(892) 287 3250 5

2e[CundashLndash(H

2O)2]119899

C22H16Br2N2O8Cu 65973 Green 70 gt250 4005(4000)

244(238)

425(421)

963(958) 199 3941 6

2f[ZnndashLndash(H

2O)2]119899

C22H16Br2N2O8Zn 66156 White 45 gt250 3994(3988)

244(239)

423(417)

988(982) D 3312 5

aMelting points were checked by standard open capillary method and were found uncorrected buncorrected120583eff BM magnetic moment119872

119899 number of average molecular weights DP degree of polymerization and D diamagnetic

Table 2 FT-IR frequencies and electronic spectral data of the ligand and its oligomer metal complexes

Compound minusCOOH minusCONH minusOH minusC=O minusCONH COOminus CndashO MndashO MndashN Electronic spectral datacmminus1 Transitions

1 L 3555 3237 mdash 1712 1688 1465 1047 mdash mdash mdash mdash

2a [MnndashLndash(H2O)2]119899

mdash 3212 2982 1692 1665 1453 1029 623 528164861776923140

6A1g rarr 4T1g(4G)6A1g rarr 4T2g(4G)6A1g rarr 4A1g 4Eg

2b [FendashLndash(H2O)2]119899

mdash 3220 2979 1694 1673 1455 1026 628 531 1901136062

5T2g(F) rarr 3Eg5T2g(F) rarr 3T1g

2c [CondashLndash(H2O)2]119899

mdash 3211 2983 1690 1672 1447 1028 630 52998451555322948

4T1g(F) rarr 4T2g(F)4T1g(F) rarr 4A2g(F)4T1g(F) rarr 4T1g(P)

2d [NindashLndash(H2O)2]119899

mdash 3214 2977 1695 1669 1449 1025 634 52698511557022934

3A2g rarr 3T2g3A2g rarr 3T1g(F)3A2g rarr 3T1g(P)

2e [CundashLndash(H2O)2]119899

mdash 3225 2969 1689 1671 1450 1027 629 532 1594922746

2T2g rarr 2Egcharge transfer

2f [ZnndashLndash(H2O)2]119899

mdash 3213 2973 1687 1668 1446 1026 632 527 mdash mdash

strains (Salmonella typhimurium (ST) and Escherichia coli(EC)) utilizing the agar diffusion assay [24 25] The wellswere dug in the media with the help of a sterile metallicborer Recommended concentration (100120583L) of the testsample (1mgmL in DMSO) was introduced in the respectivewells Other wells supplemented with DMSO and referenceantibacterial drug ciprofloxacin were served as negativeand positive controls respectively The plates were incubatedimmediately at 37∘C for 24 hours Activity was determinedby measuring the diameter of zones showing completeinhibition (mm) Growth inhibition was compared with thestandard drug In order to clarify any participating role ofDMSO in the biological screening separate studies werecarried out with the solutions alone of DMSO and theyshowed no activity against any bacterial strains

242 Antifungal Activity (In Vitro) Compounds (1 and2andashf) were also examined for antifungal activity againstdifferent fungal strains that is Penicillium expansum (PE)Botryodiplodia theobromae (BT) Nigrospora sp (NS) andTrichothecium sp (TS) The antifungal drug ketoconazolewas used as a positive control Antifungal screening forcompounds (1 and 2andashf) and positive control was performedat a recommended concentration The fungal strains weregrown and maintained on potato dextrose agar plates Thecultures of the fungi were purified by single spore isolationtechnique Each compound (1 and 2andashf) in DMSO solutionwas prepared for testing against spore germination of eachfungus The fungal culture plates were inoculated and incu-bated at 25 plusmn 2∘C for 48 h The plates were then observedand the diameters of the zone of inhibition (in mm) were

4 International Scholarly Research Notices

measuredThe percentage inhibition for fungi was calculatedafter five days using the formula given below

Percentage of inhibition = 100 (119883 minus 119884)119883 (1)

where 119883 is area of colony in control plate and 119884 is area ofcolony in test plate

3 Results and Discussion

31 Synthesis of Ligand 25-Bis((4-bromophenyl) carbamoyl)Terephthalic Acid (1) To the best of our knowledge lig-and (1) has not been reported previously The character-ization of the reaction product provided the first unam-biguous proof of the successful synthesis of 25-bis((4-bromophenyl)carbamoyl)terephthalic acid The FT-IR spec-trum of ligand showed the most relevant peaks of thearomatic ring and 1245-tetra substituted benzene ringother than typical absorptions arising from the band at3555 cmminus1 and 1712 cmminus1 for carboxylic acid and 3237 cmminus1and 1688 cmminus1 for O=CndashNH group [26] In the 1H NMRspectroscopy the signals in the range of 848 766 and749 ppm were ascribed to the protons of the aromaticrings The singlet at 1087 ppm was ascribed to the protonsof carboxylic ndashOH group and a singlet at 909 ppm wasattributed to the ndashNH proton of amide group which wasfurther confirmed by 13C NMR value that is 1679 and1712 attributed to carboxylic carbon and amide carbonrespectively The expected structure was thus clearly verifiedby the spectroscopic analysis which indicated moreover theabsence of any detectable impurity particularly of the tworeagents used to prepare ligand

32 Synthesis of Oligomer Metal Complexes

321 Physical Properties Elemental analysis of all polymermetal complexes was in good agreement with proposedstructures All polymer metal complexes exhibited 1 1 metalto ligand stoichiometry The structures of oligomer metalcomplexes were consistent with the FT-IR electronic spectraand TGA The geometry of the central metal ion wasconfirmed by electronic spectra and magnetic susceptibilitymeasurements The degrees of polymerization (DP) for alloligomer metal complexes are in the range of 5 to 6 (Table 1)All the data provides good evidence that the chelates arepolymeric in nature The suggested structure of the polymermetal complexes is shown in Scheme 1

322 Infrared Spectra IR spectral bands of the ligand and itsoligomer metal complexes suggest the formation of desiredoligomer metal complexes and support their structure Spec-tral features provide valuable information regarding thenature of functional group attached to the metal atom(Figure 1) In order to study the bonding mode of ligandto the oligomer metal complexes the IR spectrum of freeligand was compared with the spectra of oligomer metalcomplexes (Table 2) Considerable differences to be expectedwere observed The band at about 3555 cmminus1 for carboxylic

40000 3000 2000 1500 1000 4000

FT-IR of

FT-IR of

(cmminus1)

2e

1

Figure 1 FT-IR of ligand and Cu-metal complex

acid in ligand had virtually disappeared from the spectraof oligomer metal complexes Oligomer metal complexesexhibit more broadened band in the region near 2980 cmminus1indicating the presence of coordinated water molecules [27]The coordinated water in all the oligomer metal complexespresents different peaks at 980 cmminus1 (rocking) and 770 cmminus1(wagging) whereas none of these vibrations appear in thespectra of uncoordinated ligands A band at sim1640 cmminus1in free ligand is due to ]CndashN vibration The shifting ofthis group to lower frequency (sim1610 cmminus1) in the oligomermetal complexes when compared to free ligand suggested thecoordination of metal ion through nitrogen atom of amidegroup [28] it is expected that coordination of nitrogen to themetal atom would reduce the electron density in the amidelink and thus lower the absorption [29] A band at 1712 cmminus1is assigned to ]C=O stretching frequency in the spectrum offree ligand which is also shifted to lower frequency rangingfrom 1687 to 1694 cmminus1 in all the oligomer metal complexesThis indicates the involvement of oxygen atom of hydroxylgroup of ndashCOOH group in bonding with metal ions [30]New bands which were not present in the spectrum ofligand appeared in the spectra of oligomer metal complexesfor example presence of sharp band in the region of 525ndash535 cmminus1 can be assigned to ]MndashN [30] which indicatedthe involvement of nitrogen in coordination The mediumintensity bands for ]MndashO [31] have been observed at 625ndash635 cmminus1 due to MndashO coordination The appearance of ]MndashN and ]MndashO vibrations supports the involvement of N andOatoms in complexationwithmetal ions under investigationThese overall data suggest that the amide-N and carboxylate-O groups are involved in coordination with the metal (II) ionin oligomer metal complexes These features confirmed theproposed structure of oligomer metal complexes as shown inScheme 1

323 Magnetic Moments and Electronic Spectral Data Theinformation regarding geometry of the oligomeric metalcomplexes were obtained from their electronic spectral dataandmagneticmoment values (Table 2)The diffuse electronicspectrum of the [Cu(L)(H

2O)2]119899shows two broad bands

International Scholarly Research Notices 5

around 15949 cmminus1 and 22746 cmminus1 due to the 2T2g rarr 2Egtransition while the second may be due to charge transferrespectivelyThis suggests a distorted octahedral structure forthe [Cu(L)(H

2O)2]119899polymerwhichwas further confirmed by

its120583eff value 199 BMThe [Ni(L)(H2O)2]119899coordination poly-

mer shows two absorption bands at 15570 cmminus1 22934 cmminus1and 9851 cmminus1 due to 3A2g rarr 3T1g(F) and 3A2g rarr3T1g(P) and 3A2g rarr 3T2g respectively The [Co(L)(H

2O)2]119899

polymer shows that two absorption bands at 22948 cmminus115553 cmminus1 and 9845 cmminus1 corresponding to 4T1g(F) rarr4T1g(P) 4T1g(F) rarr 4A2g(F) and 4T1g(F) rarr 4T2g(F) trans-itions respectively indicated an octahedral configurationfor the [Ni(L)(H

2O)2]119899and [Co(L)(H

2O)2]119899polymers [32]

This configuration was further confirmed by its 120583eff values287 BM and 425 BM The spectrum of [Fe(L)(H

2O)2]119899

shows bands at 36062 cmminus1 and 19011 cmminus1 assigned to thetransitions 5T2g(F) rarr 3T1g and 5T2g(F) rarr 3Eg and its 120583eff498 BM suggesting octahedral configurationThe spectrumof [Mn(L)(H

2O)2]119899shows weak bands at 16468 17769 and

23140 cmminus1 assigned to the transitions 6A1g rarr 4T1g(4G)6A1g rarr 4T2g(4G) and 6A1g rarr 4A1g 4Eg respectively sug-gesting an octahedral structure for the [Mn(L)(H

2O)2]119899

polymer [33]This configuration was further confirmed by its120583eff value 554 BM As the spectrum of the [Zn(L)(H

2O)2]119899

polymer is not well interpreted its 120583eff value shows that itis diamagnetic as expected Magnetic moments 120583eff of alloligomer metal complexes revealed that all oligomers exceptZn(II) metal ion polymer are paramagnetic while Zn(II)metal ion oligomer is diamagnetic

324 Thermal Analysis The thermal behavior was investi-gated by Perkin Elmer TGA analyzer at a heating rate of 10∘Cminminus1 in the temperature range 50ndash700∘C under nitrogenwhich provides much information about the coordinationcompounds In all the oligomer metal complexes decompo-sition occurred in two steps (Figure 2) First step occurredbetween 100∘C and 200∘C which might be attributed to massloss corresponding to water molecules The value of weightloss during this step was consistent with theoretical valueof two water molecules indicating that two water moleculeswere coordinated to the metal ion Second step occurredbetween 200∘C and 700∘C which exhibits a mass loss cor-responding to decomposition of ligand part in polymerThe weight loss of polymer metal complexes was noticeablebetween 300 and 600∘C The rate of degradation becamemaximum at a temperature between 400∘C and 600∘C Thismay be due to acceleration bymetal oxidewhich forms in situEach polymer loses about 80of its weight when heated up to700∘C On the basis of the relative decomposition ( weightloss) and the nature of thermogram the oligomer metalcomplexes may be arranged in the order of their increasingstability as Cu lt Fe lt Ni lt Co lt Zn ltMn

33 Biological Activity

331 Antibacterial Activity Based on the data from theantibacterial studies against both Gram-positive and Gram-negative bacterial strains the following observations can be

110

100

90

80

70

60

50

40

30

20

10

0

0 100 200 300 400 500 600 700

Temperature

Wei

ght l

oss (

)

Perkin Elmer thermogravimetryanalyzer at a heating rate of10

∘C minminus1 in the temperaturerange 50ndash700∘C

2a2b2c

2d2e2f

Figure 2 Thermogram of oligomer metal complexes

0

10

20

30

40

50

60

BS SA ST EC

Zone

of i

nhib

ition

Ciprofloxacin

12a2b2c

2d2e2f

Figure 3 Antibacterial activity of ligand and its oligomer metalcomplexes

made All compounds (1 and 2andashf) exhibited antibacterialactivity against both Gram-positive and Gram-negative bac-terial strains with zones of inhibition (ZOI) ranging from20mm to 37mm (Figure 3)

Schiff base 25-bis((4-bromophenyl) carbamoyl)tereph-thalic acid was found less active than its metal complexesAmong the analogs 2andashf compound 2e (ZOI

(BS) = 36mmZOI(SA) = 35mm ZOI

(ST) = 37mm and ZOI(EC) = 36mm)

was identified as a potent antibacterial agent against all Gram-positive and Gram-negative bacterial strains Compound2b (ZOI

(BS) = 33mm ZOI(SA) = 32mm ZOI

(ST) = 33mmand ZOI

(EC) = 32mm) also had good antibacterial activityagainst bacterial strains Compounds 2a 2c 2d and 2fexhibited moderate antibacterial activity Compounds 1 and2andashf exhibited less antibacterial activity as compared to

6 International Scholarly Research Notices

0

10

20

30

40

50

60

PE BT NS TS

Zone

of i

nhib

ition

Ketoconazole2f2e2d

2c2b2a1

Figure 4 Antifungal activity of ligand and its oligomer metalcomplexes

standard antibiotic drug ciprofloxacin (ZOI(BS) = 45mm

ZOI(SA) = 46mm ZOI

(ST) = 45mm and ZOI(EC) = 47mm)

Comparative study of the growth inhibition zone valuesof Schiff base and its oligomermetal complexes indicated thatthe oligomer metal complexes exhibited higher antibacterialactivity than free Schiff base (Figure 3) Such increasedactivity of the oligomer metal complexes can be explained onthe basis of Overtonersquos concept and Tweedyrsquos chelation theory[34] According to Overtonersquos concept of cell permeabilitythe lipid membrane that surrounds the cell favors the passageof only lipid soluble materials due to which liposolubilityis considered to be an important factor that controls theantimicrobial activity Chelation reduces the polarity [3536] of the metal ion mainly because of the partial sharingof its positive charge with the donor groups and possiblythe 120587-electron delocalization within the whole chelate ringsystem thus formed during coordination This process ofchelation thus increases the lipophilic nature of the centralmetal atom which in turn favors its permeation through thelipoid layer of the membrane This in turn is responsible forincreasing the hydrophobic character and liposolubility of themolecule in crossing cell membrane of the microorganismand hence enhances the biological utilization ratio andactivity of the testing drugcompoundThe biological activityof compounds also depends on the nature of the ligandconcentration lipophilicity nature ofmetal ion coordinatingsites and geometry of the complex

332 Antifungal Activity Based on the screening data fromthe antifungal studies the following observations can bemade All compounds (1 and 2andashf) exhibited antifungalactivity against different fungal strains (Figure 4) Schiffbase 25-bis((4-bromophenyl) carbamoyl)terephthalic acidwas found less active than its oligomer metal complexesCompound 2e (ZOI

(PE) = 35mmZOI(BT) = 33mmZOI

(NS) =36mm and ZOI

(TS) = 34mm) was identified as more activeagainst all fungal strains Compound 2b (ZOI

(PE) = 33mmZOI(BT) = 30mm ZOI

(NS) = 32mm and ZOI(TS) = 31mm)

also had good antifungal activity against fungal strainsCompounds 2a 2c 2d and 2f exhibited moderate antifungalactivity Compounds 1 and 2andashf exhibited less antifungalactivity as compared to standard antibiotic drug ketocona-zole (ZOI

(PE) = 43mm ZOI(BT) = 42mm ZOI

(NS) = 45mmand ZOI

(TS) = 41mm)

4 Conclusions

Ligand and its oligomer metal complexes have been synthe-sized and were duly characterized by various spectroscopictechniques The geometry of a central metal ion was con-firmed by electronic spectra andmagnetic susceptibilitymea-surements Antimicrobial activity of ligand and its oligomermetal complexes suggests that the complexes are more potentthan the ligand

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

The author is greatly thankful to the Principal GovernmentScience College Gandhinagar for providing the necessaryresearch facility

References

[1] A C Tsipis ldquoDFT flavor of coordination chemistryrdquo Coordina-tion Chemistry Reviews vol 272 pp 1ndash29 2014

[2] D-S Li J Zhao Y-PWu et al ldquoCo5Co8-cluster-based coordi-

nation polymers showing high-connected self-penetrating net-works syntheses crystal structures and magnetic propertiesrdquoInorganic Chemistry vol 52 no 14 pp 8091ndash8098 2013

[3] D-S Li P Zhang J Zhao et al ldquoTwo unique entangling Cd II-coordination frameworks constructed by square Cd 4-buildingblocks and auxiliary NN1015840-donor ligandsrdquo Crystal Growth andDesign vol 12 no 4 pp 1697ndash1702 2012

[4] Y Hijikata S Horike M Sugimoto M Inukai T Fukushimaand S Kitagawa ldquoPore design of two-dimensional coordinationpolymers toward selective adsorptionrdquo Inorganic Chemistryvol 52 no 7 pp 3634ndash3642 2013

[5] B Zheng J Luo F Wang et al ldquoConstruction of sixcoordination polymers based on a 551015840-(12-ethynyl)bis- 13-benzenedicarboxylic ligand Synthesis structure gas sorptionand magnetic propertiesrdquo Crystal Growth amp Design vol 13 no3 pp 1033ndash1044 2013

[6] Y-Y Liu H-Y Liu J-F Ma Y Yang and J Yang ldquoSynthesesstructures and photoluminescent properties of Zn(II) andCd(II) coordination polymers with flexible tripodal triazole-containing ligandsrdquo CrystEngComm vol 15 no 10 pp 1897ndash1907 2013

[7] M-L Tong S Hu J Wang S Kitagawa and W N SeikldquoSupramolecular isomerism in cadmium hydroxide phasesTemperature-dependent synthesis and structure of photolu-minescent coordination polymers of 120572- and 120573-Cd

2(OH)

2(24-

pyda)rdquoCrystal GrowthampDesign vol 5 no 3 pp 837ndash839 2005

International Scholarly Research Notices 7

[8] W-G Lu L Jiang and T-B Lu ldquoLanthanide contraction andtemperature-dependent structures of lanthanide coordinationpolymers with imidazole-45-dicarboxylate and oxalaterdquo Crys-tal Growth and Design vol 10 no 10 pp 4310ndash4318 2010

[9] G-P Yang Y-YWang L-FMa et al ldquoHydrothermal synthesesand characterizations of three coordination polymers basedon mixed organic ligandsrdquo European Journal of InorganicChemistry vol 24 pp 3892ndash3898 2007

[10] J-J Wang L Gou A-M Hu et al ldquoLigand and pH-controlledZnII bilayer coordination polymers based on biphenyl-331015840441015840-tetracarboxylaterdquo Crystal Growth and Design vol 7no 8 pp 1514ndash1521 2007

[11] S Q Zang Y Su Y Li Z Ni H Zhu and Q Meng ldquoInter-weaving of triple-helical and extended metal-O-metal single-helical chains with the same helix axis in a 3D metal-organicframeworkrdquo Inorganic Chemistry vol 45 no 10 pp 3855ndash38572006

[12] X Duan J Lin Y Li C Zhu and Q Meng ldquoSynthesesstructures and properties of a series of organic-inorganiccomplexes based on methylenediisophthalic acid (H4MDIP)rdquoCrystEngComm vol 10 no 2 pp 207ndash216 2008

[13] C-Z Mei W-W Shan and B-T Liu ldquoSynthesis crystal struc-ture and luminescent properties of one 3D Cd(II) coordinationpolymer [Cd(H3BPTC)2(bpy)]n (H4BPTC = 111015840-biphenyl-221015840661015840-tetracarboxylic acid bpy = 441015840-bipyridine)rdquo Spec-trochimica ActamdashPart A Molecular and Biomolecular Spec-troscopy vol 81 no 1 pp 764ndash768 2011

[14] C-Z Mei J-X Wang and W-W Shan ldquoSynthesis and crystalstructure of an infinite sandwich-type Cu(I) coordination poly-mer [Cu(abpy)2](H3bptc)sdot(H2O)n constructed by a tetracar-boxylic acidrdquo Chinese Journal of Structural Chemistry vol 30no 8 pp 1194ndash1198 2011

[15] Y S Patel H S Patel and B Srinivasulu ldquoSynthesis spectralmagnetic thermal and biological aspects of pyromellitic dian-hydride based co-ordination polymersrdquo International Journal ofPlastics Technology vol 16 no 2 pp 117ndash124 2012

[16] Y S Patel K D Patel and H S Patel ldquoSpectral and antimi-crobial studies on novel ligand and its co-ordination polymersrdquoJournal of Saudi Chemical Society 2012

[17] Y S Patel R B Dixit and H S Patel ldquoSynthesis characteriza-tion and biological activity of coordination polymers derivedfrom pyromellitic dianhydriderdquo Turkish Journal of Chemistryvol 37 no 6 pp 978ndash986 2013

[18] Y S Patel P N Patel and H S Patel ldquoStudies on coor-dination polymers derived from 25-bis (naphthalen-1- ylcar-bamoyl)terephthalicacidrdquo Journal of Macromolecular Science APure and Applied Chemistry vol 51 no 2 pp 134ndash143 2014

[19] S F Vanparia T S Patel N A Sojitra et al ldquoSynthesis char-acterization and antimicrobial study of novel 4-[(8-hydroxy-quinolin-5-yl)methyl]aminobenzenesulfonamide and its oxi-natesrdquo Acta Chimica Slovenica vol 57 no 3 pp 660ndash667 2010

[20] A I VogelATextbook of Quantitative Inorganic Analysis Long-man London UK 3rd edition 1961

[21] G H Jeffery J Bassett J Mentham and R C Denney VogelsTextbook of Quantitative Inorganic Analysis Longman HarlowUK 5th edition 1989

[22] S K Chatterjee and N D Gupta ldquoEffects of structure and com-position on the titration curves of some synthetic copolymersin non aqueous mediardquo Journal of Polymer Science A PolymerChemistry vol 11 no 6 pp 1261ndash1270 1973

[23] R Hasanzadeh P NajafiMoghadam andN Samadi ldquoSynthesisand application ofmodified poly (styrene-alt-maleic anhydride)

networks as a nano chelating resin for uptake of heavy metalionsrdquo Polymers for Advanced Technologies vol 24 no 1 pp 34ndash41 2013

[24] S Alam ldquoSynthesis antibacterial and antifungal activityof some derivatives of 2-phenyl-chromen-4-onerdquo Journal ofChemical Sciences vol 116 no 6 pp 325ndash331 2004

[25] M J Pelzar E C S Chan andN R KriegAntibiotics andOtherChemotherapeutic Agents inMicrobiology Blackwell New YorkNY USA 5th edition 1998

[26] R M Silverstein and F X WebsteWebste Spectrometric Identi-fication of Organic Compounds John Wiley amp Sons New YorkNY USA 6th edition 2004

[27] P K Panchal P B Pansuriya and M N Patel ldquoIn-vitro bio-logical evaluation of some ONS and NS donor Schiff rsquos basesand their metal complexesrdquo Journal of Enzyme Inhibition andMedicinal Chemistry vol 21 no 4 pp 453ndash458 2006

[28] K Nakamoto Infrared and Raman Spectra of Inorganic andCoordination Compounds Wiley New York NY USA 3rdedition 1978

[29] A B P Lever Electronic Spectra of dn Inorganic Electronic Spec-troscopy Elsevier Amsterdam The Netherlands 2nd edition1984

[30] AMalik S Parveen T Ahamad SMAlshehri P K Singh andN Nishat ldquoCoordination polymer synthesis spectral charac-terization and thermal behaviour of starch-urea based biode-gradable polymer and its polymer metal complexesrdquo Bioinor-ganic Chemistry and Applications vol 2010 Article ID 8481308 pages 2010

[31] E M Soliman and M El-Shabasy ldquoSynthesis characterizationand electrical conductivity properties of homo- and hetero-di and trimetallic complexes of mixed azo dyesrdquo Journal ofMaterials Science vol 29 no 17 pp 4505ndash4509 1994

[32] J Lewis and R S Wilkins Modern Coordination ChemistryWiley-Interscience New York NY USA 1960

[33] R Pappalardo ldquoNote on the optical absorption of MnCl2and

MnBr2rdquoThe Journal of Chemical Physics vol 33 no 2 pp 613ndash

614 1960[34] B G Tweedy ldquoPlant extracts with metal ions as potential

antimicrobial agentsrdquoPhytopathology vol 55 pp 910ndash914 1964[35] Z H Chohan M Arif Z Shafiq M Yaqub and C T

Supuran ldquoIn vitro antibacterial antifungal amp cytotoxic activityof some isonicotinoylhydrazide Schiff rsquos bases and their cobalt(II) copper (II) nickel (II) and zinc (II) complexesrdquo Journal ofEnzyme Inhibition and Medicinal Chemistry vol 21 no 1 pp95ndash103 2006

[36] Z H Chohan and C T Supuran ldquoOrganometallic compoundswith biologically active molecules in vitro antibacterial andantifungal activity of some 111015840-(dicarbohydrazono) ferrocenesand their cobalt(II) copper(II) nickel(II) and zinc(II) com-plexesrdquo Applied Organometallic Chemistry vol 19 no 12 pp1207ndash1214 2005

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

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International Journal ofPhotoenergy

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Carbohydrate Chemistry

International Journal of

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Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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