Aggarwal, R. C.

Prasad, Lakshman

Singh, N. K.

English

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Indian JournaI of ChemistryVol. 14A, May 1976, pp. 325-327Complexes of VO(IV), Mn(ll), Co(ll), Ni(II), Cu(II) & Zn(lI)with N-Acetyl-N' -isonicotinoylhydrazineR. C. AGGARWAL, N. K. SINGH & LAKSHMAN PRASADDepartment of Chemistry, Banaras Hindu University, Varanasi 221005Received 18 April 1975; accepted 2 August 1975Complexes of N-acetyl-N'-isonicotinoylhydrazine (AINH) of the compositions VO(AINH-2H).H20, M(AINH-2H). 2H20[M=Mn(I1), Co(I1), Ni(I1) or Zn(I1)) and Cu(AINH-2H) have beenprepared and characterized on the basis of analytical, magnetic susceptibility and infrared andelectronic spectral data. Analytical data and IR spectra of the complexes show that AINH actsas a quadrfdentate ligand and water molecules are coordinated. Magnetic and electronicspectral data indicate that Cu(I1) complex is square-planar, whereas Mn(I1), Co(I1) and Ni(I1)form high-sptn octahedral complexes. .PREVIOUS studies show that benzoyl hydrazine(BH) coordinates to the transition metal ionsin the keto forml,2 while isonicotinic acidhydrazide (INH) coordinates in the keto as well asthe enolic Iorms-+. In earlier communicationsfromthis laboratory on transition metal complexes ofN-benzoyl-N'-isonicotinoylhydrazine (BINH)6 andN-acetyl-N'-benzoylhydrazine", only one of thecarbonyl groups of the ligands, viz., isonicotinoyl>C=O and acetyl >C=O was found to undergoenolization. It was of interest to study the beha-viour of N-acetyl-N'-isonicotinoylhydrazine(AINH),where both the ketonic groups are expected toundergo enolization, on complex formation withtransition metal ions. Accordingly, the complexesof AINH with VO(IV), Mn(II), Co(II), Ni(II) ,Cu(II) and Zn(II) have been studied and the resultsare reported in this paper.Materials and MethodsN-Acetyl-N'-isonicotinoylhydrazine (AINH) wasprepared by acetylation of INH as describedearlier".Preparation and analysis of the complexes-Cu(AINH-2H) was prepared by mixing aqueoussolutions of Cu(II) nitrate or sulphate and AINHand heating the mixture on a water-bath. Theresulting precipitate was filtered, washed with water,ethanol and dried at room temperature. Complexesof VO(IV), Mn(II), Co(II), Ni(II) and Zn(II) wereprepared by mixing aqueous solutions of metalnitrates or sulphates and AINH and raising the pHof the solution, with NH4Cl-NH40H buffer, till aslight turbidity appeared. The reaction mixture ineach case was refluxed on a water-bath for ,....,t hrto complete the reaction when the complexes pre-cipitated. The precipitate was filtered, washed anddried as before.The complexes were analysed for metal, nitrogenhydrazine and water content as described earlier",The analytical data are given in Table 1.Magnetic susceptibility, electronic and infraredspectral measurements of the complexes were madeas described earlier",Results and DiscussionThe insolubility of the complexes in commonorganic solvents and their high decomposition-temperatures (>250°) indicate their ionic or poly-meric nature.TABLE 1 -COLOUR, ANALYTICALAND MAGNETICMOMENTDATA OF THE COMPLEXESComplex Colour Calc. (%) Found (%) [leff(BM)Metal N N2H4 H2O Metal N N2H4 HzOVO(AINH-2H).H2O Deep blue 20·20 16·66 12·70 7·14 20·00 16·95 12·40 7·40 1-65[Mn(AINH-2H) (H 20)2] Dirty yellow 20·49 15·67 11·94 13-43 20·65 15·90 12·20 13·15 5'85[CO(AINH-2H) (H2O).] Reddish 21·67 15-40 11·76 13·23 21'41 15·16 12-00 13-50 4-80[Ni(AINH-2H) (H2O).] Green 21'43 15·40 11·76 13·23 21·00 14·70 11'55 13·80 3-20Cu(AINH-2H} Olive green 26·43 17·46 26·70 17·50 1·86[Zn(AINH-2H) (H2O).] Light yellow 23·48 15·10 11'51 12·95 24·20 15·90 11·47 12·00 Diamag,325INDIAN J. CHEM., VOL. 14A, MAY 1976Magnetic studies - Zn(AINH-2H) (H20)2 is dia-magnetic as expected for a dlO electronic configura-iion while the [LeI!. values of AINH complexes ofl\1n(II), Co(II) and Ni(II) are well within the rangeobserved for most of the octahedral complexes of'these metal ions". The magnetic moment of Cu-(AINH-2H) is close to those of Cu(II) square-planar complexes'? while that of VO(AINH-2H).H20 is normal, being close to those reported foroxovanadiumil.V) complexes'<.Electronic spectral studies (band positions in em-I)- The spectrum of AINH in water shows twobands at 30800 and 37500 which show a red shift:in the spectra of the complexes due to increase inconjugation on chelation. These bands observedin the regions 26700-29400 and 34480-35000 areassigned to intra-ligand transitions.In the visible region VO(AINH-2H).H20 showstwo bands at 11000 and 19000 which may beassigned to the transitions dxy-'?d;oz, dyz and dxy--+dx'_Y'respectively in the octahedral environment of VO(IV)complex-'.Two bands observed at 9500 and 19200 in theCo(II)-AINH complex are typical of Co(II) com-plexes in octahedral environment-" and may beassigned to the transitions 4.T1g--+4.T2g (F) and 4T1g(P) respectively. Using these assignments, the'values of 10 Dq and B' work out to be 10640 and722 crrr+ respectively and these then yield values of()'743, 25·72% and 24·25 kcaljmole for ~, ~o andLFSE respectively.The bands observed at 9500 and 15500 in thespectrum of Ni(II)-AINH may be assigned to thetransitions 3A2g--+3T2g (F) (VI) and 3A2g--+3Tlg (F) (',12)respectively in octahedral symrnetry-". The values-of the various ligand field parameters calculatedfrom VI and ',12values are as follows: 10Dq = 9500-crrr+, B' = 874 cm+, ~ = 0·83, ~o = 17·23% andLFSE = 32·57 kcaljrnole.10 Dq value of Ni(II)-AINH complex is close tothose reported for high-spin octahedral complexes-of Nj2+ in the coordination environment of twonitrogen and four oxygen atoms-! and suggests. aposition for AINH between water and ammonia mthe spectrochemical series.The 16000 crrr? band in the spectrum of Cu(II)-AINH complex in nujol is due to the transition'2Eg--+2T2g and the position of this band indicatessquare-planar geometry for the complex". Theiact that Cu(II)-AINH complex bears a colour J ALCOCK,J. F., BAKER, R. J. & DIAMANTIS,A. A., Attst.-similarity to some olive-green square-planar Cu(II) J. cu«, 25 (1972), 289.° d f h t t th 2<ISKANDAR, M. F., ZAYAN, S. E., KHALIFA, M. A. &-complexesI len s urt er suppor 0 e square- VEL-SAYED, L., J. inorg. nucl. Chem., 36 (1974), 551.planar geometry proposed for the Cu(II)-AINH~ 3. AGGARWAL,R. C., SINGH, N. K. & PRASAD, L., (un--cornplex. ~ published work).Inf, ed P t l t dies (band positions in em-I) - 4. NAGANO, K., KINOSHITA, H. & HIRAKAWA, A., Chem,njrar s ec ra s u ~ . pharm: Bull., 12 (10) (1964), 1198.All the hydrated complexes show one band m the . GEORGESCU, 1. I., CIOMARTAN,D., TEODORESCU, G.,region 3470-3300due to v(OH) of water molecule ~ HLEVCA, M. & ZAHARESCU,M., Revue Roum. chim.,present. The loss of water moleculets) at relatively 18 (7) (1973), 1159. .high temperature (> 160°) and a band in the region 6/ AGGARWAL,~. C., SINGH, N. K. & PRASAD, L., Lndia«. 1 ~. di t '-vi J. Chern: (in press).720-755m the IR spectra of the comp exes mrnca e 7 AGGARWAL,R. C. & NARANG, K. K., Inorg. chim. Acta,that the water molecules are coordinated and not 7 (1973), 651.'lattice-held-". AINH gives a broad band at 3170 ~AC:GARWAL, R. C., PRASAD, T. & YADAVA, B. N., J.which disappears in the complexes. This band may) vnorg, nucl, Chem., 37 (1975), 899. .. .. •... FIGGIS, B. N. & LEWIS, J., Modern coordtnatwn chemi-be assigned to vNH .an~ Its disappearance l~ ~he str)', edited by J. Lewis & R. G. Wilkins (Intersciencespectra of complexesindicates absence of the irnmo Publishers, New York), 1960, 403.groups. Two strong intensity amide - I bands ofthe ligand occurring at 1700and 1665 disappear andnew bands characteristic of v(C-O), v(NCO-) andcoordinated v(C=N) in the regions 1278-1225,1530-1500 and 1620-1608 respectively appear inthe spectra of complexesI6-18• This shows theenolization of both the ketonic groups of AINH inthe complexes. This is further supported by theabsence of the original anion and formation of 1: 1(metal-ligand) complexes.The ring nitrogen is not involved in bonding be-cause the bands at 1560, 1490, 1025, 995, 750 and645 arising from pyridine ring vibrations of theligand remain practically unchanged in the com-plexesl9,20. Further, the coordination of ring nitro-gen is also not favoured on steric grounds.A band occurring in the region 1035-1015in thecomplexes, showing a marked positive shift ascompared to the ligand band, is assigned to vN-N(bridging)'. Bands occurring in the ranges 360-330and 268-230in the present complexes and absent inthe lirand may be tentatively assigned to v(M+-N)and v(M-O) vibrations respectivelyw-w.The disappearance of v(NH) and v(C=O) bands,appearance of v(M-O) and v (M+-N), a negativeshift in v(C=N) compared to monosodium salt ofAINH and a marked positive shift in v(N- N),taken together, show that AINH acts as a tetra-dentate ligand in all the complexes, the bondingsites being the two enolic oxygens and both thenitrogens of the hydrazide residue.The fact that AINH behaves as a tetradentateligand and the water molecule(s) are coordinatedshow that all the metal ions except Cu(II) (which issquare-planar) are hexacoordinated in the hydratedcomplexes. Thus the IR spectral data are in accordwith the octahedral geometry of the complexesinferred from magnetic and electronic data dis-cussed earlier.AcknowledgementAuthors are thankful to Prof. G. B. Singh, formerHead of the Chemistry Department, Banaras HinduUniversity, Varanasi, for providing laboratory faci-lities. One of them (L. P.) is thankful to ICMR,New Delli also for the award of a junior researchfellowship.References326AGGARWAL et al.: COMPLEXES OF N-ACETYL-N'-ISONICOTINOYLHYDRAZINEv6. SACCONI, L. & CIAMPOLINI,M., J. chem. Soc., (1964). 17. MASHIMA, M., Bull. chem. Soc. (Japan), 35 (1962), 338.;(276. ~8. REDRICKSON, L. D., Analyt. Chem., 36 (1964), 1349.\l.- 1. SELBIN, J., Chern. Rev., 65 (1965), 165. 19 ILL, N. S., NUTTALL, R. R., SCAIFE, D. E. & SHARP.l~. MCCORMIK, B. ]., Inorg. Chem., 7 (1968), 1970. D. W. A., J. inorg, nucl. cu«: 18 (1961), 79.,,}:3. CARLIN, R. L., Trans. Metal Chem., 1 (1965), 9. 2 . GOLDSTEIN, M., MOONEY, E. F., ANDERSON, A. &~4. MANCH, 'lv. & FERNILlUS, '\T. C., J. chem. Educ., 38 GEBBIE, R. A., Spectrochim: Acta, 21 (1965), 105.J(1961),195. /._/J1. LEVER, A. B. P. & lV[ANTOVANI, E., Lnorg. Chem., 10. GAMO, I., Bull. chem. Soc. (Japan), 34 (1961), \MO, 'l6'5. (1971), 817.1ti! 1430. 2-1-, N:AKAMOTO, K., UDOVICH, C. & TUKEMOTO, J., J. Am.Jr' YAMADA, R., Bull. chem, Soc. (Japan), 32 (1959), 1051. .J chem, Soc., 92 (1970), 3922.

Complexes of VO(IV), Mn(II), Co(II), Ni(II), Cu(II) & Zn(II) with N-Acetyl-N' –isonicotinoylhydrazine

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Complexes of VO(IV), Mn(II), Co(II), Ni(II), Cu(II) & Zn(II) with N-Acetyl-N' –isonicotinoylhydrazine

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