Indian Journal of ChemistryVol. 25A. September 1986. pp. 865-867

Studies on Hydrazone & AzineDerivatives of Bis(indenyl)-

titanium (IV) & -Zirconium (IV)

A K SHARMAt. B KHERA & N K KAUSHIK*Department of Chemistry. University of Delhi, Delhi 110007

Received 5 December 1985; revised and accepted 19 February 1986

Hydrazone and azine derivatives ofbis(indenyl)-titanium (IV) and-zirconium (IV) of the types M(C.H40CR:NNHR,)(C9H,hCI andM(C.H40CR":NN:CR"OC.H4)(C9H,h. where M =Ti or Zr. R=H or CH). R'=H. C.H; or C.H)(N02h and R" =H or CH).have been synthesized by the reaction of bis(indenyl)titanium(IV)/zirconium (IV) dichloride and appropriate hydrazone or azinein equimolar ratio in refluxing tetrahydrofuran. The products havebeen characterized by chemical analyses. electrical conductance. IR.IH NMR and electronic spectral studies.

The interest in the study of hydrazones has beengrowing due to their presence in biological systems I -3

and use in analytical chemistry". In continuation ofour previous work ':" on organometallic hydrazoneand azine complexes, some pentacoordinatedhydrazone and azine derivatives of bis(indenyl)-titanium (IV) and -zirconium (IV) are reported in thisnote.

The reagents used were of AR grade. Bis(indenyl)-titanium (IV)7/zirconium (lV)8 dichloride, hydrazoneand azine ligands ' were prepared by the methodsreported in our earlier communications.

Titanium, zirconium, nitrogen and chlorine weredetermined by the standard methods".

Conductance measurements were made in DMSOon a Systronic digital direct reading conductivity metertype 304. IR spectra were recorded in KBr in the 4000-400cm -I region on a Perkin-Elmer 621 gratingspectrophotometer. IH NMR spectra were recorded indeuterated chloroform on a lEOL lNM-Fx 200 FTNMR spectrometer. Chemical shifts are expressedrelative TMS as an internal reference (I % by volume).The electronic spectra of the complexes were run on aPerkin-Elmer instrument.

Preparation of the complexesTo a stirred solution of bis(indenyl)-titanium

(IV)/zirconium (IV) dichloride (8 mmol) in 30mltetrahydrofuran, a solution containing 8mmol ofappropriate hydrazone or azine in 30ml tetrahydro-

tPresent address: Thermal Science Division. ISRO Satellite Centre.Vimanpura. Bangalore 560017.

furan was added slowly and the reaction mixture wasrefluxed for 10-12hr. It was then filtered and thevolume of the filtrate reduced to - 20 ml byevaporating the solvent under reduced pressure.Crystals of the product were precipitated on addingabout 80 ml petroleum ether (60-80°) to theconcentrated filtrate. These were filtered, washed withpetroleum ether, dried in vacuo and recrystallized fromdichloromethane.

The reactions involved in the preparation ofhydrazone and azine derivatives of bis(indenyl)-titanium (IV) and -zirconium (IV) may be representedby equations 1 and 2, respectively,

(C9H7hMCl2 +C6HiOH)CR:NNHR' T6~Y •

M(C6H*OCRNNHR')(C9H7hCI +HCl ... (I)

(C9H7hMClz

+C6HiOH)CR":NN:CR"(OH)C6H* T6~Y •

M(C6H*OCR":NN:CR"OC6H*XC9H7h +2HCl(2)

where M=Ti or Zr, R=H or CH3• R'=H. C6H5 orC6HiNOzh and R" = H or CH3.

The complexes were obtained as yellowish-brown tolight brown solids. These are moderately soluble inchloroform, dichloromethane, acetone, THF andDMSO. Electrical conductance measurements inDMSO show these complexes to be nonelectrolytes.Table 1 lists the analytical data and physicalcharacteristics of the complexes. The satisfactoryelemental analysis support the stoichiometriesassigned to these complexes.

The assignment of characteristic infrared frequen-cies was made on the basis of published work. The C- H stretching frequency at - 3090em -I in thecomplexes is indicative of the indenyl group 7

• Theperpendicular hydrogen wagging vibration around830cm -I, the parallel hydrogen wagging mode at- 1025 cm -I, the bands due to C - C stretching andthe ring breathing mode of the x-bond at -1440 and-1160cm -I, respectively further confirm thepresence of the indenyl group!". Appearance of theseindenyl bands in the complexes under investigationindicates that electrons in the indenyl group remaindelocalised and n-bonded (1'/5)to the metal12. Apartfrom this, the band at 445em -I may be assigned tometal-ring stretching vibrations II .

A strong band is observed at -1630cm -I in thespectra of free hydrazone ligands, which can be

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INDIAN J. CHEM .• VOL. 25A. SEPTEMBER 1986

Table I-Analytical and Physical Data of M(C6H40CR:NNHR,)(C9H7)2Cl and M(C6H40CR":NN:CR"OC6H4XC9H7hComplexes

R. R' or R" Yield Dec.temp. % Found (Calc.)

(%) (oq

M* N CI1 R=H. R'=H 72 219-222 10.26 6.13 7.74

(10.68) (6.24) (7.92)2 R=H. R'=C6HS 68 164-165 8.79 5.18 6.86

(9.13) (5.34) (6.77)3 R=H. R'=C6HJ(N02)2 64 185-188 7.42 9.02 5.63

(7.80) (9.11) (5.78)4 R=CHJ• R'=H 62 180-181 10.02 5.90 7.56

(10.36) (6.05) (7.68)5 R=CHJ• R'=C.Hs 68 151-152 8.48 5.04 6.35

(8.90) (5.20) (6.59)6 R =CHJ• R' =C6HJ(N02h 65 175-178 7.34 8.72 5.41

(7.62) (8.91) (5.65)7 R'=H 70 207-208 8.91 5.24

(9.28) (5.43)8 R"=CHJ 68 183-18,5 8.36 5.02

(8.81) (5.15)9 R=H, R'=H.· 70 182-185 18.13 5.47 7.03

(18.55) (5.69) (7.22)10 R=H. R'=C.Hs 60 174-176 15.84 4.78 6.09

(16.07) (4.93) (6.25)11 R=H. R'=C6HJ(N02h 60 182-185 13.52 8.57 5.56

(13.87) (8.51) (5.40)12 R=CHJ, R'=H 58 186-188 17.70 5.45 7.11

(18.04) (5.54) (7.02)13 R=CHJ, R'=C.Hs 62 137-138 15.21 4.72 5.97

(15.68) (4.81) (6.10)14 R=CHJ, R'=C.HJ(N02h 56 172-174 13.26 8.21 5.16

(13.58) (8.34) (5.28)15 R'=H 60 117-120 16.09 4.84

(16.31) (5.01)16 R"=CHJ 62 165-167 15.25 4.52

(15.53) (4.77)*M = Ti for S. No. 1-8 and Zr for S. No. 9-16.

assigned to the absorption due to the azomethine ( ::::c=N -) groupB,12. In the complexes. this band isshifted to lower wave numbers ( -1606cm -1) showingthe coordination of azomethine nitrogen to themetaJl3,14. The N - N frequency found at -940cm-1in the free ligands is shifted to higher values(-970cm -I).

A high intensity band at -1265 em -I in the freehydrazone ligands may be assigned to the phenolic C- 0 stretching8,12. In the complexes this band appearsat -1295 em -I. indicating bonding of the hydrazoneligand through oxygen. Furthermore. the disap-pearance of the broad !(OH) band (present in theligand in the 3450-3390cm -I region) from the spectraof hydrazone complexes also indicates the replacementof the hydroxyl proton with the metal.

The coordination of the azomethine nitrogen andbonding of the phenolic oxygen to the metal are

866

supported by the appearance of two new absorptionbands in the spectra of hydrazone derivatives at 530-550 and 435-470cm -1, which may be assigned to !(M+-N) and v(M -0) vibrations 15, respectively. A bandat -370cm-1 is characteristic of !(M-CI)vibration 12.

As expected, the spectra of the azine complexes donot show v(OH), v(NH) and v(M -CI) vibrations. Thesplitting and lowering of the !(C=N)vibration suggestthe coordination of one of the methine nitrogens andhence the formation of two dissimilar rings. The v(C- 0) phenolic shifts to higher frequency and v(M +- N)and v(M -0) vibrations appear as a result of complexformation.

The IH NMR spectra of the complexes have beenrecorded in deuterated chloroform. All the hydrazonecompounds give three different resonance signalscorresponding to (i) the - CR = N - group proton(s),

appearing at -158.64 (R=H) and 153.00(R=CH3),

which show a downfield shift as compared to thesignals in the corresponding free hydrazone ligands at-t58.40(R=H) and 152.75 (R=CH3), indicatingdeshielding as a result of coordination of the nitrogento metal; (ii) the resonance signals due to indenylprotons overlap with those of aromatic proton signalsof hydrazone ligand and result in a complex multipletin the range 156.70-7.80; (iii) the - NH - and - NH2protons (- 154.85 and 154.30, respectively) appear atthe same positions as observed for the free hydrazoneligands.

The 1H NMR spectra of the azine complexes showtwo different resonance signals corresponding to (i)- CR" = N - group proton(s); and (ii) aromaticprotons and are quite similar to the 1H NMR spectraof the hydrazone complexes.

~O"I~~~/~,-7 ~

R _'R-H or CHo; A'-H, c.Hs or C.H. (NOzla

I

NOTES

The electronic spectra of the complexes inchloroform exhibit a single band in the region 402-413 om in accordance to the electronic configuration (n-1~, nso of titanium and zirconium+",

Based on analytical data, general behaviour andphysicochemical studies, structures I and II may beproposed for the present hydrazone and azinederivatives respectively.

References1 Alcock J F, Baker R J & Diamantis A A, Awt J Chem, 2S (1972)

289.2 Dilworth J R, Coord chem Rev, 21 (1976) 29.3 Saha N & Bhattacharyya D, J Indian chem Soc, 54 (1977) 143.4 Katyal M & Dutt Y, Talanta, 22 (1975) 151.5 Khera B, Sharma A K & Kaushik N K, Bull Soc chim France,

(1984) 1-172.6 Khera B, Sharma A K & Kaushik N K, Bull chem Soc Japan, 58

(1985) 793.7 Khera B & Kaushik N K, Synth React inorg met-org Chem, 14

(1984) 57.8 Khera B, Sharma A K & Kaushik N K, Polyhedron, 2 (1983)

1177;Bull Soc chim France, (1983) 1-278.9 Vogel A I, A text hook of quantitatite inorganicanalysis, 4th Edn

(Longrnans Green, London) 1978.10 Kaushik N K, Singh R P, Sangari H S & Sodhi G S, Synth React

inorg met-org Chem, 10 (1980) 617.11 Coutts R S P & Wailes P C, J organometal Chem, 84 (1975) 47.12 Sharma A K, Khera B & Kaushik N K, Mh Chem, 114(1983)

907; Indian J Chem, 22A (1983) 816.13 Aggarwal R C, Singh N K & Singh R P, Inorg chim Acta, 32

(1979) L87.14 Braibanti A, Dallavale F, Pellinghelli M A & Leporati E, Inorg

Chem, 7 (1968) 1430.15 Pardhy S A, Gopinathan S & Gopinathan C, Synth React inorg

met-org Chem, 13 (1983) 385.

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