A series of new complexes of oxozirconium(IV) selenocyanate
with different ligands has been prepared. The IR spectra (4000-200
cm-1) of free ligands and complexes indicate coordination through
either oxygen or nitrogen, depending on the type of the ligand

A. N. Pandey

J. R. Chopra

R. K. Agarwal

S. P. Sharma

English

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CROATICA CHEMICA ACTA CCA-1331 CCACAA 55 (3) 283-286 (1982) YU ISSN 0011-1643 UDC 546.831.546.23 Original Scientific Paper Infrared Studies of Some Selenocyanato Complexes of Oxozirconium(IV) with 0 and N Donor Ligands J. R. Chopra, A. N. Pandey,* S. P. Sharma,** and R. K. Agarwal Physics and Chemistry Department L. R. (P. G.) College, Sahibabad, (Ghaziabad), India *Molecular Spectroscopy Research Lab., Meerut College, Meerut, India **N. P. L. Hillside Road, New Delhi, India Received August 7, 1981 A series of new complexes of oxozirconium(IV) selenocyanate with different ligands has been prepared. The IR spectra (4000-200 cm-1) of free ligands and complexes indicate coordination through either oxygen or nitrogen, depending on the type of the ligand. Structural investigations of several oxozirconium (IV) thiocyanate com-plexes have been reported in previous papers1- 5• Selenocyanate group offers interesting bonding pcssibilities6• In metal ion complexes it may coordinate through either nitrogen {M- NCSe)7, selenium (M-- SeCN)8 or bridging (M - SeCN - M)9• Examples of complexes containing all types of seleno-cyanate bonding are also known. No attempt has been made so far to inve-stigate the complexes of oxozirconium (IV) selenocyanate. It was, therefore, considered worthwhile to study the complexes formed by oxozirconium (IV) selenocyanate with antipyrine (apy); 4-amino antipyrine (aapy), pyridine N-oxide (pyo); 2,2'-bipyridyl N-N'-dioxide (bipyo2); triphenyl phosphine oxide (tppo); bis (tri n-butyl tin) oxide (tbto); pyridine (py); 2,4-lutidine (ln); 2,2'-bipyridyl (bipy); 1,10-phenanthroline (phen); hydrazine (hy) and phenyl hydrazine phhy). Stoichiometries of the isolated complexes have been established by elemental analyses (Table 1). All the complexes are non-hygroscopic and quite stable. The molar conductances of 10-3 M solution in acetonitrile are within the range 4.9-6.3 ohm-1 cm2 mole-1 indicating the absence of ionic 1species. The infrared spectra of the free ligands and the complexes were recorded in the 4000-200 cm-1 region. The positions of the X = 0 (X = C, N m P) streching bands in all oxygen donor ligands are significantly different in the complexes (Table II) . A marked negative shift in y (X = 0) from free ligands in all the complexes confirm the oxygen linkage between the metal and ligands10•11• The JR studies also reveal bidentate nature of aapy and bipyo2 coordination occurring through amino nitrogen and carbonyl oxygen in case of aapy and through both the oxygen atoms of bipyo210•11 • The Sn-0--Sn streching absorption which occurs at 783 cm-1 rin free tbto12, shifts on 284 J . R. CHOPRA ET AL. TABLE I Analytical Data of Oxozirconium(IV) Complexes O/o Analysis Found (Calcd) Complex Zr c H N ZrO(SeCN)2 · 2apy 13.49(13.13) 41.78(41.55) 3.57(3.46) 12.32(12.12) ZrO(SeCN)2 · aapy 17.72(17.50) 30.12(30.00) 2.61(2.50) 13.59(13.46) ZrO(SeCN)2 · 2pyo 17.69(17.94) 28.59(28.40) 2.01(1.97) 11.32(11.04) ZrO(SeCN)2 · bipyo2 18.32(18.01) 28.73(28.51) 1.69(1.58) 11.34(11.08) ZrO(SeCN)2 · 2tppo 10.61(10.42) 52.69(52.23) 3.72(3.43) 3.42( 3.20) ZrO(SeCN)2 · 2tbto 6.21( 6.03) 39.98(39.76) 7.42(7.15) 1.92( 1.85) ZrO(SeCN)2 · 2py 19.31(19.15i 30.72(30.31) 2.31(2.10) 11.98(11. 78) ZrO(SeCN)2 · 2bn 17.36(17.13) 36.70(36.15) 3.51(3.38) 10.69(10.54) ZrO(SeCN)2 · bipy 19.49(19.23) 30.82(30.44) 1. 78(1.69) 11.57(11.83) ZrO(SeCN)2 · phen 18.56(18.30) 33.60(33.80) 1.68(1.60) 11.49(11.26) ZrO(SeCN)2 · 2hy 23.97(23.88) 6.41( 6.29) 2.30(2.09) 22.19(22.04) ZrO(SeCN)2 · 2phhy 17.32(17.07) 31.79(31.51) 3.12(3.00) 15.92(15. 75) coordination to 710 cm-1 indicates the metal-oxygen linkage in the complex13. The metal-oxygen stretching vibrations occur in all these complexes in the region 390-360 cm-11-a,1a. In complexes wi:th heterocyclic ligands, several strong absorptions in the spectra of free bases occur in the 1625-1400 cm-1 region and have been attributed to C=C, C=N and ring stretchings. Out of these, the absmptions associated with the cyclic riing are apparently unaffected on complexation, while those arising from the heterocyclic ring are shifted to higher frequencies due to tightening of the ring on coordination with hetero N-atom14,15. In the IR spectra of hydrazine and phenyl hydrazine complexes the two bands in the 3000 cm-1 region and one band at the 1600 cm-1 region observed, which are obviously the result of N-H stretching and bending vibrations respe-ctively and are lower in frequency than the bands observed in gaseous hydra-zine16 and phenyl hydrazine17 , clearly indicates that these ligands are coordi-nated through nitrogen atom. The bidentate behaviour of these ligainds is further confirmed by the presence of N--N stretching frequency1B around 955 cm-1. M-N stretching frequency in all these complexes14 ,15,17 fall within the region 385-360 cm-1• The intensity of the CN stretching band is useful in distinguishiing the N- and Se-bonded complexes7• The v (CN), v (CSe) and I) (NCSe) in all the complexes occur at 2080-2050; 695-625 and 435-420 cm-1 region respectively thus indicating the N-bonded selenocyanate group7- 9• N-bonding is further evidenced by the presence of bands in region 250--215 cm-1 due to v (Zr-N) (selenocyanate). A medium intensity band in the 960-900 cm-1 region is assigned as (Zr=O) stretching mode in all the complexes1,2•19. TABLE II Infrared Data of Oxoziroconium(IV) Complexes Complex Selenocyanate vibrations v (X = 0) (X = C, N or P) v (M = X) v(CN) 1'(C-Se) i5(NCSe) 11 (Zr-N) Ligand Complex X=O or N ZrO(NCSe)2 · 2apy 2065 s 690m 430m 220m 1660 s 1575 s 380m [fl 1565 s t'1 t"' t'1 ZrO(NCSe)2 · aapy 2070 s 695m 425m 215m 1670 s 1560 vs 385m z 0 1640 s 350m (') >< ZrO(NCSe)2 · 2pyo 2075 s 690m 430m 225m 1265 s 1220 s 380m ;i. z ZrO(NCSe2) · bipyo2 2070 s 230m ;i. 685m 430m 1264 s 1255 s 390m >'I 1260 s 1220 s 0 (') ZrO(NCSe)2 · 2tppo 2070 s 695m 420w -1195 s 1120 s 380m 0 ;;: ZrO(NCSe)2 · 2tbto 2080 s 675w 220m v(Sn-0-Sn) 390 mpr "tJ -t"' 625m 783 s 710 s t'1 ~ t'1 C=C, C=N and ring stret-[fl ching of heterocyclic ring 0 "'.! ZrO(NCSe)2 · 2py 2070 s 685m 420m 250 m, br 1625 mbr, 1600 m, 1530 mbr, 380m 0 1490m ~ 0 ZrO(NCSe)2 · 2bn 2080 s 650m 430m 1620 vs br, 1560 sh, 1525 m 365m N -H !:d (') ZrO(NCSe)2 · bipy 2050m 685m 430m 232m 1620 m, 1595 s, 1525 vs, 360m 0 z 1495 m, 1470 m H q ZrO(NCSeh · phen 2080m 650m 420m 250 m, br 1625 m, 1516 m, 1585 m, ;;: ;:; 1540 sh, 1520 s, 1490 sh, 370m $ 1415m v (NH) o (NH) 1' (N-N) ZrO(NCSeh · 2hy 2065m 690m 435m 235w 3230 m, 1600 br, 955 m 335m 3190m ZrO(NCSe)2 · 2phhy 2060m 690m -225w 3220 s, 1610 m, 980 w, 1595 s 375m I\!) 00 <:11 286 J. R. CHOPRA ET AL. EXPERIMENTAL Oxozirconium(IV) selenocyanate was prepared in solution by mixing methanolic solutions of Zr0(N03)2 and KNCSe in 1 : 2 ratio and filtering out the precipitated KN03• Since ZrO(SeCN)2 solution has a tendency to decompose to a red coloured solution, it should be used immediately after filtration. The complexes were prepared by mixing methanolic solutions of ZrO(SeCNh and the ligand in required molar proportion and the reaction mixture was shaken ' thoroughly. Some complexes separated out either immediately or after a certain period of time. All the complexes were suction filtered, washed with methanol followed by ether and dried in vacuo over P 40 10. Acknowledgement: The authors are thankful to Dr. A. K. Srivastava, Meerut College, Meerut for taking keen interest in the research. REFERENCES 1. R. K. Agar w a 1, A. K . S riv a st a v a, and T. N. S r i v a s t a v a, Indian J. Chem. 18A (1979) 459. 2. R. K. Agarwal, A. K. Srivastava, V. Kapur, and T. N. Sri v a-s ta v a, National Acad. Sci. Lett (India), 2 (1979) 447. 3. R. K. Ag a r w a 1, A. K. S riv a st av a, and T. N. S riv as ta v a, Inorg. Nucl. Chem. Letters 16 (1980) 311. 4. R. K. Agar w a 1, A. K. S riv a s t av a, and T. N. S r i v as t av a, Croat. Chem. Acta 54 (1981) 329. 5. R. K. Agarwal, Mahe sh Srivastava, T. N. Srivastava, and A. K. Srivastava, J. Inorg. Nucl. Chem. 43 (1981) 2141. 6. K. Na k a mot o, Infrared spectra of inorganic and Coordination Compounds, p. 190, 1963, John Wiley J. Sons. 7. J. L. Burmeister and L. E. W i 11 i ams, Inorg. Chem. 5 (1966) 1113. 8. M. E. Frago and J. M. James, Inorg. Chem. 4 (1965) 1706. 9. F. A. Cotton, D. M. L. Good game, M. Good game, and T. E. Haas, Inorg. Chem. 1 (1962) 565. 10. R. K. Agar w a 1, A. K. Srivastava, and T. N. Srivastava, Curr. Sci. 48 (1979) 1077. 11. R. K. Agarwal, Studies on Complexing Behaviour of Oxygen donor mole-cules with Th(IV) and Zr(IV), Ph. D. Thesis, Meerut University, 1979. 12. Von H. Kreig s man, H. Hofman, and H. G e i s 1 er, Z. Anorg. Allegem. Chem., 341 (1965) 24. 13. R. C. Pa u 1, V. K. Mah a j an, S. C. Ah 1uwa1 i a , R. K. S h a rm a, and S. P. Na r u 1 a, norg. Nucl. Chem. Letters, 9 (1973) 893. 14. T. N. S riv a st av a, S. K. T an d o n, and Nee 1 u B h a k r u , J. Inorg. Nucl. Chem. 40 (1978) 1180. 15. R. K. A g a r w a 1, A. K. S r i v a s t a v a, M a h e s h S r i v a s t a v a , N e e 1 u B ha k r u, and T. N. S riv a st av a, J. Inorg. Nucl. Chem. 42 (1980) 1775. 16. P. A. Gig u er a and J. D. Liu, J. Chem. Phys. 20 (1952) 136. 17. A. L. Vars h n e y, Coordination Compounds of Hydrazine Derivatives With Some Transition Metals, Ph. D. Thesis, Meerut University, 1978. 18. D. Ni ch o 11 s, M. Row 1 e y, and R. S wind e 11 s, J. Chem. Soc. (A), (1966) 930. 19. S. K. Ma d an and A. M. Donohue, J. Inorg. Nucl. Chem. 28 (1966) 1330. SAZETAK IR studij oksocirkonij(IV) selenocijanato kompleksa s 0 i N donorskim ligandima J. R. Chopra, A. N. Pandey, S. P. Sharma i R. K. Agarwal Pripravljen je niz novih kompleksa oksocirkonij(IV) selenocijanata s razlicitim ligandima. Infracrveni spektri, snimljeni u podrucju od 4000 do 200 cm-1, ukazuju na koordinaciju preko kisika ili dusika , ovisno o tipu liganda. 

Infrared Studies of Some Selenocyanato Complexes of Oxozirconium(IV) with 0 and N Donor Ligands

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