Neelam, (Mrs) N. S.

Siddiqi, K. S.

Zaidi, S. A. A.

English

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carboxylate groups. A band at f'> 1730 cm-1 whichhas been assigned to vC=O in metal carboxylatess-",where carboxylic acid behaves as a unidentate ligand,was found to be present in all these derivatives.Two other bands present at f'>1560 and f'>1450 crrr !may be assigned to vaCOO- and vsCOO- respectively.These indicate the bidentatef nature of carboxylategroups.No bands are observed in the regions f'>3500,f'>1130 and 1100-900 cm-1 corresponding to hydroxy,isopropoxy and Ti=O stretching+P respectively,indicating the absence of any free acid orTi(OPri)2(00CR)2 species. However, a broad bandaround 835 crrr+ observed in these derivatives maybe assigned to Ti=O-+Ti type of linkage". As themolecular weight data are not in agreement withpolymeric or dimeric structures, it may be suggestedthat the coordination between terminal oxygen andtitanium atoms is destroyed in solution giving riseto monomeric species and consequently the mole-cular weight falls corresponding lO the molecularcomplexity 1·3.These derivatives have no tendency of adductformation with nitrogen containing ligands likepyridine.The compounds are thermally stable up to 200°above which temperature these decompose slowly,giving CO, CO2, H20 and leaving TjO, as theresidue, About 80% of its decomposition is com-pleted around 300°.This mode of decomposition of TiO(00CR)2 deri-vatives is different from that of other metal carboxy-lates13,14 in which the decomposition proceeds withthe formation of a ketone as an intermediateproduct.The authors thank Prof. K. C. Joshi, Head of theDepartment of Chemistry, University of Rajasthan,Jaipur, for providing laboratory facilities and theCSIR, New Delhi, for the award of a JRF toG. K. P.References1. DEHNICKE, x.. Chem Ber., 98 (1965), 29t.2. COLLIS, R. E., J. chem, Soc. (A), (1969), 1895.3. SELBIN, J., J. chcm . Educ., 41 (1964), 87.4. HARWOOD, J. H., Industrial apphcations of organo-metallic compounds (Chapman & Hall, London),1962.5. PANDEY, K. C. & MEHROTRA, R. C., J. prakt . Chem., 5(1967), 101.6. PIKE, R. M. & LUONGO, R. R., J. Am. chem. Soc., 87(1965), 1403.7. PIKE, R. M. & LUONGO, R. R., J. Am. chem. s«; 88(1966), 2972-8. STEPHENSON, 1'. A., MOREHOUSE, S. M., POWELl., A. R.,HEFFER, J. P. & WILKINSON, G., J. chem, Soc. (A),(1965), 3632.9. Cox, M., LEWIS, J. & NYHOLM, R. S., J. chem, Soc., (1965),2840.10. FOWLES, G. W. A., LEWIS, D. F. & WALTON, R. A., J.chem, Soc. (A), (1968). 1468.11. BARRACLOUGH, C. G., LEWIS, J. & NYHOLM ,R. S., J.chem, Soc., (1959), 3552.12 KALINNIKOV, v. T., ZELENTSOV, V. V., VOLKOV, M. N.& SHOSTAKOVSKII, S. M., Chem . .Abstr., 62 (1965),9941 C. r'13. MISRA, S. N., MISRA, 1'. N. & MEHROTRA, R.C.,J.inorg.nucl. Chem., 25 (1963), 195.14. RAI, A. K. & MEHROTRA, R. C., J. Indian chem. Soc., 40(1963), 359.NOTESPentacoordinated Ti(IV) Chloride &Sn(IV) Bromide & Iodide Complexes withAcridine & PiperazineS. A. A. ZAIDI, K. S. SIDDIQI & (Mrs) N. S. NEELAMDepartment of Chemistry, Aligarh Muslim UniversityAligar h 202001Received 24 December 1974; accepted 31 March 1975Donor-acceptor type complexes of TiCI., SnBr. andSnl. with acridine and piperazine have been preparedand characterized 011 the basis of conductance and IRdata. A pentacoordlnated tr+gonal blpyramldal struc-ture has been proposed for all the complexes. The(TICI.>,-plperazlne complex has been found to bebinuclear.IN continuation of our earlier workl,2 on the com-plexes of acridine and piperazine with SnCl4 andGeCI4, the preparation and characterization of TiCI4,SnBr4 and SnI4 complexes with these donor mole-cules are reported in this note. The possibility ofthe formation of a binuclear complex with pipera-zine has also been considered. Molecular additioncompounds of group (IV) halides have extensivelybeen studied>".Acridine (Fluka AG, m.p. 108°) was recrystallizedfrom alcohol. Piperazine hexahydrate (E. Merck, m.p.56°) was used as such without further purification.Anhydrous Ti(IV) chloride (BDH) was used whereasSn(IV) bromide and iodide were prepared accordingto standard methods".Acridine complexes - A solution of Sn(IV) bro-mide/iodide in ethanol-chloroform mixture was addedto an ethanolic solution of acridine in approxi-mately equimolar quantity. Sn(IV) bromide yieldeda greenish yellow crystalline substance but Sn(IV)iodide gave a gelatinous mass which dissolved onstirring. However, this solution later yielded ayellowish orange compound. Ethanolic solutions ofTi(IV) chloride and excess of acridine when leftovernight after mixing yielded needle-shaped crys-tals. All the solids obtained were washed withethanol and dried in vacuo.Piperazine complexes - These were also preparedas above but the complex formation was rapid inthe case of Sn(IV) iodide and Ti(IV) chloride where-as with Sn(IV) bromide a granular product wasobtained after a few minutes.The melting points and analyses of the complexesare given in Table 1. All the addition compoundsformed with acridine and piperazine are of the typeMX4: L, except the adduct of TiCl4 with piperazinewhich is of (MX4)z: L type.The molar conductances (Systronix conductivitybridge) of approximately 10-3 millimolar solutionsof the adducts of acridine in nitromethane at roomtemperature fall well below the range for a uni-univalent electrolyte-", indicative of non-ionic natureof these adducts.Acridine exhibits two strong bands in its IRspectrum at 1515 and 1555 crrr? attributable tovC=C and vC=N respectively. Its adducts withTiCI4, SnBr4 and SnI4 exhibit '1C=C and '1C=N2091itNDtAN 1. CREM., VOL. HA, MARCH 19763. ROLSTEN, R. F. & SISLER, H. H., J. Am. chem, s«., 79(1857). 1068 .4. SISLER, H. H., BATEY. H. R .• PFAHLER. B. & MATTAIRR.. J. Am. chem, Soc .• 70 (1948), 3021.5. SISLER. H. H., SHILLING. E. E. & GROVES. W.O .•-N------ X- J. Am. chem, Soc., 73 (1951), 426.J6. AGGARWAL.R. C. & SINGH. P. P., J. inorg . nucl, Chem4·06 38'62 28 (1966), 165l.(3-80) (38'91) J. AGGARWAL,R. C. & SINGH. P. P .• J. inorg, nucl, Chem2'41 51'20 28 (1966). 1655.(2-26) (51'71) ~~~ BEATTIE. I. R.. Q. Rev. chem, Soc .• 17 (1963), 382.2'10 63'62, . Handbook Of preparative inorganic chemistry, edited by(1'73) (63'20)' G. Brauer (Academic Press. New York). 1963. 729.5'99 30'03 jA'0. GEARY. W. J .• Coord. chem. Rev .• 7 (1971). 1130.(6'20) (30'40) 11. GREENWOOD. N. N. & WADE. K.. J.chem. 50c .•(1960).5'41 62·01 IBO.(5'34) (61'60) lY.OKISHI. Y .• IMAI. Y. & AIDA. K.. J. inorg . nucl . Chem4'21 71-68 V 35 (1973). 101.(3'90) (71'30).TABLE 1 - ADDUCTSOF ACRIDINE AND PIPERAZINEAdduct m.p.°CTiCl,,-Acr 235SnBr,-Acr 246·SnI,-Acr 177(TiCl,l.Ppr 300·SnBr,-Ppr 283*SnI,-Ppr 350·Found (%) (Calc.)Acr = acridine; Ppr = piperazine*Melted with decomposition.at 1590, 1625; 1575, 1630; and 1575, 1640 respec-tively. It is known that coordination through thenitrogen atom of the pyridyl group'! causes anincrease in the C=N stretch. It is noteworthythat this shift in the Sn(IV) halide adducts increasewith increasing halogen size and is smallest forTi(IV) chloride adducts. All the complexes arethus suggested to have a trigonal bipyramidalgeometry. However, the possibility of a hexa-coordinated structure with halide bridging couldnot be ruled out.In the far IR spectrum the acridine complexesof TiCl4 show two strong bands at 410 and 460crrr" and a weak band at 375 crrr+ which may bedue to Ti-N and Ti-Cl bands.Molar conductances of piperazine adducts couldnot be measured owing to their insolubility inorganic solvents.A comparison of IR spectra of piperazine and itscomplexes shows appreciable negative shift in thevN-H; from 3328 crrr'! in the ligand to 3150, 3000and 3080 and 3300 crrr? in adducts with TiC14,SnBr4 and SnI4 respectively. An increase in theC=N stretching frequency from 1444 crrr" in thefree ligand to 1460. 1480 and 1450 crrr+ in theadducts with TiCI4, SnBr4 and SnI4 respectively isalso observed. The decrease in the vN-H is attri-buted to coordination of Sn(IV) or Ti(IV) with thenitrogen atom of piperazine. The 1: 2 complex ofTiCl4 with piperazine'< may assume a five-coordi-nated binuclear structure by coordinating with twoTiC14 molecules through the nitrogen atoms of apiperazine molecule. Two distinct bands at 378and 365 crrr? in the far IR region have been observedand assigned to Ti-Cl bond.The authors are thankful to Prof. W. Rehmanfor providing research facilities, to (Miss) TalatMah for the IR spectra and the Head of theDepartment of Chemistry, IIT, Kanpur for themicroanalyses. One of them (K. S. S.) thanks theCSIR, New Delhi, for financial assistance.ReferencesJt. ZAIDI. s. A. A. &)379 (1970). 329.. ZAIDI. S. A. A. &35 (1973). 655.SIDDIQI. K. S.• Z. anorg, allg. Chern.•SIDDIQI. K. 5 .• J. inorg . nucl, Chem .•210Complexes of.Re(IV) with 2-Hydroxy- &8-Hydroxy-quinolines & o-PhenanthrolineBIMANESHSURDepartment of Chemistry. Jadavpur UniversityCalcutta 700032Received 6 March 1975; accepted 14 April 19752-hydroxy- and 8-hydroxy-quinolines and o-phenan-throline initially form compounds of the types H2[hydroxyquinoline).ReCl.] and H2 [(o-phen).ReCl.]respectively with potassfum hexachlororhenate(IV).On reaction with excess ligands, these compounds areconverted into the corresponding hydroxo complexesof the types Re(OH)CI(oxyquinolineh and Re(OH)Cla-(o-phen). The compounds are paramagnetic with!let!= 2·1-3·78 BM indicating a quadrivalent state forRe in these compounds,IN continuation of our earlier work>" on Re(IV andV) complexes of pyridine and picolines, furtherwork on the complexes of Re(IV) with hydroxy-quinolines and o-phenanthroline is reported in thisnote.Re(IV) complexes with hydroxyquinoline« - Twotypes of compounds were formed with 2- and8 - hydroxyq uinolines. H2[(2 - hydroxyquinoline kReCI6] and H2[(8-hydroxyquinoline)2ReC16] wereobtained as yellow crystalline solids on mixing anaqueous solution of hexachlororhenate! (1 g) withthe respective hydroxyquinolines (1·5 g) dissolved indilute acetic acid. The solid obtained in each casewas filtered, washed and dried over fused CaC12.The compounds are almost resistant towards diluteacids but turn black on treatment with alkali.The hydroxochloro-bis(oxyquinoline) Re(IV) com-plexes, [Re(OH)Cl(2-oxyquinoline)2] and [Re(OH)CI-[S-oxyquinolinejj], were formed when the respectiveyellow hydroxyquinoline salts were warmed withexcess of the respective hydroxyquinolines in aceticacid (0·1M) on a water-bath. The precipitate sepa-~ated in each case was filtered, washed and dried~n vacuo.The compounds are insoluble in water or ethanolbut completely dissolve in boiling nitrobenzene.The compounds did not suffer any loss in weight onheating to 1300• These are non-conducting in nitro-benzene.1

Pentacoordinated Ti(IV) Chloride & Sn(IV) Bromide & Iodide Complexes with Acridine & Piperazine

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Pentacoordinated Ti(IV) Chloride & Sn(IV) Bromide & Iodide Complexes with Acridine & Piperazine

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