IBN AL- HAITHA M J. FO R PUR E & APPL. SC I VOL.22 (4) 2009 Synthesis and Structural Study of Some Mo(II) Carbonyl Complexes with Triazole and Oxadiazole Derivatives Sh. M. H. Obed Department of Chemistry, College of Eduction Ibn-Al-Haitham, University of Baghdad Abstract A new carbonyl complexes of triazole and oxadiazole were synthesized. These complexes were identified and their structural geometric were suggested by using FT-IR and UV-Vis spectra, conductivity measurements and other chemical and physical properties. The spectra data (FT-IR, UV, Vis.) with the substantial aid of group theoretical calculations gave so many evidences for the proposed geometries and the type of bonding of these compounds Introduction Transition metal carbonyl complexes are the basic starting materials for the synthesis of many organometallic compounds, which are mainly used as catalysts for the reactions of unsaturated hydrocarbonates[1-4]. Heterocycles and in particular the five-membered rings e.g. mercapto derivatives of triazole and oxadiazole have received more attention during the last decades as bioactive moieties and of industrial application of these rings [5-7]. Also,they were included in many basic structures of drugs and important ones of octane numbers [8]. Further, the triazole and oxadiazole derivatives were suggested that (-SH) group attached to heterocyclic nucleus may induce fungicidal activity [9,10]. The interaction of these rings with metal carbonyl complex gives a great interest for versatility and diversity form the point of structural, biological and catalytically espects. Also, beside their useful application, they have the effect on the coordination nature of the resulted ones, especially the olefinic group in the triazole structure is a good coordinating moiety may link to number of metal ions forming organometallic compounds structure [11]. Also, subsequently nature of bands and numbers of CO group were attached to metal [12,13]. Hence, the present work investigated the reaction of the three ligands from the Bis - triazole and Bis-oxadiazole derivatives with carbonyl groups Mo(CO)4bipy was prepared from the reaction of 2,2'-bipyridly with Mo(CO)6 under in an atmosphere of nitrogen to formaly a new carbonyl complexes. According, the characterization of these complexes would be presented and the results would be discussed with spectroscopic investigation, physical techniques group theoretical calculations. Experimental Materials All chemicals used were of highest purity available. Physical Measurements Melting points were recorded uncorrected of Stuart melting point apparatus. FT-IR spectra were obtained by using Shimadzu FT-IR-8400 Spectrophotometer in the rang (4000- IBN AL- HAITHA M J. FO R PUR E & APPL. SC I VOL.22 (4) 2009 200) cm -1 , U.V-Vis spectra were recorded by using Shimadzu UV-160A Spectrophotometer in CHCl3 solvent in the rang (200-700) nm. Conductivity measurements were obtained by PW 9525 digital conductivity meter. Preparation of Compounds Preparation of the ligands 1- Preparation of (OTRZ) [4,5diphenyl-3(2-propynyl) thio1,2,4-triazole]. (OTRZ) was prepared from ethy l benzoate as according to the literature method [11] and as shown by scheme (1). Scheme (1) 2- Preparation of (TRZ) [bis(4-phenyl-3-thiol-1,2,4-trizaole 5yl)butane]. (TRZ) was prepared following general procedures decribed in the literature [14] as shown in scheme (2). Scheme (2) 3- Preparation of (OXZ) [bis(3-thiol-1,3,4-oxadiazole-5yl) butane]. (OXZ) was prepared by a modified literature method [15] and as shown in scheme (3). . Scheme (3) IBN AL- HAITHA M J. FO R PUR E & APPL. SC I VOL.22 (4) 2009 Preparation of the Metal Carbonyl Complex [Mo (CO)4 bipy] (M) Tetra carbonyl mono -2,2'-bipyridyl molybdenum (O) was prepared according to the literature method [16]. The mixture of Mo(CO)4 (53mmole, l.4g) and bipyridyl (5.12mmole,0.8g) were refluxed in toluene (50ml) for l.5hr under N2. After cooling, the red crystalline complex was washed with a mixture of toluene, (15ml) and light petroleum (30ml) and dried under vacuum. The product was stable toward air and moisture, soluble in polar solvents but insoluble in petroleum sp irit and water. Preparation of the Mixed Ligand Carbonyl Complexes. [Mo II (CO)3 bipy (OTRZ)]I2 (MI), [Mo II (CO)3 bipy (TRZ)]I (MII) and [MoII(CO)3bipy (OXZ)]I (MIII) These complexes were prepared by dissolving Mo(CO)6bipy (0.16mmole) in chloroform (50ml) then treated with iodine (0.40mmole,0.1g) in (25ml) chloroform with stirring at OC o , the bright orange mixtures were obtained. (OTRZ) (0.32mmol,0.09) and (TRZ) (0.32mmol,0.13g)dissolved in (10ml) chloroform while, the (OXZ) (0.32mmole,0.09g) dissolved in (1:1) ml of a (chloroform /ethanol ) mixture were added drop wise, stirring at OC o for 6hr., then the solvent was slowly evaporated to obtain nicely colored crystals. These complexes are stable in air, have high melting points as shown in table (1) and soluble in DMF and CHCl3 solvents but insoluble in water. The complexes were indentified by spectral (FT-IR and U.V) and physical methods. Table (1,2). Results and Discussion Spectroscopic Characterization of New Complexes Vibrational Spectra The characteristic (FT-IR) bands observed and the vibrationl assignment of the ligands and their metal complexes are explained in detail in tabled (2). The spectrum of (OTRZ) is characterized by the presence of an essential band which belongs to the olefinic group at (1630cm -1) and other bands at (965 & 885 cm-1) which was originated out of the plane bending vibration of the vinylic group, where the spectrum of the complex (MI) shows red shifts of the olefinic band absorp tion to (1550um -1 ) and to (925&832cm -1 ) for the vinylic CH2 group, which indicate  -bonding between the metal and olefinic group [17], this was further indicated by the appearance of (Mo-C) band absorption, table (2). A comparison of the IR spectrum of the ligands (TRZ and OXZ) and their complexes leads to the medium -SH band of the ligands at (2530& 2560cm -1 ) respectively, which disappear indicating the disp lacement of hydrogen SH by means of metal ion. The C=N+C=S band of the (TRZ) at (1270cm-1) is sp litted on coordination at (1310&1253 cm-1) while , the (OXZ) showed two distinct peaks,the first one at(1315cm-1) and the second at (1250 cm-1) red shift in complex to (1570 cm-1) which could be attributed to C=N stretching . This account for the C=N and sulphur that coordinated to the metal ion [18-21]. The appearance of new bands in the IR spectra of these complexes in table (2) is propably due to the formation of (M-C), (M-N) and (M-S) developed through complexation (21) . IR Spectra for Carbonyl Groups of (MI, MII and MIII) and Their Group Theoretical Calculations Scheme (5) IBN AL- HAITHA M J. FO R PUR E & APPL. SC I VOL.22 (4) 2009 The compound studied in the present work is of the formula [Mo (CO)4 bipy] , where (M) is bipy either monodentate or bidentate nitrogen donor. Hence, the bidentate ligand must belong to the C2v group[12,22],while the geometrical isomer is shown in scheme (4). Theoretically ,the cis-isomer should give four IR bands, the spectra of the prepared (M),showed four principle bands in the region(2000-1825)cm -1 in table(2), fig(1), which can be assigned to terminal CO virbrations. The presence of four bands indicated cis- isomeration. for the bidentate bipy complex . . First of all, it was found that the CO spectral band position for Mo complexes, showed that all the CO groups to be terminal, no bridging CO exist in fig (2). The prepared complexes are contain three Carbonyl groups which may have facial configurations. The point group for the molecules is Cs,while the point group considering for CO moieties is C3v for facial configuration and the main axis of symmetry is shown in scheme (5). According to the group theoretical calculations based on C3v point groups, the number of CO vibration modes were calculated and the results are shown in table (3). The CO stretch of the E mode (C3v) sp lits A' and A'' compounds characteristic of the overall molecular symmetry of Cs, this was the case for the complex (MI), i.e. three carbonyl bands, due to 2A',/A''modes were found . The other complexes show only two bands as in the case of compounds (M II, MIII), this is because the two close-lying bands due to A +E modes were observed. Generally the E mode is the lower frequency band [23,24]. Electronic Spectra Many carbonyl compounds of group VIB elements of the periodic table were studied [24,25]. Gray and Beach [26,27] measured the UV absorption spectra of M(CO)6 of group VIB elements and assigned the band on the MOT basis. The new complexes are conducting and most diagnostic bands, their assignments are shown in table (4), fig (3). The used solvent is chloroform ,causes blue shift for all absorption bands, the characteristic in the spectra of the complexes is the appearance of a new band at around (27.470)cm -1 which is not found in the spectrum of the parent (M) , this is assigned as I L' ( * ) for donor moieties of legends (olefin, nitrogen and sulfur atoms). The absorption bands in high energy region can be assigned to the two components of ( * ) transitions of carbonyl groups .Besides that, the LF transition can't be assigned easily, since they may be overlap with that of ( * ) absorption bands [24,28,29]. S che me (4) IBN AL- HAITHA M J. FO R PUR E & APPL. SC I VOL.22 (4) 2009 The general formula of the prepared complexes can be depicted as shown in table (1) and the proposed structures pentagonal bipyrmidal for the selected complexes can be given as follows: MI Wh e re R= IBN AL- HAITHA M J. FO R PUR E & APPL. SC I VOL.22 (4) 2009 References 1. Borg, S.J.; Bondin,M.I. ; Best,S.P. ; Razavet,M.; Liuand X. and Pickett,C.J. (2005), Biochemical Society Transactions Vol.33(1). 2. Okayran, S. O.; Kayran,C. and Kreiter,C. G. (1992),Organomet J. Chem., 434:79. 3. Rigaut,S.; Touchard, D. and Dixneuf, P.H. (2003), J.Organomet.Chem.,684:68. 4. Ammar,H.B.; Lenotre,G.; Salan, M.; Kaddachi, M.T .; Toupet,L.; Renaud,J.L.; Bruneau ,C. and Dixneuf, P.H. (2003), Eur.J.Inorg.Chem.,4055. 5. Jassim, A.H. (1993), Ph. D. Thesis,Al-Nahrain University of Engineering and Science Iraq. 6. Rasol N.(1987),M. Sc. Thesis, University of Baghdad ,Iraq and References Cited Therein. 7. AL-Zahawi,S. K. A.(1986), M. Sc. Thesis, University of the Baghdad Iraq . 8. Vahren Kemp,H. (1975), Angew. Chem. Int. Ed. Engl.,14:322 . 9. GreenWood ,N.N. and Earnshaw, A. (1998) "Chemistry of the Elements"Second Eddition , Pergamon Press. 10. Nesmeyanov ,A. N. and Nesmeganov, N.A . (1981),"Fundamental of Organic Chemistry" Vol. III, Mir Publishers, M oscow. 11. Mishar ,L. and Anjali, Jha, (1996) Indian J. of Chemistry,35A: l00l. 12.Cottonn ,F. A. and Willkinson ,G.S. (1987),"Advanced Inorganic Chemistry" Acomprehensive Text, Fifth Eddition, John. Wiley. 13. Abbas,M . H. (1991) Ph. D. Thesis, Nottingham. 14. Musa, F.H. (1998),Iraqi :J.of Chem.,Vol.24 (2). MII MIII Wh e re R'= Wh e re R''= IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L. 23 (1) 2010 15. Musa,F.H. ; Mahmoud ,M.J. and Mustafa,I.F. (2002),Ibn Al-Haitham , J.for Pure and Appl . Sci ., Vol . 15(3):44. 16. Stiddard,M. H. B. (1962) J. Chem. .Soc., 4712. 17. Nakamoto, K. (1997)," Infrared Spactro of Inorganic and Coordination Compounds", 6th. Ed. Wily, Intersience, New York. 18. Al-Obaidi, E. Z. M .; Nadir,K. M . and Eur. Roche, V. E .(1991)J. Med. Chem., 26. 19. Singh, B. and Singh, R. D. (1977), J. Inorg. Chem ., 39: 25. 20. Mustafa,I.F. ; Atto , A.T. and Musa, F.H. (1991),Iraq J.Chem., 16. 21. Dilsky Stefan and Schenk Wolfdieter,A. (2006) , Z.Naturforsch , 61b:570 . 22. ACotton,F. (1971)."Chemical Application of Group Theory"2nd.Ed.New York,Wiley Interscience. 23. Tripath ,S. C. and Srivastava ,S. C. (1970) J. Organomet. Chem., 25:193 . 24. Stoeffler,H.D.; Thornton,N.B.; Temkin, S.L; Schanze, K. S. (1995),J.Am.Chem. Soc., 117:7119 25. George, M.W. and Turner, J.J. (1998),Coord.Chem.Rev.,177:201. 26. Gray, H. B. and Beach,N.A. (1963) J. Am. Chem. Soc., 85:2922. 27. Beachand,N.A. and Grya,H.B. (1968),J.Amer.Chem .Soc.,90:5713. 28. Friedman,A.E.; Chamborn,J.C.; Sauvage,J.P.; Turro N.J. and Barton,J.K. (1990),J.Am.chem.soc.,112:4960. 29. Geoffroy,G.L. and Wrighton, M.S. (1979) "Organometallic Photochemistry " Academic Press. New York. Table (1) Some Physical Properties of [Mo(CO)4bipy] . (M) and new Prepared Complexes Colour M.P.(Co) %Yield Chemical Formula M Red (189-191) 95 C14H8N2O4Mo MI Deep brown (244-246) 77 C30H21N5O3SMoI2 MII Orange (280- 282)dec. 75 C33H28N8O3S 2MoI MIII Brown (174-176) 87 C21H18N6O5S 2MoI ` IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L. 23 (1) 2010 Table (3) CO Vibrational Modes and their assignments for Cis-Mo (CO)4- bipy and fac. Mixed ligand Molybdenum tri-carbonyl compounds Compound A1 (2) A1 (1) B1 B2 M 2012 1918 1887 1820 Compound A1 A' A" MI 1967 1910 1869 Compound A1 E MII 1991 1870 MIII 1992 1890 Where L= bipyridyl (bipy) L'= triazole or oxadiazole group Table (4): Electronic Spectra and Conductance (in CHCl3) for Metal Carbonyl Complexes Fi g. (1) : The sele cte d C O ba n ds of tetracabo n yl s (Mo) in the stretchi n g re gi on Band nm (cm -1 ) Band nm (cm-1)(M) Assignm ent MI MII MIII Assignm ent sc m -1 486(20.576) MoL CT 366(27.322) 365(27.397) 361(27.700) *IL' 80 370(27.027) *IL 331(30.211) 343(29.154) 343(29.154) Mo * COCT 50 343(29.154) Mo * COCT 255(39.215) 259(38.610) 254(39.370) Mo * COCT 50 256(39.062) Mo * COCT IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L. 23 (1) 2010 Fi g. (2) : S ele cte d C O ba n d of Mo comple xe s in the CO s tre tchin g re gion Fig. (3):Absorption spectra of Mo(CO)4 bipy and their complexes in chloroform solvent لمجلد لتطبیقیة ا لصرفة وا ا لوم للع لهیثم ن ا 2009) 4 (22مجلة اب تحضیر ودراسة تركیبیة لبعض معقدات كاربونیالت مع مشتقات الترایازول واالوكسادایازول) II(المولبیدینیوم شذى محمد حسن عبید قسم الكیمیاء، كلیة التربیة ابن الهیثم، جامعة بغداد الخالصة زول واالكــسادایازول الكاربونیلیــة الجدیـدة الحاویــة علــى مــشتقات الترایــاعــدد مــن المعقــداتحـضرت الفیزیائیــة المناســبة بطیــف االشــعة تحــت الحمــراء واالشــعة ائقتــم تشخــصیها واقتــراح شــكلها الهندســي بــالطر . الكیمائیة القیاسیة والخواص الفیزیائیةائقًفوق البنفجسیة المرئیة، التوصیلیة الكهربائیة فضال عن الطر المرئیـة مـع الحــسابات -ء واالشـعة فـوق البنفــسجیةاعطـت نتـائج الدراسـة بطیــف االشـعة تحـت الحمــرا النظریــة باســتخدام نظریــة المجموعــة بــراهین اضــافیة مهمــة للــصیغ التركیبیــة المفترضــة ونــوع االرتبــاط فــي .هذه المركبات