Transition metal complexes of 1,3,4- Oxadiazole ligands

Transcription

1 المجلة القطرية للكيمياء المجلد الرابع والعشرون,69-6 ational Journal of Chemistry, 006, Volume Transition metal complexes of,,- xadiazole ligands ajat Al- baidy, Khalil K. Abid, Yusra J. Al- iami Department of Chemistry, College of cience, Al-Mustansiryah University (JC) (Received on 5 /0/005) (Accepted for publication on 5/ /006) Abstract ome transition metal ions Cr(III), Mn (II), Fe(III) Co(II)and Cu(II), were used to prepare complexes with a new ligand [-(acetyl methyl thio)-5- (o-hydroxy phenyl),,- oxadiazole. These complexes were characterized by using: I.R, UVvisible spectroscopy, Atomic absorption, molar conductivity and Magnetic susceptibility measurements. الخلاصة استخدمت بعض ا يونات العناصر الانتقالية,, + Cr Cu +, Co +, Fe +, Mn +, في تحضير معقدات مع المشتق الجديد [ -(اسيتايل مثيل ثايو)- 5 - (اورثو هايدروكسي فنيل) - اوكسادايازول. وقد تم تشخيص هذه المعقدات من خلال ا جراء الفحوصات: الا شعة تحت الحمراء الا شعة فوق البنفسجية والمري ية المطياف الذري التوصيلية المولارية والحساسية المغناطيسية. Introduction Three main derivatives of,,- xadiazole were prepared I, II, III (), and from these three derivatives a large number of compounds were prepared depending upon the nature and type of the substituents on the position and 5 (-6). R H R H R [I] [II] [III] H We concentrated our attention on derivative I due to the presence of biological activity of the thiol group, and the ligand ability to form 69

2 المجلة القطرية للكيمياء المجلد الرابع والعشرون,69-6 ational Journal of Chemistry, 006, Volume complexes with many transition metal ions (7). Derivative I can exist in two tautomeric forms Ia and Band the shift to any one form might be induced by reaction conditions. H R Thiol a H [I] R Thion b Complexes of some transition metals were prepared with different derivatives of I (8-0), like - thiolaetic acid -5- phenyl-,,- oxadiazole with the metal ions; Co +, i +, Cu +, Cd +, and the analysis of the complexes were assigned an octahedral geometry (IV). C H C M Ph IV ther complexes with dimer forms were also prepared with hydroxyl binding bridges () (V). Ph H C C H H L Fe H Py V Derivatives of compound I and its complexes exhibit biological H Fe L Py activity and medical uses as drugs (- 5), and this encourage searchers to 60

3 المجلة القطرية للكيمياء المجلد الرابع والعشرون,69-6 ational Journal of Chemistry, 006, Volume prepare new derivatives and complexes and to study their biological activity. Physical Measurements:- The following instruments were used in the physical measurements of the ligand and it's complexes: -C.H.. analysis were measured by using Elemental Analyser EA08 -Metal percentage was identified using Flame Atomic Absorption -m.p for the ligand and the complexes were measured by using Gallenkamp MFB-600 Melting Point Apparatus - pectroscopic Measurements : Hitachi U.V. pectrophotometer was used for Electronic spectra (00-00nm), while the Infra-red pectra were measured using Pye Unicam pectrophotometer(000-00)cm- with KBr disc for the ligand and CsI for the complxes. 5- Molar Conductivity were calculated for the complexes using DM as a solvent and the instrument(electrolytic Conductivity Measuring et Model MC--Mark V). 6- Magnetic Measurements with Faraday Method were measured for the complexes using the instrument ( Balance Magnetic usceptibility ). Practical work: a- Preparation of the ligand - (acetyl methyl thio)-5- (ohydroxy phenyl),,- oxadiazole (.9 gm, 0 mmole) of -(acetyl methyl thio)-5- (o- hydroxy phenyl),,- oxadiazole and (0.56 gm, 0 mmole) of KH were dissolved in absolute ethanol. The mixture then warmed with water bath and stirring until a white suspension is formed. (0.80 gm, 0 mmole) of - chloro acetone dissolved in (0 ml) absolute ethanol was added to the suspention with stirring at room temperature for 0 minutes and then refluxed for additional 0 minutes. The resulting precipitate filtered then washed with cold water to remove the adhered KCl. Recrystallization from absolute ethanol gave white crystals (. gm, 8% yield), (scheme ). + K H H EtH K H [VI] H K C l + ClCH CCH -CH -C-CH H [VII] cheme - 6

4 المجلة القطرية للكيمياء المجلد الرابع والعشرون,69-6 ational Journal of Chemistry, 006, Volume b- Preparation of the complexes: ne mmole of the metal chloride (MnCl.H, CoCl.6H, FeCl and CrCl.6H ) dissolved in (0ml) of absolute ethanol and (mmole) of the ligand (one mmole in case of Cr + complex) dissolved in (0ml) of absolute ethanol were mixed and the mixture refluxed for hr., cooled and filtered. Recrystallization from hot absolute ethanol afford a fine crystals. For i + complex the mixture was stirred at room temperature for 0 minutes, and the product was recrystallized form DM/ Ethanol, 50/50. Table -- show some physical properties of the prepared complexes: Table -: Physical properties of the ligand and complexes ymbol Molecular Formula omenclature A [Cr(C H 0 )Cl ] A [Mn(C H 0 ) ]Cl A [Fe (C H 0 ) Cl ]Cl A [Co(C H 0 ) ]Cl A 5 [i(c H 0 ) ]Cl Tri chloro[- (acetyl methyl thio) 5- (o-hydroxy phenyl),,- oxadiazole] Chromium (III) Bis [- (acetyl methyl thio) 5- (o-hydroxy phenyl),,- oxadiazole] Manganese (II) chloride µ- Tetra chloro bis [- (acetyl methyl thio) 5- (o-hydroxy phenyl),,- oxadiazole] di Iron (III) chloride Bis [- (acetyl methyl thio) 5- (o-hydroxy phenyl),,- oxadiazole] Cobalt (II) chloride Bis [- (acetyl methyl thio) 5- (o-hydroxy phenyl),,- oxadiazole] ickel (II) chloride Yield % 59 (0.0) 60 (0.75) 67 (0.55) 5 (0.56) 5 (0.65) m.p C ver d Color Light green White Black Light green Light green d*= decomposed Results and Discussions: Infra-red spectra: The ligand VI showed a weak band at 7cm - referring to -H stretching bond (), which subsequently disappeared in the prepared ligand VII indicating a substitution occurred on position, and a new absorption band appeared at 700, 85 and 9 cm - referring to the stretching frequency of the keto (>C=), methyl (>CH) and terminal methyl (-CH ) groups( Fig-). 6

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6 المجلة القطرية للكيمياء المجلد الرابع والعشرون,69-6 ational Journal of Chemistry, 006, Volume The complexes showed some shifts in the stretching frequencies of the main absorbing bands ν C-, ν C=, ν C= and the shifts was download for some complexes and upwards for the others, indicating the formation of the coordinating bonds by with, and atoms (6,7), and that was supported by the appearance of a new bands in the region (00-600) cm - (8,9). Also detected the non-ligand band for M-Cl bond in the region (-89) cm - (0), and the bridging M-Cl-M for Fe + complex at the region 5 cm - (). Table -. Table -: Major infra- red absorption bands (cm - ) for the ligands and its complexes o. Compounds υ C= υ C= υ C- υ M- υ M- υ M- υ M-Cl υ M-Cl-M L 5 C 8 H _ A [Cr(C H 0 )Cl ] _ A [Mn(C H 0 ) ]Cl A [Fe (C H 0 ) Cl ]Cl A [Co(C H 0 ) ]Cl A 5 [i(c H 0 ) ]Cl Continuous variation method for detecting the chemical formula of the prepared complexes were applied, and it showed that the complexes were coordinated with : ligand: metal for the metal ions (i +, Co + and Mn + ) and : for the metal ions (Fe +, Cr + ), Figure -- a and b. 6

7 المجلة القطرية للكيمياء المجلد الرابع والعشرون,69-6 ational Journal of Chemistry, 006, Volume V m V L Abs Absorbance (a) Vm/(VL+Vm) L: Fe + (λ max = 55 nm) V m V L Abs Absorbance (b) Vm/VL+Vm L: Cr + (λ max = 05 nm) Figure -: Continuous variation slop for Fe + and Cr + ions Magnetic measurements: Magnetic suseptibiliy were measured for the prepared complexes, the complexes (Cr +, Mn +, Co + and i + ) showed magnetic moment values of (6.9, 5.98,.9 and.7) B. M. which are very close of the theoretical values for the octahedral configurations (,), while the Fe + complex showed magnetic moment of 0.0 B.M, which mean that the complex had a 65

8 المجلة القطرية للكيمياء المجلد الرابع والعشرون,69-6 ational Journal of Chemistry, 006, Volume diamagnetic properties with octahedral configuration dimer (). Table -. Molar Conductivity: The molar conductivity for the complexes were measured. With the concentration of (0 - M) in DM. ome of the complexes showed very little value and good value for the others, Table -. And the presence of chloride ion outside of the coordinated sphere was checked by using Ag solution. Table -:Molar conductivity and Magnetic measurements complexes ymbol tructure Molar conductivity µ eff (B.M) Geometry A [Cr(L )Cl ] 5.69 o.h A [Mn(L ) ]Cl o.h A [Fe (L ) Cl ]Cl 6 0 (o.h) A [Co(L ) ]Cl 65.7 o.h A 5 [i(l ) ]Cl 7.95 o.h for the Electronic spectra: The electronic spectra for the ligand showed three bands at 0, 56 and nm corresponding to the electronic transition n-π* for C=, π- π* for C= and π-π* for C= which interact with π-π* of C= (5) ( Fig--). Three bands for the Cr + complexes detected at 69, 096 and 6595 cm - corresponding the transition of Ag ν Tg, A g ν T g g ν T g(p) A and respectively, and that agree with octahedral configuration (6). Three bands as well detected for Mn + complex in the regions 786, 8 and cm - for the transition (G) A g ν T g, A g ν A g ν E g A T g g (G) and respectively, and again these value agree with octahedral configuration (7). A broad band in the region nm containing three bands corresponding to the transitions A g ν T g, A g ν A Eg (G) A (D) g (G) and g ν Eg at the 77, and 7777 cm - respectively. These values agree with the octahedral 66

9 المجلة القطرية للكيمياء المجلد الرابع والعشرون,69-6 ational Journal of Chemistry, 006, Volume configuration (8) (low spin). Again the cobalt complex showed three bands in the regions 69, and 857 cm - corresponding to the transition T g ν Tg, T g ν T g ν A g T g (P) and respectively and these values agree with the octahedral configuration (9) (high spin), while i + complex showed only two bands in the region 8 and 685 cm - corresponding to the transition A g T g (P) A g ν T g ν respectively. and The first band did not appear but we measured it theoretically at the region 090 corresponding to the transition A g ν T g and these values agree with the distorted octahedral configuration (0), Table -. ymbol Table -: Electronic spectra bands (nm) for the ligand and the complexes Charge Band I Band II Band III transfer Geometry λ max υcm - λ max υcm - λ max υcm - λ max υcm - L A h A h A (.h) A h A h Conclusion According to all the chemical and physical measurements as the prepared complexes, we can suggested the chemical configuration for the complexes as shown in the figures, 5 and 6. 67

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11 المجلة القطرية للكيمياء المجلد الرابع والعشرون,69-6 ational Journal of Chemistry, 006, Volume CH C CH Cl H H Cr Cl Cl H C C CH M CH Figure: -- C CH H Figure:-5- where: M= Mn +, Co +, i + H H Cl Cl H C Fe Fe CH H C C Cl C CH Figure:-6 - References - A. R. Katritzky, The Chemistry of Heterocyclic Compounds, vol. 7, p: 8-, 6 th ed., (978); rd ed., (986). - G. Rama Rao, K. Mogilaiah and B. reenivasulu, Indian J. Chem., vol. 5B, p: 9-, April (996). - Hassan A. Al-bar, Mohamad. I. Makki and Hassan M. Faidallah, Indian J. Chem., 996, 5B,, Jan. 69

12 المجلة القطرية للكيمياء المجلد الرابع والعشرون,69-6 ational Journal of Chemistry, 006, Volume - B.. Vashi, D.. Metha and V. H. hah, Indian J. Chem., 996, 5B,, Feb.. 5- G.. Gadaginamath,. A. Patil and A.. hyadligevi, Indian J. Chem., 996, 5B, 68, July. 6- L. D.. Yadar, andhya aigai and upriya hukla, Indian J. Chem., 996, 5B, 85, April. 7- Kadhim K. Al- Janabi, Fuad H. Kamel, Ahmmad M. Al- Meshhadani and Khalid T. Al- Rasoul, Iraqi J. Chem., 00, 7, no. (), W. David llis Hetrocyclic Compounds, p: - (976). 9- Frederick Kurzer and Michael Wilknson, Chemical Reviews, (970). 0- A. R. Katritzky, Hetrocyclic Compounds, (997). - Lallan Mishra and Mustafa Kamil aid, Indian J. Chem., 996, 5A, 0. - H. haihaja Rani, K. Mogilaiah, J. udhakar Rao and B. reenivasulu, Indian J. Chem., 996, 5B, 75, July. - Anil K. engupta and Madhuri Goyal, J. Indian Chem. oc., 98, LX, 766, August. - El- ayed H., El-Tamaty, Mohy E. Abdel- Fattah and Ibrahim M. El- Deen, Indian J. Chem., 996, 5B, 067, ct. 5- Hansong Chen, Ahengmingli and Yufeng Han, J. Agric Food Chem., 000, 8, Patricia Gomez- aiz, Javier Garcia- Tojal, Miguel A. Maestro, Francissco J. Arnaiz and Teofilo Rojo, Inorg. Chem., 00,, K.. Thimmaiah, G. T. Chandrappa, Winston D. Lloyd and Cyril Parkanyi, Inorganica Chimica Acta, 985, 07,. 8- A. Jassim, A. J. Abdul- Ghani and G. A. Alwan, I. J. of Chem., 00, 7, no., Z. Muhi- Eldeen, Al- baidi, M. adir, and Vf. Roche, Med. Chem., 99, 7, Lallan Mishra, Ashok Kumar, Pandey and Rajendra Prasl ingh, Indian J. Chem., 99, A, 95, March. - Lallan Mishra, Mustafa Kamil aid, and Koichi Takeya, Bioorganic and Medicinal Chemistry, 995,, Issue 9,, ep. - ديفي د ن يكلس ترجم ة د. وس ام إب راهيم عزي ز "المعق دات وعناص ر ال دورة الانتقالي ة الا ول ى" الطبعة العربية (988). - A. M. aade and A. Mihsan Inorganic and coordination Chemistry Arabic Version (988). - Muthar Y. M., Iraqi J. of ciences, 999, 0A, o.(). 60

13 المجلة القطرية للكيمياء المجلد الرابع والعشرون,69-6 ational Journal of Chemistry, 006, Volume 5- A. b. P. Lever Inorganic Electronic spectroscopy, Elsevir Amsterdam London (968). 6- M.. Patial and J. R. hah, Indian J. Chem. oc., 98, LVIII, R. K. Lonibala and T. R. Rao, Proc. Indian Acal. ci., (Chem. ci.), vol. III, 8- J. C. Bailer, H. J. Emeleus and R. ypholm Comperhenisve Inorganic Chem. Pergamon Press (97). 9-. B. singh and J. ingh, J. Inorg. ucl. Chem., 979,, green Wood and A. Eamshaw Chemistry of the Elements Perganmon Press (986). 6