Research Journal of Chemical Sciences ______________________________________________ ISSN 2231-606X Vol. 3(6), 54-59, June (2013) Res. J. Chem. Sci. International Science Congress Association 54 Synthesis and Characterization of Ni+2, Cu+2 and Zn+2 complexes with Benzoxazole-2-thionate, Diphenyl Phosphinomethane and Iodine Buttrus N.H.*1 and Mohamed S.M.Department of Chemistry, College of Science, Mosul University, IRAQ Teachers Training Institute, Nineveh, IRAQ Available online at: www.isca.in Received 22nd April 2013, revised 30th May 2013, accepted 13th June 2013Abstract The metal powder nickel, copper or zinc react with bis-benzoxazole disulfide (C14) (L) in refluxing toluene to give the complexes of the type [M(L)], where M = Ni+2, Cu+2, Zn+2 and L = benzoxazole-2-thionate (CNSO) through an oxidative addition reaction. The complexes of type [M(L)PhP(CH)PPh] were prepared by the reaction of [M(L)] with diphenylphosiphomethane in (1:1) and (2:2) molar ratio respectively. The reaction of some of the above complexes with iodine were also carried out. The complexes were characterized by IR, UV-Vis spectroscopy, metal content, elemental analysis, molar conductivity and magnetic measurements. Electronic and magnetic measurements indicate that some of the complexes have square planar geometry and the other contain tetrahedral geometry. Iodinated complexes behave as typical semi conductors and their conductivities were increases with temperature. Key words: Complexes, benzoxazole-2-thionate, diphenyl phosphinomethane, iodine. Introduction Coordination chemistry of metallo-nitrogen or sulfur compounds are a source of stimulation to many research workers, due to the fact that it possesses unique stereochemical, magnetic and spectral properties metal complexes of ligands containing nitrogen and sulfur as donor atoms were reviewed by Yuan and Huynh1-4. Copper and nickel powder react directly with sodium dithiocarbamate in organic solvents and produce the corresponding metal complexes. The result showed that the copper powder react in chloroform more readily than any other system examined. This reaction has been successfully applied in the determination of copper content in brass and bronze powder. The powder is oxidized by EtP(S)SS(S)PEt to tin(II) diethyldithiophosphate, the reaction involve the insertion of the metal in to the S-S bond. Tetramethylthiuram disulfide (DTS) an inhibitor or rephrotoxcity of Pt(II) drugs, an efficient agent in the treatment of chronic alcoholism and heavy metal toxicity. The reactions of tetramethylthiuram disulfide with KPtCl in 1:1 or 1:2 molar ratio gave the compounds [PtCl(DTS)] and [Pt(S(NEt) respectively, were described by Cervantas. Indium metal react with (CS) or (C14) in refluxing toluene give the compounds [In(L1)] and [In(L2)] , L1 = C , L2 = C14 through an oxidative addition reaction. Trinuclear complexes of the formula [In(L1)(MCl] and [In(L2)(MCl] were prepared by direct reaction of MCl.6HO (M = Co, Ni) or CuCl.2HO and ZnCl.XHO with the above indium complexes. The prepared compounds and complexes were characterized by micro analysis, IR, UV-Vis spectra, metal content, conductivity and magnetic measurements. Palladium(II) and Platinum(II) complexes containing the mixed ligands PhP(CHPPh (n=1-4) and benzo-1,3-imidazoline-2-thione, benz-1,3-oxazoline-2-thione or benzo-1,3-thiazoline-2-thione have been prepared and characterized by elemental analysis, spectral and magnetic studies as well as 31P,H-NMR data. Homo binuclear complexes of the type [ClMRC=CRMCl] [M= Ni(II), Pd(II) or Pt(II) and R = 5-Phenyl-1,3,4-oxadiazole-2-thiol, 4,5-diphenyl-1,2,4- triazole-3-thiol, or 2-mercapto-benzothiozole] have been prepared and characterized. Octahedral environment around Ni(II), while square planar geometry around Pd(II) or Pt(II) have been deduced on the basis magnetic and spectra measurements10. Metal dithiolene complexes possess a delocalized electron system as a planar central core [M(C]. The conduction band is formed by the ligand or orbital or mixed-metal-ligand orbital where the sulfur atoms play an important role11. Matsubayashi etal. reviewed donor abilities of the diimiredi-thiolene complexes. The complexes provide cation salts with various anions including I , Br. In view of there interesting results and in continuation of our comprehensive studies on transition and non transition metals complexes with sulfur containing12-13 and other various donating ligands14-15, we reported here the preparation of some Ni(II), Research Journal of Chemical Sciences ___________________________________________________________ ISSN 2231-606XVol. 3(6), 54-59, June (2013) Res. J. Chem. Sci. International Science Congress Association 55 Cu(II) and Zn(II) complexes with hybrid ligands of benzimidazole-2-thionate and diphosphine. Material and Methods All the chemical used were of high purity according to the supplier (Fluka). Analysis of ligand and complexes were carried out using CHNS elemental analyzer model 2400 Perkin Elmer. The metal content was estimated spectrophotometrically using Shimadza AA670 spectrophoto- meter. Melting point or decomposition temperature were determined on a Buchi melting point apparatus and were uncorrected, infrared spectra were recorded on a FTIR Brucker Tensor 27 Co. spectrophotometer in the 250-4000 cm-1 range using CsI disc. Electronic spectra were obtained with a Shimadzu UV-Vis recording UV1600 spectrophotometer at room temperature. The measurements were recording using a concentration of 10-3 M of the complexes in DMSO. The magnetic moments were carried out at 25C on the solid state by Faradays method using Brucker BM6 instruments, conductivities were measured using Conductivity meter model PCM3- Jenway. These measurements were obtain using DMSO over the 10-3 M at 25C. The solid state electrical conductivities of compact samples were measured as a function of temperature (308-328 oK), on a Hewlett-Pukard LCR meter by the conventional two probe method. The pellets were prepared at load of (5-7 tor/cm) and the contact on the pellet surface was made with the help of silver paste. Benzoxazoledisulfide was synthesized by a standard method16. Synthesis of the complexes: Preparation of [M(L)] complexes, M = Ni+2, Cu+2 or Zn+2, L = (CNSO): A clear solution of Benzoxazoledisulfide (0.3g, 0.001 mol) in tetrahydrofuran (20cm) was added to the metal powder (M = Ni, Cu or zn) (0.001 mol) in (30cm) ethanol-toulene. The reaction mixture was stirred under reflux for 12 h, by which time the metal was completely dissolved, refluxing was stopped at this stage and the stirred mixture was cooled to ambient temperature . The formed precipitate was filtered off washed with ethanol and diethylether and dried under vacuum. Preparation of [M(L)(Dppm)] complexes: A solution of [Ni(L)] complexes (0.36 g, 0.001mol) in (10cm) toluene was added to a solution of (0.38 g, 0.001mol) of Dppm in (5 cm) toluene. The reaction mixture was stirred under reflux for 4 h . The formed precipitate was filtered off, washed with toluene and diethylether then dried under vacuum for severed hours. The rest of the complexes were prepared using the above procedure. Preparation of [M(L)(Dppm)],M= Ni+2,Cu+2, Zn+2: A solution of [Ni(L)] (0.72 g, 0.002 mol) in (20 cm) toluene was added to a solution of (0.77 g, 0.002 mol) of Dppm in (10 cm) ethanol-toluene. The mixture was stirred under reflux for 6 h. The mixture was left at room temperature for 12 h. A coloured precipitate formed in solution was filtered off, washed with ethanol and diethylether, then dried under vacuum for several hours. Preparation of [M(L)]I complexes, M = Ni+2,Cu+2: A solution of [M(L)] (1 mmol) in ethanol-toluene (20 cm) was added to iodine (0.25 g, 0.002 mol) in (20 cm) of toluene. The mixture was refluxed for 10 h with continuous stirring. The precipitate was obtained after evaporation of the reside solution to about 1/3 of its volume, which was filtered off, washed with ethanol and diethylether, then dried under vacuum. Results and DiscussionThe complexes of the type [M(L)] were prepared through an oxidative addition reaction. The mechanism of oxidative addition reactions involving the initial cleavage of the S-S bond of the ligand to form the thiolate ion and the oxidation of the metal from M to M+2 16. Treatment of the prepared complexes [M(L)] with the diphosphine in (1:1) molar ratio gave new hybrid ligand complexes of the type [M(L)PhPCHPPh], where as the dinuclear complexes were obtained from the reaction of the mononuclear complexes [M(L)] with diphosphine in (2:2) molar ratio. The analytical data of the ligand and its complexes are given in table 1. These data were in a good agreement with the proposed formula. All these complexes are air stable at room temperature and insoluble in common organic solvents but they are soluble in dimethylformamide (DMF) or dimethylsulfoxide (DMSO). The molar conductivity of 10-3 M solution of the complexes indicate that they are non-electrolyte in DMSO17, also it was found that they are insulator in solid state , while the complexes of the type [M(L)]I are (1:1) electrolyte. This is consistent with the stoichiometry for the complexes on the basis of analytical data. The most important diagnostic feature of IR spectra of the complexes were listed in table 2. The IR spectra of the ligand showed a bands due to (C=N) appear at 1618 cm-1 and (C-S) 842 cm-1 , (C-O-C) band at 1290 cm-1 and the (S-S) band appeared at 473 cm-110. In the complexes the band (C-O-C) appear at the same position indicating that this band was not shared in coordination, while the (S-S) band disappeared due to the cleavage of this bond as discussed before. The (C-S) band observed at lower frequency which indicate it was shared in coordination with the metal ions. Further support of this coordination is provided by the appearance of new band 370-400 cm-1 which tentatively attributed to the (M-S)18. The (C=N) band of the ligand was shifted to a lower wavelength number and appeared in the region 1590-1665 cm-1 in the spectra of metal complexes indicating coordination through the azomethine nitrogen atom to the metal atom. Formation of a metal nitrogen band was further supported by the present of the band at about 430-490 cm-1 for (M-N)19-20. Research Journal of Chemical Sciences ___________________________________________________________ ISSN 2231-606XVol. 3(6), 54-59, June (2013) Res. J. Chem. Sci. International Science Congress Association 56 The IR spectra of diphosphine ligand show a medium to strong band at 1050-110 cm-1 , which may be a signal to vibration of (C-P) group, the IR spectra of complexes showed new bands at 515-560 cm-1 assigned to (M-P)21-22. In order to obtain some information about the coordination properties of the metal ions, the electronic spectra has been recorded as 10-3 M solution in DMSO and the results were presented in table 2. The bands observed at 36300-31100 cm-1 table 2, due to disulfide ligand which may assigned n-* or to * transition respectively. The magnetic moments of Ni(II) complexes (No. 1,4,7and 10) are diamagnetic which suggest a square planer geometry around the nickel atom. The electronic spectra of mono and dinuclear Ni(II) complexes (No. 1,4,7 and 10) shoe two band at 15000-16000 cm-1 and 25510-26455 cm-1 table 2. These bands were assigned g g and g Eg transition. These results suggested a square planer geometry around the nickel ion23-24. The magnetic moments of mono and binuclear Cu(II) complexes (No. 2,5,8 and 11) has been found to be (2.00,1.70,2.01 and 1.89 B.M) which indicate the presence of one unpaired electron. The Cu(II) complexes No. (2 and 5) showed a band at 10162 cm-1 and 13204 cm-1 which are assigned to E transition in tetrahedral environmental25. The magnetic susceptibility measurements showed that all Zn(II) complexes (3,6 and 9) were diamagnetic, and the electronic spectra of these complexes do not show any d-d band. In the complexes of the formula [M(L)]I, similar observation was found in the IR and UV/Vis spectra expected to have a dark coloured complexes. The electrical conductivities of the compact sample of the complexes were nonconducting the conductivities values in solid state are 1.3-9.61 × 10-12 -1cm-1 , while the complexes of the type [M(L)]I and [M(L) PhPCHPPh]I recorded in the temperature range 30-55 C (303-328 K) showed that the complexes exhibit typical semi conducting behavior. The conductivities of present complexes are well in the range of 3.10-3.39 × 10-8 -1cm-1 which similar to a number of transition metal containing polymers such as [M(C)] , M= Ni(II) ions26. The temperature dependent measurements of electrical conductivities of some of the complexes over the range 303-328 K, figures 1 and 2 indicate thermally activated conductivity. The plot of log verse 1/T almost liner over this temperature range and the activation energy is low, table 3. The increasing in electrical conductivities of these complexes with increasing of temperature shows the semi conducting properties of the complexes. The band gaps evaluated from these plots and by using equation 1, were found to be low 2.9 and 6.12 KJ mol-1 which is also indicative semi conducting behavior. = e (1)The thiolate ligand used in this study, coordinated to metal ions in mono or bidentate fashion form thiolate sulfur atoms and azomethine group for mono nuclear complexes or from thiolate sulfur atom, where is the diphosphene coordinated in bidentate fashion in mono nuclear and dinuclear complexes as shown in figure 3. Figure-1 Correlation between Ln conductivity an 1/T E / KT Research Journal of Chemical Sciences ___________________________________________________________ ISSN 2231-606XVol. 3(6), 54-59, June (2013) Res. J. Chem. Sci. International Science Congress Association 57 Figure-2 Correlation between Ln conductivity an 1/T NH S NO S M ON S ON S M Ph Ph (CH P Ph Ph M = Ni, Cu, Zn (1-3)(4-6) ON S Ph Ph (CH P Ph Ph Ph Ph (CH P Ph Ph M ON S ON S ON S M = Ni, Cu complexes (7-9)Figure-3 Suggested structure for the complexes Research Journal of Chemical Sciences ___________________________________________________________ ISSN 2231-606XVol. 3(6), 54-59, June (2013) Res. J. Chem. Sci. International Science Congress Association 58 Table-1 Physical properties of the ligands and its complexes No Complexes Colour m.p C Analysis found (Calc) .ohm - 1 . cm2 moleff (B.M) C% H% N% S% M% L1 (C) Pale yellow 190 56.10 (56.00) 2.53 (2.66) 9.30 (9.33) 21.29 (21.33) --- 10 --- 1 [Ni(L)] Green 230 46.96 (46.83) 2.18 (2.07) 7.73 (7.81) 17.91 (17.80) 16.39 (16.36) 4 Dia 2 [Cu(L)] Dark Brown 360 46.42 (46.22) 2.44 (2.20) 7.43 (7.70) 17.69 (17.60) 17.54 (17.47) 16 2.00 3 [Zn(L)] Pale grey 22046.00 (45.97) 2.03 (2.19) 7.80 (7.66) 17.54 (17.51) 17.91 (17.89) 12 Dia 4 [Ni(L)(Dppm)] Dark green 26067.00 (66.79) 4.50 (4.28) 3.87 (3.94) 9.00 (9.13) 8.25 (8.30) 4.9 Dia 5 [Cu (L)(Dppm)] Brown 25066.39 (66.33) 4.67 (4.25) 3.73 (3.96) 9.00 (9.07) 9.10 (9.00) 9 1.70 6 [Zn (L)(Dppm)] Pale grey 340 66.75 (66.15) 4.03 (4.24) 3.12 (3.96) 9.16 (9.04) 9.94 (9.24) 8 Dia 7 [Ni (L)(Dppm)] Olive 30064.98 (64.78) 4.30 (4.38) 2.52 (2.36) 5.21 (5.39) 9.92 (9.90) 20 Dia 8 [Cu (L)(Dppm)] Pale brown 27064.72 (64.07) 4.56 (4.34) 2.14 (2.34) 5.41 (5.34) 10.71 (10.90) 5 2.01 9 [Zn (L)(Dppm)] yellow 344 64.01 (63.96) 4.47 (4.33) 2.14 (2.33) 5.95 (5.33) 10.80 (10.88) 15 Dia 10 [Ni(L)]I Dark brown 28034.96 (34.59) 1.53 (1.65) 5.67 (5.64) 13.77 (13.17) 12.31 (12.08) 40 Dia 11 [Cu(L)]I Black 230 34.65 (34.15) 1.42 (1.63) 5.52 (5.63) 13.60 (13.17) 12.50 (12.94) 42 1.89 Table-2 Electronic and infrared spectra data of the ligand and their complexes No Band maximum (cm - 1 ) max IR band assignment (cm - 1 ) (C-S) (C=N) (C-P) (M-S) (M-N) (M-P) L 36300, 31100 840 S 1618 S --- --- --- --- 1 1500,26200 830 S 1605 S --- 380 m 430 m --- 2 10162 824 S 1600 S 1050 m 370 m 480 m --- 3 32000,30000 820 S 1590 S 1070 m 400 m 450 m --- 4 16000,26000 829 S 1603 S 1100 w 390 w 460 m 525 w 5 13204 822 S 1595 S 1090 w 375 m 490 m 540 m 6 33000 819 S 1598 S 1095 m 395 m 470 m 560 m 7 15980,26453 820 S 1615 S 1100 S 400 w --- 550 m 8 15974 815 S 1620 S 1090 s 390 w --- 540 s 9 32000 810 S 1618 S 1080 w 400 m --- 550 s 10 15900,26000 815 S 1600 S --- 390 w 460 w --- 11 16286 820 S 1590 S --- 380 w 470 m --- Conclusion In this research we reported synthesis and characterization a bidentate and monodentate ligands and its nickel, copper and zinc complexes. 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