مجلة إبن الھیثم للعلوم الصرفة و التطبیقیة 2012 السنة 25 المجلد 1 العدد Ibn A l-Haitham Journal f or Pure and Applied Science No. 1 Vol. 25 Year 2012 DB18C6 مع الزئبق ثایوسانات للمعقد المذیبي االستخالص في دراسة راضي وحید سامي، الحیدري المحسن عبد ، المرعب رزوقي صفاء ، الكبیسي قدوري رافع بغداد جامعة ، الهیثم ابن التربیة كلیة، الكیمیاء قسم 2000 نيالثا كانون 16 :في البحث قبل 1999 األول تشرین 2 :في البحث استلم الخالصة تـاثیر ودرس DB18C6 االیثـري المركـب باسـتخدام الثایوسـیانات ایونـات مع ایوني كزوج الزئبق ایون استخالص تم عامــل هـي الزئبــق اسـتخالص بنــسب تـؤثر التــي العوامـل هــذه . االسـتخالص مــن النظـام هــدا طبیعـة فــي المـؤثرة العوامـل وتركیــز الموجـب االیــون وتركیـز الموجـب االیــون وتركیـز طبیعــة وعامـل الثایوسـیانات ایــون تركیـز وعامــل الحامـضیة الدالـة مهمـه عوامـل تثبیـت عنـد االسـتخالص اجـراء امكانیـة النتـائج بینـت .العـضوي المـذیب ونـوع الحـرارة ودرجة العضوي الكاشف .اعاله العوامل هي -انـدبتوكر 18C6.DCH ،BC6 , 15C5 مثـل اخـرى ركبـاتم باسـتخدام) II (الزئبـق اسـتخالص امكانیـة دراسـة تـم كـذلك الفـــوق واالشــعه الحمـــراء تحــت االشـــعة ومطیافیــة المیـــل طریقــة باســـتخدام المستخلــصة االجـــزاء تكافؤیــة دراســـة تــم . 222 اكـدت التحالیـل وجمیع االنصهار ودرجة CHN تحلیل جهاز باستخدام CHN تحلیل واجراء . المرئیة واالشعه البنفسجیة 2[Hg (SCN)4][k+.CE] الصیغة وجود والنتروجیني الهیدروجیني الكاربون تحلیل ، التاجیة األثیرات ،الزئبق المذیبي األستخالص :المفتاحیة الكلمات مجلة إبن الھیثم للعلوم الصرفة و التطبیقیة 2012 السنة 25 المجلد 1 العدد Ibn A l-Haitham Journal f or Pure and Applied Science No. 1 Vol. 25 Year 2012 Study o n Solvent Extraction of Mercury Complex With DB18C6 R.K.Alk ubaisy. S.R.Almureb . A.M.Alhaideri. S.W. Radhi Departme nt of Chemistry, Colleg of Education I bn Al-Haltham, Unive rsity of Baghdad Received in : 2 October 1999 Accepte d in : 16 January 2000 Abstract M ercury (II) ion is extracted as ion p air with thiocy anate using DCM .The effects of different p arameters affecting the ease of extraction are determined . These p arameters are p H ,T hiocy anate ion concentration ,ty p e and concentration of the counter cation concentration of the reagent , temp erature and ty p e of solvents .Ot her crown ethers (15C5 DB24C , DCH18C6 and 18C6 and cryp tand- 222 are invest igated as extracting reagents using slop analysis method UV-visible and IR sp ectrometry .CHN analysis and melting p oints determination are p erfored for comlex analysis .All these invest igations indicated the formula [k+CE]2[Hg (SCN )4]-2. Key words: solvent extraction ,mercury ,crown ethers CHN analy siss Introduction Separation methods are the imp ortant st ep to be taken before determination of any chemical sp ecies. The best sep aration ensure the accurate determination .Various p rinciples are emp loyed in sep arating the sp ecies in the form and p hy sical static suitable for the method of determination. Solvent extraction st ands as the best technique for sep arating trace and large amounts of chemicals since it is fast , Simp le , low cost and selective. M ercury (II) form number of comp lexes and coordination numbers and st ereo st ructures .It forms linear comp lexes with coordination number 2 and square p laner comp lexes with coordination number 4. Octahedral comp lexes of Hg (II) are less common[1].The bonds between Hg (II) and ligands show covalent p rop erties when the coordination number is tow[2]. Hg(II)is classified as soft base and chloride ion as hard base . Hg (II) form st able comp lexes with ligands coordinating through sulfur ,nitrogen and oxy gen[3]. Titanium can not be extracted form nitric acid meditm using oxy genic solvents and TBP[4]. 1.10.p henanthroline iron(II) :2-dip y ridyl iron (II)are used for extracting acids [7] and chelate comp ounds[8],dithiocarbamate [9], Diethy l ammonium diethy l dithiocarbamate [10] and dithiazone [11] are used for extraction of Hg (II) . Crown ethers with their chemical variety are emp loyed for extracting many elements on laboratory [12]. In the p resent work DB18C6 and other crown ethers are investigated as extractants for Hg(II).and the effect of various related p arameters are invest igated. مجلة إبن الھیثم للعلوم الصرفة و التطبیقیة 2012 السنة 25 المجلد 1 العدد Ibn A l-Haitham Journal f or Pure and Applied Science No. 1 Vol. 25 Year 2012 Materials and Methods Chemicals and reagents: All chemicals and reagents used are of A.R. grade sup p lied and emp loyed in the p reparation p rocess . M and B M erck and other comp anies . M ercury st andard solution is p repared by dissolving 1.713gm of Hg (NO3)2- H2O in liter of doubly distilled water . The diluted solutions of mercury were freshly p repared due to inst ability .Doubly distilled water is washed with dithiazone in CC14 before using. All other chemicals are used without further p urification. Instrumentations 1.Single beam UV-visible sp ectrop hotometer 4050-012. 2.Double beam U V-visible sp ectrop hotometer shimadzu-160. 3.Temp erature control circulator Churchill chiller.16.00139-40. 4. PW-9418 p H meter .p hilips. 5. M elting p oint measuring sy stem(England). 6. Electrical shaker. Scientifically supp lies(W.Germany). 7.CHN Elemental Analy zer.EA-1108. Mercury measurement Orange yellow complex is formed at p H 2.5 by shaking the aqueous solution with dithizone solution in CCl4. The organic p hase is washed and the measurement is carried out at max=485 nm using UV-visible sp ectrop hotometer. Results and Discussions The calibration curve for the determination of Hg(II).using dithiazone method is determined . It gave a linear relation on the concentration range of 4.98 x10-7 - 2.94x10-5M (1-50ug). On evaluating the effect of KSCN concentration on D value of Hg extraction with DB18C6 in DCM form a medium of p H=3. Results indicated increasing of D value till 1.6 M KSCN , after which D value decreases. This att ributed to the extraction of the sp ecies [K+SCN][SCN]. Fig.(1) the best p H for extracting Hg(II) is found to be 2.5 although D value is constant over p H range 3-7. At lower pH t he sp ecies [H+CH] [SCN - ] increases. T able (1). مجلة إبن الھیثم للعلوم الصرفة و التطبیقیة 2012 السنة 25 المجلد 1 العدد Ibn A l-Haitham Journal f or Pure and Applied Science No. 1 Vol. 25 Year 2012 D value is found to be increasing with increasing DB18C6 concentration in DCM . The relation between log D and log [DB18C6] is p resented in fig. (2). The slop e of the st raight line obtained is 1.82 the value which p redict the extracted sp ecies [K+ CE]2 [Hg (SCN)4]-3 with a little con the extraction sy st em is carried out at acidic medium (HCl) The sp ecies centration is of [K+CE] [HG(SCN)3] the dominating sp ecies is since [H+CE ] 2[Hg(SCN)4]-2 are extracted. Increasing of Hg (II) concentration gave increasing D value for Hg (II) . Plotting of log D against log [Hg] gave a st raight line with a slop e of 0.9. This means t hat t he contribution of Hg(II) in the extracted sp ecies is constant fig.(3). Ten minutes is found to be the best time of equilibration for the sy st em. Using of different organic solvents indicate that nitrobenzene is the best .Plotting of log D against log ∑ gave a st raight line while of log D versus 1/∑.Gave two linear relations due to the p resence of more then two sp ecies .fig.(4).Table (2,3) show D values for the extraction of Hg (II) using different crown ethers it can seen that DCH18C6 is the best due to matching between linic raddi and cavitt suize of the crown ether (K+ionic raddi is 2.66A0). Using different salts of SCN ion gave increasing D values in the order KSCN≥RbSCN≥NaSCN=Cs SCN. Performing the extraction at different temp eratures indicated exothermic extration in the p resence of K+ and Cs+ and endothermic reaction Na+ Rb + fig.(5). Slope analy sis indicated that Hg:DB18C6 ratio is :2.[K+CE]2[Hg(SCN)4]-2.T his ratio is sup p orted by mole ratio method tablel (3). Subst oichiometric exraction also sup p orted this ratio fig (7). Using of chloride ion instead of thiocy anatc ion gave no extraction .UV- visible and IR sp ectra sup p orted the p redicted formula (max DB18C^=250.max [K+CE]2[Hg(scn)4]- 2=CHN analysis gave the following results which is also in accordance with theoretical calculations table (4). KOH was found to be effective in back extracting H g(II) . It is found that 2.5M of KOH decreases t he D value to 0.23. Cry ptand 222 in nitrobenzene is used for the extraction of Hg(II) as thiocy anate and chloro complexes . Thiocy anate complex with cryptand -222 was p romising while that of chlorid e is not . Recent advances in the solvent extraction of mercury(II) with calivareneo and crown ethers [13] , Extraction of mercury(II) with dichloro18 crown 6 and its app lications in the treatments of industrial wast es [14], and the comp lexes of mercury (II) cyndates of crown ethers in dimethy l sulfoxide [15]. Re ferences 1.Cotton, F.A.; Wilkinson ,G . (1972) Advanced Inorganic Chemist ry ,Third Edition Isohn Wiley 2.Bailar, J. C.; Emeleus ,R.N .and Dickenson .T.A.F . (1975) Comprehensive Inorganic مجلة إبن الھیثم للعلوم الصرفة و التطبیقیة 2012 السنة 25 المجلد 1 العدد Ibn A l-Haitham Journal f or Pure and Applied Science No. 1 Vol. 25 Year 2012 Chemistry Ip ergramon Press 3.M orris, D.F.C. ;Short ,E.I .and Staters, D. N. (1963),Inory .J. Inorg. Chem. 25: 975. 4.Choi, S. S .and Tuck, D.G. (1970) J. Inorg. Chem. 2 :2422 . 5.Kot suji ,K.(1965)Bull Chem. Soc. Jap. 38: 402. 6.Yamamoto,Y. ; Kum amaru, T.; Tatchat ,A. and Yamnd a, N . (1970)Anal. Chem. Acta 50: 433. 7.Deshnkh ,G.S and Rao ,A.L . (1965)J. Chem. Soc. Jap 38: 1393. 8.Stanton ,R.E. and Ronald ,A.J . (1962)M c , Charmichael .I , Analy st 87: 134 . 9.Bode, H . Z. (1955)Anal Chem, 144: 165. 10.Bode, H. and Neumann .F , Z . (1960) Anal. Chem. 172: 11 . Ashizawa, T. L. (1961) Bunsek Kagaku 10 :443. 12. Alnoor ,T. (1996) PH .D T hesis Univercity of Baghdad ,Study on Solvent Extraction and Complexes of Lanthanides with Crown comp ounds. 13 . Reddy, L.P and Francis , (2001) Solvent Extraction and Ion Exchan ge 9 Iss. (5): 14. Francis ,T . ;M eera, M . and Reddy , L . (2001) Separation Sciences and Technology , 36 Iss. (10): 15. Jan ,S. (2003) Jawaski , J. Includin g Pheno mena M y crocy cic Chemist ry , 46 :207 – 211 Table(1): Effect of pH on D value of Hg(II). D value PH 2.72 1 2.78 2 2.84 3 2.88 4 2.86 5 2.84 6 2.80 7 مجلة إبن الھیثم للعلوم الصرفة و التطبیقیة 2012 السنة 25 المجلد 1 العدد Ibn A l-Haitham Journal f or Pure and Applied Science No. 1 Vol. 25 Year 2012 Table (2): D values of Hg using different crown e the rs. Cavity size D value(Hg) Crown ether 1.7-2.2 1.72 15C5 2.6-3.2 3.27 18C6 2.6-3.2 4.11 DCH18C6 2.6-3.2 2.95 DB18C6 4.5-5.6 1.56 DB24C8 Table(3): Mole ratio method. D value M:DB18C6 0.05 0.668 0.19 1.3336 0.46 2.005 0.55 2.673 0.59 3.341 0.62 4.010 0.64 4.678 0.66 5.346 Table (4): CHN analysis and mel ting points determination C% H% N% m.p.C DB18C 65.21 Theo 6.92% Theo - 195 DB18C 66.68 exp 6.66 exp - [K+CE]2Hg(SCN)4]2- 40.01 Theo 4.72 Theo 3.87 Theo. 182 [K+CE]2Hg(SCN)4]2- 42.91 exp 3.90 exp 4.55 exp. مجلة إبن الھیثم للعلوم الصرفة و التطبیقیة 2012 السنة 25 المجلد 1 العدد Ibn A l-Haitham Journal f or Pure and Applied Science No. 1 Vol. 25 Year 2012 Fig. (1): D Values of Hg (II) extraction as a function of KS CN concentration Fig .(2):l og D of Hg (II) extraction Vs. log[HDB18C6] مجلة إبن الھیثم للعلوم الصرفة و التطبیقیة 2012 السنة 25 المجلد 1 العدد Ibn A l-Haitham Journal f or Pure and Applied Science No. 1 Vol. 25 Year 2012 Fig. (3): l og D of Hg (II)extraction Vs.log[Hg] 2+ concentration Fig. (4): Log D of Hg (II)extraction as afunction of 1/∑ of the solvent مجلة إبن الھیثم للعلوم الصرفة و التطبیقیة 2012 السنة 25 المجلد 1 العدد Ibn A l-Haitham Journal f or Pure and Applied Science No. 1 Vol. 25 Year 2012 Fig.(5) : Log D as a function of temperature in the presence of different cations Fig . (6): slope anal ysis مجلة إبن الھیثم للعلوم الصرفة و التطبیقیة 2012 السنة 25 المجلد 1 العدد Ibn A l-Haitham Journal f or Pure and Applied Science No. 1 Vol. 25 Year 2012 Fig.(7): mole ratio method