ࡱ> q` RbjbjqPqP2::$0 x $ h7#4 pɘ0k$^k$zk$$"2            Kinetics and mechanism of oxidation of 1,3-propylene glycol by dihydroxyditellutoargentate (III) in alkaline medium Shan Jinhuan, Huo Shuying, Shen Shigang, Sun Hanwen (Key Laboratory of Analytical Science of Hebei Province, College of Chemistry and Environmental Science, Hebei University, Baoding 071002, China) Received on Oct.3,2003; Supportted by the Nationaol Science Foundation of Hebei Province (NO.295066) Abstract The kinetics of oxidation of 1,3-propylene glycol(PG) by dihydroxyditellutoargentate(III) (DDA) was studied spectrophotometrically between 303.2K and 318.2K in alkaline medium. The reaction rate showed first order dependence in DDA and1.18-1.26 order in PG. It was found that the pseudo-first order rate constant kobs increased with an increase in concentration of [OH-] and a decrease in concentration of [TeO42-]. There was a negative salt effect and no free radical was detected. In view of this the dihydroxymonotelluratoargentate (III) species is assumed to be the active species. A plausible mechanism involving a two-electron transfer is proposed and the rate equations derived from mechanism can explain all experimental results. The activation parameters along with the rate constants of the rate-determining step were calculated. Keywords dihydroxyditellutoargentate(III), 1,3-propylene glycol, redox reaction, kinetics and mechanism Recently, the study of the higher oxidation state of transition metals has intrigued many researchers. Transition metals in a higher oxidation state generally can be stabilized by chelation with suitable polydentate ligands. Metal chelates such as diperiodatoargentate(III)[1], ditellutsargentate(III)[2], ditelluratocuprate(III)[3], diperiodatonickelate(IV)[4] are good oxidants in a medium with an appropriate pH value. The use of complexes as good oxidizing agents in analytical chemistry has been reported.[5,6].The oxidation of a number of organic compounds and metals in lower oxidation state by Ag(III) have also been performed[3]. But no further information on the kinetics is available. In this paper ,the mechanism of oxidation of PG by dihydroxyditellutoargentate(III) is reported. 1. EXPERIMENTAL SECTION 1.1 Materials All the reagents used were of A.R. grade. All solutions were prepared with doubly distilled water. Solution of [Ag(OH)2(H4TeO6)2]3- (DDA) was prepared and standardized by the method reported earlier[7]. Its UV spectrum was found to be consistent with that reported. The concentration of DDA was derived by its absorption at l =351nm. Solution of DDA was always freshly prepared before use with solution and double-distilled water. The ionic strength m was maintained by adding KNO3 solution and the pH value of the reaction mixture was regulated with KOH solution. 1.2 Apparatus and Kinetics Measurements All kinetics measurements were carried out under pseudo-first order conditions. Solution (2 mL) containing definite [Ag (III)], [OH-], [TeO42-] and ionic strength m and reductant solution (2mL) of appropriate concentration were transferred separately to the upper and lower branch tubes of a type two-cell reactor. After it was thermally equilibrated at desired temperature in thermobath (made in Shanghai), the two solutions were mixed well and immediately transferred to a 1cm thick rectangular quartz cell in a constant temperature cell-holder (0.1C). The reaction process was monitored automatically by recording the disappearance of Ag(III) with time (t) at 351 nm with a UV-8500 spectrophotometer (made in Shanghai). All other species did not absorb significantly at this wavelength.Details of the determinations are described elsewhere.[8] 1.3 Product Analysis and Stoichiometry Solution having known concentrations of [Ag (III)] and [OH-] was mixed with an excess of PG. The completion of the reaction was marked by the complete discharge of Ag (III) color. After completion of the reaction, the oxidation product was identified[9] as aldehyde alcohols, which was transformed into a precipitate of 2,4-dinitrophenyldrazone derivative by gravimetric analysis. It is found that one mole of PG consumed one mole Ag (III) by weighing. 2. RESULTS AND DISCUSSION 2.1 Evaluation of Pseudo-First Order Rate Constants Under the conditions of [Reductant]0>>[Ag(III)]0, the plots of ln(At-A") versus time are lines, indicating the reaction is first order with respect to [Ag(III)], where At and A" are the absorbance at time t and at infinite time respectively. The pseudo-first-order rate constants kobs were calculated by the method of least squares (re"0.999). To calculate kobs generally 8-10 At values within three times the half-life were used. kobs values were at least averaged values of three independent experiments and reproducibility is within 5%. 2.2 Rate Dependence on [PG] At fixed [Ag(III)],[OH-],[TeO42-], ionic strength m and temperature, k obs values increased with the increase of [PG] and the order in [PG]was found to be 1.18-1.26. The plots of [PG]/kobs versus1/ [PG] are straight lines with a positive intercept. (re"0.995) (Fig. 1). 2.3 Rate Dependence on [TeO42-] At fixed [Ag(III)],[OH-],[PG], ionic strength m and temperature, kobs decreased with the increase of [H4TeO62-] .The plots of 1/kobs versus [H4TeO62-] are straight lines with a positive intercept .(r e"0.999).(Fig 2.) 2.4 Rate Dependence on [OH-] and Ionic Strength  At fixed [Ag(III)], [H4TeO62-], [PG], ionic strength m and temperature. kobs increased with the increase of [OH-].The plots of 1/kobs versus1/ [OH-] are lines (r e"0.999).(Table1)The rate is decreased by the addition of KNO3 solution(Table2), it indicates that there is a negative salt effect which is consistent with the common regulation of the kinetics[10].  INCLUDEPICTURE "http://china.chemistrymag.org/cji/2004/images/06100109.gif" \* MERGEFORMATINET  Fig.1. Plots of [PG]/kobs vs 1/[PG] at different temperatures, [Ag(III)]=6.21410-4molL-1, [OH-]=1.72110-2molL-1,[TeO42-]=1.62310-3molL-1, m=4.0010-2 molL-1  INCLUDEPICTURE "http://china.chemistrymag.org/cji/2004/images/06100111.gif" \* MERGEFORMATINET  Fig.2 Plots of 1/.kobs vs [TeO42-]. [Ag(III)]=6.21410-4molL-1,[OH-]=1.72110-2molL-1,[PG]=0.10molL-1,m=4.7010-2 molL-1,T=308.2K. Table 1 Rate dependence on [OH-] [OH-]/mol L-10.0150.0350.0450.060.075103kobs/s-15.2046.3396.6116.8637.006[Ag(III)]=6.21410-4molL-1, [H4TeO62-]=1.62310-3molL-1, [PG]=0.08molL-1, m=8.5010-2molL-1, T=308.2K. Table 2 Rate dependence on ionic strength m m/molL-10.060.080.10.20.3103kobs/s-18.0157.7807.3326.0465.544[Ag(III)]=6.21410-4molL-1, [H4TeO62-]=1.66310-3molL-1, [PG]=0.10molL-1, [OH-]=1.5010-2molL-1, T=308.2K. 3. DISCUSSION OF THE REACTION MECHANISM In the alkaline medium, the electric dissociation equilibrium of telluric acid was given earlier [11] (here pKw=14) H5TeO6- + OH-  INCLUDEPICTURE "http://china.chemistrymag.org/cji/2004/images/06100110.gif" \* MERGEFORMATINET H4TeO62- + H2O lg b1=3.049 (1) H4TeO62- + OH-  INCLUDEPICTURE "http://china.chemistrymag.org/cji/2004/images/06100110.gif" \* MERGEFORMATINET H3TeO63- + H2O lg b2=-1.00 (2) The distribution of all species of tellurate in aqueous alkaline solution can be calculated from equilibriums (1)-(2). In alkaline medium such as [OH-]=0.01molL-1, [H4TeO62-]:[H5TeO6-]:[H3TeO63-]=1000:89:1, so in the concentration of OH- range used in this work, H5TeO6- and H3TeO63- can be neglected,the main tellurate species is [H4TeO62-].According to the report[12] the main DDA species was [Ag(OH)2(H4TeO6)23-]over the experimental range of [OH-]. The addition of acrylonitrile or acrylamide to the reaction mixture under nitrogen atmosphere neither changed the rate nor initiated any polymerization, showing no free radical in the reaction. In our study, we also believe that it is a similar type of a one-step two-electron transfer mechanism. According to the above experimental facts, we bring forward the mechanism of the reaction as below. [Ag(OH)2(H4TeO6)2]3- + OH- INCLUDEPICTURE "http://china.chemistrymag.org/cji/2004/images/06100101.gif" \* MERGEFORMATINET  [Ag(OH)2(H3TeO6)]2- + H4TeO62-+H2O (3) DDA DMA [Ag(OH)2(H3TeO6)]2-+[CH2(OH)CH2CH2OH] INCLUDEPICTURE "http://china.chemistrymag.org/cji/2004/images/06100102.gif" \* MERGEFORMATINET  [Ag(OH)2(H3TeO6)]2-[CH2(OH)CH2CHOH] (4) Adduct [Ag(OH)2(H3TeO6)]2-[CH2(OH)CH2CHOH] + [CH2(OH)CH2CH2OH] INCLUDEPICTURE "http://china.chemistrymag.org/cji/2004/images/06100103.gif" \* MERGEFORMATINET  [Ag(OH)2(H3TeO6) ( CH2OHCH2CH2OH)][CH2(OH)CH2CHOH] (5) complex complex  INCLUDEPICTURE "http://china.chemistrymag.org/cji/2004/images/06100104.gif" \* MERGEFORMATINET Ag(st   E F H [ \ mpZ_uvbeघ{{ h Yh YCJKHOJQJ^Jh Yh YCJH*KHh Yh YCJH*KHh Yh Y6CJKH]h Yh Y5CJKH\$h Yh YCJKHOJQJ^JaJh Yh YCJKHaJh Yh YCJKHhs 0JCJ$aJ$o(h Y0JCJ$aJ$/t \ vl*B*`*l*x****$dd$1$If[$\$a$gd Y$dd1$[$\$a$gd Y  8:<FIJqknjlNPflZ\hlӹӭǭӭӹӭӭәӋӋyӋyӋ#h Yh YCJH*KHOJQJ^Jh Yh Y6CJKH]&h Yh Y5CJKHOJQJ\^Jh Yh YCJH*KHh Yh Y5CJKH\h Yh YCJH*KHh Yh YCJKH h Yh YCJKHOJQJ^J h Yh YCJKHOJQJ^J/8:@bfl@v  n!p!!!!!!!!!""" ""۰h Yh Y5CJH*KH\h Yh Y5CJH*KH\ h Yh YCJKHOJQJ^Jh Yh YCJH*KHh Yh Y5CJKH\ h Yh YCJKHOJQJ^Jh Yh YCJH*KHh Yh Y6CJKH]h Yh YCJKH2"."0"2"T"V"\""""""""""""""b#d######## $$$$$$"$$$&$0$4$R$T$V$x$z$$$$$ŹŹ|Ź&h Yh Y5CJKHOJQJ\^Jh Yh Y5CJH*KH\h Yh Y5CJKH\h Yh YCJH*KHh Yh YCJH*KHh Yh Y6CJKH] h Yh YCJKHOJQJ^J h Yh YCJKHOJQJ^Jh Yh YCJKH0$$$ %%,%.%%%V&Z&\&]&&&&&&&&&''''' '!'+'-'2'4'9':'<'F'H'M'O'(((("(&(((*(۾ۯۯۡېx/jh Yh Y5CJKHOJQJU\^J h Yh YCJKHOJQJ^Jh Yh Y5CJKH\jh Yh YCJKHU h Yh YCJKHOJQJ^Jh Yh YCJH*KHh Yh YCJKHh Yh YCJH*KHh Yh Y6CJKH].*((((((())).)0)4)^)b)l)p)x)z))))))))))))))**<*>*@*Լ쮣}}}}}}}l}}쮣} h Yh YCJKHOJQJ^Jh Yh YCJH*KHh Yh YCJH*KHh Yh Y6CJKH]h Yh YCJKHh Yh Y5CJKH\/jh Yh Y5CJKHOJQJU\^J/jh Yh Y5CJKHOJQJU\^J&h Yh Y5CJKHOJQJ\^J$@*B*H*J*Z*^*`*j*l*v*x*************************++$+(+0+2+8+:+>+R+V+`+d+++++ؽˣˣ˕˕ˣˣˣ˂$h Yh YCJKHOJQJ^JaJh Yh YCJH*KHaJh Yh YCJH*KHaJh Yh YCJH*KHh Yh Y6CJKH]h Yh YCJKHaJh Yh YCJH*KHh Yh YCJKH h Yh YCJKHOJQJ^J3****5 $dd$1$If[$\$a$gd YkdZ!$$IfֈT w9!     0H!634ab*****$dd$1$If[$\$a$gd Y**+",5%%$dd1$[$\$a$gd Ykd("$$IfֈT w9!     0H!634ab+++++++++,,",$,0,4,6,>,@,H,J,P,R,X,Z,`,b,d,h,j,l,r,v,z,|,,,,,,,,,,,,,,,,ɻڪɪڞڞڞh Yh YCJH*KHh Yh Y6CJKH]h Yh YCJH*KH h Yh YCJKHOJQJ^Jh Yh Y5CJKH\ h Yh YCJKHOJQJ^Jh Yh YCJKHh Yh YCJH*KHaJh Yh YCJKHaJ0",6,@,J,R,Z,b,$dd$1$If[$\$a$gd Yb,d,|,,5 $dd$1$If[$\$a$gd Ykd"$$IfֈC ;9!RRRRRR0H!634ab,,,,,$dd$1$If[$\$a$gd Y,,-1l65%%%$dd1$[$\$a$gd Ykd#$$IfֈC ;9!RRRRRR0H!634ab,,-----(-,-L-P-Z-\-n-r-|------T.Y.`.b.c.j.k.n.o.p.u.x.y........˺ˠ˒ˆˆˠwwhwˆj$h Yh YCJKHUjh Yh YCJKHUh Yh YCJH*KHh Yh Y6CJKH]h Yh YCJH*KHh Yh Y5CJKH\ h Yh YCJKHOJQJ^Jh Yh YCJKHh Yh YCJH*KHaJh Yh YCJKHaJh Yh YCJH*KHaJ(..... /000R0T0Z0\0`0j0l0n0p00121416181:1@1B1F1N1P11111122222222222222222222223333 3 3˺ܫܫܺjM)h Yh YCJKHUjh Yh YCJKHU h Yh YCJKHOJQJ^J h Yh YCJKHOJQJ^Jh Yh YCJKHh Yh YCJH*KHh Yh YCJH*KH= 3333D3E3H3I3K3d3h333333333333T5U5W5X5[5\5]5^5_5a5f5g5h555555555555555555555k6l6s6t6v6w6z6{6}66666̻ h Yh YCJKHOJQJ^J j .h Yh YCJH*KHU jh Yh YCJH*KHUh Yh YCJH*KHh Yh YCJH*KHh Yh YCJKHC66666666666677777 7 77777777777777777777777777:8;8<8=8j8k8m8n8q8r8x8y8}8~888888ٞj7h Yh YCJKHU h Yh YCJKHOJQJ^Jh Yh YCJH*KHj2h Yh YCJKHUjh Yh YCJKHUh Yh YCJKHh Yh YCJH*KH>l67hklmnptju~uuu$dd$1$If[$\$a$gd Y $1$[$\$a$gd Y$dd1$[$\$a$gd Y 8899v9w9x9y9:hh h hhh&h(h.h0h4hhDhFhhhjjjj k kkkk kNkPkkkl lllllllllȷَjAh Yh YCJKHUh Yh Y6CJKH]h Yh YCJH*KH h Yh YCJKHOJQJ^JUj<h Yh YCJKHUjh Yh YCJKHUh Yh YCJKHh Yh YCJH*KH1`!)+CH2(OH)CH2CHO+ H4TeO62-+ OH-+ H2O (6) Reaction (3) and (4) belong to dissociation and coordination equilibrium, whose reaction rates are generally faster, reaction (5) belongs to electron-transfer reaction, whose reaction rate is generally slower, so reaction (5) is the rate-determining step. -d[Ag(III)]t/dt=k[Adduct] [CH2(OH)CH2CH2OH] Where [Ag(III)]t stands for any kind of form of Ag(III) complexes which existed in equilibrium. -d[Ag(III)]t/dt = INCLUDEPICTURE "http://china.chemistrymag.org/cji/2004/images/06100105.gif" \* MERGEFORMATINET [Ag(III)]t = kobs[Ag(III)]t (7)  INCLUDEPICTURE "http://china.chemistrymag.org/cji/2004/images/06100106.gif" \* MERGEFORMATINET  (8)  INCLUDEPICTURE "http://china.chemistrymag.org/cji/2004/images/06100107.gif" \* MERGEFORMATINET  (9)  INCLUDEPICTURE "http://china.chemistrymag.org/cji/2004/images/06100108.gif" \* MERGEFORMATINET  (10) From equation (9), the plots of [PG]/kobs vs.1/[PG] is straight lines and the rate constants of rate-determining step at different temperature were obtained from the intercept of the straight line. Equation (10) suggests that the plot of 1/kobs vs [H4TeO62-] is straight line. Activation energy and the thermodynamic parameters were evaluated by the method given earlier.[9](Table3) Dissociation equilibrium constant K1 and coordination equilibrium constant K2 of [PG] is respectively 2.257 and 63.569 L/mol (t=30C). Table3 Rate constants (k) and activation parameters of the rate-determining step ConstantsT/KActivation parameters (298.2K)PG303.2308.2313.2318.2Ea KJ/molDH# KJ/molDS# J/(molk)k (mol-1Ls-1)0.1140.1590.2590.37665.140.4462.660.44-56.690.47The plots of ln k vs 1/T have the following intercept (a) slope(b) and relative coefficient (r )PG : a=23.64 b= -7835.31 r=0.997 REFERENCES [1] Kumar A. Vaishali. Ramamurthy P. Int. J. Chem. Kinet. 2000, 32: 286. [2] Prasad T R, Sethuram B, Rao T N. Indian J. Chem, 1982, 21A: 169. [3] Reddy K B, Murthy C P, Sethuram B. et al. Indian J. Chem, 1981, 20A: 272. [4] Shan J H, Wei H Y, Wang L et al. Chemical Journal on Internet, 2001, 3 (11): 03b055pe. [5] Jaisswal P K,Yadava K L. Talanta. 1970, 17: 236. [6] Chandra S, Yadava K L. Talanta. 1968, 15: 349. [7] Balikungeri, A, Pelletier M, Minnier, D. Inorganica Chemica Acta, 1977, 22: 7. [8] Shan J H, Liu T Y, Acta Chimica Sinica.(Huaxue xuebao) 1994, 52: 1140. [9] Feigl F, Spot Tests in Organic Analysis, New York: Elsevier Publishing Co, 1956, 208. [10] Jin J J. Kinetics Principle of Chemical Reaction in Liquid Phase (Yexiang huaxue fanying donglixue yuanli), Shanghai: Science and Technology Press, 1984, 186. [11] The Teaching and Research Section of Analytical Chemistry in Zhongnan Mining Institute, Handbook of Analytical Chemistry (Fenxi huaxue shouce), Beijing:Science Press.,1984, 567. [12] Raviprasad T, Sethuram B, Rao T N. Indian J Chem, 1979, 18A: 40. lllllmmmmmnnnnnnnooooooppppppqq qrrrrrrrⷨ⨙ԇufjNh Yh YCJKHU#jOJh Yh Y6CJKHU]#jh Yh Y6CJKHU]jEh Yh YCJKHUjh Yh YCJKHU h Yh YCJKHOJQJ^Jh Yh YCJH*KHh Yh Y6CJKH]h Yh YCJKH#h Yh YCJH*KHOJQJ^J&rrsssstNtPtRtttttttthuju|u~uuuuuuuuuuuuuuuuvvvvvvvv$v&v(v*v,v.v@v软轢轑轑#h Yh YCJH*KHOJQJ^J h Yh YCJKHOJQJ^Jh Yh YCJKHaJh Yh Y5CJKH\ h Yh YCJKHOJQJ^Jh Yh YCJH*KHh Yh Y6CJKH]h Yh YCJKHh Yh YCJH*KH2uuuuuuuvvv&vt_________$dd$1$If[$\$a$gd YkdS$$IfF# 0 $6    34ab  &v.vBv$dd$1$If[$\$a$gd Y@vBvDvFvPvTvVvXvZv\v`vbvdvnvpvzv|vvvvvvvvvvvvvvwwwwwwwɽɽ h Yo(h Yh Y5CJKH\h Yh YCJH*KHh Yh YCJKHh Yh Y6CJKH]h Yh YCJKHaJ h Yh YCJKHOJQJ^J'BvDv kd{T$$Ifִ 7#ggEr0 $6    34ab Dvdvpv|vvvvvv$dd$1$If[$\$a$gd Yvv kdU$$Ifִ 7#ggEr0 $6    34ab vwwww&ckdaW$$If##0 $634abakdV$$If##0 $634ab$dd$1$If[$\$a$gd Yw$dd1$[$\$a$gd Y0182P. A!"#$%S DdV  S 2A06100109b%PjMDnPjMPNG  IHDR[(PLTE@@@bKGDH cmPPJCmp0712Hs ~IDATx^흋z( Mcǀp1 om ?^km?([eۏ@Uʶ~5nm?jV*~լG?(U@+7k|1p,!gbmZo0^=^KIz=DЭ+s+['NljNAU`)0T(,[0lPs`*-` 6B9n`ن1|%d;lK+_V%*[--سJ*` fHЦˠ)m9R` n DYP,waSk3$kYS'uz*fƗuםܢV6w0W:e1 @jd`{5s-\3C#S4FX]ˎVzhkYGyMT۞%L'&mw7l+fUql5dn.('$wnZo:]؎mWQ,`ZѠEL*n/6l ǖķA0hXl`ƷV&9+T`\l`ls?ȍ=@(\e<l'MfĜ;̞c,B;gn|p+uy'1]]]`c`Wb`QCrh  ],~2Xb;픹-dF0EZ]\O[1ފ)$#㖉M!AuJ, bl#KX3`ocsZS*Y2/ vOnt+] ˍ_e[܏^`[ہDb _l;_pR>[oH6[eϖn}_d4?[uOH:|_ v~p[,7.X9|99 ?7~--[8|Dn2e"Irr dF-L~|A]a:y6Eϊl_ہ˾=\ 7[veqf_`o~Ll ,?om7^#{jjpb}n̨V,3)o;/[ dTvքy0 cZWZ?0ФswVYv.X2XmF`ݮ`h> SM;'Po٦!@&WCLCpQ+O9b` [Lɗ+*R׫lF6UAZ)@wH>N`CtNܸ{X^B`fn^a?Jyrv`;H$K"_yZ ۭ8{Aaݵ0 ;!xY}㔏d>Эa໱~^;%06].i2u ?wr# j|-=1F1᪺Z;aاNݠWu eE=[Nn|sJ4(. q6ܸ9YognkYf6[5rA֝&mڲ  =˛u6bznz*5[P`RoMtiѧRlSykP?ٙWd~穫(cZӞ;/6nl%z-c]g9`1 \;nJS֥'4J9|ok: 0]{+]p_@iu-EE?Ke CH;Β%znrMTsj^@i=+at}Z` 6"e.C}`Zzg9hQ; ;Ml]}.2't{DJ<ۚ`o^d8X<O{m|q#[Deæpk22Emg]Zc~-fcGqf4M(tCqƶ1 -sT(,[0lPs6ӏmݞwz=l{Pu*[eۏ@).܏~y0} lJa`F H[J /cZVUrlOp*LYoLccu.- 0e]Za-BH" (~êlm?j&uyb[>F-Hu+ISEo)1`5|c!0Z%ʖʢd{_Nv-c! \[P{e;+[n<13aJsYN׆$m:©2͡ewuCΓNOCFJYmdVjo̖n$ cȡƾSYnyuЈ5e5_F́t2c`a\Ӽ |l;~lNtaǮP6;0jd˹¾6OUϕmlaelWV#Яfխ WX%x['VUF2rSZxd=>g[րmyGFٔ윲%f 3hz ]L#imM^\ZeONAawU؞Ը1f\*n/zׁlqw=BƯգ>VZY@UPl<۸BgiA<gVӏm֘]3ۤliFʶ]NҌJ-m)9Z(Rrt9eK3*PrʖfTj?⣐7IENDB`DdIV  S 2A06100111b͚4h2"G2mƣ.n͚4h2"G2mƣ.PNG  IHDRr<'PLTE.obKGDH cmPPJCmp0712Hs :IDATx^흍( zK*B[L^Qgrs909P909P909P909P90(Q% !d&lnz^ {`Bf榇j/LLܒeqC@8Yt䟌psmOy#,$༌%o(DPڤJȵ+Ќu/tI|;,0KG\mUcˇ8(lpUCcl@Mgh T3;Y!#~ܼ8OGAOqe! HZ\ˎȾ$LM>" c9FO 'Jǒia,[˥ƒdrIr265Kk,̓ABltܒe(O؜u}71ib H¥GדƢJKYꚦc)::9;ok*Pytj ?tVŊy}33*Ms2)e*msi/Rnnae*o$qUoGe,aּ!q O-y yS@D,Uљ>Nm%X7a,?JjOȿ!z WhfA<3oېõq:QT̄[Ǚ$ͦ drx~?q+;rUwyI{ڧ9q[W'NG~eq 3 UN۴Qx߽10O}*yu8#cIuI੊Na|33-OB| c8ȧ!> 9NW#/G S iEj\E |d4^>2m|>ލeB⾑Og|F||Rtc+7Js>ws8 yyBެ<9qCNl*N G<{fS|vT>=qo'qn2^e/_ކ%25;B\ܼy:ĽB} _^.$q93bj9ȷĵh^3zðfs9|m^8XtK $D%zϙ I\p 9|]T0NW&{ _6UY$Hx֖xey"~7}>pO!q5V9^L|99$~S2;fM~tJG~}5T"ax 5yZnĿs&uq&r~s?ږ~a h%Ep &9r_Q"f*'|byoGPl]+qaߍ{B,o1p{9rܥ$Qw@Y  x~GZ9l)#ċĕ@L\9sy"6N)ą{ DjAJ'K6s<[^iwKjjzNq;K#/=B<G B{IiiGU%h:/uzRS*'M ,<>#&%CR)j,Qg+ "LZW@N㤸+¤u4N["LZW@N㤸+¤u5r\FV!'[6It:Ԋ OfC> Ai5m_sϱz{QTP%_O\w6ܜy\ DzYu7J呝W9<6<6m(䑡e262C/ Oˋ*'0[h.㹳ӑIaRx>({gN_ & 0ȿ'X$?"9,x~!Uqrs@B@nN< TB@nN< TB@nN< TB@nN< TB@nNʧq8f<3nzH Bv>ʧq8fPNG  IHDRLgVPLTE#tRNS0JbKGDH cmPPJCmp0712HsIDATHKA 0 ڴ`HX/qA#.%2Q{C"E]LsAIќhhw{ e3#Ϳ=hyB h'K'+ֳ҂E{bJe?~dw'c^qRIENDB`DdZV  S 2A06100103bWА.*fqAoW3"8n+А.*fqAoWPNG  IHDRG~PLTE#tRNS0JbKGDH cmPPJCmp0712HsIDATHK͕Q DNRSaU>b>r qLP ! #8, _WR"DOؠR `RI~iP91u䧪lmNyh#fѓuGP39"\dW{mOnN&g[IENDB`DdIV  S 2A06100104b7/_꡾G'#=n /_꡾G'PNG  IHDRG#(PLTE#tRNS0JbKGDH cmPPJCmp0712HsIDAT8O; Du)Zj]@(wĭ}NP*J0bU]MqSAu FCȯ~:ä52O߀Wڸ=b\[ j Q)Kmm8;M-ͯ?_w8M {*A2_ǩ!V*_ ϏR|H .|v,4>JJl V(~G1!((fX6aBz[-4mC{'e~ZrPd"?b? D#G&/-J=Wڊn8ԙ}T]+wspJMs:.Z?́L=s{ӑKn4]O[鰮P&8A$fb ґMMϮ7x g\đfEr+BMf &\Gv9f2.f] ӉM8<+ڥhcYa]r`A%.<<:c#-w iCR0|RcﲬI8%֪_*2 gH8w~5ҥB&{. ](\3p &)Ybf*Ϩ^Faam LFFg&^W("O3=O0#<;pkRWU7IENDB`kDdV   S 2A 06100106 b˵u˦=!B(Fn˵u˦=!BPNG  IHDR1pbKGD#2 cmPPJCmp0712Om%IDATH͖JA# X;C)K B ]!OP<& 4 Q 623~g7W[ɩ3|7fkOզ͘O;7^gpq"s>y>tW+p-81p&\Ag1;ߌ5Ou.;wǺQnY8 *朥}-B Z7Ywme~2P*ds \V׮MZliLA1' &-NSSˊ!N* A0)VlccL^v]%j1f['nV!MȫE3U0NC 9 iJna'u>C 9 PNG  IHDR19mbKGD#2 cmPPJCmp0712OmIDATHOO`H &WK @|{(%#W+j2jzMy[1;p )#CjD'ݝ۬>.{c5%DkDۥ\s6St* ;9l(`K?o>kpnmpZc$f{ºiϯn:=Z#rlhUe|ſ7x?8&r+nxqB'iGJGʆqJN:{bQX p֑ίUW1G: <…hQW$S u$ kCqv;Iv_sEGN݅+oZsR)ZnN;_M^W?gh5V#uu|@dzI0tY13…2uQWQƵŊXyr9sdw]u8ϛ?O;O_Zie7$/5AMm6ꞡ3M~~ ;OolƮ=IENDB`1DdV   S 2A 06100108 bwIk`lcNn[wIk`lPNG  IHDR1Q bKGD#2 cmPPJCmp0712OmIDATHnFpV*jC9%>BH}DTBf 5OZeUj)RrJo9a@+5  c2|$ Exf1| ݳ2Wqoaނ| 76NXOשݪݩz=:3=HX( >sIJL Jħю|\UTRPe(he€SkH@\K!\ҕ+J^ }B^=V^g!UGl.Y;uiPNj}bCY.a/v/tsV "]դ'3Oxpʋ!D&R"unKd}"&gVݭ!$Mj lD8t oX)Ԍ!WItX%B<;|mI3B#o%2V8e涬Z0_\=0X0]J %^,l;>G"o?7caGP{T?Ȇ_ d EN%}R*=3h]&ȓ=6`"(r O$ϕX G/ ^Tjwqg+Xďf,8A5h!5?kPAVx^Ȟ gtuk .@I ddJBw} %^z2Vܴ/x,XIENDB`$$If!vh55 5#v#v #v:V 0 $6,55 5/ 34 ($$If!vh5555k555P5#v#v#v#vk#v#v#vP#v:V 0 $6,5555g55E5r/ 34 ($$If!vh5555k555P5#v#v#v#vk#v#v#vP#v:V 0 $6,5555g55E5r/ 34 $$If!vh5 $#v $:V 0 $65#/ 34 $$If!vh5 $#v $:V 0 $65#/ 34 N@N cke $1$a$$CJKHPJ_HaJmH nHsH tH$A@$ ؞k=W[SOFi@F nfh5ddVGpVddRs  Yrblqvz~************** ++++!+,+7+C+D+++++&0@#0#0x; #0#0 QQQQ[[#$0@,@ "$L@(*,\@0d@hUnknownGz Times New Roman5Symbol3& z Arial;[SOSimSun 1hiClC/(W/(W!-!),.:;?]}    & 6"0000 0 0 00000 =@\]^([{  0 0 00000;[ 0 02HX)?t Y2sKinetics and mechanism of oxidation of 1,3-propylene glycol by dihydroxyditellutoargentate (III) in alkaline medium MC SYSTEM MC SYSTEMOh+'0 4@L\ p|   tKinetics and mechanism of oxidation of 1,3-propylene glycol by dihydroxyditellutoargentate (III) in alkaline medium MC SYSTEMNormal MC SYSTEM1Microsoft Office Word@F#@!d@k/(՜.+,0 X`t|  MC SYSTEMW 0   !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwyz{|}~Root Entry FPData LW1Tablexk$WordDocument2SummaryInformation(DocumentSummaryInformation8CompObjm  FMicrosoft Office Word ĵ MSWordDocWord.Document.89q