Coorditio equiliri Stility d competitio + + :L :L + 17.02.09 JJ Stepwise complex formtio 1 Wilso s disese A recessive geetic disorder resultig i copper ccumultio i liver d ri: Liver prolems d eurologicl d psychitric symptoms Tretmet: cheltio therpy 17.02.09 JJ Stepwise complex formtio 2 Cheltio therpy To decrese copper levels i liver: peicillmie (orlly) or triethyleetetrmie Why these ligds? Wht out zic-levels? Selectivity? (relies o reltive stilities) 17.02.09 JJ Stepwise complex formtio 3 1
Stepwise complex formtio [(H 2 O) N-+1 L -1 ] + L [(H 2 O) N- L ] + H 2 O Cosecutive stility costt K [L ] = K [L -1 ][L] [(H 2 O) N ] + L [(H 2 O) N- L ] + H 2 O Overll stility costt β [L ] = β [][L] 17.02.09 JJ Stepwise complex formtio 4 A exmple Cd 2+ -CN - Cd 2+ + CN - CdCN + K 1 CdCN + + CN - Cd(CN) 2 K 2 Cd(CN) 2 + CN - Cd(CN) - 3 K 3 Cd(CN) 3- + CN - Cd(CN) 2-4 K 4 Cd 2+ + 4CN - Cd(CN) 4 2- β 4 17.02.09 JJ Stepwise complex formtio 5 The Cd 2+ -CN - system Cd 2+ + CN - Cd(CN) (-2)- β logk logβ 1 5.62 5.62 2 5.18 10.8 3 4.9 15.7 4 3.5 19.2 19-02-2015 JJ Stepwise complex formtio 6 2
Distriutio of cetrl tom Degree of formtio of L α = [L ]/C < 1 Σ α = 1 C = C Σ α 17.02.09 JJ Stepwise complex formtio 7 The Cd 2+ -CN - system α 0 α 1 α 2 α 3 α 4 17.02.09 JJ Stepwise complex formtio 8 Distriutio of cetrl tom Degree of formtio α of L α = [L ]/C Σ α = 1 use [L ] = β [][L] 17.02.09 JJ Stepwise complex formtio 9 3
Distriutio of ligd use [L ] = β [][L] C L -[L] = C Σα 17.02.09 JJ Stepwise complex formtio 10 Degree of formtio of the system = me (verge) ligd umer Determie [L], clculte d do tht for N differet solutios Solve N equtios with N ukow β s 17.02.09 JJ Stepwise complex formtio 11 Fid [L] usig The ligd method LH L K HL H esure ph i solutios of high (costt) cocetrtio of LH + slt e.g. LHNO 3 The cidity costt of LH + should therefore e determied. 17.02.09 JJ Stepwise complex formtio 12 4
Cse study 1 1,2-ethedimie s ligd Arevitio : e Acidity costts questios1,2,3 17.02.09 JJ Stepwise complex formtio 13 The cetrl io Potetiometry: + / reversile electrode E = E 0 + (RTl10/F) log[ + ] C L, C C ΔE = (RTl10/F) log(c /[ + ]) = - (0.0592/) logα 0 0 C 10 0 (E E ) 0.0592 17.02.09 JJ Stepwise complex formtio 14 Cse study 1 Ligd: 1,2-ethedimie Cetrl tom: Cd 2+ Questio 7 Acidity costts, ph = 6.43: cosider distriutio of ligd ΔE = 25.6 mv cosider distriutio of metl io 17.02.09 JJ Stepwise complex formtio 15 5
Q7 ph=6.43: [e] ~0 => [eh 2 2+ ] = [eh + ] 10-6.43+7.49 25.6 mv = (59.2/2) log(α 0 0.0990/0.00990) α 0 =0.735 => α 1 =0.265 => [Cde 2+ ] =.0990 0.265 = 0.0262 C e =0.0787 = [eh 2 2+ ]+ [eh + ]+ [Cde 2+ ] ([e]~0) 0.0525 = [eh 2 2+ ]+ [eh + ] => [eh + ]=4.21 10-3 [e]=[eh + ] 10 6.43-10.20 =10-6.14 logk 1 =log(α 1 / α 0 ) + 6.14 = 5.70 17.02.09 JJ Stepwise complex formtio 16 Coloured compouds A λ = ε λ C l A λ = ε λ () [] l + ε λ (L) [L] l + ε λ (L 2 ) [L 2 ] l + ε λ (L 3 ) [L 3 ] l +.+ ε λ (L N ) [L N ] l ε λ = ε λ () α 0 + ε λ (L) α 1 + ε λ (L 2 ) α 2 +.+ ε λ (L N ) α N esure spectr of solutios with differet C d C L Approch experimet to solutios hvig ideticl ε λ - The solutios re sid to e correspodig : α (1)= α (2) 17.02.09 JJ Stepwise complex formtio 17 Correspodig solutios All α s re ideticl i differet correspodig solutios. It c e show tht lso the free ligd cocetrtio [L] is ideticl i the two solutios : C L L C L L i.e. C C L C L C C C C from which c e foud L C 17.02.09 JJ Stepwise complex formtio 18 6
Correspodig solutios I correspodig solutios the vlues of (the degree of formtio of the system or the me ligd umer) re the sme. The degree of formtio of ech sigle species (d ll the α s) re the sme. If α i oe solutio is the sme s α i other solutio the the two solutios re correspodig. Electrochemicl (α 0 ) or spectroscopic (ε) methods. 17.02.09 JJ Stepwise complex formtio 19 Correspodig solutios Prolems.. o oodle The determitio of stility costts simple exmple + + 2L L 2 + C = 0.01; C L = 0.02 C = 0.03; C L = 0.04 36=60log(C /[ + ]) : α 0 =.25 [L] = 0.01 ň = 1 K 1 = 200 K 2 = 50 17.02.09 JJ Stepwise complex formtio 20 Reltive mgitude of cosecutive costts pk 1 pk 2 dpk 0 1.28 4.19 2.96 1 2.87 5.70 2.83 2 4.22 5.70 1.48 3 4.35 5.40 1.05 4 4.44 5.44 1.00 5 4.51 5.51 1.00 6 4.52 5.52.99 7 4.56 5.53.97 8 4.58 5.54.96 Acidity costts for pk 1 pk 2 dpk 2 7.17 9.98 2.83 dicroxylic cids d for 3 8.71 10.31 1.60 α,ω-dimoium ios (25 0 C ) - is the umer of cro 4 5 9.49 9.92 10.67 10.77 1.19.85 6 10.12 10.80.68 toms i the chi coectig 7 10.16 10.85.69 the two cid groups 8 10.27 10.88.61 Cosider proilities 10 10.35 10.94.59 K K 2 [HBB ] [H [HBBH] ] [HBB ] 2 [H ] [ BB ] 1 1 2 1 dpk=0.6 17.02.09 JJ Stepwise complex formtio 21 7
Cd 2+ -NH 3 logk log(k /K +1 ) 1 2.66 0.57 2 2.09 0.66 3 1.43 0.5 4 0.93 17.02.09 JJ Stepwise complex formtio 22 K K Proility of formig L Reltive proilities re foud: There re N sites to occupy with equl proility ut some hve lredy ee occupied 1 [L] [L] [L] N 1 1 [L ] [L] [L ] N 1 1 17.02.09 JJ Stepwise complex formtio 23 Cd 2+ -NH 3 logk mx logk mx logk log(k /K +1 ) mi - clc N = 4 N = 6 exp N = 4 N = 6 1 2.66 0.57 2 2.09 0.66 3 1.43 0.5 4 0.93 17.02.09 JJ Stepwise complex formtio 24 8
Nickel(II)-mmoi experimetl d predicted Logβ (stt) Logβ (exp) K /K +1 1-2.78 12/5 2 5.18 5.05 15/8 3 7.05 6.70 16/9 4 8.10 8.01 15/8 5 9.05 8.66 12/5 6 8.93 8.74 JJ Stepwise complex formtio 25 Cse study 1 1,2-ethedimie s ligd Arevitio : e 6 JJ Stepwise complex formtio 26 Cd 2+ -NH 3 C =1m; C L =1 m + + hh + + ll y- m H h L l (m-ly+h)+ β mhl m, h, l 1, 0, 1 1, 0, 2 1, 0, 3 1, 0, 4 1, 0, 5 1, 0, 6 0, 1, 1 logβ mhl 2.66 4.75 6.18 7.11 6.84 4.4 9.38 log K 2.66 2.09 1.43 0.93-0.27-2.24 17.02.09 JJ Stepwise complex formtio 27 9