For Martin´s draft



Supporting Information

For

Systematic synthesis of asymmetric FeZn model complexes for plant purple acid phosphatases

Martin Jarenmark,a Håkan Carlsson,a Vladimir M. Trukhan,a Matti Haukka,b Sophie E. Cantona, Monica Walczaka, Wilfred Fullagara, Villy Sundströma, Ebbe Nordlandera*

aChemical Physics, Center for Chemistry and Chemical Engineering, Lund University, Box 124, SE-221 00 Lund, Sweden

bDepartment of Chemistry, University of Joensuu, Box 111, FIN-80101 Joensuu, Finland

*To whom correspondence should be sent. E-mail: ebbe.nordlander@chemphys.lu.se

Analysis of complexes 1-4

[Fe(H2ICIMP)(H2O)Cl][Fe(H2ICIMP)(MeOH)Cl][ClO4]4 (1)

Yield 76 % FAB-MS m/z (rel. intensity % 56Fe) 544 (Fe(ICIMP)ClH, 100), 509 (Fe(ICIMP), 50). Anal. C51H82Cl6Fe2N12O26 Calc.: C, 38.20; H, 5.15; N, 10.48; Found: C, 37.53; H, 4.82; N, 10.71. IR (KBr, cm-1) 3157(s, br), 2028 (w), 1622 (s), 1582 (s), 1511 (w), 1475 (m), 1434(w), 1406 (m), 1316 (m), 1282 (w), 1253 (m), 1217 (w), 1111 (s), 1086 (s), 969 (m), 925 (w), 906 (w), 870 (w), 803 (m), 766 (m), 731 (w), 624 (s), 541 (m), 431 (w). UV/vis (nm, MeCN) 561(m), 285(s), 219(sh).

[Fe(H2IPCPMP)Cl2][PF6] (2)

Yield 60% FAB-MS m/z (rel. intensity %, 56Fe): 560 ([Fe(IPCPMP)Cl]+Na+, 100), 538 ([Fe(IPCPMP)Cl]+H+, 60); Elem. Anal. C27H35Cl2F6FeN4O3P %Calc. C, 44.10; H, 4.80; N, 7.62; Found: C, 44.48; H, 4.26; N, 8.10; IR (KBr, cm-1) 3095(m), 1662(s), 1621(s), 1582(s), 1476(s), 1449(m), 1407(m), 1388(m), 1260(s), 842(vs), 769(s), 577(s); UV/vis (MeCN, nm), 557 (( = 1302 M-1cm-1), 358 (4061 M-1cm-1), 296 (9228M-1cm-1), 254 (14405 M-1cm-1)

[FeZn(ICIMP)(OAc)2][ClO4]·2CH3OH (3).

Yield 71% FAB-MS m/z (rel. intensity %, 56Fe) 783 (12), 690 (FeZn(ICIMP)Ac2, 100), 631 (FeZn(ICIMP)Ac, 60). Anal. C29.50H41ClFeN6O12.50Zn Calc.: C, 42.36; H, 4.94; N, 10.05; Found: C, 42.0; H, 4.69; N, 10.26. IR (KBr, cm-1) 3448 (s), 2923 (w), 1576 (s), 1411 (s), 1339 (m), 1146 (m), 1114 (m), 1083 (m), 1021 (w), 940 (w), 887 (m), 805 (w), 765 (w), 673 (w), 637 (m), 625 (m). UV/vis (MeCN) 474 (m, br), 289 (s).

[FeZn(IPCPMP)(OAc)2(CH3OH)][PF6] (4)

Yield 66.7% FAB-MS m/z (rel. intensity %, 56Fe) 684 ([FeZn(IPCPMP)(OAc)2]+, 100), 625 ([FeZn(IPCPMP)(OAc)]+, 60). Anal. C30H36F6FeN4O7PZn Calc.: C, 43.37; H, 4.37; N, 6.74; Found: C, 43.55; H, 4.92; N, 7.60; IR (KBr, cm-1) 3090(w), 2926(w), 1659(m), 1608(s), 1477(w), 1421(m, br), 1343(m), 1026(m), 843(vs), 554(m); UV/vis (nm, MeCN) 494 (1375 M-1cm-1), 288 (15 654M-1cm-1), 257 (24 695M-1cm-1)

Note! Although we did not encounter any problems, perchlorate salts of oxidizable compounds are potentially explosive and should only be prepared on small scale and handled with extreme care.

EXAFS measurements and modelling

X-ray absorption spectra were collected at beamline KMC2, BESSY, Germany, both in transmission and fluorescence mode. Solution samples were prepared by dissolving 4 in acetonitrile:water (1:1 v/v) to a concentration of 20mM and then loading the solution in a Kapton-tape covered PTFE cell. All experiments were carried out at room temperature. No spectral modification in the pre-edge and near-edge region (XANES) was observed over the accumulation time, which guarantees that the integrity of sample was maintained during the measurements.

The Horae (Athena/Artemis) suite of programs1-3 was used to perform the pre processing and fitting EXAFS analysis. The chi(k) extracted from data was fitted in k space using a k3 weighting and a Kaiser-Bessel k window, with k ranging from 1.5 to 12 Å-1, Δk = 2. Alternatively, it was fitted in R space using a Kaiser-Bessel R window, with k ranging from 1 to 2.3 Å-1, ΔR = 0.1. Common parameters were assigned to the O/N atoms in the first coordination sphere.

The solid samples could be modelled using the coordinates obtained from the crystal structure described in the main article. The first-shell analysis demonstrates that the local environment around both metal centres is similar in solid and solution phase. Fitting parameters are displayed in table S1.

The complete XANES and EXAFS analysis, necessary for an accurate estimation of the Fe-Zn distance,4 is currently being undertaken.

[pic]

Figure S1 The normalized Fe K edge spectrum of 4 for the solid (transmission and fluorescence) and solution (fluorescence). The normalized derivatives of these signals are displayed in the inset. The lack of changes in the 1s (( 3d transitions and near edge structure, characteristic of Fe III, provides further evidence that the local metal environment is the same in solid and solution.

[pic]

Figure S2 The normalized Zn K edge spectrum of 4 for the solid (transmission and fluorescence) and solution (fluorescence). The normalized derivatives of these signals are displayed in the inset. The similarity in the near-edge structure indicates strong similarities between the local metal environments in the solid state and in solution.

[pic] [pic]

[pic][pic]

Figure S3 The Fe K edge spectrum of the solid sample of 4 diluted in boron nitride (top left) and the Fe K edge spectrum of the solution (bottom left). Also shown is the corresponding R-space spectrum for the solid (top right black) with the spectrum generated by the first shell fitting analysis (top right green) and for the solution (bottom right red) also with the spectrum from the first shell fitting analysis (bottom right green).

[pic] [pic]

[pic] [pic]

Figure S4 The Zn K edge spectrum of the solid sample of 4 diluted in boron nitride (top left) and the Zn K edge spectrum of the solution (bottom left). Also shown is the corresponding R-space spectrum for the solid (top right black) with the spectrum generated by the first shell fitting analysis (top right green) and for the solution (bottom right red) also with the spectrum from the first shell fitting analysis (bottom right green).

Table S1 Fitting parameters for the first shell analysis of the solid and solution of complex 4.

| |Solid |Solution |

| |Transmission |Fluorescence |

| | | |

|E0(Zn) |4.60 (1.35) |3.17 (1.52) |

|S02(Zn) |0.90 (0.13) |0.95 (0.13) |

|ΔR(O/N)(Zn) |-0.02 (0.01) |-0.03 (0.01) |

|σ2(O/N)(Zn) |0.008 (0.002) |0.01 (0.002) |

|R% |0.2 |0.2 |

|(2 red |54 |12 |

| | | |

|E0(Fe) |10.95 (2.14) |10.14 (1.98) |

|S02(Fe) |0.82 (0.18) |0.90 (0.18) |

|ΔR(O/N)(Fe) |0.0004 (0.023) |-0.011 (0.021) |

|σ2(O/N)(Fe) |0.004 (0.003) |0.005 (0.005) |

| | | |

|R% |0.90 |0.60 |

|(2 red |267 |90 |

References

(1) Newville, M., J. Synchrotron Rad. 2001, 8, 322-324.

(2) Ravel, B., J. Synchrotron Rad. 2001, 8, 314-316.

(3) Ravel, B., Newville, M., J. Synchrotron Rad. 2005, 12, 537-541.

(4) Riggsgelasco, P. J.; Stemmler, T. L.; Pennerhahn, J. E., Coord. Chem. Rev. 1995, 144, 245-286

HPNP transesterification

The HPNP transesterfication was followed by UV/vis spectroscopy following the increase in concentration of the deprotonated product p-nitrophenol, measuring the absorbance at 400 nm at 25°C in quartz suprasil cuvettes using a Cary 300 Bio equipped with a 12 position thermostated cell changer. Substrate and catalyst concentrations were 0.80 mM and 0.25mM respectively and the ionic strength and pH were kept constant by using total concentrations of 0.1 M NaClO4 and 0.01 M buffer (EPPS 8.0). The pH of the buffer was adjusted in standard solutions using a calibrated pH meter before addition to the cuvettes. Each cuvette was prepared by consecutive addition of 980 (l acetonitrile, 30 (l of a 0.0375 M standard solution of the complex in acetonitrile/H2O (2:1 v/v) and 970 (l of a 0.0207 M buffer solution containing 0.207 M NaClO4. After mixing the zero absorption was measured. Then 20 (l of a 0.080 M standard solution of the substrate in H2O was added and after quick mixing the increase in absorption over time was measured at 400nm, first every minute but after 4 h every 5 minutes and after 8 h every 15 minutes. The initial rates were calculated by fitting a straight line to the curve corresponding to abs ................
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