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. 2008 Dec 15;47(24):11816-24.
doi: 10.1021/ic801542w.

New nitrosyl derivatives of diiron dithiolates related to the active site of the [FeFe]-hydrogenases

Matthew T Olsen  1 , Aaron K Justice, Frédéric Gloaguen, Thomas B Rauchfuss, Scott R Wilson
Affiliations

New nitrosyl derivatives of diiron dithiolates related to the active site of the [FeFe]-hydrogenases

Matthew T Olsen et al. Inorg Chem. .

Abstract

Nitrosyl derivatives of diiron dithiolato carbonyls have been prepared starting from the precursor Fe(2)(S(2)C(n)H(2n))(dppv)(CO)(4) (dppv = cis-1,2-bis(diphenylphosphinoethylene). These studies expand the range of substituted diiron(I) dithiolato carbonyl complexes. From [Fe(2)(S(2)C(2)H(4))(CO)(3)(dppv)(NO)]BF(4) ([1(CO)(3)]BF(4)), the following compounds were prepared: [1(CO)(2)(PMe(3))]BF(4), [1(CO)(dppv)]BF(4), NEt(4)[1(CO)(CN)(2)], and 1(CO)(CN)(PMe(3)). Some of these substitution reactions occur via the addition of 2 equiv of the nucleophile followed by the dissociation of one nucleophile and decarbonylation. Such a double adduct was characterized crystallographically in the case of [Fe(2)(S(2)C(2)H(4))(CO)(3)(dppv)(NO)(PMe(3))(2)]BF(4). This result shows that the addition of two ligands causes scission of the Fe-Fe bond and one Fe-S bond. When cyanide is the nucleophile, nitrosyl migrates away from the Fe(dppv) site, yielding a Fe(CN)(2)(NO) derivative. Compounds [1(CO)(3)]BF(4), [1(CO)(2)(PMe(3))]BF(4), and [1(CO)(dppv)]BF(4) were also prepared by the addition of NO(+) to the di-, tri-, and tetrasubstituted precursors. In these cases, the NO(+) appears to form an initial 36e(-) adduct containing terminal Fe-NO, followed by decarbonylation. Several complexes were prepared by the addition of NO to the mixed-valence Fe(I)Fe(II) derivatives. The diiron nitrosyl complexes reduce at mild potentials and in certain cases form weak adducts with CO. IR and EPR spectra of 1(CO)(dppv), generated by low-temperature reduction of [1(CO)(dppv)]BF(4) with Co(C(5)Me(5))(2), indicates that the SOMO is located on the FeNO subunit.

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Figures

Figure 1
Figure 1
Side-on (left) and end-on (right) views of [2(CO)3]BF4. Thermal ellipsoids are shown at 35% probability and are omitted on the phenyl rings for clarity, as are the anion (one phenyl group is perpendicular to the plane of the page). Selected bond distances (Å): Fe(1)–Fe(2), 2.5931(7); Fe(1)-P(1), 2.2791(10); Fe(1)-P(2), 2.3128(10); Fe(1)-N(1), 1.659(2); Fe(2)-C(4), 1.806(3); Fe(2)-C(5), 1.806(3); Fe(2)-C(6), 1.785(3).
Figure 2
Figure 2
Structure of the cation in [2(CO)3(PMe3)2]BF4. Thermal ellipsoids are shown at 35% probability and are omitted on the phenyl rings for clarity, as are the anion. Selected bond distances (Å): Fe(1)-N(1), 1.618(9); Fe(1)-C(1), 1.860(11); Fe(1)-P(1), 2.231(3); Fe(1)-P(2), 2.270(3); Fe(1)-S(1), 2.323(3); Fe(2)-S(1), 2.376(2); Fe(2)-S(2), 2.306(3); Fe(2)-C(2), 1.749(11); Fe(2)-C(3), 1.741(11); Fe(2)-P(3), 2.312(3); Fe(2)-P(4), 2.270(3); Fe(1)-Fe(2), 3.969.
Figure 3
Figure 3
202 MHz 31P NMR spectra of Et4N[1(CN)2(CO)] (CD2Cl2 soln) at 20 (top) and -60 °C (bottom).
Figure 4
Figure 4
Structure of [1(CO)(dppv)]. Thermal ellipsoids are shown at 35% probability and are omitted on the phenyl rings for clarity. Selected bond distances (Å): Fe(1)–Fe(2), 2.5528(13); Fe(2)-P(1), 2.253(2); Fe(2)-P(2), 2.237(2); Fe(2)-N(1), 1.695(6); Fe(1)-C(3), 1.719(7); Fe(1)-P(3), 2.2026(19); Fe(1)-P(4), 2.247(2).
Figure 5
Figure 5
Structure of 1(CN)(CO)(PMe3). Thermal ellipsoids are shown at 35% probability and are omitted on the phenyl rings for clarity. Distances (Å): Fe(1)–Fe(2), 2.275(4); Fe(1)-N(2), 1.631(12); Fe(1)-P(3), 2.275(4); Fe(1)-C(4), 1.926(15); Fe(2)-P(1), 2.183(4); Fe(2)-P(2), 2.208(4); Fe(2)-C(3), 1.713(14).
Figure 6
Figure 6
Cyclic voltammogram of 1 mM [1(CO)(dppv)]BF4 in CH2Cl2 solution (50 mM Bu4NPF6, 20 °C, 100 mV/s).
Figure 7
Figure 7
Cyclic voltammograms of complex 1 mM [2(CO)3]BF4 in CH2Cl2 (∼50 mM Bu4NPF6) solution as a function of [CF3CO2H] (0, 1, 2, 3, 5, 7, and 10 expressed as molar equiv). Scan rate 100 mV s-1 at a glassy carbon electrode 0.3 cm in diam.
Figure 8
Figure 8
Plots of the catalytic current as a function of the acid concentration for [1(CO)3]+ (squares) and [2(CO)3]+ (triangles): ik and ip are the peak current in the presence and in the absence of acid, respectively.
Scheme 1
Scheme 1
Diiron Dithiolato Nitrosyl Complexes Described in this Work.
Scheme 2
Scheme 2
Isomerization Processes for the Fe(dppv)(NO)+ Subunit.
Scheme 3
Scheme 3
Pathway Proposed for Substitution of [2(CO)3]+ by PMe3.
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References

    1. Liu X, Ibrahim SK, Tard C, Pickett CJ. Coord Chem Rev. 2005;249:1641–1652.
    2. Mejia-Rodriguez R, Chong D, Reibenspies JH, Soriaga MP, Darensbourg MY. J Am Chem Soc. 2004;126:12004–12014. - PubMed
    3. Zhao X, Georgakaki IP, Miller ML, Yarbrough JC, Darensbourg MY. J Am Chem Soc. 2001;123:9710–9711. - PubMed
    1. Vincent KA, Parkin A, Armstrong FA. Chem Rev. 2007;107:4366–4413. - PubMed
    1. Liu T, Darensbourg MY. J Am Chem Soc. 2007;129:7008–9. - PubMed
    2. Justice AK, Rauchfuss TB, Wilson SR. Angew Chem, Int Ed. 2007;46:6152–6154. - PMC - PubMed
    1. Justice AK, Zampella G, De Gioia L, Rauchfuss TB, van der Vlugt JI, Wilson SR. Inorg Chem. 2007;46:1655–1664. - PMC - PubMed
    1. Butler AR, Megson IL. Chem Rev. 2002;102:1155–1165. - PubMed

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