Next Article in Journal
Previous Article in Journal
Synthesis of N1-(3,5-Bis(trifluoromethyl)benzyl)benzene-1,2-diamine and N,N-Bis(2-nitrophenyl)-3,5-bis(trifluoromethyl)aniline
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:

Mono- and Dinuclear Carbonyl Dithiolene Complexes Related to the [FeFe]-Hydrogenases

Laboratoire de Chimie, Electrochimie Moléculaires et Chimie Analytique, UMR 6521 CNRS, Université de Bretagne Occidentale, CS 93837, 6 Avenue Le Gorgeu, CEDEX 3, 29238 Brest, France
Author to whom correspondence should be addressed.
Molbank 2023, 2023(3), M1719;
Received: 25 July 2023 / Revised: 31 August 2023 / Accepted: 1 September 2023 / Published: 6 September 2023


The di-iron carbonyl dithiolene bridged complex [Fe2(CO)6(µ-S2C2(CO2Me)2)] (1) reacts with 1 equivalent of phosphane PR3 (R = Ph, OMe) to give, as major products, monosubstituted derivatives [Fe2(CO)5L(µ-S2C2(CO2Me)2)] (L = PPh3 (2), P(OMe)3 (3)). In the presence of an excess (3–4 equiv.) of P(OMe)3, the cleavage of 1 arises partly and a mixture of the mononuclear species [Fe(CO)(P(OMe)3)2(κ2-S2C2(CO2Me)2)] (4) and 3 is obtained. The compounds 24 were analyzed by IR and 1H, 31P-{1H} NMR spectroscopies. Their structures in solid state were determined by X-ray diffraction analyses, which accord with their spectroscopic characteristics.

1. Introduction

The chemistry of carbonyl dithiolato di-iron complexes [Fe2(CO)6−xLx(µ-dithiolato)] has attracted a lot of attention during the two last decades in reason of the resemblance of such compounds with the active site of [FeFe]-hydrogenases (H-cluster) (Scheme 1a) and in view to obtain efficient bioinspired non-noble metal electrocatalysts for the reversible H+/H2 conversion [1,2,3,4,5]. A wide number of di-iron systems with various combinations of thiolate bridges and terminal ligands have been studied in order to tune the electronic and steric properties of the dinuclear site as well as to functionalize the second sphere of coordination with non-innocent functionalities (redox and proton relays) [6].
Within the course of our research in this topic, we have been interested to study di-iron complexes with a dithiolene (alkene dithiolate) bridge (Scheme 1b) bearing an electron-withdrawing group, such as CO2Me, in reason of the capacity of this bridge to act as a redox active ligand as well as its electronic effect on the di-iron framework which allows us to decrease the potential of reduction of such derivatives and to stabilize reduced species [7]. Relatively few examples of di-iron complexes [Fe2(CO)6−xLx(µ-dithiolene)] have been reported [7,8,9,10,11,12]. The hexacarbonyl precursors can be prepared following various pathways, which have been previously reported in the literature [1,2,3,4,11]. The substitution of carbonyl groups by phosphanes, through photochemical, thermal or electrochemical activation, allows us to prepare monosubstituted [Fe2(CO)5L(µ-dithiolene)] and symmetrically disubstituted [Fe2(CO)4L2(µ-dithiolene)] derivatives (one CO being replaced at each iron atom). However, clean substitution processes are often limited by the fragmentation of the dinuclear entity into mononuclear complexes, [Fe(CO)3−xLx(κ2-dithiolene)] (x = 0–2) in the reaction conditions [10,11]. Herein, we report our preliminary attempts to prepare substituted di-iron derivatives by reacting the hexacarbonyl precursor [Fe2(CO)6(µ-S2C2(CO2Me)2)] (1) with PPh3 and P(OMe)3.

2. Results and Discussion

The complex [Fe2(CO)6(µ-S2C2(CO2Me)2)] (1) was reacted with one equivalent of phosphane (PPh3 or P(OMe)3) to give, according to the experimental conditions, the monosubstituted derivatives [Fe2(CO)5L(µ-S2C2(CO2Me)2)] (L = PPh3 (2), P(OMe)3 (3)) as the major products of the reaction (Scheme 2, Appendix A). The formation of side products 5,6 were also detected. When a large excess of P(OMe)3 was used, only one product, 4, could be isolated together with a small amount of 3. It was assigned to the mononuclear iron derivative [Fe(CO)(P(OMe)3)2(κ2-S2C2(CO2Me)2)] (Scheme 2, Appendix A).
Compounds 24 were characterized by spectroscopic analyses (IR, NMR) and their structures were confirmed by X-ray analyses of single crystals. The infrared spectra of 2 and 3 recorded in CH2Cl2 display a similar pattern in the terminal ν(CO) region, which is typical of an {Fe2(CO)5L(µ-dithiolate)} framework with four bands at 2058(s), 2002(s), 1988(m, sh), 1946(w) cm−1 and 2061(s), 2008(vs), 1989(s), 1955(w) cm−1, respectively. Their 1H NMR spectra in CDCl3 exhibit one singlet at 3.48 ppm (for 2) and 3.66 ppm (for 3) which is assigned to two equivalent methyl groups of the dithiolate ligand, which accords with a position of the C=C axis of the dithiolene bridge perpendicular to the Fe-Fe bond. The signals of the phosphanes PR3 (R = Ph, OMe) were detected at the expected chemical shifts with related proton integrations. The 31P-{1H} NMR spectra of 2 and 3 show one singlet at 60.8 or 172.1 ppm for PPh3 and P(OMe)3, respectively. The IR spectrum of 4, in CH2Cl2, presents in the carbonyl region one single band at 1971 (vs) cm−1. Its 1H NMR spectrum displays, in the alkyl region, a singlet at 3.91 ppm assigned to the methyl group of the chelating dithiolene, and a multiplet at 3.43 ppm is attributed to two phosphite ligands. In the 31P-{1H} NMR spectrum, a single resonance at 175.0 ppm was observed for the P(OMe)3 groups. The formation of the analogous compound [Fe(CO)(P(OMe)3)2(κ2-S2C2Ph2)] was observed together with a disubstituted complex [Fe2(CO)4(P(OMe)3)2(µ-S2C2Ph2)] when [Fe2(CO)6(µ-S2C2Ph2)] is warmed in the presence of an excess of P(OMe)3 in refluxing toluene [10].
The co-products 5 and 6 were detected in the 1H and 31P-{1H} NMR spectra of 2 and 3, respectively. Unfortunately, we have been unable to separate them satisfactorily by chromatography from their mixture with 2 and 3. It was not possible on the basis of the spectroscopic data of 5 to distinguish a disubstituted di-iron structure with two PPh3 in symmetrical position (Scheme 3(5A)) from a mononuclear geometry with two equivalent phosphines (Scheme 3(5B)), its IR pattern being overlapped with that of 2. The geometry of 6 was ascertained as [Fe(CO)2(P(OMe)3)(κ2-S2C2(CO2Me)2)] (Scheme 3) by the presence of two ν(CO) bands at 2036(s) and 1988(s) cm−1 in its infrared spectrum, as well as by the observation in the 1H NMR spectrum of a doublet (3JP-H = 12.0 Hz) at 3.45 ppm counting for nine protons with respect to six protons of the methyls of the dithiolene group. The formation of the analogous complex [Fe(CO)2(PPh3)(κ2-S2C2Ph2)] was proposed to arise from the decomposition of the air-sensitive disubstituted species [Fe2(CO)4(PPh3)2(µ-S2C2Ph2)] [11].
Single crystals of 24 suitable for X-ray diffraction studies were obtained from diethyl ether solutions of the complexes, at −15 °C (Figure 1, Table 1 and Tables S1–S3).
The {Fe2S2} core in these complexes adopts a butterfly conformation as previously observed, for example, in related crystallographically characterized monosubstituted di-iron compounds [Fe2(CO)5(L){µ-(SCH2)2(Ph)P=O}] (L = PPh3, and P(OEt)3) [13]. The local environment of each iron atom is a square pyramid supplemented by a metal–metal bond. In both complexes 2 and 3, the two iron atoms are bridged by the dithiolene linker, whose C=C bond lies perpendicularly to the iron–iron axis. The PR3 ligand coordinated to the Fe(1) atom lies in apical position in 2 and in a basal one in 3. The Tolman’s angles, θ, of PPh3 and P(OMe)3 are, respectively, 145° [14] and 107° [15]. The more crowded PPh3 ligand in 2 lying in an apical position, the basal position of P(OMe)3, observed in 3, is probably due to a higher repulsion between the CO2Me functionality of the dithiolene ligand and the methoxy group of P(OMe)3, than that between the apical PPh3 and CO2Me in 2. Thus, the apical/basal positions in 2 (PPh3) and 3 (P(OMe)3), respectively, differ from the apical/apical ones observed in solid state in the two di-iron complexes [Fe2(CO)5(L){µ-(SCH2)2(Ph)P=O}] [13] with L = PPh3, and P(OEt)3 (θ = 109° [14]). This difference could mainly be due to a steric effect rather than an electronic one, when one compares such an effect in the two series of complexes implying, respectively, a bridging electron-withdrawing dithiolene ligand in 2 and 3, and the bridging phosphine oxide dithiolato moiety in [Fe2(CO)5(L){µ-(SCH2)2(Ph)P=O}] [13]. In the case of these latter complexes, the P=O bridging head of the dithiolate orientates in the opposite direction of the iron atom bearing the phosphane, thus allowing its apical position.
The Fe-Fe bond distances in complexes 2, and 3, 2.4834 (6) Å and 2.4772 (6) Å, respectively, are slightly shortened than that observed in their hexacarbonyl precursor 1 (2.4870 (19) Å [7]. A similar trend is observed for the two dithiolene compounds [Fe2(CO)6(µ-S2C2Ph2)] and [Fe2(CO)4{P(OMe)3}2(µ-S2C2Ph2)] for which the Fe-Fe distances are 2.4821(8) Å [9] and 2.4797 Å [10], respectively. In the case of the complexes [Fe2(CO)5(L){µ-(SCH2)2(Ph)P=O}], the distances Fe-Fe are 2.5148(9) Å, 2.5006 (14) Å and 2.5152 (8) Å when L = CO [16], PPh3 [13] and P(OEt)3 [13], respectively. It is obvious that the replacement of one carbonyl by various phosphanes affects the Fe-Fe bond lengths and could be tentatively related to their σ-electron-donor power (pKa(PPh3) = 2.73 and (pKa(P(OMe)3) = 2.6) [17]. On the other hand, it should also be noted that reverse effects on the Fe-Fe distance are observed for di-substituted derivatives in other close di-iron species, for example, the compounds [Fe2(CO)4L2(µ-bdtf] (bdtf = 3,4 dimercaptobenzaldehyde) (L = PPh3, P(OMe)3) [18]. This shows that such slight effects are the result of very fine electronic and steric balance depending on the nature of the thiolate bridge, the characteristics (θ, pKa) of the phosphanes, their number and the geometry of the considered isomer, rendering rationalization quite intricate. The Fe-C(O) and C-O bond lengths for 2 and 3, reported in Table S4, are very close and do not reflect noticeable changes of electron density at the iron core and electron back donation from the iron atom to carbonyl group when substituting PPh3 with P(OMe)3.
The structural analysis of 4 reveals a pentagonal geometry similar to that of the analogous compound [Fe(CO)(P(OMe)3)22-S2C2Ph2)] [10]. The dithiolene ligand adopts a bidentate geometry through the coordination of its two sulfur atoms. The coordination sphere of the iron atom is completed with one carbonyl and two P(OMe)3 ligands. An average value of the calculated Addison parameters of 0.84 indicates that 4 adopts a distorted trigonal-pyramid geometry [19].

3. Materials and Methods

All the experiments were carried out under an inert atmosphere, using Schlenk techniques for the syntheses. Solvents were deoxygenated and dried according to standard procedures. The literature method was used for the preparation of the starting compound [Fe2(CO)6}(µ-S2C2(CO2Me)2] (1) [8]. All other reagents were commercially available and used as purchased. NMR spectra (1H, 31P-{1H}) were recorded at room temperature with Bruker AMX 400 or AC 300 spectrometers (Billerica, MA, USA) of the “Service général des plateformes, Université de Bretagne Occidentale, Brest” and were referenced to SiMe4 (1H) and H3PO4 (31P). The infrared spectra were recorded with Bruker Vertex 70 and FT IR Perkin Elmer spectrum 2 spectrometer. In a typical experiment, single crystals of 2–4 were obtained from solutions prepared by solubilization of partially purified residues of 2–4 (10 mg), which were obtained after chromatography, in degassed diethyl ether (5 mL) in Schlenk tubes. These solutions were stored, at −15 °C, overnight or for several days. Crystal data of compounds 24 were collected with an Oxford Diffraction X—Calibur-2 CCD diffractometer, equipped with a jet cooler device and graphite-monochromated Mo-Kα radiation (λ = 0.71073 Å). The structures were solved and refined by standard procedures [20]. Deposition numbers CCDC 2277613, 2277614, and 2277616 contain the supplementary crystallographic data for 2, 3 and 4. These data can also be obtained free of charge from the Cambridge Crystallographic Data Centre via (accessed on 28 June 2023).

4. Conclusions

These preliminary results show that the formation of monosubstituted dithiolene complexes [Fe2(CO)5L(µ-S2C2(CO2Me)2)] (L = PPh3, and P(OMe)3) arises easily in mild reaction conditions, at room temperature in the presence of one equivalent of phosphane, while disubstituted species [Fe2(CO)4L2(µ-S2C2(CO2Me)2)] turn out to be more difficult to prepare because of the readily decomposition of the dinuclear entity, with an electron-withdrawing dithiolene group, into mononuclear species [Fe(CO)3−xLx(κ2-S2C2(CO2Me)2)] when harsher reaction conditions are set (thermolysis and an excess of phosphane). This suggests that photolytic or electrochemical activation could be more suitable than thermolysis for preparing polysubstituted dithiolene derivatives [Fe2(CO)6−xLx(µ-S2C2(CO2Me)2)] (x > 1).

Supplementary Materials

The following supporting information are available online, Table S1: Crystal data and structure refinement for complex 2; Table S2: Crystal data and structure refinement for complex 3; Table S3: Crystal data and structure refinement for complex 4; Table S4: Comparison of the Fe-C(O) and C-O bond lengths (Å) in complexes 2 and 3; Figure S1: IR spectrum in CH2Cl2 of 2 (carbonyl bands of 5 are overlapped); Figure S2: 1H NMR (CDCl3) mixture of 2 + 5: (a) aromatic and methyl groups chemical shifts region; (b) complete spectrum; Figure S3: 31P{1H} NMR (CDCl3) mixture of 2 + 5; Figure S4: IR spectrum in CH2Cl2 of 3; Figure S5: IR spectrum in CH2Cl2 of 6 (3 as impurity); Figure S6: 1H NMR (CDCl3) of 3: (a) methyl group chemical shift region; (b) complete spectrum; Figure S7: 31P{1H} NMR (CDCl3) of 3; Figure S8: 1H NMR (CDCl3) of 6: (a) methyl groups chemical shifts region; (b) complete spectrum; Figure S9: 31P{1H} NMR (CDCl3) of 3; Figure S10: IR spectrum in CH2Cl2 of 4; Figure S11: 31P{1H} NMR (CDCl3) of 4.

Author Contributions

M.K. prepared and characterized the compounds 14. P.S. supervised the syntheses and X-ray, spectroscopic characterizations. C.E., F.Y.P. and P.S. contributed to the writing of the manuscript. All authors have read and agreed to the published version of the manuscript.


This research received no external funding.

Data Availability Statement

Not applicable.


CNRS (Centre National de la Recherche Scientifique), the Université de Bretagne Occidentale, are acknowledged for financial support. We are grateful to Dr F. Michaud for the crystallographic measurements of 2, 3 and 4.

Conflicts of Interest

The authors declare no conflict of interest.

Appendix A

-Reaction of 1 with 1 equiv. of PPh3. To a solution of 1 (50 mg, 0.10 mmol) in THF (30 mL), 1 equiv. of PPh3 (27 mg, 0.10 mmol) and 1 equiv. of Me3NO·2H2O were added. The mixture was stirred at room temperature, and the progress of the reaction was monitored by IR until the ν(CO) bands of the starting complex 1 have totally disappeared (~6 h). After evaporation of the solvent, the residue was purified by chromatography on a silica gel column. An orange band was eluted with pure dichloromethane. Removal of volatiles afforded an orange powder (m = 45 mg). Analysis of CDCl3 solution of this solid by 1H and 31P-{1H} NMR spectroscopy indicated the presence of two products in the 2/1 ratio. The major compound was identified as a monosubstituted di-iron complex 2, while the minor one can be attributed to either a disubstituted di-iron or a mono-iron complex 5. Attempts to separate the two products by chromatography by varying the relative amounts of CH2Cl2-hexane eluents failed. Only crystals of the major complex 2 were grown from a diethyl ether solution of the mixture of the two products.
Complex 2: IR (CH2Cl2, cm−1): ν(CO) 2058 (s), 2002 (s), 1988 (m, sh), 1946 (w), 1719 (w, CO2Me). 1H NMR (CDCl3, δ, ppm): 7.68–7.36 (m, 15H, Ph), 3.48 (s, 6H, CO2Me). 31P-{1H} NMR (CDCl3, δ, ppm): 60.8 (s).
Complex 5: IR (CH2Cl2, cm−1): ν(CO), bands overlapped with those of 2. 1H NMR (CDCl3, δ, ppm): 7.68–7.36 (m, 30H, Ph), 3.17 (s, 6H, CH3). 31P-{1H} NMR (CDCl3, δ, ppm) 57.5 (s).
-Reaction of 1 with 1.2 equiv. P(OMe)3. To a THF (30 mL) solution of 1 (90 mg, 0.185 mmol), 1.2 equiv. of P(OMe)3 (0.025 mL, 0.222 mmol) and 1 equiv. of Me3NO. 2H2O were added. The mixture was stirred at room temperature for 12 h. After evaporation of the solvent, the residue was purified by chromatography on a silica gel column. Two bands were eluted with a dichloromethane-hexane-THF (90/5/5) mixture. The first eluted orange band gave, after evaporation of the volatiles, a quasi-pure solid 3 as the major product of the reaction (70 mg). A second eluted garnet-red band afforded a mixture of 3 and 6 in the ratio 1/24. Single crystals of 3, suitable for X-ray diffraction studies, were grown from a diethyl ether solution at −15 °C.
Complex 3: IR (CH2Cl2, cm−1): ν(CO) 2061 (s), 2008 (vs), 1989 (s), 1955 (w), 1717 (w, CO2Me). 1H NMR (CDCl3, δ, ppm): 3.80 (d, J = 12.0Hz, 9H, P(OMe)3), 3.66 (s, 6H, CO2Me). 31P-{1H} NMR (CDCl3, δ, ppm): 172.1 (s).
Complex 6: IR (CH2Cl2, cm−1):ν(CO) 2036 (s), 1988 (s). 1H NMR (CDCl3, δ, ppm): 3.93 (s, 6H, CO2Me), 3.45 (d, J = 12.0Hz, 9H, P(OMe)3). 31P-{1H} NMR (CDCl3, δ, ppm): 168.2 (s).
-Reaction of 1 with 3 equiv. of P(OMe)3. To a solution of 1 (93 mg, 0.191 mmol.) in THF (30 mL), 3 equiv. of P(OMe)3 (0.062 mL, 0.555 mmol) and 2 equiv. of Me3NO. 2H2O were added. The mixture was stirred under reflux condition for 2 hrs. After evaporation of the solvent, the residue was purified by chromatography on a silica gel column. A garnet-red main band was eluted with a CH2Cl2-hexane-THF mixture in the 90/5/5 ratio, affording after evaporation to dryness a powder (40 mg) that contains a mixture of 4 and 3 in a ratio 86/14 according to NMR analysis.
Complex 4: IR (CH2Cl2, cm−1): ν(CO) 1971 (vs), 1731 (w, CO2Me). 1H NMR (CDCl3, δ, ppm): 3.91 (s, 6H, CO2Me), 3.43 (m,18H, P(OMe)3). 31P-{1H} NMR (CDCl3, δ, ppm): 175.0 (s).


  1. Hogarth, G. An unexpected leading role for [Fe2(CO)6(μ-pdt)] in our understanding of [FeFe]-H2ases and the search for clean hydrogen production. Coord. Chem. Rev. 2023, 490, 215174. [Google Scholar] [CrossRef]
  2. Kleinhaus, J.T.; Wittkamp, F.; Yadav, S.; Siegmund, D.; Apfel, U.-P. [FeFe]-Hydrogenases: Maturation and reactivity of enzymatic systems and overview of biomimetic models. Chem. Soc. Rev. 2021, 50, 1668–1784. [Google Scholar] [CrossRef] [PubMed]
  3. Li, Y.; Rauchfuss, T.B. Synthesis of di-iron(I) dithiolato carbonyl complexes. Chem. Rev. 2016, 116, 7043–7077. [Google Scholar] [CrossRef] [PubMed]
  4. Apfel, U.-P.; Pétillon, F.Y.; Schollhammer, P.; Talarmin, J.; Weigand, W. Chapter 4 [FeFe] Hydrogenase Models an Overview. In Bioinspired Catalysis; Weigand, W., Schollhammer, P., Eds.; Wiley-VCH: Weinheim, Germany, 2015; pp. 79–103. ISBN 978-3-527-33308-0. [Google Scholar]
  5. Elleouet, C.; Pétillon, F.Y.; Schollhammer, P. Chapter 17 [FeFe]-Hydrogenases Models. In Advances in Bioorganometallic Chemistry; Hirao, T., Moriuchi, T., Eds.; Elsevier: Amsterdam, The Netherlands, 2019; pp. 347–364. [Google Scholar] [CrossRef]
  6. Elleouet, C.; Pétillon, F.Y.; Schollhammer, P. Role of a redox-active ligand close to a dinuclear activating framework. In Modes of Cooperative Effects in Dinuclear Complexes, 70; Kalck, P., Ed.; Topics in Organometallics Chemistry; Springer International Publishing: New York, NY, USA, 2022; pp. 99–156. [Google Scholar] [CrossRef]
  7. Charreteur, K.; Kdider, M.; Capon, J.-F.; Gloaguen, F.; Pétillon, F.Y.; Schollhammer, P.; Talarmin, J. Effect of electron-withdrawing dithiolate bridge on the electron-transfer steps in di-iron molecules related to [2Fe]H subsite of the [FeFe]-hydrogenases. Inorg. Chem. 2010, 49, 2496–2501. [Google Scholar] [CrossRef] [PubMed]
  8. Seyferth, D.; Henderson, R.S. Photochemically induced insertion of acetylenes into µ-dithiobis(tricarbonyliron). J. Organomet. Chem. 1979, 182, C39–C42. [Google Scholar] [CrossRef]
  9. Mousser, H.; Darchen, A.; Mousser, A. Unexpected fragmentation of phenyldithiobenzoate, formation and X-ray structure of [µ,η2(S,S)-1,2-(dithio)-1,2-(diphenylethylene)] di-iron hexacarbonyl complex. J. Organomet. Chem. 2010, 695, 786–791. [Google Scholar] [CrossRef]
  10. Boukrina Makouf, N.; Bouzidi Mousser, H.; Darchen, A.; Mousser, A. Carbon monoxide substitutions by trimethyl phosphite in di-iron dithiolate complex: Fe-Fe bond cleavage, selectivity of the substitutions, crystal structures and electrochemical studies. J. Organomet. Chem. 2018, 866, 35–42. [Google Scholar] [CrossRef]
  11. Adams, H.; Morris, M.J.; Robertson, C.C.; Tunnicliffe, H.C.I. Synthesis of mono- and di-iron dithiolene complexes as hydrogenase models by dithiolene transfer reactions, including the crystal structure of [{Ni(S2C2Ph2)}6]. Organometallics 2019, 38, 665–676. [Google Scholar] [CrossRef]
  12. Radu, L.-F.; Attia, A.A.A.; Silaghi-Dumitrescu, R.; Lupan, A. Binuclear ethylenedithiolate iron carbonyls: A density functional theory study. Inorg. Chim. Acta 2021, 519, 120260. [Google Scholar] [CrossRef]
  13. Almazahreh, L.R.; Imhof, W.; Talarmin, J.; Schollhammer, P.; Görls, H.; El-khateeb, M.; Weigand, W. Ligand Effects on the electrochemical behavior of [Fe2(CO)5(L){μ-(SCH2)2(Ph)P=O}] (L = PPh3, P(OEt)3) hydrogenase model complexes. Dalton Trans. 2015, 44, 7177–7199. [Google Scholar] [CrossRef] [PubMed]
  14. Tolman, C.A. Steric effects of phosphorus ligands in organometallic chemistry and homogeneous catalysis. Chem. Rev. 1977, 77, 313–348. [Google Scholar] [CrossRef]
  15. Tolman, C.A. Phosphorus ligand exchange equilibriums on zerovalent nickel. Dominant role for steric effects. J. Am. Chem. Soc. 1970, 92, 2956–2965. [Google Scholar] [CrossRef]
  16. Almazahreh, L.R.; Apfel, U.-P.; Imhof, W.; Rudolph, M.; Görls, H.; Talarmin, J.; Schollhammer, P.; El-khateeb, M.; Weigand, W. A novel [FeFe] hydrogenase model with a (SCH2)2P=O moiety. Organometallics 2013, 32, 4523–4530. [Google Scholar] [CrossRef]
  17. Rahman, M.-M.; Liu, H.-Y.; Eriks, K.; Prock, A.; Giering, W.P. Separation of phosphorus(III) ligands into pure σ-donors and σ-donor/π-acceptors: Comparison of basicity and donicity. Organometallics 1989, 8, 1–7. [Google Scholar] [CrossRef]
  18. Abul-Futouh, H.; Costabel, D.; Hotzel, K.; Liebing, P.; Görls, H.; Weigand, W.; Peneva, K. Mono- and di-substituted [FeFe]-hydrogenase H-cluster mimics bearing the 3,4-dimercaptobenzaldehyde bridge moiety: Insight into synthesis, characterization and electrochemical investigations. Inorg. Chim. Acta 2023, 551, 121469. [Google Scholar] [CrossRef]
  19. Addison, A.W.; Rao, T.N.; Reedijks, J.; van Rijn, J.; Vershoor, G.C. Synthesis, structure, and spectroscopic properties of copper(II) compounds containing nitrogen–sulphur donor ligands; the crystal and molecular structure of aqua[1,7-bis(N-methylbenzimidazol-2′-yl)-2,6-dithiaheptane]copper(II) perchlorate. J. Chem. Soc. Dalton Trans. 1984, 7, 1349–1356. [Google Scholar] [CrossRef]
  20. Farrugia, L.J. WinGX suite for smallmolecule single-crystal crystallography. J. Appl. Crystallogr. 1999, 32, 837–838. [Google Scholar] [CrossRef]
Scheme 1. Representation of the H-cluster (a) and a dinuclear carbonyl alkenedithiolate complex (b).
Scheme 1. Representation of the H-cluster (a) and a dinuclear carbonyl alkenedithiolate complex (b).
Molbank 2023 m1719 sch001
Scheme 2. Reactivity of 1 towards PPh3 (a) and P(OMe)3 (b,c). The ratios given for complexes have been determined by NMR and correspond to those of the major fractions collected after purification by chromatography.
Scheme 2. Reactivity of 1 towards PPh3 (a) and P(OMe)3 (b,c). The ratios given for complexes have been determined by NMR and correspond to those of the major fractions collected after purification by chromatography.
Molbank 2023 m1719 sch002
Scheme 3. Proposed geometries for 5 and 6 on the basis of their spectroscopic data.
Scheme 3. Proposed geometries for 5 and 6 on the basis of their spectroscopic data.
Molbank 2023 m1719 sch003
Figure 1. Molecular structure of compounds 2, 3 and 4 with thermal ellipsoids at 30% probability.
Figure 1. Molecular structure of compounds 2, 3 and 4 with thermal ellipsoids at 30% probability.
Molbank 2023 m1719 g001
Table 1. Selected bond lengths (Å) and angles (°) of 24.
Table 1. Selected bond lengths (Å) and angles (°) of 24.
Fe(1)-Fe(2)2.4834 (6)2.4772 (6)
P(1)-Fe(1)2.2496 (8)2.1651 (9)2.1621 (9)
P(2)-Fe(1) 2.1214 (9)
S(1)-Fe(1)2.2852 (8)2.2762 (9)2.1762 (8)
S(1)-Fe(2)2.2886 (8)2.2908 (9)
S(2)-Fe(1)2.2872 (8)2.2810 (9)2.1983 (8)
S(2)-Fe(2)2.2742 (8)2.2667 (9)
C(1)-Fe(1)1.771 (3)1.786 (4)1.768 (3)
C(2/3)-Fe(1)1.769 (3)1.778 (4)
C(4)-Fe(2)1.794 (3)1.789 (3)
C(5)-Fe(2)1.776 (3)1.793 (3)
C(6)-Fe(2)1.812 (3)1.811 (3)
C(7)-C(8)1.323 (4)1.329 (4)1.354 (4)
Fe(1)-S(1)-Fe(2)65.77 (2)65.69 (3)
Fe(1)-S(2)-Fe(2)65.97 (2)66.01 (3)
C(1)-Fe(1)-S(1)90.95 (9)90.42 (11)
C(1)-Fe(1)-S(2)161.07 (10)163.16 (12)170.23 (10)
C(2/3)-Fe(1)-S(1)156.84 (10)105.76 (12)
P(1)-Fe(1)-S(1)106.47 (3)156.95 (4)151.49 (4)
P(2)-Fe(1)-S(1) 116.47 (4)
P(1)-Fe(1)-S(2)102.98 (3)95.07 (3)
P(2)-Fe(1)-S(2) 96.24 (3)
P(1)-Fe(1)-C(1)95.94 (10)87.60 (11)90.95 (11)
P(2)-Fe(1)-C(1) 93.47 (10)
P(1)-Fe(1)-C(2/3)96.26 (9)97.27 (12)
P(1)-Fe(1)-P(2) 93.98 (3)
C(1)-Fe(1)-C(2/3)91.30 (3)97.09 (17)
S(1)-Fe(1)-S(2)79.80 (9)80.62 (3)
C(4)-Fe(2)-C(5)91.19 (13)90.11 (14)
C(4)-Fe(2)-S(1)91.50 (9)92.81 (10)
C(4)-Fe(2)-S(2)154.58 (10)146.25 (11)
C(5)-Fe(2)-S(1)159.48 (11)164.82 (11)
C(5)-Fe(2)-S(2)88.98 (9)88.71 (11)
C(6)-Fe(2)-Fe(1)149.44 (10)148.77 (11)
P(1)/C(3)-Fe(1)-Fe(2)153.93 (3)150.45 (12)
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Kdider, M.; Elleouet, C.; Pétillon, F.Y.; Schollhammer, P. Mono- and Dinuclear Carbonyl Dithiolene Complexes Related to the [FeFe]-Hydrogenases. Molbank 2023, 2023, M1719.

AMA Style

Kdider M, Elleouet C, Pétillon FY, Schollhammer P. Mono- and Dinuclear Carbonyl Dithiolene Complexes Related to the [FeFe]-Hydrogenases. Molbank. 2023; 2023(3):M1719.

Chicago/Turabian Style

Kdider, Mohamed, Catherine Elleouet, François Y. Pétillon, and Philippe Schollhammer. 2023. "Mono- and Dinuclear Carbonyl Dithiolene Complexes Related to the [FeFe]-Hydrogenases" Molbank 2023, no. 3: M1719.

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop