Reactivity of [Fe2(CO)6(μ-S2)] toward a base-containing diphosphine (Ph2PCH2)2NCH 3: Formation of diiron carbonyl compounds having polydentate heterofunctionalized phosphine (PNS = Ph2PCH2N(CH 3)CH2S) and bidentate thiophosphinito (Ph2PS = PS) bridges

Article abstract of DOI:10.1021/om9011054

Reaction of the base-containing diphosphine (Ph₂PCH ₂)₂NCH₃ with [Fe₂(CO) ₆(μ-S₂)] (1) yielded at room temperature the novel compound [Fe₂(CO)₄(μ-k¹:k ¹-SPPh₂){μ-k²:k²-SCH ₂N(Me)CH₂PPh₂)] (2) resulting from S-S and P-C bond cleavage concomitant with P-S and C-S bond formation. Experiments at low temperature allowed the isolation of an intermediate species, [Fe ₂(CO)₅(μ-k¹:k¹-SPPh ₂){μ-k²:k¹-SCH₂N(Me)CH ₂PPh₂)] (3), differing from 2 by the coordination mode of the PNS ligand and the presence of one additional carbonyl group. When the reaction was performed in the presence of an excess of tBuNC, an analogous compound of 3 was obtained. The X-ray analysis of this species, 4, revealed that an isocyanide replaced a carbonyl ligand in the axial position at one iron center.

Full text of DOI:10.1021/om9011054

1296 Organometallics 2010, 29, 1296–1301
DOI: 10.1021/om9011054
Reactivity of [Fe2(CO)6(μ-S2)] toward a Base-Containing Diphosphine
(Ph2PCH2)2NCH3: Formation of Diiron Carbonyl Compounds Having
Polydentate Heterofunctionalized Phosphine
(PNS = Ph2PCH2N(CH3)CH2S) and Bidentate Thiophosphinito
(Ph2PS = PS) Bridges
‡
Sondes Lounissi, Jean-Franc-ois Capon, Frederic Gloaguen, Fatma Matoussi,
†
†
‡
ꢀ
ꢁ ꢁ
Franc-ois Y. Petillon, Philippe Schollhammer,* and Jean Talarmin
†
,†
†
ꢁ
†UniversiteꢁEuropeꢁenne de Bretagne, France, and CNRS, UMR 6521 “Chimie, Electrochimie Moleꢁculaires et
‡
Chimie Analytique”, ISSTB, CS 93837, Universite de Brest, 29238 Brest-Cedex 3, France, and Departement
ꢁ
de Chimie, Faculte des Sciences de Tunis, Campus Universitaire, 2092, Tunis, Tunisia
ꢁ
ꢁ
Received December 22, 2009
Reaction of the base-containing diphosphine (Ph2PCH2)2NCH3 with [Fe2(CO)6(μ-S2)] (1) yielded
at room temperature the novel compound [Fe2(CO)4(μ-κ1:κ1-SPPh2){μ-κ2:κ2-SCH2N(Me)CH2-
PPh2}] (2) resulting from S-S and P-C bond cleavage concomitant with P-S and C-S bond forma-
tion. Experiments at low temperature allowed the isolation of an intermediate species, [Fe2(CO)5-
(μ-κ1:κ1-SPPh2){μ-κ2:κ1-SCH2N(Me)CH2PPh2}] (3), differing from 2 by the coordination mode of
the PNS ligand and the presence of one additional carbonyl group. When the reaction was performed
in the presence of an excess of tBuNC, an analogous compound of 3 was obtained. The X-ray analysis
of this species, 4, revealed that an isocyanide replaced a carbonyl ligand in the axial position at one
iron center.
Introduction
[Fe2(CO)6(μ-S2)] (1)3 is one of the major precursors of
bioinspired models of the H-cluster because it allows obtain-
ing easily functionalized dithiolate (aza- and oxa-dithiolate)
diiron molecules.4
It is well known that the chemical activity of 1 is mainly
centered on the dithio bridge. In the presence of reducing
reagents, such as LiBHEt3, the single S-S bond is broken,
giving a bridging disulfido species that could be protonated
at the sulfur atoms to afford a dihydrosulfido compound
(Scheme 1).5
In the continuity of our work concerning the use of
bidentate ligands, such as diphosphine, phenanthroline,
and N-heterocyclic carbene, in diiron molecules having a
propane- or aza-dithiolate bridge,6 we have explored the
reactivity of the dithio precursor 1 toward diphosphine in
view to synthesize novel dissymmetrically substituted diiron
systems containing a simple dithio functionality as a bridge.
In quest for [2Fe2S] or [2Fe3S] electrocatalyst species,
bioinspired by the active site of [FeFe]-hydrogenases, for
the reduction of protons to dihydrogen, the chemistry of
organometallic carbonyl diiron molecules with a sulfur en-
vironment has been widely investigated during the past
decade.1 The recent and fast advances in the understanding
of the functioning of the active site of [FeFe]-hydrogenases
have been possible because of the numerous and systematic
studies concerning bis-thiolate hexacarbonyl diiron chemis-
try that have been performed during the last forty years.2 In
this context, the μ-dithio-bis(tricarbonyl iron) complex
*Corresponding author. E-mail: schollha@univ-brest.fr.
ꢁ
(1) See for example: (a) Capon, J.-F.; Gloaguen, F.; Petillon, F. Y.;
Schollhammer, P.; Talarmin, J. Coord. Chem. Rev. 2009, 253, 1476–
1494. (b) Tard, C.; Pickett, C. J. Chem. Rev. 2009, 109, 2245–2274.
(c) Gloaguen, F.; Rauchfuss, T. B. Chem. Soc. Rev. 2009, 38, 100–108.
(d) Felton, G. A. N.; Mebi, C. A.; Petro, B. J.; Vannucci, A. K.; Evans, D. H.;
Glass, R. S.; Lichtenberger, D. L. J. Organomet. Chem. 2009, 694, 2681–
(5) Seyferth, D.; Womack, G. B.; Henderson, R. S.; Cowie, M.;
Hames, B. W. Organometallics 1986, 5, 1568–1575.
(6) (a) Ezzaher, S.; Capon, J.-F.; Gloaguen, F.; Petillon, F. Y.;
ꢁ
ꢁ
2699. (e) Capon, J.-F.; Gloaguen, F.; Petillon, F. Y.; Schollhammer, P.;
Talarmin, J. C. R. Chim. 2008, 11, 842–851. (f) Capon, J.-F.; Gloaguen,
Schollhammer, P.; Talarmin, J. Inorg. Chem. 2007, 46, 9863–9872.
ꢁ
ꢁ
F.; Petillon, F. Y.; Schollhammer, P.; Talarmin, J. Eur. J. Inorg. Chem. 2008,
(b) Ezzaher, S.; Capon, J.-F.; Gloaguen, F.; Petillon, F. Y.; Schollhammer,
4671–4681.
P.; Talarmin, J.; Pichon, R.; Kervarec, N. C. R. Chim. 2008, 11, 906–914.
ꢁ
(2) (a) King, R. B.; Bitterwolf, T. E. Coord. Chem. Rev. 2000,
206-207, 563–579. (b) Song, L.-C. Acc. Chem. Res. 2005, 38, 21–28.
(3) Seyferth, D.; Henderson, R. S.; Song, L.-C. Organometallics 1982,
1, 125–133.
(c) Morvan, D.; Capon, J.-F.; Gloaguen, F.; Petillon, F. Y.; Schollhammer, P.;
Talarmin, J.; Yaouanc, J.-J; Michaud, F.; Kervarec, N. J. Organomet. Chem.
2009, 694, 2801–2807. (d) Ezzaher, S.; Capon, J.-F.; Dumontet, N.;
ꢁ
Gloaguen, F.; Petillon, F. Y.; Schollhammer, P.; Talarmin, J. J. Electroanal.
ꢁ
(4) (a) Lawrence, J. D.; Li, H.; Rauchfuss, T. B.; Benard, M.; Rohmer,
Chem. 2009, 626, 161–170. (e) Ezzaher, S.; Orain, P.-Y.; Capon, J.-F.;
ꢁ
M.-M. Angew. Chem., Int. Ed. 2001, 40, 1768–1771. (b) Lawrence, J. D.; Li,
H.; Rauchfuss, T. B. Chem. Commun. 2001, 1482–1483. (c) Song, L.-C.;
Yang, Z.-Y.; Bian, H.-Z.; Liu, Y.; Wang, H.-T.; Liu, X.-F.; Hu, Q.-M.
Organometallics 2005, 24, 6126–6135.
Gloaguen, F.; Petillon, F. Y.; Roisnel, T.; Schollhammer, P.; Talarmin, J.
Chem. Commun. 2008, 2547–2549. (f) Ezzaher, S.; Capon, J.-F.; Gloaguen,
F.; Petillon, F. Y.; Schollhammer, P.; Talarmin, J.; Kervarec, N. Inorg. Chem.
ꢁ
2009, 48, 2–4.
r
pubs.acs.org/Organometallics
Published on Web 02/03/2010
2010 American Chemical Society

Article
Organometallics, Vol. 29, No. 5, 2010 1297
Scheme 1
Scheme 2
We report here the reaction of the complex [Fe2(CO)6-
isostructural with rare complexes having a butterfly {Fe2(μ-
SR)(μ-μ-κ1:κ1-SPPh2)} core with triangular Fe2P and tetra-
gonal Fe2P2 wings, recently reported by Song et al and which
are obtained through the reaction of the S-centered anion
[Fe2(CO)6(μ-SR)(μ-S)]- with Ph2PCl.8 The geometry around
each iron atom could be described as a distorted trigonal bi-
(μ-S2)] (1) with the base-containing diphosphine (Ph2PCH2)2-
NCH3 that leads to the formation of novel compounds
featuring a bridging polydentate heterofunctionalized phos-
phine (PNS=Ph2PCH2N(CH3)CH2S) and a bidentate thio-
phosphinito μ-Ph2PS group.
˚
pyramid supplemented by a Fe-Fe single bond (2.6315(7) A),
Results and Discussion
two carbonyl groups, and a bridging sulfur atom of the PNS
group lying in the equatorial plane. The major structural
features of2 are the bridging bidentate thiophosphinito Ph2PS
group and the new polydentate heterofunctionalized phos-
phine Ph2PCH2N(CH3)CH2S ligand, which are coordinated
to the diiron site in a μ-κ1:κ1 and μ-κ2:κ2 fashion, respectively.
The six-membered heterometallacycle {FePCNCS} adopts a
chair conformation that is constrained due to the coordina-
tion of the nitrogen atom to the second iron center.
The reaction of [Fe2(CO)6(μ-S2)] (1) with 1 equiv of
(Ph2PCH2)2NCH3 was performed in CH2Cl2 at 20 °C. IR
and 31P{1H} NMR monitoring revealed that 1 is readily
transformed within l h. The 31P{1H} NMR spectrum of the
solution indicates a mixture of three compounds (2, 3,
and 30), each of them characterized by a doublet of doublets
with coupling constants lower than 8 Hz (Figure 1). A
prolonged 31P{1H} NMR monitoring for several hours
showed the gradual disappearance of signals of 3 and 30 over
time. After 36 h, only the phosphorus signals of 2 were
detected. The synthesis of 2 can also be carried out by heating
the reaction mixture in toluene at 50 °C for 4 h. After
crystallization in CH2Cl2-hexane, 2 was obtained pure as
an orange powder with moderate yields (60%). The IR
spectrum of 2 in CH2Cl2 displays four strong bands at
In order to identify the kinetic products of the reaction,
3 and 30, the reaction between 1 and 1 equiv of (Ph2PCH2)2-
NCH3 was realized in CH2Cl2 at low temperature (-45 °C).
After 15 min of stirring, the red solution was evaporated,
giving a red powder. 31P{1H} NMR of a CDCl3 solution of
this powder indicates only the presence of the two expected
species 3 and 30, with a ratio of 80:20. The 1H NMR spectrum
of this mixture in CDCl3 indicates that each of these species is
characterized by a set of signals similar to that observed for 2,
which can be assigned to C6H5, CH2, and CH3 groups with
the expected ratio 20H/4ꢀ1H/3H, suggesting that the struc-
tures of these three compounds are very close. The cooling
at -20 °C of a solution of 3-30 in dichloromethane-hexane
(1:1) afforded single crystals that were analyzed by X-ray
diffraction and assigned arbitrarily to 3. The analysis re-
vealed that the main difference between the structures of 2
and 3 is the coordination of the PNS ligand that is now
bound to the diiron site through the bridging sulfur atom and
the PPh2 group in a μ-κ2:κ1 fashion (Figure 3).
1
1991, 1952, 1926, and 1897 cm-1 in the ν(CO) region. H
NMR shows the signals of phenyl and methyl groups at the
expected chemical shifts with a ratio of 20:3. Each proton of
the methylene groups of the diphosphine (Ph2PCH2)2NCH3
appears as a multiplet between 5 and 2 ppm. The 31P{1H}
NMR indicates that the two phosphorus atoms are inequi-
valent and the coupling constant JPP of 7.3 Hz does not
accord with that of a typical chelated diphosphine at one iron
center.6a
These spectroscopic data are compatible with the results of
a single-crystal X-ray diffraction study of 2. Single crystals of
2 were obtained at -20 °C from a dichloromethane-hexane
(1:1) solution. Their X-ray analysis reveals that the S-S
bond in 1 and one P-C bond in the diphosphine have been
cleaved with concomitant formation of P-S and S-C
bonds, giving the two bridging Ph2PS (PS) and Ph2PCH2N-
(CH3)CH2S (PNS) ligands (Figure 2). Relatively facile P-C
cleavage at diiron centers has been previously reported.7 2 is
(7) Doherty, N. C.; Hogarth, G.; Knox, S. A. R.; Macpherson, K. A.;
Melchior, F.; Morton, D. A. V.; Orpen, A. G. Inorg. Chim. Acta 1992,
198-200, 257–270.
(8) (a) Song, L.-C.; Zeng, G.-H.; Lou, S.-X.; Zan, H.-N.; Ming, J.-B.;
Hu, Q.-M. Organometallics 2008, 27, 3714–3721. (b) Song, L.-C.; Zeng,
G.-H.; Hu, Q.-M.; Ge, J.-H.; Lou, S.-X. Organometallics 2005, 24, 16–19.

1298 Organometallics, Vol. 29, No. 5, 2010
Lounissi et al.
Figure 1. P{1H} NMR spectrum (in CDCl3) of a mixture of 2, 3, and 30 (4 and *) arising from the reaction of [Fe2(CO)6(μ-S2)] (1) with
31
1 equiv of (Ph2PCH2)2NCH3 in CH2Cl2 at 20 °C.
functionality is not coordinated (Figure 3), and the metalla-
cycle adopts the favored chair conformation with the methyl
group in equatorial position. This structure suggests that the
transformation of 3 into 2 consists in the replacement of one
carbonyl group by the amine functionality of the PNS group
(Scheme 3). We tentatively assign 30 to an isomer that may
differ by the coordination of the PPh2 group in an axial
position as depicted in Scheme 3. According to our experi-
mental results, it was not possible to specify whether 3 or 30 is
the major or the minor product of this mixture. The 31P{1H}
NMR spectrum of a sample, in CDCl3, of 3-30 stored as a
powder at -20 °C during one month indicates the presence of
2 in the mixture. This reveals that even in these conditions
of storage the decarbonylation process occurs. Such a trans-
formation of 3-30 into 2 was confirmed on stirring a
dichloromethane solution of a mixture of 3-30 for a few
hours at room temperature, as shown in Scheme 3.
The reaction of 1 with (Ph2PCH2)2NCH3 in CH2Cl2 at
room temperature was also performed in the presence of
tBuNC in the hope of isolating stable analogues of 3-30, by
replacing a carbonyl group by the more electron-donating
isocyanide ligand. Such substitutions were previously in-
volved when phosphine ligands react with [Fe2(CO)6(μ-
X2)] (X = S, Se) complexes to lead to mono- and disubsti-
tuted derivatives [Fe2(CO)6-xLx(μ-X2)] (x=1, 2).9 A mixture
of 2, 3-30, and new compounds 4-40 was obtained according
to NMR analysis. The 31P{1H} NMR spectrum of a solution
of this mixture in CDCl3 displays two novel sets of two
Figure 2. View of the molecule of [Fe2(CO)4{μ-κ1:κ1-SPPh2)(μ-
apparent singlets (at 85.5 and 50.0 ppm for the major
κ2:κ2-SCH2N(Me)CH2PPh2}] (2 2CH2Cl2) showing 50% prob-
ability ellipsoids. CH2Cl2 molecules are omitted for clarity.
3
product and 79.4 and 54.7 ppm for the minor one, with a
ratio of 60:40), which were assigned to compounds 4 and 40.
1H NMR data of these species could not be assigned with a
sufficient accuracy to report them. It was not possible to
separate satisfactorily all products by chromatography on
silica gel. The cooling at -30 °C of the reaction solution in
dichloromethane after addition of hexane afforded single
˚
Selected bond lengths (A) and angles (deg): Fe1-Fe2,
2.6315(7); Fe1-S1, 2.2697(9); Fe2-S1, 2.2633(10); Fe1-S2,
2.3541(10); Fe2-P2, 2.2035(10); Fe1-P1, 2.1738(10); P2-S2,
2.0393(12); Fe2-N1, 2.093(3); C51-S1, 1.827(4); Fe2-S1-
Fe1, 70.97(3); P2-S2-Fe1, 88.46(4); S2-P2-Fe2, 104.58(5).
It has to be pointed out that the PPh2 group of the
PNS ligand lies in the equatorial plane instead of the axial
position. An additionnal carbonyl ligand completes the
coordination sphere of the iron atom at which the amine
(9) (a) Rossetti, R.; Gervasio, G.; Stanghellini, P. L. Inorg. Chim.
Acta 1979, 35, 73–78. (b) Aime, S.; Gervasio, G.; Rossetti, R.; Stanghellini,
P. L. Inorg. Chim. Acta 1980, 40, 131–140.

Article
Organometallics, Vol. 29, No. 5, 2010 1299
Figure 3. View of the molecule of [Fe2(CO)5(μ-κ1:κ1-SPPh2){μ-κ2:κ1-SCH2N(Me)CH2PPh2}] (3 CH2Cl2) showing 50% probability
3
˚
ellipsoids. CH2Cl2 is omitted for clarity. Selected bond lengths (A) and angles (deg): Fe1-Fe2, 2.6569(6); Fe1-S1, 2.2349(9); Fe2-S1,
2.2629(9); Fe1-S2, 2.3640(9); Fe2-P2, 2.2644(9); Fe1-P1, 2.2074(9); P2-S2, 2.0368(11); C51-S1, 1.828(3); Fe2-S1-Fe1, 72.41(3);
P2-S2-Fe1, 88.62(4); S2-P2-Fe2, 106.06(4).
Scheme 3
crystals of 4. The X-ray analysis revealed that 4 has a
structure similar to that of 3 with a six-membered metalla-
cycle {FePCNCS} in a chair conformation, which is coordi-
nated to the diiron core in a μ-κ2:κ1 fashion through sulfur
and phosphorus atoms. The tBuNC ligand replaces a carbo-
nyl group in an axial position at one iron atom (Figure 4).
The IR spectrum of a solution of these single crystals in
dichloromethane displays a ν(CN) band at 2147 cm-1 and
three strong ν(CO) bands at 1990, 1952, and 1916 cm-1. No
replacement of one carbonyl group with an isocyanide in 1 or
2 was observed in the same experimental conditions. This
suggests that 3 and 30 are the precursors of the isocyanide
compounds 4 and 40, as summarized in Scheme 4. As we did
for 3 and 30, we propose that 4 and 40 are two isomers
differing by the equatorial or axial position of the PPh2
group of the metallacycle as depicted in Scheme 4, but their
difference could also be related to equatorial or axial co-
ordination of the tBuNC ligand.
its structure has never been reported. 5 could be obtained
by sulfurization of the diphosphine due to either partial
decomposition of 1 or the presence of sulfur-containing
impurities in the reactional mixture. NMR data of 5 in
CDCl3 were similar to those of a sample obtained by
straigthforward reaction of the diphosphine with sulfur.
The signal of the two equivalent phosphorus atoms is
observed as a singlet at 35.6 ppm in the 31P{1H} NMR
spectrum (CDCl3). A 1H NMR recording shows typical
signals of C6H5, CH2, and CH3 groups (see experimental
data).
Conclusion
Novel diiron complexes with polydentate heterofunctio-
nalized (PNS) phosphine and bidentate thiophosphinito
ligands have been obtained from the reaction of [Fe2(CO)6-
(μ-S2)] (1) with the base-containing diphosphine (Ph2-
PCH2)2NCH3. Unfortunately, their unstability in acidic
media and reducing conditions limits their use as electro-
catalysts for the reduction of protons. Use of robust chelating
ligands with a lower affinity toward sulfur such as 1,10-
phenanthroline and other cyclic base-containing dipho-
sphines is now under investigation.
It has to be pointed out that single crystals of a side pro-
duct were obtained in some crystallization attempts. Their
X-ray analysis revealed that the diphosphine disulfide mo-
lecule, {Ph2P(S)CH2}2NMe (5) (see Figure 5 in Supporting
Information), is formed in some experiments. The formation
of 5 is not uncommon, but to the best of our knowledge

1300 Organometallics, Vol. 29, No. 5, 2010
Lounissi et al.
Figure 4. View of the molecule of [Fe2(CO)4(tBuNC)(μ-κ2:κ1-SPPh2){μ-κ2:κ1-SCH2N(Me)CH2PPh2}] (4 C6H14) showing 50%
3
˚
probability ellipsoids. Hexane is omitted for clarity. Selected bond lengths (A) and angles (deg): Fe1-Fe2, 2.6350(10); Fe1-S1,
2.2501(14); Fe2-S1, 2.2583(14); Fe1-S2, 2.3534(14); Fe2-P2, 2.2384(14); Fe1-P1, 2.2067(15); P2-S2, 2.0449(17); C51-S1, 1.824(5);
Fe2-C65, 1.886(6); C65-N60, 1.139(6); Fe2-S1-Fe1, 71.53(4); P2-S2-Fe1, 88.98(6); S2-P2-Fe2, 105.78(7).
Scheme 4
suppliers and used as received. The NMR spectra (1H, 31P) were
recorded at room temperature in CDCl3 solution with Bruker
DRX 500, Bruker AMX 400, or AC300 spectrometers and were
referenced to SiMe4 (1H) and H3PO4 (31P). The infrared spectra
were recorded on a Nicolet Nexus Fourier transform spectro-
meter. Chemical analyses were made by the Service de Micro-
analyses ICSN, Gif sur Yvette, France.
Crystal data (Table 1) for compounds 2, 3, 4, and 5 were
collected on a Oxford Diffraction X-Calibur-2 CCD diffract-
ometer, equipped with a jet cooler device and graphite-mono-
˚
chromated Mo KR radiation (R = 0.71073 A). The structures
were solved and refined by standard procedures.11
Preparation of 2. In a 250 mL round-bottom flask, 250 mg
(0.73 ꢀ 10-3 mol) of [Fe2(CO)6(μ-S2)] (1) was reacted with 1
equiv of PNP (320 mg) in toluene (50 mL) at 50 °C for 4 h. The
solvent was then evaporated to dryness under vacuum, and
the residue was solubilized in dichloromethane-hexane (1:1).
After overnight crystallization at -20 °C, 2 was obtained as
orange crystals (yield: 315 mg, 60%). Data for 2 are as follows. IR
1
(CH2Cl2, cm-1): ν(CO) 1991(s), 1952(vs), 1926(s), 1897(s). H
NMR (CDCl3, 25 °C): δ 7.97-7.21 (m, 20H, C6H5), ({4.60 (m,
1H), 3.46 (m, 1H), 2.87 (m, 1H), 2.47 (m, 1H)}, PCH2NCH2S),
2.64(s, 3H, NCH3). 31P{1H} NMR(CDCl3, 25 °C): δ 82.0 (d, J =
7.3 Hz), 80.1 (d, J = 7.3 Hz). Anal. Calcd for C31H27Fe2NO4-
P2S2 1.5CH2Cl2: C, 46.32; H, 3.58; N, 1.66. Found: C, 46.36; H,
3.81; N, 1.56.
Experimental Section
3
Preparation of 3-30. A 200 mg (0.58 10-3 mol) portion of 1
was reacted with 1 equiv of PNP (320 mg) in CH2Cl2 (5 mL)
at -45 °C for 15 mn. The orange solution turned readily to red.
The solvent was then evaporated to dryness under vacuum, and
the residue was solubilized in dichloromethane-hexane (1:1).
After overnight crystallization at -20 °C, 3-30 were obtained as
General Procedures. All the experiments were carried out
under an inert atmosphere, using Schlenk techniques. Solvents
were distilled immediately before use under nitrogen from
appropriate drying agents. [Fe2(CO)6(μ-S2)]3 and (Ph2PCH2)2-
NCH3 (PNP)10 were prepared according to reported procedures.
Other reagents were purchased from the usual commercial
(10) Curtis, C. J.; Miedaner, A.; Ciancanelli, R.; Ellis, W. W.; Noll, B.
C.; Rakowski Dubois, M.; Dubois, D. L. Inorg. Chem. 2003, 42, 216–
227.
(11) Programs used: (a) Sheldrick, G. M. SHELX 97; University of
€
Gottingen: Germany, 1998. (b) Farrugia, L. J. WinGX-AWindows Program
for Crystal Analysis. J. Appl. Crystallogr. 1999, 32, 837.

Article
Organometallics, Vol. 29, No. 5, 2010 1301
Table 1. Crystallographic Data for Complexes 2, 3, 4, and 5
2 2CH2Cl2
3
3 CH2Cl2
3
4 C6H14
3
5
empirical formula
fw
C33H31Cl4Fe2NO4P2S2
885.15
170(2)
monoclinic
P21/c
16.5283(8)
14.1976(5)
17.4895(8)
C33H29Cl2Fe2NO5P2S2
828.23
170(2)
orthorhombic
Pbca
15.9177(4)
17.2413(5)
25.6580(7)
C42H50Fe2N2O4P2S2
884.60
170(2)
monoclinic
P21/n
19.1289(10)
9.3337(4)
25.7957(13)
C27H27NP2S2
491.56
170(2)
monoclinic
P21/c
15.3111(8)
7.7994(4)
21.3862(12)
temperature/K
cryst syst
space group
˚
a (A)
˚
b (A)
˚
c (A)
R (deg)
β (deg)
γ (deg)
V (A )
Z
114.527(6)
106.165
103.533(6)
3
˚
3733.8(3)
4
1.575
7041.6(3)
8
1.562
4423.6(4)
4
1.328
4
1.315
0.359
0.39 ꢀ 0.22 ꢀ 0.08
2.74-28.28
21 306
F
calc (Mg mm-3
)
μ (mm-1
cryst size (mm)
)
1.299
1.227
0.863
0.26 ꢀ 0.13 ꢀ 0.02
2.56-26.37
28 168
0.25 ꢀ 0.14 ꢀ 0.11
2.49-26.37
51 898
0.18 ꢀ 0.10 ꢀ 0.05
2.45-24.71
28 904
0.1154
7526
range of θ (deg)
reflns measd
Rint
unique data/params
R1 [I > 2σ(I)]
R1 (all data)
0.0634
0.0662
0.0360
7619/441
0.0429
0.0896
7197/425
0.0344
0.0720
6145/290
0.0427
0.0784
0.0479
0.1248
wR2 (all data)
goodness of-fit on F2
0.1022
0.950
0.695, -0.569
0.0953
1.015
0.633, -0.456
0.1065
0.889
0.453, -0.333
0.1168
0.967
0.600, -0.470
-3
˚
ΔFmax, ΔFmin (e A
)
red crystals (yield: 280 mg, 65%). Data for 3-30 are as follows.
IR (CH2Cl2, cm-1): ν(CO) 2032(s), 1980(s), 1969(sh). Major
product (80%) 1H NMR (CDCl3, 25 °C): δ 7.92-7.23 (m, 20H,
C6H5), ({4.58 (m, 1H), 3.97 (m, 1H), 3.56 (m, 1H), 2.96 (m, 1H)},
PCH2NCH2S), 2.70 (s, 3H, NCH3). 31P{1H} NMR (CDCl3,
25 °C): δ 73.9 (d, J = 4.6 Hz), 60.0 (d, J = 4.6 Hz). Minor
product (20%) 1H NMR (CDCl3, 25 °C): δ 7.92-7.23 (m, 20H,
C6H5), ({4.75 (m, 1H), 3.99 (m, 1H), 3.55 (m, 1H), 2.90 (m, 1H)},
PCH2NCH2S), 2.50 (s, 3H, NCH3). 31P{1H} NMR (CDCl3,
25 °C): δ 78.7 (d, J = 4.4 Hz), 56.5 (d, J = 4.4 Hz).
Reaction of 1 with (Ph2PCH2)2NCH3 in the Presence of
tBuNC. A typical procedure was used: 300 mg (0.87 ꢀ 10-3
mol) of 1 was reacted with 1 equiv of PNP (480 mg) in CH2Cl2
(10 mL) in the presence of an excess of tBuNC (300 μL, 4 equiv)
for 3 h at room temperature. The solution was then evaporated
to dryness under vacuum to give a red residue, which was
analyzed without any further purification. Attempts to purify
products of the reaction were performed by crystallization in
dichloromethane-hexane (1:1) and did not give satisfactory
separation. Data for 5 are as follows. 1H NMR (CDCl3, 25 °C):
δ 7.83-7.39 (m, 20H, C6H5), 4.03 (s, 4H, CH2), 2.48 (s, 3H,
NCH3). 31P{1H} NMR (CDCl3, 25 °C): δ 35.6 (s).
Acknowledgment. We are grateful to Dr. F. Michaud
for the crystallographic measurements of 2, 3, 4, and 5. We
thank the CNRS and the University of Bretagne Occiden-
ꢀ
talefor financialsupport. TheMinistere de l’Enseignement
Superieur, de la Recherche Scientifique et de la Technolo-
ꢁ
gie of Tunisia is acknowledged for funding (S.L.).
Supporting Information Available: CIF files and Figure 5.
This material is available free of charge via the Internet at http://
pubs.acs.org.