Syntheses, structures and reactivity of electron-rich Fe and Ru complexes with the new pentadentate ligand Et2NpyS4-H2 {4-(diethylamino)-2,6-bis[(2-mercaptophenyl)thiomethyl]pyridine}

Article abstract of DOI:10.1002/ejic.200400404

The new pentadentate thioether thiolate ligand Et₂NpyS ₄^2- {= 4-(diethylammo)-2,6-bis[(2-mercaptophenyl) thiomethyl]-pyridine(2-)} has been synthesised from dimethyl 4-bromo-pyridine-2,6-dicarboxylate by treatment with Et₂NH followed by reduction and tosylation. The tosylated product was subsequently used for the template alkylation of [Ni(S₂C₆H₄) ₂]^2- to give [{Ni(Et₂NpyS₄)} ₂] (4). Acidic hydrolysis of 4 resulted in the formation of the ligand Et₂NpyS₄-H₂·HCl (5). The dianion Et₂NpyS₄^2- reacted with FeCl ₂·H₂O to afford the dinuclear high-spin species [{Fe(Et₂NpyS₄)}₂] (6) [μ_eff (297 K) = 5.15 μ_B]. Aerial oxidation of dinuclear 6 afforded the sulfinato complex [{Fe(Et₂NpyS₄-O₂)} ₂] (7). Complex 6 proved to be a good precursor for the syntheses of [Fe(L)(Et₂NpyS₄)] [L = CO (8), CNCy (9), NO (11) and N₂H₄ (12)] and [Fe(NO)-(Et₂NpyS ₄)]BF₄ (10). Protonation or alkylation of the thiolate donor atoms resulted in a series of complexes [Fe(CO)(Et₂NpyS ₄-R)]BF₄ [R = H (8a), Et (Bb)] and [Fe(CO)(Et ₂NpyS₄-Et₂)](BF₄)₂ (8c) but no labilisation of the Fe-CO bond was observed. Only in complex 8 could the CO coligand be exchanged by NO⁺ to give [Fe(NO)-(Et ₂NpyS₄)]BF₄ (10). Reduction of 10 using N ₂H₄, NH₃ or N₃^- afforded the 19 valence electron species [Fe(NO)(Et₂NpyS₄)] (11). [Ru(NO)(Et₂NpyS₄)]Br (13) was synthesised by template alkylation of Bu₄N[Ru(NO)(S₂C₆H ₄)₂] using Et₂Npy(CH₂Br)₂ (3). Under reducing conditions, 13 releases the NO coligand to give [{Ru(Et₂NpyS₄)}₂] (14), while in the presence of N₂H₄, [Ru(N₂H₄)(Et ₂NPyS₄)] (15) was formed. The complexes were well characterised including the solid-state structures in most cases. X-ray structural analyses of 7, 8, 9, 10, 12 and 15 revealed that all complexes exhibit trans-thiolate donors irrespective of the σ-π- or σ-ligand character of L. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004).

Full text of DOI:10.1002/ejic.200400404

FULL PAPER
Syntheses, Structures and Reactivity of Electron-Rich Fe and Ru Complexes
with the New Pentadentate Ligand Et2NpyS4؊H2 {4-(Diethylamino)-
2,6-bis[(2-mercaptophenyl)thiomethyl]pyridine}
Dieter Sellmann,[a][†] Shaban Y. Shaban,*[a] and Frank W. Heinemann[a]
Keywords: Electron density / Iron / Nitrogenase / Ruthenium / S ligand
2−
The new pentadentate thioether thiolate ligand Et2NpyS4
{= 4-(diethylamino)-2,6-bis[(2-mercaptophenyl)thiomethyl]-
[Fe(CO)(Et2NpyS4−R)]BF4 [R
[Fe(CO)(Et2NpyS4−Et2)](BF4)2 (8c) but no labilisation of the
= H (8a), Et (8b)] and
pyridine(2−)} has been synthesised from dimethyl 4-bromo- Fe−CO bond was observed. Only in complex 8 could the CO
pyridine-2,6-dicarboxylate by treatment with Et2NH fol-
lowed by reduction and tosylation. The tosylated product
was subsequently used for the template alkylation of
coligand be exchanged by NO+ to give [Fe(NO)-
(Et2NpyS4)]BF4 (10). Reduction of 10 using N2H4, NH3 or N3
−
afforded the 19 valence electron species [Fe(NO)(Et2NpyS4)]
[Ni(S2C6H4)2]2− to give [{Ni(Et2NpyS4)}2] (4). Acidic hydro- (11). [Ru(NO)(Et2NpyS4)]Br (13) was synthesised by template
lysis of
4
resulted in the formation of the ligand
alkylation of Bu4N[Ru(NO)(S2C6H4)2] using Et2Npy(CH2Br)2
(3). Under reducing conditions, 13 releases the NO coligand
to give [{Ru(Et2NpyS4)}2] (14), while in the presence of N2H4,
[Ru(N2H4)(Et2NpyS4)] (15) was formed. The complexes were
2−
Et2NpyS4−H2·HCl (5). The dianion Et2NpyS4 reacted with
FeCl2·H2O to afford the dinuclear high-spin species
[{Fe(Et2NpyS4)}2] (6) [µeff (297 K) = 5.15 µB]. Aerial oxidation
of
dinuclear
6
afforded
the
sulfinato
complex well characterised including the solid-state structures in most
[{Fe(Et2NpyS4−O2)}2] (7). Complex 6 proved to be a good pre-
cursor for the syntheses of [Fe(L)(Et2NpyS4)] [L = CO (8),
CNCy (9), NO (11) and N2H4 (12)] and [Fe(NO)-
(Et2NpyS4)]BF4 (10). Protonation or alkylation of the thiolate
cases. X-ray structural analyses of 7, 8, 9, 10, 12 and 15 re-
vealed that all complexes exhibit trans-thiolate donors irre-
spective of the σ−π- or σ-ligand character of L.
( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
donor atoms resulted in
a
series of complexes Germany, 2004)
Introduction
Transition metals in sulfur-dominated coordination
spheres form the active centres of numerous oxidoreduct-
ases such as nitrogenases, hydrogenases and CO dehydro-
genases.[1] In the search for low-molecular weight com-
pounds that combine structural and reactivity features of
these [MS] enzymes, we have found that transition metal
Scheme 1. Schematic structures of RpyS4ϪH2 ligands and
[M(RpyS4)] fragments (M ϭ Fe, Ru; R ϭ H, Et2N)
2Ϫ
complexes containing [M(pyS4)] fragments [pyS4 ϭ 2,6-
As was pointed out earlier,[3] and even more so for the
syntheses of the first pair of mono- and dinuclear N2 com-
plexes [Ru(N2)(PiPr3)(N2Me2S2)][4] and [µ-N2{Ru(PiPr3)-
(N2Me2S2)}2][5] [N2Me2S22Ϫ ϭ N,NЈ-dimethyl-1,2-ethanedi-
amine-N,NЈ-bis(2-benzenethiolate)(2Ϫ)] which formed di-
rectly from N2 and sulfurϪmetal complex fragments under
mild conditions, a major factor for the binding of N2 can
be considered to be a high electron density at the metal
centres. Although the position of the ν(CO) bands in [Fe-
bis(2-mercaptophenylthiomethyl)pyridine(2Ϫ)] (M ϭ Fe,
Ru) bind many nitrogenase-relevant molecules such as CO,
NO, N2H4, N2H2 and NH3, although not N2 (Scheme 1).[2]
[‡]
Transition Metal Complexes with Sulfur Ligands, 166. Part 165:
D. Sellmann, K. Hein, F. W Heinemann, Inorg. Chem. Acta
2004, 357, 3739Ϫ3745.
[a]
Institut für Anorganische Chemie der Universität Erlangen-
Nürnberg,
(CO)(pyS4)] (1963 cmϪ1 [6]
)
and [Ru(CO)(pyS4)] (1954
cmϪ1 [2g]
)
indicate a relatively high electron density at the
Egerlandstraße 1, 91058 Erlangen, Germany
Fax: (internat.) ϩ 49-9131-8527367
E-mail: shaban@anorganik.chemie.uni-erlangen.de
metal centres, no N2 complexes could be obtained. It is pos-
sible that the electron density is not high enough to enable
[†]
Deceased.
Eur. J. Inorg. Chem. 2004, 4591Ϫ4601
DOI: 10.1002/ejic.200400404
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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D. Sellmann, S. Y. Shaban, F. W. Heinemann
FULL PAPER
the coordination of N2. Numerous efforts have been made Syntheses and Reactions of Complexes
to increase the electron density in [M(pyS4)] fragments by
Schemes 3 and 4 summarise the syntheses and reactions
of Et2NpyS4 complexes.
modifying the benzene ring substituents with electron-do-
nating groups but these have remained unsuccessful.[2d,6]
Apparently, the electronic changes in the benzene rings are
not transmitted beyond the sulfur donor atoms to the metal
centres. These findings prompted us to start a systematic
study of the influence of the pyridine ring substituents on
the electron density at the metal centres and the reactivity
of the resultant complexes. We describe herein the syntheses
of the new Et2NpyS4ϪH2 ligand and some related iron and
ruthenium complexes. The similarities and differences be-
tween [M(Et2NpyS4)] and [M(pyS4)] complexes (M ϭ Ru
and Fe) are discussed in detail.
2Ϫ
Results and Discussions
Synthesis of the New Ligand Et2NpyS4؊H2
The target ligand Et2NpyS4ϪH2·HCl (5) was synthesised
according to the route indicated in Scheme 2.
Scheme 3. Synthesis and reactions of iron complexes: a) ϩ FeCl2·4
H2O, THF, room temp.; b) ϩ air, CHCl3, 72 h; c) ϩ CO, THF,
room temp.; d) ϩ HBF4, CH2Cl2, Ϫ78 °C or Et3OBF4, room temp.;
e) ϩ Et3OBF4, CH2Cl2; f) 2 Et3OBF4, CH2Cl2; g) ϩ L (CNCy or
N2H4)/THF; h) ϩ NOBF4, CH2Cl2, 0 °C; room temp.; i) ϩ
NOBF4, CH2Cl2, room temp.; j) ϩ N2H4, MeOH or DMF; k)
NO, CH2Cl2.
Scheme 2. Synthesis of the target Et2NpyS4ϪH2·HCl ligand 5: a)
ϩ Et2NH, K2CO3, DMSO, 55 °C; b) ϩ NaBH4, EtOH, reflux,
16 h; c) ϩ tosyl chloride, KOH, THF; d) ϩ Na2[Ni(S2C6H4)2],
THF, MeOH, 60 °C, 2 h; e) HClaq., CH2Cl2
Treatment of dimethyl 4-bromopyridine-2,6-dicar-
boxylate[7] with excess Et2NH and K2CO3 in DMSO at 55
°C for 28 h afforded dimethyl 4-diethylaminopyridine-2,6-
dicarboxylate (1). The resultant ester 1 was reduced with
NaBH4 and continuously extracted with CHCl3 at 45 °C
for 72 h to yield 4-(diethylamino)-2,6-bis(hydroxymethyl)-
pyridine (2). Treatment of 2 with either HBr or tosyl chlo-
ride afforded 2,6-bis(bromomethyl)-4-(diethylamino)pyrid-
Scheme 4. Synthesis and reactions of ruthenium complexes: a)
ine (3) or 4-(diethylamino)-2,6-bis(tosyloxymethyl)pyridine ϩHBr/H2O, reflux, 16 h; b) ϩ Bu4N[Ru(NO)(S2C6H4)2], THF, 60
°C, 2 h; c) ϩ NH3, MeOH, 1 h; d) ϩ N2H4, THF, 2 h, room temp.
(3a), respectively. Compound 3a was subsequently used for
the template alkylation of [Ni(S2C6H4)2]2Ϫ[8] to give
2Ϫ
[{Ni(Et2NpyS4)}x] (4). Complex 4 is paramagnetic with µeff
The reaction between FeCl2·4H2O and the Et2NpyS4
(293 K) ϭ 2.25 µB which is consistent with two unpaired anion resulting from deprotonation of 5 with 3 equiv. of
electrons per Ni centre. A solution of 4 in CH2Cl2 was read- LiOMe afforded yellow paramagnetic [{Fe(Et2NpyS4)}x]
ily hydrolysed when treated with aqueous concentrated HCl (6) [µeff (293 K) ϭ 5.15 µB]. The solid-state structure of 6
to afford Et2NpyS4ϪH2 as its HCl salt.
has not yet been determined. However, x is probably 2. Aer-
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Pentadentate Ligand Et2NpyS4ϪH2 {4-(Diethylamino)-2,6-bis[(2-mercaptophenyl)thiomethyl]pyridine}
FULL PAPER
ial oxidation of
[{Fe(Et2NpyS4ϪO2)}2] (7) showing νa(SO2) and νs(SO2) IR (11), showing a ν(NO) band at 1637 cmϪ1 in its IR (KBr)
(KBr) bands at 1238, 1185, 1133 and 983 cmϪ1 [9]
An X- spectrum. Subsequent experiments revealed that even N2H4
6 afforded the sulfinato complex yielding the neutral 19 VE complex [Fe(NO)(Et2NpyS4)]
.
ray structure determination established that 7 is dinuclear or solvents such as MeOH or DMF could reduce the cat-
and exhibits a trans-thiolate structure. A possible reason for ionic [10]ϩ to give neutral 11. Alternatively, 11 could be
this mild thiolate oxidation could be the high basicity of the synthesised directly from 6 and an equimolar amount of
thiolate donors originating from the presence of the Et2N NO gas. Complex 11 is highly reactive and can be oxidised
substituent. Dinuclear 6 readily coordinates CO or CNCy to give the [10]ϩ cation.
to give the C2-symmetric and diamagnetic mononuclear
Treatment of an equimolar amount of 6 with N2H4 af-
complexes [Fe(CO)(Et2NpyS4)] (8) and [Fe(CNCy)- forded the hydrazine complex [Fe(N2H4)(Et2NpyS4)] (12).
(Et2NpyS4)] (9), respectively, indicating that 6 partially dis- Complex 12 is stable and could be isolated as a solid and
sociates in solution into two unsaturated monomers. Com- completely characterised. This is in contrast to the anal-
plexes 8 and 9 exhibit characteristic ν(CO) (1948 cmϪ1) and ogous [Fe(N2H4)(pyS4)][2a] which is highly labile towards
ν(CNCy) (2105 cmϪ1) bands in their IR (KBr) spectra. The N2H4 elimination and could be isolated in crystalline form
ν(CO) of 8 is low when compared with that of [Fe(CO)- only in the presence of excess N2H4. One possible reason
(pyS4)] (1963 cmϪ1),[6] indicating a high electron density at for this high stability could be that all N2H4 hydrogen
the Fe centre which in turn results in a strong FeϪCO atoms are involved in both intra- and intermolecular hydro-
bond. Complex 8 could also be obtained directly from gen bonding as found for solid 12 in the solid state.
2Ϫ
FeCl2·4H2O and Et2NpyS4 in the presence of CO.
The unsuccessful attempts to obtain an [Fe(Et2NpyS4)]
During attempts to diminish the inertness of [Fe(CO)- dinitrogen complex prompted us to also study ruthenium
(Et2NpyS4)] (8) towards substitution, the thiolate donor complexes which could be expected to be less labile
atoms were protonated or alkylated using either HBF4 or (Scheme 4).
Et3OBF4,
affording
the
thioether
derivatives
As a first target complex [Ru(NO)(Et2NpyS4)]Br (13) was
[Fe(CO)(Et2NpyS4ϪR)]BF4 [R ϭ H (8a), Et (8b)] and prepared. It was obtained by template alkylation of Bu4N-
[Fe(CO)(Et2NpyS4ϪEt2)](BF4)2 (8c). Complexes 8aϪc were [Ru(NO)(S2C6H4)2][11] with Et2Npy(CH2Br)2 (3) in boiling
completely characterised and each shows a characteristic THF. Complex 13 exhibits a low ν(NO) frequency (1858
ν(CO) band in the 1975Ϫ2016 cmϪ1 range but they proved cmϪ1 in KBr) compared with the related complex [Ru(NO)-
as inert towards substitution as their precursor 8. For ex- (pyS4)]Tos (1892 cmϪ1).[2e] This again indicates a higher
ample, 8a is deprotonated in solvents such as Et2O, H2O, electron density at the ruthenium centre. Attempts to ob-
MeOH, DMF or THF to regenerate 8 indicating that the tain an [Ru(Et2NpyS4)] dinitrogen complex from the reac-
protonation is reversible and does not lead to CO cleavage. tion of 13 with NH3 in MeOH resulted in the formation
This is in contrast to the parent complex of the thiolate bridged dinuclear [{Ru(Et2NpyS4)}2] (14).
[Fe(CO)(pyS4ϪH)]BF4, in which the CO ligand is labile and Monitoring of the reaction by solution IR spectroscopy
undergoes elimination to give [{Fe(pyS4ϪH)}2](BF4)2.[6] showed that at first 13 [ν(NO) ϭ 1880 cmϪ1 in MeOH] is
One possible reason for the stability of the FeϪCO bond in reduced to give the 19 VE electron species [Ru(NO)-
8a may be the higher electron density at the iron centre. A (Et2NpyS4)] [ν(NO) ϭ 1640 cmϪ1 in MeOH][2b] which is
comparison of the ν(CO) bands (in KBr) of highly labile and releases NO to give dinuclear 14. Complex
[Fe(CO)(Et2NpyS4ϪH)]BF4 (8a) and [Fe(CO)(pyS4ϪH)]- 14 is practically insoluble in all common solvents and inert
BF4 (1975 cmϪ1 vs. 1996 cmϪ1 [6]
centres in the [Fe(Et2NpyS4)] fragments have a higher elec- sion of 13 was treated with N2H4, a green solution was
tron density than in the [Fe(pyS4)] fragments, thus favour- formed from which the hydrazine complex
)
shows that the iron towards cleavage reactions. When a red brown THF suspen-
ing bonding of the good π-acceptor CO. The low ν(CO) [Ru(N2H4)(Et2NpyS4)] (15) was isolated. Complex 15 is
frequency of 8 prompted us to attempt to obtain an stable over prolonged periods of time in both the solid state
[Fe(Et2NpyS4)] dinitrogen complex. For this purpose, a and solution.
solution of 8 was UV-irradiated under N2 for a prolonged
period of time at different temperatures. However, the CO
Characterization and General Properties of the Complexes
coligand dissociated and dinuclear 6 formed. Complex 8
As far as possible, all complexes have been characterised
was found to react only with NOBF4 at 0 °C to afford the by common spectroscopic methods and elemental analyses
18 valence electron (VE) complex [Fe(NO)(Et2NpyS4)]BF4 and, with the exception of 6 and 11, they are all diamag-
(10). Complex 10 could also be obtained directly from 6 netic. All complexes, except the dinuclear species 6 proved
and NOBF4.
to be soluble in THF, CH2Cl2 and DMF. The IR (KBr)
The relatively high ν(NO) frequency of 10 (1882 cmϪ1 in spectra show a typical pattern for the [M(Et2NpyS4)] frag-
KBr) made the [10]ϩ cation a candidate for attempts to con- ment besides the characteristic bands of the coligands. For
vert the NO into an N2 ligand by addition of nitrogen nu- example, the ν(CNCy) band at 2105 cmϪ1 indicates coordi-
cleophiles to the nitrosyl N atom.[10] For this purpose, 10 nation of the CNCy ligand in 9. Characteristic strong
was treated with NH3, N2H4 or N3Ϫ. However, in none of ν(CO) bands were observed for 8 (1948 cmϪ1), 8a (1974
these cases did a nucleophilic addition to the NO coligand cmϪ1), 8b (1980 cmϪ1) and 8c (2007 cmϪ1), while weak
take place and, rather, the nucleophiles acted as reductants ν(NϪH) bands at 3318, 3285 and 3237, and 3318, 3242 and
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D. Sellmann, S. Y. Shaban, F. W. Heinemann
FULL PAPER
3100 cmϪ1 appeared for the hydrazine complexes 12 and ring substituents increases the electron density. This con-
15, respectively. Strong ν(NO) bands at 1882, 1637 and clusion is supported by the high basicity of the sulfur donor
1858 cmϪ1 characterise the nitrosyl complexes 10, 11 and atoms which form strong hydrogen bonds as found in the
13, respectively.
solid-state structures of 12, 15 and 15·N2H4. Further sup-
The mass spectra in all cases exhibited peaks correspond- porting observations include the cyclic voltammograms of
ing to either the molecular ion or ions resulting from loss the isoelectronic iron complexes [Fe(CO)(Et2NpyS4)] (8)
of the coligands. The 13C{1H} NMR spectra proved par- and [Fe(CO)(pyS4)][6] as well as the nitrosylruthenium com-
ticularly helpful in establishing the diastereomeric purity of plexes [Ru(NO)(Et2NpyS4)]Br (13) and [Ru(NO)(Et2Npy-
the complexes and the twofold symmetry of the S4)]Tos[2e] (Figure 1, Table 2). A comparison of the redox
1
[M(Et2NpyS4)] fragments. H and 13C{1H} NMR spectra potentials of the carbonyliron complexes [Fe(CO)-
corroborated the C2 symmetry of complexes 8, 8c, 9, 10, (Et2NpyS4)] (8) and [Fe(CO)(pyS4)][6] (ϩ361 mV vs. ϩ514
12, 13 and 15, and the C1 symmetry of complex 8b. The mV in CH2Cl2) indicates the electron-donating nature of
hydrazine complex 12 gave rise to a broad singlet at δ ϭ 2.9 the Et2N substituent which makes oxidation easier. On the
pm which can be attributed to Fe-bound and terminal NH2 other hand, the redox potentials of the nitrosylruthenium
groups, while 15 gave rise to two doublets at δ ϭ 4.2 and cations [Ru(NO)(Et2NpyS4)]ϩ (13) and [Ru(NO)-
4.4 ppm which can be attributed to an Ru-bound NH2 (Et2NpyS4)][2e] (Ϫ467, Ϫ1524 mV vs. Ϫ275, Ϫ1200 mV in
group and a multiplet at δ ϭ 3.3 ppm which can be assigned DMF) indicate that the Et2N substituent renders cationic
to the terminal NH2 group.
complexes with [Fe(Et2NpyS4)] fragments more difficult to
reduce. Keeping all these observations in mind, we can con-
clude that the Et2N substituent has a significant influence
on the electron density in [M(Et2NpyS4)] cores.
Benzene and Pyridine Ring Substituent Effects
In the search for complexes which exhibit electron-rich
metal centres, we have found that the benzene ring substitu-
ents have no significant influence on the electron density at
the metal centres. In other words, the electronic changes in
the benzene rings cannot be transmitted beyond the sulfur
donors to the metal centres.[6,12] The ν(CO) or ν(NO) fre-
quencies which sensitively reflect electronic changes at the
metal centres are practically identical in the corresponding
complexes (Table 1). It was therefore of interest to examine
whether such an electron-donating effect of the pyridine
ring Et2N substituent would reach and be detectable at the
metal centres of the homologous complexes.
Table 1. The ν(CO) and ν(NO) frequencies of [Fe(NS4)] cores with
electron-donating benzene and pyridine ring substituents
Figure 1. Cyclic voltammograms of a) [Fe(CO)(Et2NpyS4)] (8) in
CH2Cl2, b) [Ru(NO)(Et2NpyS4)]Br (13) in DMF (10Ϫ3 , 10Ϫ1
Bu4NPF6, v ϭ 50 mV/s, potentials given in mV)
Complex
ν(CO)[a] Complex
ν(NO)[a]
[Fe(CO)(pyS4)]
1963[6] [Fe(NO)(pyS4)]ϩ
1893[6]
X-ray Crystal Structure Determinations
[Fe(CO)(pybuS4)]
1969[6] [Fe(NO)(Et2NpyS4)]ϩ (10) 1882[b]
[Fe(CO)(Et2NpyS4)] (8) 1948[b] [Fe(NO)(pyS4)]
1648[6]
The crystal structures of the complexes [{Fe(Et2NpyS4Ϫ
O2)}2]·8CDCl3 (7·8CDCl3), [Fe(CO)(Et2NpyS4)]·CDCl3
[Fe(NO)(Et2NpyS4)] (11) 1637[b]
(8·CDCl3),
[Fe(CNCy)(Et2NpyS4)]·2THF
(9·2THF),
[a]
[b]
In KBr [cmϪ1]. This work.
[Fe(NO)(Et2NpyS4)]BF4·CH2Cl2 (10·CH2Cl2), [Fe(N2H4)-
(Et2NpyS4)] (12), [Ru(N2H4)(Et2NpyS4)] (15) and
Table 1 demonstrates that all iron complexes with [Ru(N2H4)(Et2NpyS4)]·N2H4 (15·N2H4) were determined
[Fe(Et2NpyS4)] cores show significant shifts of the ν(CO) by X-ray crystallography. Figures 2Ϫ4 depict the molecular
and ν(NO) bands to lower wave numbers by about 11Ϫ22 structures of the complexes. Tables 3 and 4 list selected
cmϪ1 indicating that the electron donation of the pyridine bond lengths and angles.
Table 2. Redox potentials of carbonyl and nitrosyl complexes with [M(NS4)] cores
Complex
Redox potentials in
CH2Cl2 [mV][a]
Complex
Redox potentials in
DMF [mV][a]
[Fe(CO)(pyS4)]
[Fe(CO)(Et2NpyS4)] (8)
ϩ 514[6]
ϩ 361[b]
[Ru(NO)(pyS4)]ϩ
Ϫ 275, Ϫ 1200[2e]
Ϫ 467, Ϫ 1524[b]
[Ru(NO)(Et2NpyS4)]ϩ (13)
[a]
[b]
Related to NHE. This work.
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Pentadentate Ligand Et2NpyS4ϪH2 {4-(Diethylamino)-2,6-bis[(2-mercaptophenyl)thiomethyl]pyridine}
FULL PAPER
Figure 2. Molecular structure of [{Fe(Et2NpyS4ϪO2)}2]·8CHCl3
(7·8CHCl3) (50% probability ellipsoids, all solvate molecules,
anions and C-bound H atoms omitted)
Figure 4. Molecular structure and hydrogen bonds (dashed lines)
observed for [Fe(N2H4)(Et2NpyS4)] (12) (50% probability ellip-
soids, C-bound H atoms omitted)
Table 3. Selected bond lengths [pm] and angles [°] for [{Fe-
(Et2NpyS4ϪO2)}2]·8CDCl3 (7·8CDCl3), [Fe(CO)(Et2NpyS4)]·
CDCl3 (8·CDCl3), [Fe(CNCy)(Et2NpyS4)]·2THF (9·2THF),
[Fe(NO)(Et2NpyS4)]BF4·CH2Cl2 (10·CH2Cl2) and [Fe(N2H4)-
(Et2NpyS4)] (12)
7·8CDCl3 8·CDCl3 9·2THF 10·CH2Cl2
12
Fe(1)ϪN(1)
Fe(1)ϪS(1)
Fe(1)ϪS(2)
Fe(1)ϪS(3)
Fe(1)ϪS(4)
Fe(1)ϪL
N(1)ϪFe(1)ϪS(1) 89.7(1)
N(1)ϪFe(1)ϪS(2 86.1(2)
N(1)ϪFe(1)ϪS(3) 84.8(2)
N(1)ϪFe(1)ϪS(4) 93.1(1)
198.8(3) 201.5(2) 200.9(4) 199.2(4)
218.8(2) 231.3(9) 231.1(2) 230.6(2)
221.6(2) 224.0(1) 221.9(2) 224.9(2)
223.3(2) 222.7(1) 221.6(2) 224.5(2)
229.9(2) 229.8(1) 230.6(2) 231.3(2)
233.4(2) 176.5(3) 183.4(5) 163.8(5)
197.1(2)
230.46(6)
222.78(5)
223.22(6)
229.42(5)
203.73(2)
90.73(5)
84.59(5)
85.26(5)
92.08(5)
178.59(7)
91.42(7) 89.8(2)
83.33(7) 84.7(2)
84.34(7) 84.7(2)
89.32(7) 90.8(2)
88.3(2)
85.1(2)
85.0(2)
87.6(2)
N(1)ϪFe(1)ϪL
176.8(1) 178.9(2) 178.6(2) 177.4(2)
range observed for diamagnetic [FeNS4] cores.[2a,2b,2e,6] The
FeϪS(thiolate) distances (average 230 pm) are slightly
longer than the FeϪS(thioether) distances (average 223
pm).
In complex 7·8CDCl3, the oxygenation causes a signifi-
cant effect in the FeϪS(sulfinate) distance while the other
FeϪS and FeϪN distances remain practically unchanged.
Figure 3. Molecular structures of [Fe(CO)(Et2NpyS4)]·CDCl3
and
[Fe(NO)(Et2NpyS4)]BF4·CH2Cl2 (10·CH2Cl2) (50% probability
ellipsoids, all solvate molecules, anions and C-bound H atoms
omitted)
(8·CDCl3),
[Fe(CNCy)(Et2NpyS4)]·2THF
(9·2THF)
The Et2NpyS4 ligand acts as a square-pyramidal coordi- The FeϪS(sulfinate) distance decreases by about 12 pm
nation cap and the overall geometry around the iron centre [218(2) pm for 7·8CDCl3 vs. 230 pm (average) for 8·CDCl3,
is pseudo-octahedral. The pyridine N1 donor and the col- 9·2THF and 12]. An explanation could be that the FeϪS
igand L or the bridging S donor of a second Fe fragment distances are governed by three factors: 1) the σ-donor
as well as the two thiolate and the two thioether donor ability, expected to be best in the thiolate which decreases
2Ϫ
atoms of the Et2NpyS4
ligand occupy corresponding with increasing oxygenation, 2) a contraction in the size of
trans positions and thus provide the steric rigidity of the the sulfur atoms as the formal oxidation state of the sulfur
py(CH2)2 backbone. A comparison of the geometrical par- atoms changes from Ϫ2 (for FeϪS in complexes 8·CDCl3,
ameters of 8·CDCl3, 9·2THF and 10·CH2Cl2 demonstrates 9·2THF and 10) to ϩ2 [for FeϪS(sulfinate) in complex
that the FeϪdonor distances in all cases lie in the usual 7·8CDCl3], and 3) the destabilisation of the FeϪS bond due
Eur. J. Inorg. Chem. 2004, 4591Ϫ4601
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D. Sellmann, S. Y. Shaban, F. W. Heinemann
Table 4. Selected bond lengths [pm] and angles [°] for [Ru(N2H4)(Et2NpyS4)] (15) and [Ru(N2H4)(Et2NpyS4)]·N2H4 (15·N2H4)
FULL PAPER
15
15·N2H4
15
15·N2H4
Ru(1)Ϫ(N1)
Ru(1)ϪS(1)
Ru(1)ϪS(2)
Ru(1)ϪS(3)
Ru(1)ϪS(4)
Ru(1)ϪN(3)
N(3)ϪN(4)
N(5)ϪN(6)
205.6(3)
237.51(9)
230.49(9)
231.06(9)
237.23(9)
213.70(3)
146.40(4)
Ϫ
205.4(3)
239.2(2)
230.7(1)
228.6(1)
237.9(2)
213.7(4)
144.6(5)
139.6(6)
N(1)ϪRu(1)ϪS(1)
N(1)ϪRu(1)ϪS(2)
N(1)ϪRu(1)ϪS(3)
N(1)ϪRu(1)ϪS(4)
N(1)ϪRu(1)ϪN(3)
Ru(1)ϪN(3)ϪN(4)
90.33(8)
83.21(8
83.71(8)
91.81(8)
179.09(11)
115.90(2)
90.54(9)
83.60(9)
84.29(9)
90.63(9)
176.6(2)
118.3(3)
to a repulsive interaction between the filled d orbital of the and a similar effect may stabilise the intermediate diazene
metal atom and two lone pairs of the thiolate sulfur complex which is assumed to be essential for N2 fixation.[2c]
atom.[9a,13]
The crystal structures of the complexes 12, 15 and
15·N2H4 deserve special interest because all types of hydra-
zine hydrogen atoms are involved in a system of inter- and
intramolecular NϪH···S and NϪH···N hydrogen bonding
with the sulfur donors (thiolate, thioether) as well as the
solvate hydrazine N atoms. The hydrogen bonds are indi-
cated by both the NϪΗ···S and NϪΗ···N vectors as well
as the distances which are shorter than the sum of the cor-
responding van der Waals radii (rH ϭ 120 pm, rS ϭ 185
pm).[14] Figure 3 shows the molecular structures and the hy-
drogen bonding geometry for 12 and 15·N2H4. The param-
eters of the hydrogen bonds are collected in Table 5.
The crystal lattices of 12 and 15 contain chains of mol-
ecules which are connected by intermolecular
NϪΗ···S(thiolate) hydrogen bonds and each molecule exhi-
bits additional intramolecular NϪΗ···S hydrogen bonds.
Figure 5. Molecular structure and hydrogen bonds (dashed lines)
The type of bonds, bond lengths and bond angles in the two
complexes are very similar, only 12 contains an additional
NϪΗ···S bond. The crystal lattice of 15·N2H4 additionally
contains intermolecular NϪΗ···N hydrogen bonds between
the solvate hydrazine and the coordinated hydrazine. This
system of hydrogen bonds is of interest because it contrib-
observed for [Ru(N2H4)(Et2NpyS4)]·N2H4 (15·N2H4) (50% prob-
ability ellipsoids, C-bound H atoms omitted)
Conclusion
The new pentadentate Et2NpyS4ϪH2 ligand has been
utes significantly to the stabilisation of the N2H4 coligand synthesised with the aim of preparing transition metal com-
Table 5. Hydrogen bond parameters [pm and °] for [Fe(N2H4)(Et2NpyS4)] (12), [Ru(N2H4)(Et2NpyS4)] (15) and [Ru(N2H4)-
(Et2NpyS4)]·N2H4 (15·N2H4)
DϪH···A
d(D···A)
d(DϪH)
d(H···A)
ν(DHA)
12
15
12
15
12
15
12
15
N(3)ϪH(3A)···S(1A)[a]
N(3)ϪH(3A)···S(3)
N(3)ϪH(3B)···S(1)
N(4)ϪH(4A)···S(4)
N(4)ϪH(4A)···S(2)
N(4)ϪH(4B)···S(1A)[a]
15·N2H4
N(3)ϪH(3A)···N(5)
N(4)ϪH(4A)···S(1)
N(5)ϪH(5A)···N(4)
N(5)ϪH(5A)···N(3)
N(6)ϪH(6A)···S(4)
344.1(2)
311(2)
304.5(2)
348.1(2)
316.3(2)
340.1(2)
335.3(3)
Ϫ
316.8(3)
359.9(3)
327.7(3)
337.3(3)
89(3)
99
Ϫ
82
88
88
83
277(3)
300(3)
268(3)
292(3)
285(3)
265(3)
260
Ϫ
288
301
291
266
134(2)
88(2)
105(2)
123(2)
103(2)
144(2)
132
Ϫ
103
126
107
145
89(3)
90(3)
88(3)
88(3)
88(3)
323.6(6)
337.2(4)
314.9(6)
323.6(6)
366.7(5)
102
227
256
218
259
264
157
135
151
119
157
104
106
106
105
[a]
Symmetry transformations used to generate equivalent atoms: x ϩ 1/2, y, Ϫz Ϫ 1/2.
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Eur. J. Inorg. Chem. 2004, 4591Ϫ4601

Pentadentate Ligand Et2NpyS4ϪH2 {4-(Diethylamino)-2,6-bis[(2-mercaptophenyl)thiomethyl]pyridine}
FULL PAPER
suspension was cooled to room temperature and poured onto ice-
cold water (250 mL). A yellow solid formed which was separated
by filtration, washed with water and dried in vacuo. Yield: 6.32 g
of 1 (34%). 1H NMR (CDCl3, 269.60 MHz): δ ϭ 1.20 (t, 6 H,
2CH2CH3), 3.44 (q, 4 H, 2CH2CH3), 3.95 (s, 6 H, 2COOCH3), 7.45
(s, 2 H, Hβ, pyridine) ppm. IR (KBr): ν˜ ϭ 1748, 1708, (vs, CϭO)
cmϪ1. MS (FDϩ, CHCl3): m/z ϭ 266 [Mϩ]. C13H18N2O4 (266.29):
calcd. C 58.63, H 6.81, N 10.52; found C 58.44, H 6.92, N 10.37.
plexes which exhibit electron-rich metal centres, possess a
core configuration with thiolate, thioether and amine do-
nors related to the structure of [M(pyS4)] fragments (M ϭ
Fe and Ru), and bind biologically relevant small molecules.
This goal was achieved as evidenced by the low ν(CO) fre-
quency of [Fe(CO)(Et2NpyS4)] (1948 cmϪ1) compared with
the analogous [Fe(CO)(pyS4)] (1963 cmϪ1). The
[M(Et2NpyS4)] fragments (M ϭ Fe, Ru) were found to bind
and stabilise many nitrogenase-relevant molecules such as
CO, NO, NOϩ, CNCy and N2H4. The results also revealed
that the Et2N substituent not only increases the electron
density at the metal centres but also at the sulfur donor
atoms which leads to highly basic sulfur donors. This high
basicity influences the reactivity of the MϪL bonds. For
example, the protonated complex [Fe(CO)(Et2NpyS4ϪH)]-
BF4 is deprotonated only in solution to give [Fe(CO)-
Et2Npy(CH2OH)2 (2): NaBH4 (2.96 g, 40 mmol) was added por-
tionwise to 1 (4.05 g, 16 mmol) in ethanol (200 mL). The mixture
was kept at room temperature for 1.5 h and was then heated to
reflux for 16 h. The solvent was evaporated, the residue treated with
a saturated solution of NaHCO3 (50 mL) and heated to reflux for
1.5 h. H2O (100 mL) was added and the aqueous phase was ex-
tracted continuously with CHCl3 (500 mL) over 2 d. The CHCl3
was evaporated to give a colourless solid. Yield 2.83 g of 2 (88%).
3
1H NMR ([D6]DMSO, 269.60 MHz): δ ϭ 1.10 (t, JH,H ϭ 7.1 Hz,
2
(Et2NpyS4)], while the related complex [Fe(CO)- 6 H, CH2CH3), 3.33 (q, 4 H, CH2CH3), 4.35 (d, JH,H ϭ 5.5 Hz, 4
3
H, 2CH2), 5.14 (t, JH,H ϭ 5.8 Hz, 2 H, 2OH), 6.51 (s, 2 H, Hβ
(pyS4ϪH)]BF4 is labile and undergoes CO elimination to
give [{Fe(pyS4ϪH)}2](BF4).
pyridine) ppm. MS (FD, DMSO): m/z ϭ 210 [Mϩ].
The X-ray structural analyses of [Fe(N2H4)(Et2NpyS4)]
and [Ru(N2H4)(Et2NpyS4)] revealed that such complexes
can form intra- and intermolecular NϪH···S and NϪH···N
hydrogen bonds. This stabilises the hydrazine complex
Et2Npy(CH2Br)2 (3): A solution of 2 (400 mg, 1.9 mmol) in 40%
aqueous HBr (50 mL) was heated to reflux for 16 h. The aqueous
phase was extracted with CHCl3 (3 ϫ 100 mL). The CHCl3 extract
was dried with MgSO4 and the solvent removed in vacuo to give a
1
[Fe(N2H4)(Et2NpyS4)] and makes it isolable and stable in white solid residue. Yield: 400 mg of 3·0.16THF (62%). H NMR
(CDCl3, 269.60 MHz): δ ϭ 1.21 (t, 6 H, 2CH2CH3), 3.41 (q, 4 H,
the solid state. This is in contrast to the parent complex
[Fe(N2H4)(pyS4)] which was highly labile with respect to
elimination of the N2H4 coligand and could not be isolated.
2CH2CH3), 4.50 (s, 4 H, 2CH2), 6.55 (s, 2 H, Hβ pyridine), 13C{1H}
NMR (CDCl3, 67.83 MHz):
δ ϭ 12.27 (CH2CH3), 33.43
(CH2CH3), 44.31 (CH2Br), 105.24, 154.02, 156.01 [C(aryl)] ppm.
IR (KBr): ν˜ ϭ 3033, 2969 (m, CϪH) cmϪ1. FD MS: m/z: 336 [M]ϩ.
C11.7H17.3Br2N2O0.17 (348.10): calcd. C 40.26, H 5.02, N 8.05;
found C 40.12, H 5.13, N 8.13.
Experimental Section
[{Ni(Et2NpyS4)}2] (4). a): A solution of 2·0.75MeOH (1.17 g,
5.34 mmol) in THF (30 mL) was combined with KOH (0.9 g,
General: Unless noted otherwise, all procedures were carried out
under nitrogen using Schlenk techniques. Stringently dried solvents
were used. As far as possible, reactions were monitored by IR or
NMR spectroscopy. Spectra were recorded with the following in-
struments: IR (KBr discs or CaF2 corvettes, solvent bands were
compensated): PerkinϪElmer 983, 1620 FT-IR, and 16PC FT-IR.
NMR: Jeol-JNM-GX 270, EX 270, and Lambda LA 400 with the
proton solvent signals used as an internal reference. Spectra were
recorded at 25 °C. MS: Jeol MSTATION 700 spectrometer. El-
emental analyses: Carlo Erba EA 1106 or 1108 analyser. Magnetic
susceptibility: Johnson Matthey susceptibility balance. Cyclic vol-
tammograms were recorded using an EG&G potentiostat PAR
model 264A and a conventional three-electrode configuration con-
sisting of a glassy carbon working electrode, a platinum auxiliary
electrode and a platinum reference electrode. Ferrocene was used
as an internal reference, E(Fc/Fcϩ) ϭ ϩ400 mV (vs. NHE).[15] The
reversibility of the voltammograms and the number of electrons
involved in the redox processes at 25°C were determined as de-
scribed in the literature.[16] ‘‘S2’’ϪH2 (1,2-benzenedithiol),[17] di-
methyl 4-bromo-pyridine-2,6-dicarboxylate[7] and Bu4N[Ru-
(NO)(S2C6H4)2][11] were prepared as described in the literature. An-
hydrous hydrazine was obtained by twofold distillation of
N2H4·H2O from KOH under reduced pressure.
17.80 mmol) and cooled to
0 °C. Tosyl chloride (2.43 g,
10.68 mmol) in THF (20 mL) was added dropwise and the resultant
suspension was stirred at 0 °C for 5 h and at room temperature for
14 h. The resultant solid was removed by filtration and washed with
THF (30 mL). The washings and the filtrates were dried in vacuo,
yielding a light brown viscous residue. Yield 2.6 g of Et2Npy(CH2-
OTs)2 (3a) (90%) which was used without further purification. b):
Sodium (453 mg, 19.67 mmol) was dissolved in methanol (40 mL)
and combined with 1,2-benzenedithiol (1.12 mL, 9.83 mmol) and a
solution of Ni(ac)2·4H2O (1.22 g, 4.92 mmol) in MeOH (50 mL).
Addition of Et2Npy(CH2OTs)2 (3a) (2.55 g, 4.92 mmol) in THF
(70 mL) to the dark-brown solution resulted in a brown precipitate
which was isolated after 3 h, washed with THF and MeOH
(30 mL each) and dried in vacuo. Yield: 2.0 g of
[{Ni(Et2NpyS4)}2]·1.5MeOH (4·1.5MeOH) (76%). IR (KBr): ν˜ ϭ
3050, 2968, ν(CϪH) cmϪ1. MS (FDϩ, MeOH): m/z ϭ 514
[Ni(Et2NpyS4)]ϩ, 1028 [{Ni(Et2NpyS4)}2]ϩ. C23H24N2NiS4
(515.40): calcd. C 52.22, H 5.36, N 5.00; found C 52.66, H 5.16, N
5.12. µeff ϭ 2.25 µB (297 K).
Et2NpyS4؊H2·HCl (5): Concentrated hydrochloric acid (15.14 mL)
was added to a suspension of 4·1.5MeOH (4.86 g, 9.60 mmol) in
CH2Cl2 (200 mL) and the mixture was stirred for 30 min. The
CH2Cl2 phase was separated from the aqueous green phase, dried
Et2Npy(CO2Me)2 (1): Anhydrous K2CO3 (4.15 g, 30 mmol) and di-
ethylamine (20 mL, 192.5 mmol) were added to a white suspension with anhydrous Na2SO4 and the solvents were evaporated to dry-
of
dimethyl
4-bromo-pyridine-2,6-dicarboxylate
(6.89 g,
ness yielding a grey-green solid. Yield 1.7 g of 5·2CH3OH (32%).
3
25.1 mmol) in DMSO (200 mL). The resultant yellow-brown mix-
1H NMR (CD2Cl2, 269.60 MHz): δ ϭ 0.94 (t, JH,H ϭ 7.2 Hz, 6
ture was heated at 55Ϫ60 °C for 48 h. The resultant orange-brown
H, 2CH2CH3), 3.14 (q, 4 H, 2CH2CH3), 4.38 (s, 2 H, 2SH), 4.40
Eur. J. Inorg. Chem. 2004, 4591Ϫ4601
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D. Sellmann, S. Y. Shaban, F. W. Heinemann
(s, 4 H, 2CH2), 5.92 (s, 2 H, Hβ, pyridine), 7.04Ϫ7.38 (m, 8 H, Hβ, pyridine), 7.00 (m, 2 H, C6H4), 7.32 (d, 1 H, C6H4), 7.61Ϫ7.51
FULL PAPER
2
C6H4), 7.78 (d, JH,H ϭ 6.5 Hz, 1 H, NH) ppm. IR (KBr): ν˜ ϭ
(m, 3 H, C6H4), 7.74 (m, 1 H, C6H4), 8.09 (m, 1 H, C6H4) ppm.
3414, 3255, 3070 (w, NϪH), 2412 (w, SϪH) cmϪ1. MS (FDϩ, 13C{1H} NMR (CD2Cl2, 67.83 MHz): δ ϭ 12.33 (CH2CH3), 13.34
CH2Cl2): m/z ϭ 495 [M]ϩ. C25H35ClN2O2S4 (559.3): calcd. C 53.69,
(CH2CH3), 41.51 (CH2CH3), 44.97 (CH2CH3), 55.80, 55.90
(CH2), 105.38, 105.64, 124.03, 129.69, 129.95, 130.57, 132.22,
132.38, 132.78, 133.61, 133.90, 135.75, 137.14, 152.90, 154.14,
H 6.31, N 5.01; found C 53.94, H 5.91, N 4.69.
[{Fe(Et2NpyS4)}2] (6): Solid FeCl2·4H2O (77 mg, 0.39 mmol) was
added to a light yellow solution of 5·H2O (220 mg, 0.39 mmol) and
LiOMe (1.17 mL of a 1  solution in MeOH) in THF (20 mL). A
yellow precipitate resulted which was separated by filtration after
30 min, washed with THF (20 mL) and dried in vacuo. Yield:
155.48, 156.58 [C(aryl)], 213.24 (CO) ppm. IR (KBr): ν˜
1980 (vs, CO), 1055 (vs, BϪF) cmϪ1. MS (FDϩ, CH2Cl2):
m/z
512 [Fe(Et2NpyS4)]ϩ, 1024 [{Fe(Et2NpyS4)}2]ϩ.
26.3H29.6FeBCl0.6F4N2OS4 (684.74): C 46.19, H 4.37, N 4.09;
ϭ
ϭ
C
found C 46.39, H 4.73, N 4.04.
105 mg of 6 (53%). IR (KBr): ν˜ ϭ 3050, 2966 (s, CϪH) cmϪ1. MS
(FDϩ, DMF): m/z ϭ 512 [Fe(Et2NpyS4)]ϩ, 1024 [Fe(Et2NpyS4)]2
.
ϩ
[Fe(CO)(Et2NpyS4؊Et2)](BF4)2
(8c):
Et3OBF4
(0.40 mL,
C23H24FeN2S4 (513.55): calcd. C 53.90 H 4.72, N 5.47, S 25.02;
found C 53.65, H 5.11, N 5.46, S 24.86. µeff ϭ 5.15 µB (297 K).
0.40 mmol of a 1  solution in CH2Cl2) was added to a red solution
of 8·0.7H2O (110 mg, 0.20 mmol) in CH2Cl2 (15 mL). The colour
immediately changed from red to brown. After 24 h, the reaction
mixture was reduced in volume to 3 mL. Addition of Et2O (30 mL)
precipitated a brown solid which was separated by filtration,
washed with Et2O (20 mL) and dried in vacuo. Yield 120 mg of
8c·0.5CH2Cl2 (72%). 1H NMR (CD3OD, 269.60 MHz): δ ϭ
[{Fe(Et2NpyS4؊O2)}2] (7): A yellow suspension of 6 (120 mg,
0.12 mmol) in CHCl3 (30 mL) was stirred in air for 24 h. The re-
sultant red-brown fine crystals were isolated, washed with CHCl3
then H2O (30 mL each) and dried in vacuo. Yield: 80 mg of
7·3CHCl3·H2O (23%). IR (KBr): ν˜ ϭ 2960 (s, CϪH), 1238, 1185,
3
1.02Ϫ0.97 (t, JH,H ϭ 7.2 Hz, 6 H, 2CH2CH3), 1.53Ϫ1.62 (t,
1133, 983 (s, SO2) cmϪ1
[Fe(Et2NpyS4)]ϩ,
1024
.
MS (FDϩ, CHCl3): m/z
ϭ
512
1088
3JH,H ϭ 7.2 Hz, 6 H, 2CH2CH3), 3.21Ϫ3.34 (m, 4 H, 2CH2CH3),
[{Fe(Et2NpyS4)}2]ϩ,
2
3.35Ϫ3.49 (m, 4 H, CH2CH3), 4.79Ϫ4.82 (d, JH,H ϭ 16.69 Hz, 2
[{Fe(Et2NpyS4ϪO2)}2]ϩ. C49H53Cl9Fe2N4O5S8 (1459.77): calcd. C
40.17, H 3.65, N 3.82, S 17.51; found C 40.12, H 4.09, N 3.84,
S 17.85.
H, CH2), 5.17Ϫ5.23 (d, 2JH,H ϭ 16.70 Hz, 2 H, CH2), 6.77 (s, 2 H,
Hβ, pyridine), 7.65 (t, 3JH,H ϭ 7.4 Hz, 3 H, C6H4), 7.77 (t, 3JH,H ϭ
2
7.20/7.60 Hz, 3 H, C6H4), 7.97 (d, JH,H ϭ 7.64 Hz, 2 H, C6H4),
2
8.32 (d, JH,H ϭ 7.83 Hz, 2 H, C6H4) ppm. 13C{1H} NMR
[Fe(CO)(Et2NpyS4)] (8): A stream of CO was passed through a yel-
low suspension of 6 (70 mg, 0.14 mmol) in THF (20 mL) for 10 min
during the course of which a red solution formed which was kept
under CO for a further 12 h, filtered and reduced in volume to
about 2 mL. Addition of Et2O (20 mL) precipitated a red solid
which was separated by filtration and dried in vacuo. Yield 62 mg
(CD3OD, 67.83 MHz): δ ϭ 12.01 (CH2CH3), 13.09 (CH2CH3),
41.41 (CH2CH3), 44.59 (CH2CH3), 54.74 (CH2), 107.23, 133.47,
134.15 134.20, 134.83, 135.42, 136.42, 154.96, 158.00 [C(aryl)],
210.00 (CO) ppm. IR (KBr) : ν˜ ϭ 2007 (vs, CO), 1056 (vs, BϪF)
cmϪ1. MS (FDϩ, CH3OH): m/z ϭ 512 [Fe(Et2NpyS4)]ϩ, 1024
[{Fe(Et2NpyS4)}2]ϩ. C28.5H35FeB2ClF8N2OS4 (814.77): C 42.00, H
4.33, N 3.44, S 15.74; found C 41.68, H 4.57, N 3.64, S 15.98.
1
of 8·0.7H2O (84%). H NMR (CD2Cl2, 269.60 MHz): δ ϭ 1.06 (t,
4
3JH,H ϭ 7.05 Hz, 6 H, 2CH2CH3), 3.22 (q, JH,H ϭ 6.20 Hz, 4 H,
2
2
2CH2CH3), 4.34 (d, JH,H ϭ 16.2 Hz, 2 H, CH2), 4.86 (d, JH,H
ϭ
[Fe(CNCy)(Et2NpyS4)] (9): Cyclohexyl isocyanide (0.032 mL,
0.30 mmol) was added to a yellow suspension of 6 (100 mg,
0.20 mmol) in THF (20 mL). A red solution resulted which was
stirred for 12 h, filtered and reduced in volume to about 5 mL.
Addition of Et2O (20 mL) precipitated a red-orange solid which
was separated by filtration and dried in vacuo. Yield: 60 mg of
9 (57%). 1H NMR ([D8]toluene, 269.60 MHz): δ ϭ 0.39 (t, 6 H,
2CH2CH3), 0.93 (t, 10 H, C6H11), 7.85 (m, 1 H, C6H11), 2.35 (m,
4 H, 2CH2CH3), 3.98Ϫ3.92 (d, 2 H, CH2), 4.85Ϫ4.80 (d, 2 H,
CH2), 5.68 (s, 2 H, Hβ, pyridine), 6.68Ϫ6.83 (m, 4 H, C6H4),
7.53Ϫ7.24 (m, 2 H, C6H4), 7.80 (d, 2 H, C6H4) ppm. IR (KBr): ν˜ ϭ
2105 (vs, CN), 2969, 2932 (m, CϪH) cmϪ1. MS (FDϩ, toluene):
m/z ϭ 512 [Fe(Et2NpyS4)]ϩ, 620 [Fe(CNCy)(Et2NpyS4)]ϩ, 1024
[{Fe(Et2NpyS4)}2]ϩ. C30H35FeN3S4 (621.73): calcd. C 57.95, H
5.67, N 6.76, S 20.63; found C 57.34, H 6.21, N 6.77, S 20.43.
16.2 Hz, 2 H, CH2), 6.39 (s, 2 H, Hβ, pyridine), 6.93 (m, 4 H,
2
2
C6H4), 7.41 (d, JH,H ϭ 6.5 Hz, 2 H, C6H4), 7.56 (d, JH,H
ϭ
6.5 Hz, 2 H, C6H4) ppm. 13C{1H} NMR (CD2Cl2, 67.83 MHz):
δ ϭ 9.6 (CH2CH3), 41.9 (CH2CH3), 53.8 (CH2), 101.2, 119.7, 126.2,
127.9, 129.5, 131.0, 149.4, 153.9, 155.2 [C(aryl)], 214.4 (CO) ppm.
IR (KBr): ν˜ ϭ 1948 (vs, CO), 2966 (m, CϪH) cmϪ1. MS (FDϩ,
CH2Cl2): m/z ϭ 512 [Fe(Et2NpyS4)]ϩ, 1024 [{Fe(Et2NpyS4)}2]ϩ.
C24H25.4FeN2O1.7S4 (552.02): calcd. C 52.17, H 4.62, N 5.07, S
23.21; found C 52.21, H 4.76, N 5.01, S 23.00.
[Fe(CO)(Et2NpyS4؊H)]BF4 (8a): At Ϫ78 °C, (0.013 mL, 0.1 mmol)
HBF4 (54% in Et2O) was added to a red suspension of 8·0.7H2O
(50 mg, 0.1 mmol) in CH2Cl2 (15 mL). After 1 h of stirring, during
the course of which the resultant grey solution was reduced in vol-
ume to about 3 mL at Ϫ78 °C, addition of n-hexane (15 mL) pre-
cipitated a grey solid which was isolated and dried in vacuo. Yield:
40 mg (69%) of 8a. IR (KBr): ν˜ ϭ 2503 (w, SϪH), 1974 (vs, CO)
cmϪ1. MS (FDϩ, CH2Cl2): m/z ϭ 512 [Fe(Et2NpyS4)]ϩ, 1024
[{Fe(Et2NpyS4)}2]ϩ. C24.5H26FeBClF4N2OS4 (670.49): C 43.86, H
3.91, N 4.17; found C 43.66, H 3.79, N 3.91.
[Fe(NO)(Et2NpyS4)]BF4 (10). a) From 8: Solid NOBF4 (5 mg,
0.04 mmol) was added to a red solution of 8·0.7H2O (20 mg,
0.04 mmol) in CH2Cl2 (10 mL). During the course of 10 min, a
yellow-green solution resulted which was filtered and reduced in
volume to about 5 mL. Addition of Et2O (20 mL) precipitated a
yellow-green solid which was separated by filtration and dried in
[Fe(CO)(Et2NpyS4-Et)]BF4 (8b):
A red solution of 8·0.7H2O
(90 mg, 0.17 mmol) in CH2Cl2 (10 mL) was combined with a 1  vacuo. Yield: 15 mg of 10·CH2Cl2·Et2O (65%). b) From 6: At 0 °C,
Et3OBF4 solution in CH2Cl2 (0.17 mL, 0.17 mmol). The resultant
brown solution was reduced in volume to 3 mL. Addition of Et2O
(20 mL) precipitated a brown solid which was separated by fil-
solid NOBF4 (5 mg, 0.04 mmol) was added to a yellow suspension
of 6 (20.5 mg, 0.04 mmol) in CH2Cl2 (10 mL). After stirring at 0
°C for 70 min and at room temperature for 30 min, the resultant
tration, washed with Et2O (20 mL) and dried in vacuo. Yield 85 mg yellow-green mixture was filtered, reduced in volume to about 5 mL
of 8b·0.3CH2Cl2 (76%). 1H NMR (CD2Cl2, 269.60 MHz): δ ϭ 0.98
(m, 6 H, 2CH2CH3), 1.46 (m, 3 H, CH2CH3), 3.12 (m, 6 H,
3CH2CH3), 4.48 (m, 2 H, CH2), 4.90 (m, 2 H, CH2), 6.43 (d, 2 H,
and combined with Et2O (20 mL). The resultant green solid was
separated by filtration and dried in vacuo. Yield: 18 mg
10·CH2Cl2·Et2O (82%). 1H NMR (CD2Cl2, 269.60 MHz): δ ϭ 1.05
4598
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
Eur. J. Inorg. Chem. 2004, 4591Ϫ4601

Pentadentate Ligand Et2NpyS4ϪH2 {4-(Diethylamino)-2,6-bis[(2-mercaptophenyl)thiomethyl]pyridine}
FULL PAPER
(t, 6 H, 2CH2CH3), 3.25 (q, 4 H, 2CH2CH3), 4.46 (d, 2 H, CH2),
5.00 (m, 2 H, CH2), 6.46 (s, 2 H, Hβ?, pyridine), 7.28 (m, 4 H,
[Ru(N2H4)(Et2NpyS4)] (15): N2H4 (0.5 mL, 16 mmol) was added to
a red-brown suspension of 13·0.3THF (110 mg, 0.16 mmol) in THF
C6H4), 7.45 (m, 2 H, C6H4), 7.65 (d, 2 H, C6H4) ppm. 13C{1H} (10 mL). Gas evolved and a red solution formed which was concen-
NMR (CD2Cl2, 67.83 MHz): δ ϭ 11.9 (CH2CH3), 45.1 (CH2CH3),
trated in volume to 3 mL. Addition of MeOH (10 mL) led to pre-
55.1 (CH2), 106.2, 126.26, 128.1, 129.5, 131.1, 132.1, 151.3, 152.7, cipitation of a red microcrystalline solid which was separated,
156.65 [C(aryl)] ppm. IR (KBr): ν˜ ϭ 1882 (vs, NO), 1081 (vs, BϪF) washed with MeOH (10 mL) and ether (20 mL) then dried in va-
cmϪ1. MS (FDϩ, CH2Cl2): m/z ϭ 512 [Fe(Et2NpyS4)]ϩ, 1024
cuo. Yield 40 mg of 15·0.3 N2H4·0.6H2O (41%). 1H NMR
[{Fe(Et2NpyS4)}2]ϩ. C28H36BCl2F4FeN3OS4 (788.42): calcd. C ([D6]DMSO, 269.60 MHz): δ ϭ 1.02Ϫ0.83 (t, 6 H, 2CH2CH3),
42.65, H 4.60, N 5.33, found C 42.68, H 4.21, N 5.76.
3.10Ϫ2.99 (m, 4 H, 2CH2CH3), 3.30 (m, 1 H, NH2), 4.24Ϫ4.22 (d,
1 H, NH2), 4.31Ϫ4.28 (d, 2 H, CH2), 4.37 (d, 2 H, CH2), 4.42 (d,
1 H, NH), 6.19 (s, 2 H, Hβ, pyridine), 6.67Ϫ6.59 (m, 4 H, C6H4),
7.37Ϫ7.35 (m, 2 H, C6H4), 7.50Ϫ7.47 (m, 2 H, C6H4) ppm.
13C{1H} NMR (DMF-d7, 67.83 MHz): δ ϭ 12.02 (CH2CH3), 43.25
(CH2CH3), 56.69 (CH2), 102.93, 119.93, 130.61, 132.19, 132.98,
149.98, 158.28 [C(aryl)] ppm. IR (KBr): ν˜ ϭ 3318, 3242, 3100 (m,
NϪH) cmϪ1. MS (FDϩ, CH2Cl2): m/z ϭ 558 [Ru(Et2NpyS4)]ϩ,
[Fe(NO)(Et2NpyS4)] (11): By means of a syringe, NO gas (5 mL,
0.21 mmol) was injected into a stirred yellow suspension of 6
(80 mg, 0.158 mmol) in CH2Cl2 (20 mL). A brown mixture resulted
which was stirred for 24 h, filtered and reduced in volume to about
5 mL. Addition of Et2O (20 mL) precipitated a brown solid which
was separated by filtration and dried in vacuo. Yield: 78 mg
11·0.5CH2Cl2 (92%). IR (KBr): ν˜ ϭ 1637 (s, NO) cmϪ1. MS (FDϩ,
CH2Cl2): m/z ϭ 512 [Fe(Et2NpyS4)]ϩ, 544 [Fe(NO)(Et2NpyS4)]ϩ,
1024 [{Fe(Et2NpyS4)}2]ϩ. C23.5H25ClFeN3OS4 (565.15): calcd. C
48.25, H 4.31, N 7.18; found C 48.77, H 4.49, N 7.11.
590
[Ru(N2H4)(Et2NpyS4)]ϩ,
1116
[{Fe(Et2NpyS4)}2]ϩ.
C23H29.7N3.3O0.6RuS4 (611.5): calcd. C 45.17, H 4.89, N 10.69, S
20.97; found C 45.16, H 5.07, N 10.53, S 20.63.
X-ray Structure Determination of [{Fe(Et2NpyS4؊O2)}2]·8CDCl3
(7·8CDCl3), [Fe(CO)(Et2NpyS4)]·CDCl3 (8·CDCl3), [Fe(CNCy)-
(Et2NpyS4)]·2THF (9·2THF), [Fe(NO)(Et2NpyS4)]BF4·CH2Cl2
(10·CH2Cl2), [Fe(N2H4)(Et2NpyS4)] (12), [Ru(N2H4)(Et2NpyS4)]
(15) and [Ru(N2H4)(Et2NpyS4)]·N2H4 (15·N2H4): Red-brown blocks
of 7·8CDCl3 were grown at room temperature from a saturated
CDCl3 solution of 7 over one week. Red blocks of 8·CDCl3 were
grown at room temperature from a saturated CDCl3 solution of 8
over 3 d. Red single-crystals of 9·2THF were grown at Ϫ27 °C
from a saturated THF solution of 9 over 5 weeks. Brown blocks of
10·CH2Cl2 were obtained from a saturated CH2Cl2 solution at
room temperature over 4 weeks. Brown single-crystals of 12 were
grown at room temperature from a saturated CD2Cl2 solution over
2 weeks. Red prisms of 15 were grown at room temperature from
a saturated THF solution over one week. Orange single crystals of
15·N2H4 were grown at room temperature from a saturated THF
solution of 15 over one week in the presence of excess hydrazine.
Suitable single-crystals were embedded in protective perfluoropoly-
ether oil. Data were collected either with a Siemens P4 (7·8CDCl3)
[Fe(N2H4)(Et2NpyS4)] (12): N2H4 (0.032 mL, 1.0 mmol) was added
to a yellow suspension of 6 (100 mg, 0.20 mmol) in CH2Cl2
(15 mL). During the course of 48 h, a deep red solution resulted
which was filtered and reduced in volume to about 2 mL. Addition
of Et2O (20 mL) precipitated a brown solid which was separated
by filtration and dried in vacuo. Yield: 60 mg of 12·0.25Et2O (55%).
1H NMR ([D8]THF, 269.60 MHz): δ ϭ 0.85 (t, 6 H, 2CH2CH3),
2.90 (br., N2H4), 3.32 (m, 4 H, 2CH2CH3), 4.50 (m, 4 H, 2CH2),
6.56 (s, 2 H, Hβ, pyridine), 7.44 (m, 2 H, C6H4), 7.94 (m, 2 H,
C6H4), 9.72 (m, 4 H, C6H4) ppm. IR (KBr): ν˜ ϭ 3318, 3285, 3237
(m, NϪH) cmϪ1. MS (FDϩ, THF): m/z ϭ 512 [Fe(Et2NpyS4)]ϩ,
1024 [{Fe(Et2NpyS4)}2]ϩ. C24H30.5FeN4OS4 (563.13): calcd. C
51.19, H 5.46, N 9.95; found C 50.82, H 5.71, N 9.55.
[Ru(NO)(Et2NpyS4)]Br (13): Over the course of 1 h, a solution of
Bu4N[Ru(NO)(S2C6H4)2] (2.5 g, 3.82 mmol) in THF (30 mL) was
added dropwise to a boiling solution of 3·0.16 THF (1.52 g,
4.52 mmol) in THF (30 mL). The mixture was heated to reflux for
a further 1 h and cooled to room temperature. After 2 h, the pre-
cipitated red solid was separated by filtration, washed with THF
(30 mL), ether (20 mL) and dried in vacuo. Yield 2 g of 13·0.3THF
(77%). 1H NMR ([D6]DMSO, 269.60 MHz): δ ϭ 0.92 (t, 6 H,
2CH2CH3), 3.20 (q, 4 H, 2CH2CH3), 4.94 (d, 2 H, CH2), 5.25 (d,
2 H, CH2), 6.67 (s, 2 H, Hβ, pyridine), 7.28 (m, 4 H, C6H4), 7.52
(d, 2 H, C6H4), 7.99 (d, 2 H, C6H4) ppm. 13C{1H} NMR (CD2Cl2,
67.83 MHz): δ ϭ 13.85 (CH2CH3), 44.00 (CH2CH3), 54.83 (CH2),
104.62, 124.96, 128.51, 129.73, 130.72, 132.87, 149.86,
151.80, 156.19 [C(aryl)] ppm. IR (KBr): ν˜ ϭ 1858 (vs, NO)
or
a Nonius-KappaCCD diffractometer (8·CDCl3, 9·2THF,
10·CH2Cl2, 12, 15 and 15·N2H4) using Mo-Kα radiation (λ ϭ
71.073 pm, graphite monochromator). Intensity data were cor-
rected for absorption effects using either ψ-scans[18] (7·8CDCl3) or
multiple scans of equivalent reflections (SADABS[19] for 9·2THF
and SORTAV[20] for 8·CDCl3, 12, 15 and 15·N2H4) while for
10·CH2Cl2 absorption effects were neglected. The structures were
solved by direct methods and refined on F2 using full-matrix least-
squares procedures (SHELXTL NT 5.10[21] for 7·8CDCl3 8·CDCl3,
9·2THF, 12, 15 and 15·N2H4 or SHELXTL NT 6.12[22] for
10·CH2Cl2). Hydrogen atoms were either located in a difference
Fourier map and refined with a common fixed isotropic displace-
ment parameter (7·8CDCl3 8·CDCl3, 12), kept fixed in their posi-
tions with a common fixed isotropic displacement parameter (15,
15·N2H4), or were geometrically positioned (9·2THF, 10·CH2Cl2).
The solvate molecules in the structures of 7·8CDCl3 8·CDCl3,
9·2THF and 10·CH2Cl2 are partly disordered. Table 6 lists selected
crystallographic data. CCDC-238453 (7·8CDCl3), -238454
(8·CDCl3), -238455 (9·2THF), -238456 (10·CH2Cl2), -238457 (12),
-238458 (15) and -238459 (15·N2H4) contain the supplementary
crystallographic data for this paper. These data can be obtained
cmϪ1
585
.
MS (FDϩ, CH2Cl2): m/z
ϭ
558 [Ru(Et2NpyS4)]ϩ,
[Ru(NO)(Et2NpyS4)]ϩ,
1116
[{Ru(Et2NpyS4)}2]ϩ.
C24.3H28.6BrN3O2RuS4 (704.3): calcd. C 41.49, H 4.10, N 5.97;
found C 41.37, H 4.48, N 6.18.
[{Ru(Et2NpyS4)}2] (14): NH3 gas was bubbled through a red solu-
tion of 13·0.3THF (110 mg, 0.16 mmol) in MeOH (10 mL) for 1 h.
The green solid which precipitated was separated by filtration,
washed with MeOH (10 mL), Et2O (10 mL) and dried in vacuo.
Yield 140 mg, 14·H2O (42%). IR (KBr): ν˜ ϭ 2967, 2923 (m, CϪH) free of charge at www.ccdc.cam.ac.uk/conts/retrieving.html [or
cmϪ1. MS (FDϩ, DMSO): m/z ϭ 1116 [{Ru(Et2NpyS4)}2]ϩ.
from the Cambridge Crystallographic Data Centre, 12 Union
C46H50N4ORuS8 (1115.53): C 48.74, H 4.44, N 4.94; found C 48.70, Road, Cambridge CB2 1EZ, UK; Fax: (internat.) ϩ 44-1223-336-
H 4.14, N 4.85.
033; E-mail: deposit@ccdc.cam.ac.uk]
Eur. J. Inorg. Chem. 2004, 4591Ϫ4601
www.eurjic.org
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
4599

D. Sellmann, S. Y. Shaban, F. W. Heinemann
FULL PAPER
Table 6. Crystallographic data and structure refinement details for [{Fe(Et2NpyS4-(O2)2]}2]·8CHCl3 (7·8CHCl3),
[Fe(CO)(Et2NpyS4)]·CDCl3 (8·CDCl3), [Fe(CNCy)(Et2NpyS4)]·2THF (9·2THF), [Fe(NO)(Et2NpyS4)]BF4·CH2Cl2 (10·CH2Cl2),
[Fe(N2H4)(Et2NpyS4)] (12) [Ru(N2H4)(Et2NpyS4)] (15) and [Ru(N2H4)(Et2NpyS4)]·N2H4 (15·N2H4)
7·8CDCl3
8·CDCl3
9·2THF
10·CH2Cl2
12
15
15·N2H4
Empirical
formula
Mr [g molϪ1
Crystal size
[mm]
C54H48Cl24D8Fe2N4O4S8 C25H24Cl3DFeN2OS4 C38H51FeN3O2S4 C24H26BCl2F4FeN3OS4 C23H28FeN4S4 C23H28N4RuS4 C23H32N6RuS4
]
2052.06
569.91
756.91
0.49 ϫ 0.28 ϫ
0.10
714.28
544.58
589.80
621.86
0.50 ϫ 0.28 ϫ 0.15
0.20 ϫ 0.15 ϫ 0.05
0.20 ϫ 0.07 ϫ 0.05
0.25 ϫ 0.21 ϫ 0.38 ϫ 0.22 ϫ 0.17 ϫ 0.17 ϫ
0.14
0.12
0.04
F(000)
1028
1352
1624
728
2272
2416
1280
Crystal system triclinic
monoclinic
P21/n
1286.76(3)
1316.25(3)
1642.96(4)
90
96.347(2)
90
2.7656(2)
4
monoclinic
P21/n
1595.4(2)
1320.8(2)
1799.0(3)
90
101.088(7)
90
3.7201(9)
4
triclinic
P1
orthorhombic orthorhombic monoclinic
¯
¯
Space group
a [pm]
b [pm]
c [pm]
α [°]
P1
Pbca
Pbca
P21/n
1168.6(1)
1305.7(1)
1521.6(1)
99.91(1)
111.80(1)
98.77(1
2.0632(3)
1
933.94(5)
1208.46(7)
1417.81(7)
82.880(4)
75.627(4)
67.638(4)
1.4328(2)
2
1194.52(2)
1899.01(3)
2111.16(4)
90
1199.83(3)
1922.54(4)
2105.70(4)
90
1091.05(8)
1312.29(8)
1806.19(8)
90
β [°]
90
90
90
90
96.562(5)
90
γ [°]
V [nm3]
Z
4.7890(2)
8
4.8573(2)
8
2.5691(3)
4
ρcalcd. [g cmϪ3
]
1.652
1.585
1.161
100
1.368
0.668
100
1.656
1.057
100
1.511
0.999
100
1.613
1.009
100
1.608
0.961
100
µ [mmϪ1
T [K]
]
1.375
210
θ range [°]
Measured
reflections
Unique
1.9Ϫ26.01
9209
3.34Ϫ29.00
46227
3.46Ϫ25.68
35439
3.15Ϫ25.00
18296
6.01Ϫ30.00
33984
3.3Ϫ30
47848
3.47Ϫ27.50
24316
7971
7346
6961
5037
6926
7017
5867
reflections
Rint
Observed
reflections
σ criterion
Refined
0.0392
5274
0.1189
4691
0.1036
4587
0.1415
3507
0.0808
5040
0.1335
716
0.1031
4038
I Ͼ 2σ(I)
551
I Ͼ 2σ(I)
419
I Ͼ 2σ(I)
509
I Ͼ 2σ(I)
389
I Ͼ 2σ(I)
373
I Ͼ 2σ(I)
289
I Ͼ 2σ(I)
307
parameters
R1 [I Ͼ 2σ (I)] 0.0518
wR2 (all data) 0.1084
0.0468
0.1092
0.850/0.957
0.0592
0.1472
0.795/1.000
0.0651
0.1871
Ϫ
0.0384
0.0871
0.723/0.937
0.0445
0.0892
0.807/0.885
00451
0.0897
0.888/0.972
Absorption
correction
Tmin./Tmax.
0.505/0.613
[2f]
mann, Eur. J. Inorg. Chem. 2000, 423Ϫ429.
D. Sellmann,
Acknowledgments
J. Utz, F. W. Heinemann, Inorg. Chem. 1999, 38, 5314Ϫ5322.
[2g]
We thank Prof. Dr. Horst Kisch and Prof. Dr. Andereas Grohman
for their helpful suggestions. Financial support for this work from
the Deutsche Forschungsgemeinschaft (SFB, 583: ‘‘Redoxaktive
Metallkomplexe’’) and the Fonds der Chemischen Industrie is
gratefully acknowledged.
D. Sellmann, K. Hein, F. W. Heinemann, Eur. J. Inorg.
Chem. 2004, 3136Ϫ3146.
[3] [3a]
R. A. Henderson, G. J. Leigh, C. J. Pickett, Adv. Inorg.
H. Kandler, C.
Gauss, W. Bidell, S. Rosenberger, T. Bürgi, I. L. Eremenko, D.
[3b]
Chem. Radiochem. 1983, 27, 197Ϫ292.
Veghini, O. Orama, P. Burger, H. Berke, Chem. Eur. J. 1995, 1,
[3c]
541Ϫ548.
J. Chatt, A. J. Pearman, R. L. Richards, J. Or-
ganomet. Chem. 1975, 101, 45Ϫ47.
[1] [1a]
[4]
[5]
B. K. Burgess, in ‘‘Molybdenum Enzymes, Cofactors and
D. Sellmann, B. Hautsch, A. Rösler, F. W. Heinemann, Angew.
Chem. 2001, 113, 1553Ϫ1555; Angew. Chem. Int. Ed. 2001,
40, 1505Ϫ1507.
Model Systems’’ (Eds.: E. I. Stiefel, D. Coucouvanis, W. E.
Newton), ACS Symp. Ser. 1993, 535, 144Ϫ170.
R. N. F. Thorneley, B. E. Smith, in Metalloproteins, part 1
(‘‘Metal Proteins with Redox Roles’’) (Ed.: P. Harrison), Verlag
Chemie, Weinheim, 1985.
[1b]
D. J. Lowe,
D. Sellmann, A. Hille, F. W. Heinemann, M. Moll, A. Rösler,
J. Sutter, G. Brehm, M. Reiher, B. A. Hess, S. Schneider, Inorg.
Chim. Acta 2003, 348, 194Ϫ198.
[1c]
R. R. Eady, in Perspectives in Bi-
[6]
[7]
oinorganic Chemistry (Eds.: R. W. Hay, J. R. Dilworth, K. B.
Nolan), JAI Press, London, 1991, p. 225.
N. Blum, PhD Dissertation, University of Erlangen-
Nürnberg, 2000.
[2] [2a]
D. Sellmann, N. Blum, F. W. Heinemann, Z. Naturforsch.,
H. Takato, J. Kankare, Acta Chem. Scand., Ser. B 1987, 41,
[2b]
Teil B 2001, 56, 581Ϫ588.
D. Sellmann, N. Blum, F. W.
219Ϫ221.
[8] [8a]
Heinemann, B. A. Hess, Chem. Eur. J. 2001, 7, 1874Ϫ1880. [2c]
D. Sellmann, J. Utz, N. Blum, F. W. Heinemann, Coord. Chem.
Rev. 1999, 190Ϫ192, 607Ϫ627. [2d] D. Sellmann, D. Häußinger,
M. J. Baker-Hawkes, D. Billig, H. B. Gray, J. Am. Chem.
[8b]
Soc. 1966, 88, 4870Ϫ4875.
D. Sellmann, S. Fünfgelder, G.
Pohlmann, F. Knoch, M. Moll, Inorg. Chem. 1990, 29,
[8c]
T. Gottschalk-Gaudig, F. W. Heinemann, Z. Naturforsch., Teil
B 2000, 55, 723Ϫ729.
4772Ϫ4778.
D. Sellmann, S. Fünfgelder, F. Knoch, M.
[2e]
[8d]
D. Sellmann, K. Engl, F. W. Heine-
Moll, Z. Naturforsch., Teil B 1991, 46, 1601Ϫ1608.
D.
4600
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
Eur. J. Inorg. Chem. 2004, 4591Ϫ4601

Pentadentate Ligand Et2NpyS4ϪH2 {4-(Diethylamino)-2,6-bis[(2-mercaptophenyl)thiomethyl]pyridine}
FULL PAPER
[14]
Sellmann, P. Bail, F. Knoch, M. Moll, Chem. Ber. 1995, 128,
L. Pauling, Die Natur der chemischen Bindung, VCH Verlagsge-
sellschaft, Weinheim, 1973, p. 249.
R. R. Gagne, C. A. Koval, G. C. Linsensky, Inorg. Chem. 1980,
19, 2855Ϫ2857.
A. J. Bond, L. R. Faulkner, Electrochemical Methods, Funda-
mentals and Applications, Wiley, New York, 1980.
J. Degani, R. Fochi, Synthesis 1976, 7, 471Ϫ472.
A. C. T. North, D. C. Phillips, F. S. Mathews, Acta Crystallogr.,
Sect. A 1968, 24, 351Ϫ359.
R. H. Blessing, Acta Crystallogr., Sect. A 1995, 51, 33Ϫ38.
SADABS: Bruker AXS, Inc., Madison, WI, USA, 2002.
SHELXTL NT 5.10: Bruker AXS, Inc., Madison, WI, USA,
1998.
[8e]
653Ϫ663.
D. Sellmann, P. Bail, F. Knoch, M. Moll, Inorg.
[15]
[16]
Chim. Acta 1995, 237, 137Ϫ141.
[9] [9a]
A. T. Laurie, C. N. Juan, M. O. Marilyn, K. M. Pradip,
[9b]
Inorg. Chem. 1998, 38, 616Ϫ617.
C. A. Ghilardi, S. Midol-
[9c]
lini, S. Moneti, J. Organomet. Chem. 1981, 217, 391Ϫ401.
K. Manoj, C. J. Gerard, R. O. Day, J. M. Michael, J. Am.
Chem. Soc. 1989, 111, 8323Ϫ8325.
[17]
[18]
[10] [10a]
[10b]
F. Bottomley, Acc. Chem. Res. 1978, 11, 158Ϫ163.
A. McCleverty, Chem. Rev. 1979, 79, 53Ϫ76.
J.
[19]
[20]
[21]
[11]
D. Sellmann, G. Binker, Z. Naturforsch., Teil B 1987, 42,
341Ϫ347.
[12] [12a]
D. Sellmann, K. P. Peters, F. W. Heinemann, Eur. J. Inorg.
[22]
Chem. 2004, 581Ϫ590. [12b] D. Sellmann, J. Sutter, Inorg. Chem.
2004, 52, 587Ϫ681.
SHELXTL NT 6.12: Bruker AXS, Inc., Madison, WI, USA,
2002.
[13]
P. L. Bogdan, M. Sabat, S. A. Sunshine, C. Woodcock, D. F.
Shriver, Inorg. Chem. 1988, 27, 1904Ϫ1910.
Received May 14, 2004
Early View Article
Published Online October 20, 2004
Eur. J. Inorg. Chem. 2004, 4591Ϫ4601
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4601