Synthesis and characterisation of disulfides and esters derived from their sodium organodithiophosphonate salts

Article abstract of DOI:10.1039/b406007e

Reaction of Fc(S)PS₂P(S)Fc and An(S)PS₂P(S)An with NaOR [R = Me, Et, ⁱPr] gives the non symmetric sodium phosphonodithioate salts Fc(RO)PS₂Na and An(RO)PS₂Na respectively (An = anisyl, Fc = ferrocenyl

Full text of DOI:10.1039/b406007e

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P A P E R
Synthesis and characterisation of disulfides and esters derived
from their sodium organodithiophosphonate saltsw
Ian P. Gray, Alexandra M. Z. Slawin and J. Derek Woollins*
School of Chemistry, University of St Andrews, St Andrews, Fife, UK KY16 9ST.
E-mail: jdw3@st-and.ac.uk
Received (in Durham, UK) 21st April 2004, Accepted 15th June 2004
First published as an Advance Article on the web 14th September 2004
i
Reaction of Fc(S)PS2P(S)Fc and An(S)PS2P(S)An with NaOR [R ¼ Me, Et, Pr] gives the non
symmetric sodium phosphonodithioate salts Fc(RO)PS2Na and An(RO)PS2Na respectively (An ¼ anisyl,
Fc ¼ ferrocenyl). These salts can be oxidised by I2, activated by KI, to form organodithiophosphono
disulfides of the type (R(R0O)P(S)–S–S–P(S)(OR0)R). Reactions of these salts with 2,4-dinitrosulfenyl
chloride form organodithiophosphono disulfides of the type [R(R0O)P(S)–S–S–R]. These sodium salts can
also react with benzyl bromide to form S-alkyl O-alkyl 4-methoxyphenyldithiophosphonate esters and
S-alkyl O-alkyl ferrocenyldithiophosphonate esters. All new compounds have been characterised
spectroscopically and seven demonstrative X-ray structures are reported.
Esters of O,O-dialkyl and O,O-dialkoxy phosphodithioic
Introduction
acids (–P–S–R) have also been of importance because of their
use as lubricant additives and as insecticides of low mammalian
toxicity.8 They have been synthesized via several methods, the
addition of O,O-dialkyl and O,O-dialkoxy phosphodithioic
acids to C¼C double bonds,8a,9 cleaving the S–S bridge of
the aforementioned phosphodithioate disulfides with organo-
metallic reagents such as butyl lithium or Grignard reagents5
h,10 and also by reacting alkali metal or ammonium salts of O,
O-dialkyl and O,O-dialkoxy phosphodithioic acids with alkyl
halides.10 A recent publication has detailed another successful
route using phosphorothioylsulfenyl halides (phosphinesulfe-
nyl halide P-sulfides), (RO)2PS(¼S)X (X ¼ Cl, Br, I),11 in the
past this route had been found to be problematic due to the
thermal instability of the halides and difficult synthesis. The
vast majority of the phosphodithioate disulfides and esters
discussed contain either phosphorodithioate (A) or phosphi-
nodithioate (C) phosphorus centres. Literature detailing the
synthesis, chemistry and structural behaviour of the complexes
of phosphorodithioate (A) and phosphinodithioate ligands (C)
is plentiful and widely available.4a–d Due to synthetic difficul-
ties, compounds containing phosphonodithioate ligands (B)
have received little attention.
Phosphodithioates, their corresponding acids and metal com-
plexes have been used in many commercial applications. Since
the beginning of the twentieth century, compounds of this type
have been used as flotation reagents,1 additives to lubricant
oils,2 pesticides and for chemical warfare.3
Recent studies on phosphodithioate compounds have fo-
cused largely on the use of these as ligands for metal com-
plexation.4 The ability of phosphodithioates to form organic
compounds has been largely overlooked, although this area
would benefit greatly from the use of modern techniques e.g.
crystallography and NMR spectroscopy.
Phosphodithioates can be used in the synthesis of disulfides;
these can be two dithiophosphate groups joined by a disulfide
bridge (–P–S–S–P–) or one dithiophosphate group attached via
a disulfide bridge to an organic substituent e.g. an aliphatic or
aromatic moiety (–P–S–S–R). Compounds of the former type
have been the subjects of some recent reports;5 the structures
have been elucidated using spectroscopic techniques and in a
handful of cases their X-ray structures have been obtained.5a–c
One compound has a very useful application in biological
chemistry. Oligo(nucleoside phosphorothioate)s are amongst
the most promising of the nucleotide analogues which have
been tested as antisense modulators of gene expression, bis(O,
O-diisopropoxy phosphinothioyl) disulfide has been shown to
be a highly efficient sulfurizing reagent for cost-effective synth-
esis of oligo(nucleoside phosphorothioate)s.5d It is relatively
inexpensive to prepare, easy to handle, highly efficient and can
be stored in air for several months.
Few studies of disulfides of the type (–P–S–S–R) have been
conducted in recent years. Almost twenty years ago Shabana
et al. published studies containing a few of these compounds
with their 31P NMR chemical shifts and very little other
experimental data.6 Other publications concerning these dis-
ulfides were published in the 1960’s and early 1970’s and,
although very useful, contain very little spectroscopic informa-
tion.7
Interest in phosphonodithioate (B) derivatives has increased
in recent years. Aragoni et al. have reported the synthesis and
characterisation of several square planar complexes of al-
koxy(4-methoxyphenyl)dithiophosphonate ligands with group
10 metal centres (Ni, Pd and Pt).4f They achieved this via a ring
opening reaction of the well known and well studied12 thiona-
tion compound Lawesson’s Reagent. The dimeric Lawesson’s
Reagent is cleaved by nucleophilic attack conducted by sodium
alkoxides to form sodium alkoxy(4-methoxyphenyl)dithiopho-
sphonate salts, which can be further reacted to form metal
w Electronic supplementary information (ESI) available: syntheses and
spectroscopic data. See http://www.rsc.org/suppdata/nj/b4/b406007e/
¨
complexes. A similiar method was employed by Ozcan et al. in
T h i s j o u r n a l i s & T h e R o y a l S o c i e t y o f C h e m i s t r y a n d t h e
C e n t r e N a t i o n a l d e l a R e c h e r c h e S c i e n t i f i q u e 2 0 0 4
N e w J . C h e m . , 2 0 0 4 , 2 8 , 1 3 8 3 – 1 3 8 9
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distinct isomeric forms, but in this case we believe these to be
the formation of bis[O-2,4-di-tert-butylphenyl(4-methoxyphe-
nyl)dithiophosphoato] nickel(II), an analogous compound con-
taining a bulky sterically protecting substituent.4g We have
extended this work on alkoxy(4-methoxyphenyl)dithiopho-
sphonate ligands, within our laboratory, to include complexes
of group 12 (Zn, Cd, Hg) and group 14 (Sn and Pb) metal
centres exhibiting a range of different structural motifs.13
We have also recently described the synthesis, full character-
isation and crystallographic structural study of alkoxy(ferro-
cenyl)dithiophosphato complexes4e,14 which were synthesised
using sodium alkoxy(ferrocenyl)dithiophosphonate salts ob-
tained from the cleavage of Ferrocenyl Lawesson’s Reagent, a
less well studied15 analogue of Lawesson’s Reagent. Stable
complexes exhibiting varied structural types were also formed
using group 10, 12 and 14 metals in an analogous manner.4e,14
The use of these phosphonodithioate ligands as synthons
for main group organic chemistry has been largely overlooked.
Here we report the use of sodium alkoxy(4-methoxyphenyl)
dithiophosphonate and sodium alkoxy(ferrocenyl)dithiopho-
sphonate salts in the formation of disulfides, of both
(–P–S–S–P–) and (–P–S–S–R) types, S-alkyl O-alkyl 4-meth-
oxyphenyldithiophosphonate and S-alkyl O-alkyl ferrocenyl-
dithiophosphonate esters.
due to chirality since the sodium salts 1 and 2 each possess a
chiral centre at the phosphorus atom. When the sulfur–sulfur
bridge is formed, the phosphorus atom can have either R or S
orientation, allowing two distinct isomers to be formed—where
both phosphorus atoms have the same orientation (R–R, S–S)
1
or have different orientations (R–S). The H and 13C spectra
clearly show the presence of both the aromatic and alkoxy
substituents displaying the expected coupling constants. The
IR spectra of the disulfides 3 and 4 showed one significant
difference from the starting sodium salts, the appearance of an
n(S–S) absorption from the disulfide bridge in the range
488–492 cmꢀ1. In all cases mass spectrometry found the
expected (M)1.
The X-ray structure of 3p (see Fig. 1) shows that the
compound crystallizes with two isomeric independent mole-
cules present within the unit cell. Both isomers display the same
Results and discussion
The phosphonodithioate salts 1 and 2 were prepared using the
literature procedures.4e,f,13,14 Lawesson’s Reagent and Ferro-
cenyl Lawesson’s Reagent were refluxed with 2 molar equiva-
lents of NaOMe in methanol to give salts 1m and 2m
respectively. Phosphonodithioate salts 1e, 1p, 2e and 2p were
also formed from the reaction of Lawesson’s Reagent or
Ferrocenyl Lawesson’s Reagent with the corresponding so-
dium alkoxide, but in these cases the sodium alkoxide was
prepared from the reaction of sodium metal and the corre-
sponding alcohol and used directly in the alcohol solution,
[eqn. (1)].
ð1Þ
Cleavage of these dimers generates the sodium phosphono-
dithioate salts as either white 1 or dark yellow 2 powders in
high yield (An ¼ anisyl, Fc ¼ ferrocenyl). The salts are soluble
in polar solvents such as alcohols and acetone but are insoluble
in less polar solvents e.g. dichloromethane, chloroform, hexane
etc. All of the above salts were found to be air stable both as
solids and in solution. All spectra (31P, 1H, 13C NMR, IR and
mass spectrometry) were in accord with literature values.
The dithiophosphonodisulfides 3 and 4 were prepared by the
reaction of I2, activated by KI, with phosphonodithioate salts 1
and 2 in aqueous solution [eqn. (2)].
ð2Þ
The disulfides 3m and 3e were obtained as colourless oils; 3p
was obtained as a white solid and 4m, 4e and 4p as yellow
solids. All are air stable and soluble in both dichloromethane
and chloroform. The 31P spectra contain a pair of sharp
singlets of approximately equal intensity in the range d(P) 89.2
–98.3 ppm. This result would indicate the presence of two
Fig. 1 The X-ray structure of 3p, all hydrogen atoms are omitted for
clarity. Both isomers are illustrated. Upper diagram, isomer (a); lower
diagram isomer (b).
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geometry in terms of the P2S4 backbone of the molecules.
Other studies5a have shown that this P2S4 backbone can adopt
several different geometries, anti–anti where both sulfurs not
involved in the disulfide bridge point away from the disulfide
bridge, syn–syn where both point towards the disulfide bridge
or anti–syn where one points towards while the other points
away.
It has been shown that changes in the configuration can
result in alteration of the P–S bond lengths. Anti geometries
result in short (ca. 2.1 A) P–S bonds, distortion from anti
geometries causes P–S bond length elongation. Both isomers of
3p display anti–anti geometry with S–S–P¼S torsion angles of
ꢀ171.21(3) and ꢀ170.28(3)1 for (a) and ꢀ173.52(3) and
ꢀ172.28(2)1 for (b). The P–S bond lengths are short
(2.1154(7) and 2.1022(7) A) as expected, with S–S bond lengths
of 2.0849(7) and 2.0831(7) A respectively. These lengths and
angles are consistent with literature values for disulfides of this
type with anti–anti configuration.5a Both isomers have another
common structural feature, the anisyl groups adopt an eclipsed
geometry (with respect to the P–P vector) but contain subtle
differences. For isomer (a) the distance between the centres of
the rings is 3.70(1) A and the deviation from parallel is 111,
while for (b) the distance between the centre of the rings is
larger 3.83(1) A with a larger angle of deviation (191). These
subtle differences arise from the structural differences between
the two isomeric forms. The isomerisation arises from the
differing geometries of the p-OMe group of the anisyl rings.
In the case of isomer (a) the p-OMe groups are on opposite
sides of the molecule with respect to the P–P vector, allowing
the molecule to have approximate 2-fold rotational symmetry.
In the case of isomer (b) the p-OMe groups are on the same side
of the molecule breaking the rotational symmetry. The extra
steric bulk resulting from both p-OMe groups residing on the
same side of the molecule may cause the anisyl rings to be
further apart and hence deviate further from parallel.
The X-ray structure of 4m was also obtained (see Fig. 2).
Like both isomers of 3p, 4m also adopts an anti–anti geometry
with S–S–P¼S torsion angles of ꢀ174.25(5)1 (the molecule has
crystallographic 2-fold symmetry). The P–S bond lengths are
short (2.0995(13) A) as expected whilst the S–S bond length is
2.0746(19) A. Unlike both isomers of 3p, the aromatic (ferro-
cenyl) substituents of 4m do not exhibit an eclipsed structure
with respect to the P–P vector. The ferrocenyl groups adopt a
non-eclipsed geometry allowing them to be a much greater
distance apart.
The structure of 4p (see Fig. 3) is very similar to that of 3p.
The molecule adopts an anti–anti geometry with S–S–P¼S
torsion angles of ꢀ177.10(5)1, contains P–S bond lengths of
2.087(12) A and an S–S bond lengths of 2.0808(18) A. Like 3p,
4p also adopts an eclipsed structure with the two substituted
cyclopentadiene rings of the ferrocenyl groups arranging them-
Fig. 3 The X-ray structure of 4p, all hydrogen atoms are omitted for
clarity.
selves to face each other. The centres of the rings are 3.78(1) A
apart with a deviation of 151 from parallel.
Dithiophosphonodisulfides 5 and 6 were prepared by the
reaction of sodium salts 1 and 2 with 2,4-dinitrosulfenyl
chloride in tetrahydrofuran [eqn. (3)].
ð3Þ
Disulfides 5 were obtained as greenish yellow solids while 6
were obtained as red solids. All are air stable and soluble in
both dichloromethane and chloroform. The 31P spectrum of
each contains a sharp singlet in the range d(P) 85.1–95.2 ppm.
The 1H and 13C spectra confirm the presence of the 2,4-
dinitrophenyl group as well as the aromatic and alkoxy sub-
stituents on the phosphorus centre. The IR spectra of the
disulfides 5 and 6 showed the appearance of the n(S–S)
absorption from the disulfide bridge, in the range 478–499
cmꢀ1, as well as the appearance of the two distinct nitro
environments, n(NO2)asymm 1596–1593 and 1527–1523,
n(NO2)symm 1391–1384 and 1342–1338. In all cases mass
spectrometry found the expected (M)1.
The X-ray structures of 5m and 5e were obtained (see Fig. 4).
Both molecules adopt similar structural motifs; the disulfide
bridge allows the molecule to curve round with the aromatic
rings facing each other, with S–S–C angles of 104.22(7) and
105.59(6)1 respectively. In both cases there is only a 91 devia-
tion from the rings being parallel to each other. The rings are
3.59(1) and 3.63(1) A apart for 5m and 5e respectively,
indicating the presence of long range p–p interactions. Chan-
ging from 5m to the ethyl analogue, 5e, does not significantly
alter the P–S and S–S bond lengths within the molecule. The
P–S bond lengths are 2.1199(8) and 2.1247(8) A respectively;
these are slightly longer than those for disulfides 3p, 4m and 4p,
as a consequence of the shortening of the S–S disulfide bridge.
The S–S distance has decreased from ca. 2.08 A (for 3p, 4m and
4p) to 2.0640(8) and 2.0567(8) A for 5m and 5e respectively,
due to the change in bound substituent from phosphonodithio-
ate to 2,4-dinitrophenyl. There is one significant structural
difference between 5m and 5e, the orientation of the p-OMe
of the anisyl groups. Both lie in the plane of the attached
aromatic ring but point in opposite directions, for 5e this forces
the p-OMe to be closer to the nitro groups of the neighbouring
ring; this may be the reason that 5e has a slightly longer p–p
distance (þ0.04 A).
Fig. 2 The X-ray structure of 4m, all hydrogen atoms are omitted for
clarity.
N e w J . C h e m . , 2 0 0 4 , 2 8 , 1 3 8 3 – 1 3 8 9
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ð4Þ
The esters 7 were obtained as colourless oils, 8 were obtained
as orange oils with the exception of 8p, an orange solid. All are
air stable and soluble in both dichloromethane and chloro-
form. The 31P spectrum of each contains a sharp singlet in the
range d(P) 93.6–101.1 ppm. The 1H and 13C spectra confirm the
presence the aromatic and alkoxy substituents on the phos-
phorus centre. The chemical shifts of the benzyl group are
obvious in the 1H and 13C spectra and the sulfur–carbon
linkage is confirmed by the appearance of 31P–13C and 31P–
1H coupling to the benzyl CH2 bridging carbon. The IR spectra
of the disulfides 5 and 6 showed no significant differences from
the starting sodium salts and in all cases mass spectrometry
found the expected (M)1.
The X-ray structure of 8p was obtained (see Fig. 6). The
molecule does not exhibit a curved structure like 5m or 5e but
instead adopts a more linear structure allowing the aromatic
groups to be well separated. The P–S bond length (2.0768(6) A)
is consistent with the other compounds in this paper. The
bridging S–C bond length, 1.8416(18) A, is consistent with S–C
bond lengths known16 and is considerably shorter than the
disulfide bridge S–S bond lengths we have reported. The angle
between the S–C and the C-1 of the phenyl ring, S(2)–C(14)–
C(15), is 107.651. This is significantly larger than the equivalent
S–S–C angles displayed for 5m, 5e and 6m (103.3–105.591),
which is not unexpected as carbon compounds generally adopt
more strictly tetrahedral conformations than their sulfur ana-
logues. This larger angle, coupled with the shorter bridge
length, may be the reason why the molecule does not display
any p–p interactions.
Fig. 4 Upper diagram, the X-ray structure of 5m; lower diagram, the
X-ray structure of 5e.
6m, the ferrocenyl analogue of 5m, adopts a very similar
structure to that of 5m and 5e (see Fig. 5). The molecule
exhibits the same S–S–C curve, with an angle of 103.3(3)1.
The p–p distance (3.76(1) A) is slightly longer and the deviation
from parallelism (131) is a little larger. Both P–S (2.115(3) A)
and S–S (2.056(3) A) bond lengths are not significantly differ-
ent to those in 5m and 5e.
This work clearly demonstrates the use of sodium alkoxy(4-
methoxyphenyl)dithiophosphonate and sodium alkoxy(ferro-
cenyl)dithiophosphonate salts in the preparation of organo-
dithiophosphono disulfides, of both (–P–S–S–P–) and (–P–S–S
–R) types, S-alkyl O-alkyl 4-methoxyphenyldithiophosphonate
and S-alkyl O-alkyl ferrocenyldithiophosphonate esters.
S-alkyl O-alkyl 4-methoxyphenyldithiophosphonate 7 and
S-alkyl O-alkyl ferrocenyldithiophosphonate esters 8 were
prepared by the reaction of sodium salts 1 and 2 with benzyl
bromide in methanol [eqn. (4)].
Experimental
General
Unless otherwise stated, operations were carried out under an
oxygen-free nitrogen atmosphere using predried solvents and
standard Schlenk techniques. The phosphonodithioate salts 1
Fig. 5 The X-ray structure of 6m.
Fig. 6 The X-ray structure of 8p.
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and 24e,f,13,14 and Ferrocenyl Lawesson’s Reagent15 were pre-
pared using literature procedures. All other reagents were
purchased from either Aldrich, Acros or Lancaster and used
as received. Infrared spectra were recorded as either Nujol
mulls or KBr discs in the range 4000–250 cmꢀ1 on a Perki-
ring), 4.25 (s, 5H, Fc unsubstituted ring), 3.98 (dq, 2H, 3J
3
3
(31P–1H) 3.3 Hz, J(1H–1H) 7.2 Hz, CH2), 1.35 (t, 3H, J(1H–
1
1H) 6.9 Hz, CH3). 13C NMR (CDCl3) d: 75.7 (d, J(31P–13C)
140.4 Hz, Fc substituted ring C-1), 73.1 (m, Fc substituted
ring), 72.5 (m, Fc substituted ring), 70.9 (s, Fc unsubstituted
2
nElmer System 2000 Fourier-transform spectrometer. H, 31P
ring), 61.9 (d, J(31P–13C) 6.6 Hz, CH2), 16.6 (broad s, CH3).
1
and 13C NMR spectra were recorded using a JEOL DELTA
GSX 270 FT NMR spectrometer. Microanalyses were per-
formed by the University of St. Andrews’ microanalysis ser-
vice. Mass spectra were recorded by the Swansea mass
spectrometry service.
Six typical syntheses are described below. The remaining
syntheses and spectroscopic data are available as electronic
supplementary information.w
Isomer (b). 31P NMR (CDCl3) d: 93.0. 1H NMR (CDCl3)
d 4.57 (m, 2H, Fc substituted ring), 4.41 (m, 2H, Fc substitu-
ted ring), 4.18 (s, 5H, Fc unsubstituted ring), 3.52 (dq, 2H,
3J(31P–1H) 2.7 Hz, 3J(1H–1H) 6.9 Hz, CH2), 1.21 (t, 3H, 3J(1H–
1
1H) 6.9 Hz, CH3). 13C NMR (CDCl3) d: 75.6 (d, J(31P–13C)
144.3 Hz, Fc substituted ring C-1), 72.8 (m, Fc substituted
ring), 72.2 (m, Fc substituted ring), 70.8 (s, Fc unsubstituted
2
ring), 61.8 (d, J(31P–13C) 6.6 Hz, CH2), 16.5 (broad s, CH3).
Selected IR data (KBr) n/cmꢀ1: 1184 (m), 1023 (s), 664 (s),
Bis[(ethoxy)-4-methoxyphenylthiophosphono] disulfide (3e)
536 (s), 491 (m). MS (MALDI): (M)1 650.
A solution of KI (1 g, 6.029 mmol) in H2O (9 cm3) was added
to I2 (0.141 g, 0.555 mmol) and stirred until I2 completely
dissolved. This solution was added dropwise to a solution of 1e
(0.300 g, 1.110 mmol) in H2O (20 cm3). A white suspension
formed immediately and was stirred for a further 1 h to ensure
complete reaction. The solvent was removed under reduced
pressure, the resulting yellow oil was redissolved in dichlor-
omethane and filtered through a small Celite plug. The solvent
was removed under reduced pressure to give a colourless oil
(0.235 g, 86%). Found (calc. for C18H24O4P4S4): C 44.11
(43.72), H 4.77 (4.90), S 25.33 (25.89)%.
2,4-Dinitrophenyl 4-methoxyphenyl(ethoxy)thiophosphonyl
disulfide (5e)
2,4-Dinitrosulfenyl chloride (0.087 g, 0.370 mmol) was added
to a flask containing salt 1e (0.100 g, 0.370 mmol). Upon
addition of tetrahydrofuran (10 cm3), with stirring, an im-
mediate cloudy yellow solution is formed. The reaction mixture
was stirred for 1 h resulting in a yellow/green solution. The
solvent was removed under reduced pressure, the resulting
green oily solid was redissolved in dichloromethane and filtered
through a small Celite plug. The filtrate was concentrated
under vacuum to ca. 2 cm3, hexane was added and cooled to
5 1C for 2 h to precipitate the product as a bright green solid.
(0.108 g, 65%). Yellow crystals suitable for X-ray analysis were
grown by vapour diffusion of hexane into a chloroform solu-
tion. Found (calc. for C15H15O6N2PS3): C 40.44 (40.36), H
3.55 (3.39), N 5.99 (6.28), S 21.02 (21.51)%. 31P NMR (CDCl3)
d: 87.2. 1H NMR (CDCl3) d: 8.87 (d, 1H, 4J(1H–1H) 2.5 Hz, Ph
Isomer (a). 31P NMR (CDCl3) d: 90.1. 1H NMR (CDCl3) d:
3
3
7.74 (dd, 2H, J(31P–1H) 14.1 Hz, J(1H–1H) 9.3 Hz, o-AnH),
4
3
6.87 (dd, 2H, J(31P–1H) 3.9 Hz, J(1H–1H) 9.0 Hz, m-AnH),
4.22 (dq, 2H, 3J(31P–1H) 1.8 Hz, 3J(1H–1H) 6.9 Hz, CH2), 3.80
(s, 3H, AnOMe), 1.30 (t, 3H, J(1H–1H) 6.9 Hz). 13C NMR
3
(CDCl3) d: 163.6 (d, 4J(31P–13C) 3.0 Hz, p-AnC), 133.8
(d, J(31P–13C) 12.8 Hz, m-AnC), 125.0 (d, J(31P–13C) 130.1
Hz, An C-1), 114.3 (d, 2J(31P–13C) 16.6 Hz, o-AnC), 62.6
(d, 2J(31P–13C) 7.5 Hz, CH2), 56.0 (s, AnOCH3), 16.3
3
1
4
3
H-3), 8.00 (dd, 1H, J(1H–1H) 2.5 Hz, J(1H–1H) 9.1 Hz, Ph
H-5), 7.77 (d, 1H, J(1H–1H) 9.2 Hz, Ph H-6), 7.69 (dd, 2H,
3
3
J(31P–1H) 13.6 Hz, 3J(1H–1H) 8.9 Hz, o-AnH), 6.62 (dd, 2H, 4
(d, J(31P–13C) 8.3 Hz, CH3).
3
J(31P–1H) 4.0 Hz, J(1H–1H) 9.0 Hz, m-AnH), 4.44 (dq, 1H,
3
3
J(31P–1H) 2.9 Hz, 3J(1H–1H) 6.9 Hz, CH2), 4.28 (dq, 1H, 3J(31P
Isomer (b). 31P NMR (CDCl3) d: 89.2. 1H NMR (CDCl3)
d:7.54 (dd, 2H, 3J(31P–1H) 14.0 Hz, 3J(1H–1H) 9.0 Hz, o-AnH),
–1H) 2.9 Hz, J(1H–1H) 6.9 Hz, CH2), 3.69 (s, 3H, AnOMe),
3
1.46 (t, 3H, 3J(1H–1H) 6.9 Hz. 13C NMR (CDCl3) d: 163.6 (d, 6
J(31P–13C) 4.2 Hz, p-AnC), 145.2 (s, Ph C-4), 144.9 (s, Ph C-1),
144.1 (s, Ph C-2), 133.4 (d, 3J(31P–13C) 13.5 Hz, m-AnC), 129.6
4
3
6.65 (dd, 2H, J(31P–1H) 3.9 Hz, J(1H–1H) 9.0 Hz, m-AnH),
4.06 (dq, 2H, 3J(31P–1H) 1.8 Hz, 3J(1H–1H) 6.9 Hz, CH2), 3.80
(s, 3H, AnOMe), 1.17 (t, 3H, J(1H–1H) 6.9 Hz). 13C NMR
3
(s, Ph C-3), 126.6 (s, Ph C-5), 123.1 (d, J(31P–13C) 131.8 Hz,
1
(CDCl3) d: 163.4 (d, 4J(31P–13C) 3.0 Hz, p-AnC), 133.7
An C-1), 120.8 (s, Ph C-6), 113.7 (d, J(31P–13C) 16.6 Hz, o-
2
(d, J(31P–13C) 12.8 Hz, m-AnC), 123.8 (d, J(31P–13C) 131.3
Hz, An C-1), 114.0 (d, 2J(31P–13C) 16.6 Hz, o-AnC), 62.6
(d, 2J(31P–13C) 7.5 Hz, CH2), 55.8 (s, AnOCH3), 16.3 (d,
3J(31P–13C) 8.3 Hz, CH3).
3
1
AnC), 63.1 (d, J (31P–13C) 6.2 Hz, CH2), 55.5 (s, AnOMe),
2
16.1 (d, J (31P–13C) 8.3 Hz, CH3). Selected IR data (KBr) n/
3
cmꢀ1: 1595 (vs), 1523 (s), 1389 (m), 1339 (vs), 1183 (m), 1015
(s), 672 (m), 532 (m), 491 (m). MS (ESþ):
(M ꢀ S2C6H3(NO2)2)1 215, (M)1 446.
Selected IR data (KBr) n/cmꢀ1: 1181 (s), 1026 (s), 678 (m),
530 (m), 488 (m). MS (ESþ): (1/2M)1 247, (M)1 495,
(M þ Na)1 517.
2,4-Dinitrophenyl ferrocenyl(ethoxy)thiophosphonyl disulfide
(6e)
Bis[(ethoxy)ferrocenylthiophosphono] disulfide (4e)
2,4-Dinitrosulfenyl chloride (0.067 g, 0.287 mmol) was added
to a flask containing salt 2e (0.100 g, 0.287 mmol). Upon
addition of tetrahydrofuran (10 cm3), with stirring, an im-
mediate dark orange solution is formed. The reaction mixture
was stirred for 1 h resulting in a red solution. The solvent was
removed under reduced pressure, the resulting red oil was
redissolved in dichloromethane and filtered through a small
Celite plug. The filtrate was concentrated under vacuum to ca.
2 cm3 and hexane was added to precipitate the product as a red/
orange solid. (0.109 g, 73%) Found (calc. for C18H17O5
FeN2PS3): C 41.60 (41.23), H 2.98 (3.27), N 4.89 (5.35), S
18.34 (18.31)%. 31P NMR (CDCl3) d: 91.8. 1H NMR (CDCl3)
d: 8.88 (d, 1H, 4J(1H–1H) 2.2 Hz, Ph H-3), 8.04 (dd, 1H, 4J(1H–
1H) 2.2 Hz, 3J(1H–1H) 9.1 Hz, Ph H-5), 7.86 (d, 1H, 3J(1H–1H)
A solution of KI (1 g, 6.029 mmol) in H2O (9 cm3) was added
to I2 (0.109 g, 0.431 mmol) and stirred until I2 completely
dissolved. This solution was added dropwise to a solution of 2e
(0.300 g, 0.862 mmol) in H2O (20 cm3). An obvious yellow
precipitate formed immediately and was stirred for a further 25
mins to ensure complete reaction. The product was collected by
suction filtration, washed with methanol (2 ꢁ 10 cm3) and dried
in vacuo to give a mustard yellow powder (0.246 g, 88%).
Found (calc. for C24H28O2Fe2P2S4): C 44.33 (44.31), H 4.05
(4.34), S 19.19 (19.68)%.
Isomer (a). 31P NMR (CDCl3) d: 94.6. 1H NMR (CDCl3) d:
4.60 (m, 2H, Fc substituted ring), 4.44 (m, 2H, Fc substituted
N e w J . C h e m . , 2 0 0 4 , 2 8 , 1 3 8 3 – 1 3 8 9
1387

View Online
Table 1 Selected bond lengths (A) and angles (1) for 3p, 4m, and 4p
9.2 Hz, Ph H-6), 4.47 (m, 2H, Fc substituted ring), 4.27 (m, 2H,
Fc substituted ring), 4.24 (s, 5H, Fc unsubstituted ring), 4.18
(dq, 2H, 3J(31P–1H) 1.8 Hz, 3J(1H–1H) 7.2 Hz, CH2), 1.46
(t, 3H, 3J(1H–1H) 7.2 Hz, CH3). 13C NMR (CDCl3) d: 145.2 (s,
Ph C-4), 144.9 (s, Ph C-1), 144.3 (s, Ph C-2), 129.9 (s, Ph C-3),
3p
4m
4p
S(2)–S(12)/S(2A)
P(1)–S(2)
P(1)–S(1)
2.0849(7)
2.1154(7)
1.9303(7)
1.5831(13)
1.7805(17)
104.65(3)
110.46(6)
2.0746(19)
2.0995(13)
1.9203(14)
1.580(2)
2.0808(18)
2.1087(12)
1.9289(13)
1.578(2)
1
126.6 (s, Ph C-5), 120.8 (s, Ph C-6), 79.9 (d, J(31P–13C) 134.9
2
Hz, Fc substituted ring C-1), 71.8 (d, J(31P–13C) 13.8 Hz, Fc
P(1)–O(1)/O(11)
P(1)–C(1)
2
substituted ring), 71.6 (d, J(31P–13C) 12.2 Hz, Fc substituted
1.764(3)
104.28(5)
107.79(11)
1.771(3)
102.73(6)
110.08(11)
2
ring), 70.5 (s, Fc unsubstituted ring), 63.1 (d, J (31P–13C) 7.2
P(1)–S(2)–S(12)
C(1)–P(1)–S(2)/S(2A)
3
Hz, CH2), 16.3 (d, J(31P–13C) 8.3 Hz, CH3). Selected IR data
(KBr) n/cmꢀ1: 1593 (s), 1527 (s), 1387 (m), 1338 (vs), 1177 (m),
1020 (s), 667 (m), 540 (m), 498 (m). MS (EIþ):
(M ꢀ S2C6H3(NO2)2)1 293, (M)1 524.
Table 2 Selected bond lengths (A) and angles (1) for 5m, 5e, 6m, and
8p
5m
5e
6m
8p
S-Benzyl O-ethyl 4-methoxyphenyldithiophosphonate (7e)
S(2)–S(3)
P(1)–S(2)
P(1)–S(1)
2.0640(8)
2.1199(8)
1.9291(8)
2.0567(8)
2.1247(8)
1.9231(7)
2.056(3)
2.115(3)
1.907(3)
—
Salt 1e (0.126 g, 0.468 mmol) in methanol (4 cmꢀ3) was added
to benzyl bromide (0.080 g, 0.468 mmol) in methanol (10 cmꢀ3
2.0768(6)
1.9342(6)
1.5880(11)
1.7848(15)
—
)
P(1)–O(1)
P(1)–C(1)
P(1)–C(8)
1.5797(14) 1.5880(13) 1.574(4)
1.7868(19) 1.7866(17)
and stirred for 1 h resulting in a colourless solution. The
solvent was removed under reduced pressure, the resulting
colourless oil was redissolved in dichloromethane and filtered
through a small Celite plug. The solvent was again removed
under reduced pressure to yield a colourless oil (0.128 g, 81%).
Found (calc. for C16H19O2PS2): C 56.74 (56.80), H 5.57 (5.66),
S 18.44 (18.92)%. 31P NMR (CDCl3) d: 94.6. 1H NMR
—
1.759(6)
—
—
—
S(3)–C(11)
S(3)–C(1)
1.775(2)
—
—
1.7789(17)
—
—
—
—
1.776(6)
—
S(2)–C(14)
P(1)–S(2)–S(3)
S(2)–P(1)–C(1)
1.8416(18)
—
104.36(3)
107.83(6)
102.42(3)
106.10(6)
105.59(6)
—
100.70(12)
—
—
3
3
107.83(5)
—
—
(CDCl3) d: 7.86 (dd, 2H, J(31P–1H) 13.8 Hz, J(1H–1H) 8.9
S(2)–S(3)–C(11) 104.22(7)
Hz, o-AnH), 7.21 (m, 5H, Ph), 6.94 (dd, 2H, 4J(31P–1H) 3.5 Hz,
C(1)–S(3)–S(2)
S(2)–P(1)–C(8)
P(1)–S(2)–C(14)
—
—
—
103.3(3)
106.44(19)
—
3J(1H–1H) 8.9 Hz, m-AnH), 4.19 (dq, 2H, J(31P–1H) 2.4 Hz,
3
—
—
—
101.85(6)
3J(1H–1H) 3.6 Hz, OCH2), 3.96 (d, 1H, 3J (31P–1H) 3.2 Hz,
SCH2), 3.90 (d, 1H, J (31P–1H) 2.7 Hz, SCH2), 3.83 (s, 3H,
3
AnOMe), 1.28 (t, 3H, 3J(1H–1H) 6.9 Hz, CH3). 13C NMR
(CDCl3) d: 162.9 (d, 6J (31P–13C) 3.1 Hz, p-AnC), 137.2 (d,
3J(31P–13C) 5.2 Hz, Ph C-1), 132.8 (d, 3J (31P–13C) 13.5 Hz,
m-AnC), 129.0 (s, Ph C-3), 128.6 (s, Ph C-4), 127.5 (s, Ph C-2),
126.7 (d, 1J (31P–13C) 128.7 Hz, An C-1), 114.1 (d, 2J (31P–13C)
15.6 Hz, o-AnC), 64.0 (d, 2J (31P–13C) 6.2 Hz, OCH2), 55.6
(s, AnOMe), 38.0 (d, 2J(31P–13C) 4.2 Hz, SCH2), 16.1 (d, 2J
was redissolved in dichloromethane and filtered through a
small Celite plug. The solvent was again removed under
reduced pressure to yield an orange oil (0.107 g, 77%). Found
(calc. for C19H21OFePS2): C 54.90 (54.81), H 5.04 (5.09),
S 14.86 (15.37)%. 31P NMR (CDCl3) d: 97.7. 1H NMR
(CDCl3) d: 7.26 (m, 5H, Ph), 4.58 (m, 2H, Fc substituted ring),
4.44 (m, 2H, Fc substituted ring), 4.32 (s, 5H, Fc unsubstituted
ring), 4.21 (dq, 1H, 3J(31P–1H) 1.8 Hz, 3J(1H–1H) 3.5 Hz,
OCH2), 4.00 (d, 2H, 3J (31P–1H) 13.9 Hz, SCH2), 3.84 (dq, 1H,
(31P–13C) 8.3 Hz, CH3). Selected IR data (KBr) n/cmꢀ1
1184 (s), 1027 (s), 671 (m), 549 (m). MS (EIþ): (M)1 338.
:
3
3J(31P–1H) 1.7 Hz, 3J(1H–1H) 3.6 Hz, OCH2), 1.29 (t, 3H,
S-Benzyl O-ethyl ferrocenyldithiophosphonate (8e)
J(1H–1H) 6.9 Hz, CH3). 13C NMR (CDCl3) d: 137.6 (d, 3J(31P–
13C) 3.8 Hz, Ph C-1), 129.0 (s, Ph C-3), 128.6 (s, Ph C-4), 127.3
Salt 2e (0.116 g, 0.333 mmol) in methanol (4 cmꢀ3) was added
to benzyl bromide (0.057 g, 0.333 mmol) in methanol (10 cmꢀ3
1
(s, Ph C-2), 77.9 (d, J(31P–13C) 141.2 Hz, Fc substituted ring
C-1), 71.8 (m, Fc substituted ring), 71.3 (m, Fc substituted
)
and stirred for 1 h resulting in a yellow solution. The solvent
was removed under reduced pressure, the resulting orange oil
2
ring), 70.5 (s, Fc unsubstituted ring), 61.3 (d, J (31P–13C) 7.6
Table 3 Details of the X-ray data collections and refinements for compounds 3p, 4m, and 4p
Compound
3p
4m
4p
Empirical formula
Crystal colour, habit
C20H28O4P2S4
Colourless, needle
0.15 ꢁ 0.1 ꢁ 0.01
Orthorhombic
Pca21
C22H24Fe2O2P2S4
Orange, prism
0.3 ꢁ 0.1 ꢁ 0.01
Monoclinic
C2/c
C26H32Fe2O2P2S4
Orange, prism
0.1 ꢁ 0.1 ꢁ 0.03
Orthorhombic
Pccn
Crystal dimensions/mm
Crystal system
Space group
a/A
13.0578(14)
12.8267(14)
30.749(3)
90
30.209(9)
7.430(3)
11.365(2)
90
24.880(7)
6.4620(19)
17.898(5)
90
b/A
c/A
a/1
b/1
90
90
99.838(9)
90
90
90
g/1
U/A3
5150.1(10)
8
522.60
2513.3(14)
4
622.29
2877.6(15)
4
678.40
Z
M
Dc/g cmꢀ3
1.348
0.517
1.633
2.288
1.566
1.433
m/mmꢀ1
F(000)
2192
31 641
1272
4487
1400
13 630
Measured reflections
Independent reflections (Rint
Final R1, wR2 [I 4 2s(I)]
)
9365 (0.0189)
0.0208, 0.0529
1928 (0.0312)
0.0350, 0.0731
2601 (0.0835)
0.0406, 0.0815
1388
N e w J . C h e m . , 2 0 0 4 , 2 8 , 1 3 8 3 – 1 3 8 9

View Online
Table 4 Details of the X-ray data collections and refinements for compounds 5m, 5e, 6m and 8p
Compound
5m
5e
6m
8p
Empirical formula
Crystal colour, habit
C14H13N2O6PS3
Yellow, block
0.18 ꢁ 0.1 ꢁ 0.07
Triclinic
C15H15N2O6PS3
Yellow, block
0.18 ꢁ 0.1 ꢁ 0.03
Triclinic
C17H15FeN2O5PS3
Red, prism
C20H23FeOPS2
Orange, prism
0.12 ꢁ 0.1 ꢁ 0.03
Monoclinic
P21/c
Crystal dimensions/mm
Crystal system
0.10 ꢁ 0.05 ꢁ 0.05
Triclinic
ꢀ
P1
ꢀ
P1
ꢀ
P1
Space group
a/A
7.4150(11)
10.9049(16)
11.8459(18)
101.672(2)
105.307(2)
100.104(2)
877.8(2)
2
7.137(2)
10.767(3)
13.652(4)
109.796(4)
90.755(5)
104.339(5)
950.8(5)
2
7.089(4)
10.648(6)
14.773(10)
88.56(7)
76.45(7)
77.84(6)
1059.4(11)
2
14.411(2)
12.2057(17)
11.3570(16)
90
b/A
c/A
a/1
b/1
96.061(2)
90
g/1
U/A3
1986.5(5)
4
430.32
Z
M
432.41
1.636
446.44
1.559
510.31
1.600
Dc/g cmꢀ3
1.439
1.055
m/mmꢀ1
F(000)
0.549
444
0.509
460
1.114
520
896
10 502
Measured reflections
Independent reflections (Rint
Final R1, wR2 [I 4 2s(I)]
5551
3109 (0.0109)
0.0316, 0.0805
5491
3372 (0.0128)
0.0314, 0.0841
3852
2661 (0.0319)
0.0476, 0.0828
)
3583 (0.0182)
0.0238, 0.0570
Hz, OCH2), 37.9 (d, 2J(31P–13C) 3.1 Hz, SCH2), 16.2 (d, 2J
(31P–13C) 8.1 Hz, CH3). Selected IR data (KBr) n/cmꢀ1: 1180
(s), 1028 (s), 687 (m), 560 (m). MS (EIþ): (M)1 416.
D. J. Williams and J. D. Woollins, J. Chem. Soc., Dalton Trans.,
2000, 3269; (e) I. P. Gray, H. L. Milton, A. M. Z. Slawin and J. D.
Woollins, Dalton Trans., 2003, 3450; (f) M. C. Aragoni, M. Arca,
F. Demartin, F. A. Devillanova, C. Graiff, F. Isaia, V. Lippolis, A.
Tiripicchio and G. Verani, Eur. J. Inorg. Chem., 2000, 2239; (g) Y.
¨
Ozcan, S. Ide, M. Karakus and H. Yilmaz, Acta Crystallogr. Sect.
C: Cryst. Struct. Commun., 2002, 58, 388.
X-Ray crystallography
Tables 1 and 2 list selected bond lengths and angles determined
from X-ray crystallographic studies. Tables 3 and 4 list details
of the data collections and refinements.z For 4m and 6m data
were collected at room temperature using Mo Ka radiation
with a Rigaku Mercury system, and for 3m, 4p, 5m, 5e and 8p
at 125 K using a Bruker SMART system. Intensities were
corrected for Lorentz-polarisation and for absorption. The
structures were solved by the heavy atom method or by direct
methods. The positions of the hydrogen atoms were idealised.
Refinements were by full-matrix least squares based on F2
using SHELXTL17
5
(a) P. Knopik, L. Luczak, M. J. Potrezebowski, J. Michalski, J.
Blaszczyk and M. W. Wieczorek, J. Chem. Soc., Dalton Trans.,
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Shchepinov, J. Struct. Chem., 1976, 17, 813; (c) A. Lopusinski,
´
L. Luczak, J. Michalski, A. E. Koziol and M. Gdaniec, J. Chem.
Soc., Chem. Commun., 1991, 889; (d) W. J. Stec, B. Uznanski and
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Tuli, S. Prakash, K. K. Swami and A. K. Bhatnagar, Phosphorus,
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´ ´
phorus, Sulfur Silicon Relat. Elem., 1991, 58, 61.
6
7
R. Shabana, N. M. Yousif and S. O. Lawesson, Phosphorus, Sulfur
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9
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3
4
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15 M. R. St. J. Foreman, A. M. Z. Slawin and J. D. Woollins, J.
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z CCDC reference numbers 240034–240040. See http://www.rsc.org/
suppdata/nj/b4/b406007e/ for crystallographic data in .cif or other
electronic format.
N e w J . C h e m . , 2 0 0 4 , 2 8 , 1 3 8 3 – 1 3 8 9
1389