Bis(thiophosphinoyl)amines and their neutral cobalt(II) complexes, containing stable tetrahedral CoS4 cores. Crystal structures of NH(SPMe2)(SPPh2) and [Co{(SPMe2)(SPPh2)N}2]

Article abstract of DOI:10.1039/a705086k

The compound NH(SPMe₂)(SPPh₂) was prepared using a new method, i.e. the reaction between Li[HN(S)PPh₂] and Me₂P(S)Cl in a diethyl ether-n-hexane mixture. The complex [Co{(SPMe₂)(SPPh₂)N}₂] was obtained by the reaction of CoCl₂·6H₂O and K[(SPMe₂)(SPPh₂)N] in methanol. The crystal and molecular structure of both the free acid NH(SPMe₂)(SPPh₂) and its cobalt(II) complex [Co{(SPMe₂)(SPPh₂)₂N}₂] were determined using X-ray diffractometry. The acid exhibits an anti conformation of the sulfur atoms in the SPNPS system and dimeric pairs are formed in the crystal through N(1)-H(1) ... S(2a) [2.43(9) A] hydrogen bonds, which involve only the sulfur atom of the S=PPh₂ group of each molecule. The cobalt complex consists of discrete, monomeric molecules, with isobidentate ligands [average Co-S 2.32(1), average P-S 2.031(5) A] and a distorted tetrahedral CoS₄ core (S-Co-S range 102.7-117.7°). The structures of both the free acid and its cobalt(II) derivative are discussed in relation with other bis(thiophosphinoyl)amines and metal complexes containing a CoS₄ core.

Full text of DOI:10.1039/a705086k

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Bis(thiophosphinoyl)amines and their neutral cobalt(II) complexes,
containing stable tetrahedral CoS4 cores. Crystal structures of
NH(SPMe2)(SPPh2) and [Co{(SPMe2)(SPPh2)N}2]
Cristian Silvestru,*,a Roland Rösler,a John E. Drake,*,b Jincai Yang,b Georgina Espinosa-Pérezc
and Ionel Haiduca
a Facultatea de Chimie, Universitatea ‘Babes-Bolyai’, RO-3400 Cluj-Napoca, Romania
¸
b Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario N9B 3P4,
Canada
c Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria,
Circuito Exterior, 04510 México, D.F., Mexico
The compound NH(SPMe2)(SPPh2) was prepared using a new method, i.e. the reaction between Li[HN(S)PPh2]
and Me2P(S)Cl in a diethyl ether–n-hexane mixture. The complex [Co{(SPMe2)(SPPh2)N}2] was obtained by the
reaction of CoCl2ؒ6H2O and K[(SPMe2)(SPPh2)N] in methanol. The crystal and molecular structure of both the
free acid NH(SPMe2)(SPPh2) and its cobalt() complex [Co{(SPMe2)(SPPh2)2N}2] were determined using X-ray
diffractometry. The acid exhibits an anti conformation of the sulfur atoms in the SPNPS system and dimeric
pairs are formed in the crystal through N(1)᎐H(1) ؒ ؒ ؒ S(2a) [2.43(9) Å] hydrogen bonds, which involve only the
sulfur atom of the S᎐PPh group of each molecule. The cobalt complex consists of discrete, monomeric molecules,
᎐
2
with isobidentate ligands [average Co᎐S 2.32(1), average P᎐S 2.031(5) Å] and a distorted tetrahedral CoS4 core
(S᎐Co᎐S range 102.7–117.7Њ). The structures of both the free acid and its cobalt() derivative are discussed in
relation with other bis(thiophosphinoyl)amines and metal complexes containing a CoS4 core.
Neutral cobalt() complexes containing 1,1-dithio ligands
(dithiocarbamates, dithiophosphinates, dithiophosphates) are
unstable being readily oxidized to the corresponding cobalt()
derivatives. Dithiophosph(in)ato Co(S2PR2)2 complexes (where
Experimental
Materials and instrumentation
Infrared spectra were run in the range 4000–200 cmϪ1 on a
R = alkyl, aryl or alkoxy) can be stabilized towards metal oxid-
ation, by forming square-pyramidal or octahedral adducts with
amines and phosphines.1 The stability of dithiocarbamato
derivatives, Co(S2CNR2)2, improves with the use of larger per-
ipheral alkyl R groups and in some cases a square planar–
tetrahedral equilibrium was suggested.2 However, no X-ray dif-
fractometry investigation was performed for such complexes.
To our knowledge, so far the molecular structures of only two
monomeric, neutral cobalt() complexes containing dithio
ligands have been reported, i.e. bis(dithioacetylacetonato)-
cobalt(), [Co{(SCMe)2CH}2]3 and [Co{(SPMe2)2N}2],4 which
exhibit square-planar and tetrahedral CoS4 cores, respectively.
Usually the bis(thiophosphinoyl)amide anions [N(SPR2)-
(SPRЈ2)]Ϫ (R, RЈ = alkyl or aryl) are symmetrically co-ordinated
through both sulfur atoms.5–7 The interest in metal complexes
containing this type of ligand is mainly due to the unusual
flexibility of the SPNPS system and the large S ؒ ؒ ؒ S ‘bite’ (ca. 4
Å) which allows the ligand moiety to accommodate the
requirements of various metal co-ordination geometries. For
example, [Ni{(SPR2)(SPRЈ2)N}2] complexes, containing sym-
metric ligands (R = RЈ = Me8,9 or Ph10,11), exhibit a tetrahedral
NiS4 core. By contrast the nickel() complex of the related
asymmetric ligand, [Ni{(SPMe2)(SPPh2)N}2], shows a molecu-
lar structure based upon square-planar NiS4 co-ordination
geometry.10 On the other hand, changes in the organic groups
attached to phosphorus atoms result in differences in the crystal
structure of the free bis(thiophosphinoyl)amine, i.e. dimer and
chain polymer associations through N᎐H ؒ ؒ ؒ S were observed
for the symmetric NH(SPPh2)212 and NH(SPMe2)24 derivatives.
Here we report the crystal and molecular structure of the free
asymmetric amine NH(SPMe2)(SPPh2) and of its cobalt()
complex, which are discussed in relation to other bis(thiophos-
phinoyl)amines and cobalt() complexes containing CoS4 cores.
Perkin-Elmer 283B spectrometer, as KBr discs, electronic
spectra in CHCl3 solution on a Shimadzu UV160U spectro-
1
photometer and H, 13C and 31P NMR spectra on a Varian
GEMINI 300 instrument operating at 299.5, 75.4 and 121.4
MHz, respectively. The chemical shifts (δ) in ppm are relative to
SiMe4 or 85% H3PO4, respectively. Positive-ion fast atom bom-
bardment, FAB(ϩ), and 70 eV (ca. 1.12 × 10Ϫ17 J) electron
impact (EI) mass spectra were recorded using JEOL SX-102A
and Hewlett-Packard MS-598 instruments, respectively.
Preparations
NH(SPMe2)(SPPh2). A solution of LiBun in n-hexane (40.3
cm3, 1.565 , 63.1 mmol) was added dropwise to a stirred sus-
pension of Ph2P(S)NH2 (15.03 g, 64.5 mmol) in anhydrous
diethyl ether (150 cm3), under an argon atmosphere. The reac-
tion mixture was cooled to room temperature, and then a solu-
tion of Me2P(S)Cl (5.58 g, 32.25 mmol) in anhydrous diethyl
ether (50 cm3) was added dropwise. About 100 cm3 of the sol-
vent was distilled off, water (150 cm3) was added to the resulting
suspension, and the remaining organic solvent was removed
under vacuum. The viscous solution thus obtained was filtered
and from the solid product Ph2P(S)NH2 was recovered (7.4 g,
after recrystallization from toluene). The clear viscous filtrate
containing the lithium salt of the required compound was
treated with 10% HCl until no more solid product deposited.
The white solid product was collected by suction filtration and
recrystallized from ethanol as colourless crystals. Yield: 9.27 g
(89%), m.p. 157–159 ЊC (lit.,13 156–157 ЊC) (Found: C, 51.53;
H, 5.38; N, 4.25. C14H17NP2S2 requires C, 51.67; H, 5.27; N,
4.30%); IR (cmϪ1) ν(NH) 2550s, νasym(P2NH) 905vs, ν(PC) 740s,
720s, 710s, 685s, ν(PhPS) 620s, ν(MePS) 585m; δH(CDCl3) 2.07
[6 H, d, 2J(PH) 13.6, CH3], 4.28 [1 H, s(br), NH], 7.50 (6 H, m,
J. Chem. Soc., Dalton Trans., 1998, Pages 73–78
73

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m- and p-H of Ph) and 7.86 [4 H, ddd, 3J(PH) 14.3, 3J(HH) 8.0,
1
4J(HH) 1.6 Hz, o-H of Ph]; δC(CDCl3) 25.13 [d, J(PC) 66.1,
Table 1 Crystallographic data
3
2
CH3], 128.75 [d, J(PC) 13.2, Cm], 131.00 [d, J(PC) 11.6, Co],
132.25 [d, 4J(PC) 3.2, Cp] and 134.48 [d, 1J(PC) 101.2 Hz, Cipso];
δP(CDCl3): 51.3 [d, 2J(PP) 22.8, PhPS] and 63.9 [d, 2J(PP) 22.8
Hz, MePS]; EI mass spectrum m/z 325 (100, Mϩ), 292 (58,
Me2Ph2P2SNϩ), 217 (50, Ph2PSϩ), 216 (72, Me2PhP2SNHϩ), 183
(32, Me2PNPPhϩ), 139 (49, Me2P2SNHϩ), 122 (29, PhPNϩ),
107 (16, Me2PSNϩ) and 93 (32%, Me2PSϩ).
NH(SPMe2)-
(SPPh2)
[Co{(SPMe2)-
(SPPh2)N}2]
Molecular formula
M
Space group
a/Å
b/Å
c/Å
C14H17NP2S2
325.36
C2/c
26.582(9)
9.11(1)
16.18(2)
120.42(4)
3379(6)
8
1.28
4.91
1360.0
50
3262
C28H32CoN2P4S4
707.34
P21/c
15.09(1)
11.95(1)
19.132(6)
106.75(3)
3301(4)
4
1.42
9.74
1460.0
50
6374
K[(SPMe2)(SPPh2)N]. This compound was prepared as
described earlier,10 from the free acid and KOBut in refluxing
benzene, m.p. = 251–253 ЊC. For IR and NMR (1H, 13C, 31P)
data see ref. 10.
β/Њ
U/Å3
Z
Dc/g cmϪ3
µ(Mo-Kα)/cmϪ1
F(000)
[Co{(SPMe2)(SPPh2)N}2]. Clear methanolic solutions con-
taining CoCl2ؒ6H2O (0.013 g, 0.055 mmol, in 15 cm3 MeOH)
and K[(SPMe2)(SPPh2)N] (0.04 g, 0.11 mmol, in 15 cm3
MeOH) were mixed and the mixture changed immediately from
pink to deep blue. It was stirred for 2 h at room temperature.
The blue solid which deposited was then filtered off and
recrystallized from benezene to give [Co{(SPMe2)(SPPh2)N}2]
as blue crystals (0.03 g, 77%), m.p. 172–173 ЊC (Found: C,
47.17; H, 4.66; N, 3.73. C28H32CoN2P4S4 requires C, 47.53; H,
4.56; N, 3.96%); IR (cmϪ1) νasym(P2N) 1195vs (br), ν(PC) 750m,
710m, 690vs, ν(PhPS) 565s, ν(MePS) 520s, ν(CoS) 380w,
340mw, 330m; electronic (CHCl3, cmϪ1) 15 974, 14 184 and
13 193 (sh); FAB (ϩ) mass spectrum m/z 708 (83, M ϩ Hϩ),
707 (60, Mϩ), 383 {100, Co[(SPMe2)(SPPh2)N]ϩ}, 324 [16,
(SPMe2)(SPPh2)Nϩ], 292 (20, Me2Ph2P2SNϩ), 260 (4,
Me2Ph2P2Nϩ), 217 (9, Ph2PSϩ), 154 (97, Ph2ϩ), 138 (49,
Me2P2SNϩ), 137 (52, MePhPNϩ), 107 (17, Me2PSNϩ), 93 (3,
Me2PSϩ) and 77 (15%, Phϩ).
2θmax/Њ
Reflections measured
Reflections observed
[Fo2 у 3σ(Fo)2], No
Parameters refined, Np
R
1252
2161
175
232
0.0599
0.0593
1.66
0.0659
0.0599
1.54
RЈa
Goodness of fit, Sb
a w = 1/σ2(Fo). b [Σ(|Fo| Ϫ |Fc|)/σ]/(No Ϫ Np).
N
+ 2 LiBu
+ Me2P(S)Cl
Ph2P
PMe2
S Li+
2 H2N(S)PPh2
2 Li[HN(S)PPh2]
– 2 C4H10
– H2N(S)PPh2, LiCl
–
S
– LiCl + HCl
H
N
Ph2P
PMe2
S
S
Crystallography
Scheme 1
A colourless block crystal of NH(SPMe2)(SPPh2) and a blue
block crystal of [Co{(SPMe2)(SPPh2)N}2], which had been
grown from CHCl3–n-hexane mixtures, were mounted on glass
fibres and sealed with epoxy glue. Data were collected at room
temperature on a Rigaku AFC5R diffractomer with graphite-
monochromated Mo-Kα radiation (λ = 0.710 73 Å), operating
at 50 kV and 35 mA, using the ω–2θ scan technique. Cell con-
stants and an orientation matrix for data collection, obtained
from 24 carefully centred reflections, corresponded to mono-
clinic cells of dimensions given in Table 1. On the basis of
statistical analyses of intensity distributions and the successful
solution and refinement of the structure, the space groups were
determined to be C2/c (no. 15) and P21/c (no. 14) respectively
(Table 1).
parameter shift was 0.001 times its estimated standard devi-
ation) with unweighted and weighted agreement factors of
R = Σ(|Fo| Ϫ |Fc|)/Σ|Fo| = 0.0599 and 0.0659 and RЈ = [Σw(|Fo| Ϫ
¹
2
²
2
|Fc|) /ΣwFo ] = 0.0593 and 0.0599. The standard deviations of
an observation of unit weight were 1.66 and 1.54. The weight-
ing scheme was based on counting statistics and included a
factor (p = 0.004 and 0.015) to downweight the intense reflec-
tions. Plots of Σw(|Fo| Ϫ |Fc|)2 versus |Fo|, reflection order in data
collection, (sin θ)/λ, and various classes of indices showed no
unusual trends. The maximum and minimum peaks on the final
Fourier-difference map corresponded to 0.51 and Ϫ0.48, and
0.55 and Ϫ0.56 e ÅϪ3. All calculations were performed using the
TEXSAN15 crystallographic software package.
Of the 3262 reflections for compound NH(SPMe2)(SPPh2)
and 6374 for [Co{(SPMe2)(SPPh2)N}2] which were collected,
3185 and 6130 were unique. The intensities of three represent-
ative reflections measured after every 150 remained constant
throughout data collection indicating crystal and electronic
stability (no decay correction was applied). Empirical absorp-
tion corrections based on azimuthal scans of several reflections
were applied which resulted in transmission factors ranging
from 0.67 to 1.00 and 0.66 to 1.00. The data were corrected for
Lorentz-polarization effects.
CCDC reference number 186/762. Structure-factor tables are
available from the authors.
Results and Discussion
The synthesis of NH(SPMe2)(SPPh2) was previously reported
by Schimdpeter and Ebeling13 based on the reaction of
Ph2P(S)NH2 with Me2P(S)Cl, in the presence of KOBut. We
prepared the same compound using a new procedure (Scheme
1), i.e. the reaction of the lithiated amide Li[HN(S)PPh2] with
Me2P(S)Cl, in a diethyl ether–n-hexane mixture. Since LiBu is
soluble in diethyl ether, its use instead of KOBut 13 allows a
better contact between the reactants and improves the yield
considerably. This method is also very versatile since various
phosphorus amides and chlorides might be used in the coupling
reaction. A series of compounds of the type NH(XPR2)-
(YPRЈ2) (X = O or S, R, RЈ = Me or Ph) has been prepared in
our laboratory and work is in progress to prepare similar
derivatives containing selenium as a second chalcogen atom.
The IR and 31P NMR spectra of NH(SPMe2)(SPPh2) have
previously been described and discussed in comparison with
The structures were solved by direct methods.14 For both
molecules, all of the non-hydrogen atoms were treated aniso-
tropically with the exception of the carbon atoms of the phenyl
rings in the cobalt complex. The hydrogen atom attached to
nitrogen was found from the difference map while all other
hydrogen atoms were included in their idealized positions with
C᎐H set at 0.95 Å and with isotropic thermal parameters 1.2
times that of the carbon atom to which they were attached.
The final cycle of full-matrix least-squares refinement was
based on 1252 and 2161 observed reflections [I > 3.00σ(I)] and
175 and 232 (for 2) variable parameters and converged (largest
74
J. Chem. Soc., Dalton Trans., 1998, Pages 73–78

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Table 2 Important bond lengths (Å) and angles (Њ) for NH(SPMe2)-
(SPPh2)*
Table 3 Comparative structural data (bond lengths in Å, angles in Њ)
for bis(thiophosphinoyl)amines
NH(SPR2)(SPRЈ2)
N᎐P(1)
N᎐P(2)
P(1)᎐S(1)
P(1)᎐C(1)
P(1)᎐C(2)
P(2)᎐S(2)
1.698(7)
1.692(6)
1.962(3)
1.78(1)
1.793(9)
1.946(3)
P(2)᎐C(3)
P(2)᎐C(9)
1.80(1)
1.791(9)
R = Me,
R = RЈ = Ph
(ref. 12)
RЈ = Ph
R = RЈ = Me
(ref. 4)
N᎐H(1)
H(1) ؒ ؒ ؒ S(1Ј)
N ؒ ؒ ؒ S(1Ј)
1.01(8)
2.43(9)
3.371(7)
(this work)
P(1)᎐S(1)
P(2)᎐S(2)
P᎐N (average)
S(1a) ؒ ؒ ؒ H(1)
1.950(1)
1.937(1)
1.678(8)
2.638(25)
1.962(3)a
1.946(3)b
1.695(4)
2.43(9)
1.962(2)
1.939(2)
1.677(3)
2.513(5)
N᎐P(1)᎐S(1)
N᎐P(1)᎐C(1)
N᎐P(1)᎐C(2)
S(1)᎐P(1)᎐C(1)
S(1)᎐P(1)᎐C(2)
C(1)᎐P(1)᎐C(2) 105.8(5)
N᎐P(2)᎐S(2)
N᎐P(2)᎐C(3)
109.6(3)
106.8(4)
108.1(4)
112.4(3)
113.8(3)
N᎐P(2)᎐C(9)
106.0(4)
112.5(3)
114.1(3)
107.2(4)
126.1(4)
114(5)
S(2)᎐P(2)᎐C(3)
S(2)᎐P(2)᎐C(9)
C(3)᎐P(2)᎐C(9)
P(1)᎐N᎐P(2)
P(1)᎐N᎐H(1)
P(2)᎐N᎐H(1)
N᎐H(1) ؒ ؒ ؒ S(1Ј)
P(1)᎐N᎐P(2)
N᎐P(1)᎐S(1)
N᎐P(2)᎐S(2)
132.7(1)
115.5(1)
114.6(1)
126.1(4)
109.6(3)
113.4(3)
133.2(2)
114.0(1)
107.9(1)
113.4(3)
102.7(4)
119(5)
156(6)
N(1)᎐H(1) ؒ ؒ ؒ S(1a)
178(3)
42.9c
156(6)
35.4
175.9(4)
3.1c
S(1)P(1)N/S(2)P(2)N
(dihedral angle)
* Symmetry-equivalent positions Ϫx, 1 Ϫ y, 1 Ϫ z are denoted by
primes.
Deviations from S(1)P(1)N plane
P(2)
S(2)
Ϫ1.143
Ϫ1.616
0.551
Ϫ0.054
Ϫ0.003
Ϫ0.091
Torsion angles
S(1)P(1)NP(2)
S(2)P(2)NP(1)
S(1)P(1)NH(1)
S(2)P(2)NH(1)
112.7
62.5
Ϫ48.7
Ϫ137.0
156.2
45.1
Ϫ11.6
Ϫ147.3
Ϫ179.9
Ϫ3.1
Ϫ0.2
177.2
a For the Me2PS group. b For the Ph2PS group. c Calculated from pub-
lished atomic coordinates.
cobalt() d–d transitions.18 A charge-transfer (CT) band also
appears as a broad shoulder at 32 573 cmϪ1
.
The crystal and molecular structure of both the free acid and
the cobalt() complex were investigated by single-crystal X-ray
diffractometry. In the subsequent discussion they are compared
with the previously described structures of symmetric bis(thio-
phosphinoyl)amines and related neutral or ionic cobalt()
derivatives containing CoS4 cores, respectively.
Crystal structure of NH(SPMe2)(SPPh2)
Selected bond distances and angles in NH(SPMe2)(SPPh2) are
listed in Table 2 and Fig. 1 shows the ORTEP-like view of the
molecular structure with the atom numbering scheme.
Fig. 1 An ORTEP-like drawing of the monomeric unit of NH-
(SPMe2)(SPPh2)
those of the corresponding sodium salt and the methyl
esters.13,16,17 The spectral characteristics of the potassium salt,
K[(SPMe2)(SPPh2)N], are very similar to those of the sodium
analog. In addition both the free acid and the potassium salt
The phosphorus–sulfur [P(1)᎐S(1) 1.962(3), P(2)᎐S(2)
1.946(3) Å] and –nitrogen [P(1)᎐N 1.698(7), P(2)᎐N 1.692(6) Å]
distances within the SPNPS skeleton of NH(SPMe2)(SPPh2)
are typical for double P᎐S and single P᎐N bonds [cf. the methyl
᎐
were characterized by 13C NMR spectroscopy. The 1H and 13
C
ester, MeSPPh ᎐NPPh ᎐S: P᎐S 1.956(3), P᎐S(Me) 2.069(3),
᎐
᎐
2
᎐
2
NMR spectra of NH(SPMe2)(SPPh2) show the expected reson-
ances for the organic groups attached to phosphorus, split into
two components due to the phosphorus–proton and –carbon
couplings. The presence of two different phosphorus atoms in
the molecular unit is not reflected in the 1H or 13C spectra of the
free acid. By contrast, the 13C spectrum of the potassium salt
shows a doublet signal for the methyl carbons [δ(CD3OD)
P᎐N 1.568(4), P᎐N 1.610(4) Å]19 and the PNP system is bent
᎐
[P(1)᎐N᎐P(2) 126.1(4)Њ]. Like the symmetric analogs,
NH(SPR2)2 (R = Me4 or Ph12,20,21
)
the molecule of
NH(SPMe2)(SPPh2) displays an anti conformation of the sulfur
atoms and contains an acidic proton bound to nitrogen. How-
ever, important differences accompany the change in organic
groups attached to phosphorus. Some comparative data for
the three dithio derivatives are listed in Table 3. For example,
the SPN(H)PS skeleton is non-planar in NH(SPPh2)2 and
NH(SPMe2)(SPPh2) (see the torsion angles given in Table 3)
with a S(1)P(1)N/S(2)P(2)N dihedral angle of about 35–43Њ,
while it is basically planar in NH(SPMe2)2. The reasons for the
different conformations in these three dithioacids are not yet
understood, but packing forces might be involved.
1
27.96, J(PC) 67.9 Hz], but a resonance for aromatic ipso-
carbon atoms with the expected doublet of doublets pattern
1
3
[δ(CD3OD) 143.54, J(PC) 106.6, J(PC) 5.7 Hz].10 The non-
equivalence of the two phosphorus atoms in NH(SPMe2)-
(SPPh2) is clearly reflected by the two 31P resonances, which
exhibit a doublet pattern due to the phosphorus–phosphorus
coupling [2J(PP) 22.8 Hz].
The mass spectral data confirm the identity of the
[Co{(SPMe2)(SPPh2)N}2] complex. Its electronic spectrum was
recorded in CHCl3 solution and is consistent with a tetrahedral
co-ordination geometry. Absorption maxima were observed at
15 974, 14 184 and 13 193 (shoulder) cmϪ1, characteristic for
In the crystal all three dithio acids are associated through
intermolecular N᎐H ؒ ؒ ؒ S(᎐P) hydrogen bonds involving only
᎐
one of the sulfur atoms of each molecule. As a consequence, the
phosphorus–sulfur double bond participating in the hydrogen
bonding is slightly elongated (Table 3).
J. Chem. Soc., Dalton Trans., 1998, Pages 73–78
75

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Fig. 2 View of the dimeric and polymeric associations in the crystals of (a) NH(SPPh2)2, (b) NH(SPMe2)(SPPh2) and (c) NH(SPMe2)2
Important differences are observed in the lattice of
The crystal of the cobalt complex contains discrete
NH(SPR2)(SPRЈ2) acids. Thus for R = RЈ = Me the molecules
[Co{(SPMe2)(SPPh2)N}2] molecules, in which both ligands act
as bidentate moieties. Although different organic groups are
attached to phosphorus atoms of each ligand unit the cobalt–
sulfur distances are equivalent [average Co᎐S 2.32(1) Å]. The
compound can be described as a spiro-bicyclic structure, with
cobalt as the spiro atom. The slightly distorted tetrahedral
arrangement of sulfur atoms around the metal is reflected in
the magnitude of the S᎐Co᎐S angles [range 102.7(1)–
117.7(2)Њ], the S ؒ ؒ ؒ S non-bonding distances [range
3.633(5)–3.968(5) Å] and the dihedral angles between pairs
of CoS2 planes: CoS(1)S(2)/CoS(3)S(4) 88.7, CoS(1)S(3)/
CoS(2)S(4) 86.9 and CoS(1)S(4)/CoS(2)S(3) 99.4Њ. The struc-
tural parameters of the CoS4 core are very similar to those
observed for the related [Co{(SPMe2)2N}2] neutral complex
(Table 5; and S ؒ ؒ ؒ S non-bonding distances 3.619–3.878 Å,
are associated through intermolecular N᎐H ؒ ؒ ؒ S(᎐P) hydrogen
᎐
bonds into chain-like polymers [Fig. 2(c)], while discrete dimers
are found for R = RЈ = Ph [Fig. 2(a)] and R = Me, RЈ = Ph
derivatives [Fig. 2(b)]. In addition, in the latter case the dimers
are further associated into polymeric chains through inter-
actions between the second sulfur atom of the molecular unit
and an aromatic proton of a neighbouring acid molecule
[S(2) ؒ ؒ ؒ H(17b) 2.869 Å].
Crystal structure of [Co{(SPMe2)(SPPh2)N}2]
Selected bond distances and angles in [Co{(SPMe2)(SPPh2)N}2]
are listed in Table 4 and Fig. 3 shows an ORTEP-like view of
the molecular structure with the atom numbering scheme.
76
J. Chem. Soc., Dalton Trans., 1998, Pages 73–78

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calculated from published atomic coordinates).4 They also
compare very well to those of the CoS4 core in the [Co(SAs-
Me3)4]2ϩ cation or in the [Co(SPh)4]2Ϫ anion {Table 5; S ؒ ؒ ؒ S
non-bonding distances 3.563–3.972 Å in the blue isomer of
[Co(SAsMe3)4][ClO4]2,22 and 3.464–4.005 Å in [N(C6H11)2H2]2-
[Co(SPh)4],18 calculated from published atomic coordin-
ates].18,21,22 Similar tetrahedral CoS4 cores were reported for
[PPh4]2[Co(SPh)4],23 [Me3NCH2CONH2]2[Co(SPh)4]24 and
[NMe4]2[Co(SPh)4].25 However, a significant flattening of the
idealized regular co-ordination tetrahedron was noted in the
case of the green isomer of [Co(SAsMe3)4][ClO4]2 (Table 5, and
sulfur atoms from the anti orientation in the free acid to a syn
orientation with respect to the PNP system. As a result the
S᎐P᎐N and P᎐N᎐P angles differ slightly from those in the free
acid. The six-membered CoS2P2N inorganic rings thus formed
contain equal P᎐S [average 2.031(5)] and P᎐N [average 1.59(1)
Å] bonds, of intermediate magnitude between single and
double phosphorus–sulfur and –nitrogen bonds, respectively
[see above discussion of the NH(SPMe2)(SPPh2) molecular
structure]. Compared to the free acid, while the phosphorus–
sulfur bonds are elongated, the phosphorus–nitrogen bonds are
strengthened, to keep a considerable double-bond character of
both bond types (Table 4). The cobalt–sulfur distances in both
tetrahedral [Co{(SPR2)(SPRЈ2)N}2] are significantly larger (ca.
2.32 Å) than in the square-planar [Co{(SCMe)2CH}2] complex
(ca. 2.17 Å) (Table 5).
S ؒ ؒ ؒ S non-bonding distances 3.236–4.001 Å)22 and the related
26,27
thiourea complexes [Co{SC(NH2)2}4][NO3]2
and [Co-
{SC(NHEt)2}4][ClO4]2.28
To allow chelate ring closure in [Co{(SPMe2)(SPPh2)N}2] the
SPNPS fragment must change its conformation, bringing the
Despite the averaging in bond lengths, suggesting at least
some delocalization of π electrons over the SPNPS fragment,
achieved by chelate formation, the CoS2P2N rings are not
Table 4 Selected interatomic distances (Å) and angles (Њ) in [Co-
{(SPMe2)(SPPh2)N}2]
Co᎐S(1)
Co᎐S(2)
2.313(4)
2.322(4)
Co᎐S(3)
Co᎐S(4)
2.337(4)
2.315(4)
P(1)᎐S(1)
P(2)᎐S(2)
P(1)᎐N(1)
P(2)᎐N(1)
2.035(5)
2.032(5)
1.58(1)
1.59(1)
P(3)᎐S(3)
P(4)᎐S(4)
P(3)᎐N(2)
P(4)᎐N(2)
2.024(5)
2.031(5)
1.60(1)
1.600(9)
S(1) ؒ ؒ ؒ S(2)*
3.830(5)
S(3) ؒ ؒ ؒ S(4)*
3.826(5)
S(1)᎐Co᎐S(2)
S(1)᎐Co᎐S(3)
S(1)᎐Co᎐S(4)
111.5(1)
102.7(1)
106.7(1)
S(3)᎐Co᎐S(4)
S(2)᎐Co᎐S(4)
S(2)᎐Co᎐S(3)
110.6(1)
117.7(2)
106.7(1)
S(1)᎐P(1)᎐N(1) 116.9(4)
S(3)᎐P(3)᎐N(2)
S(3)᎐P(3)᎐C(15)
S(3)᎐P(3)᎐C(16)
N(2)᎐P(3)᎐C(15)
N(2)᎐P(3)᎐C(16)
115.1(4)
109.8(5)
107.6(5)
112.6(6)
106.0(6)
S(1)᎐P(1)᎐C(1)
S(1)᎐P(1)᎐C(2)
105.4(5)
107.8(5)
N(1)᎐P(1)᎐C(1) 107.8(6)
N(1)᎐P(1)᎐C(2) 111.8(6)
C(1)᎐P(1)᎐C(2) 106.6(8)
C(15)᎐P(3)᎐C(16) 105.1(7)
S(2)᎐P(2)᎐N(1) 117.6(4)
S(4)᎐P(4)᎐N(2)
S(4)᎐P(4)᎐C(17)
S(4)᎐P(4)᎐C(23)
N(2)᎐P(4)᎐C(17)
N(2)᎐P(4)᎐C(23)
117.3(4)
110.7(4)
106.1(4)
110.4(5)
107.1(5)
S(2)᎐P(2)᎐C(3)
S(2)᎐P(2)᎐C(9)
108.9(4)
106.6(4)
N(1)᎐P(2)᎐C(3) 110.9(5)
N(1)᎐P(2)᎐C(9) 106.9(5)
C(3)᎐P(2)᎐C(9) 105.1(5)
C(17)᎐P(4)᎐C(23) 104.2(6)
P(1)᎐N(1)᎐P(2) 133.3(7)
P(3)᎐N(2)᎐P(4)
Co᎐S(3)᎐P(3)
Co᎐S(2)᎐P(2)
128.5(6)
99.9(2)
106.0(2)
Co᎐S(1)᎐P(1)
Co᎐S(2)᎐P(2)
99.9(2)
105.1(2)
Fig. 3 An ORTEP-like drawing of the monomeric [Co{(SPMe2)-
(SPPh2)N}2]
* Non-bonding distance.
Table 5 Comparative structural data (bond lengths in Å, angles in Њ) in [Co{(SPMe2)(SPPh2)N}2] and related CoS4 core-containing derivativesa
22
[Co{(SPPh2)-
(SPMe2)N}2]
(this work)
[Co(SAsMe3)4][ClO4]2
[N(C6H11)2H2]2-
[Co(SPh)4]
(ref. 18)
[Co{(SCMe)2-
CH}2]
(ref. 3)
[Co{(SPMe2)2N}2]
(ref. 4)
blue isomer
green isomer
CoS4 core geometryb
Co᎐S (average)
S ؒ ؒ ؒ S bite (average)
T
T
T
T
T
SP
2.166(3)
3.242(6)
2.32(1)
3.828(3)
2.314(7)
3.79(1)
2.30(1)
2.30(1)
2.328(11)
c
d
e
S᎐Co᎐S (endocyclic, average)
S᎐Co᎐S (exocyclic, range)
CoS(1)S(2)/CoS(3)S(4)
CoS(1)S(3)/CoS(2)S(4)
CoS(1)S(4)/CoS(2)S(3)
111.1(6)
102.7(1)–117.7(2)
88.7
86.9
88.4
110.0(5)
103.0(1)–114.3(1)
84.6
86.8
92.2
—
—
—
96.9(2)
83.1(2)
0.0
86.4
81.8
78.3
70.4
89.8
109.8
84.3
75.9
81.5
Co᎐S᎐P (average)
102.7(3.3)
102.1(1.0)
118.7(5)f
i = N
¹
(xi Ϫ x)2/(N Ϫ 1)]², where xi is ith bond
a Estimated standard deviations (e.s.d.s) for average bond lengths are calculated from the equation σ = {[ ͚
i = 1
length and x the mean of the N equivalent bond lengths. An analogous formula is used for the calculation of e.s.d.s for average bond angles.9
b T = Tetrahedral, SP = square planar. c S᎐Co᎐S range 102.0(4)–120.4(4)Њ. d S᎐Co᎐S range 89.7(3)–121.0(3)Њ. e S᎐Co᎐S range 95.6(2)–121.3(2)Њ.
f Co᎐S᎐C angle.
J. Chem. Soc., Dalton Trans., 1998, Pages 73–78
77

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9 M. R. Churchill, J. Cooke, J. Wormald, A. Davison and E. S.
Switkes, J. Am. Chem. Soc., 1969, 91, 6518.
planar. Both exhibit a slightly twisted chair conformation, a
behavior which contrasts with that observed for the related
[Co{(SPMe2)2N}2] complex where the CoS2P2N rings display
different twisted-boat conformations.
The structural changes observed in the cobalt() and
nickel() complexes of NH(SPR2)(SPRЈ2) ligands are consist-
ent with a high flexibility of the SPNPS fragment, the same
ligand moiety being able to accommodate the requirements of
various metal co-ordination geometries.
10 R. Rösler, C. Silvestru, G. Espinosa-Perez, I. Haiduc and
R. Cea-Olivares, Inorg. Chim. Acta, 1996, 241/2, 47.
11 P. Bhattacharyya, J. Novosad, J. Phillips, A. M. Z. Slawin, D. J.
Williams and J. D. Woollins, J. Chem. Soc., Dalton Trans., 1995,
1607.
12 S. Husebye and K. Maartmann-Moe, Acta Chem. Scand., Ser. A,
1983, 37, 439.
13 A. Schmidpeter and J. Ebeling, Chem. Ber., 1968, 101, 815.
14 G. M. Sheldrick, Acta Crystallogr., Sect. A, 1990, 46, 467.
15 TEXSAN-TEXRAY, Structure Analysis Package, Molecular
Structure Corporation, Woodlands, TX, 1985 and 1992.
16 A. Schmidpeter and H. Groeger, Z. Anorg. Allg. Chem., 1966, 345,
106.
Acknowledgements
This work was supported by the Romanian Academy and the
Romanian National Council for University Scientific Research
(CNCSU) and by the Natural Sciences and Engineering
Research Council of Canada. R. R. acknowledges the financial
support from Babes-Bolyai University and Deutscher Akadem-
ischer Austauschdienst (DAAD).
17 A. Schmidpeter, H. Brecht and J. Ebeling, Chem. Ber., 1968, 101,
3902.
18 W. P. Chung, J. C. Dewan and M. A. Walters, J. Am. Chem. Soc.,
1991, 113, 525.
19 C. Silvestru, R. Rösler and G. Espinosa-Perez, unpublished work.
20 H. Nöth, Z. Naturforsch., Teil B, 1982, 37, 1491.
21 P. B. Hitchcock, J. F. Nixon, I. Silaghi-Dumitrescu and I. Haiduc,
Inorg. Chim. Acta, 1985, 96, 77.
22 P. C. Tellinghuisen, W. T. Robinson and C. J. Wilkins, J. Chem. Soc.,
Dalton Trans., 1985, 1289.
23 D. Swenson, N. C. Baenziger and D. Coucouvanis, J. Am. Chem.
Soc., 1978, 100, 1932.
24 M. A. Walters, J. C. Dewan, C. Min and S. Pinto, Inorg. Chem.,
1991, 30, 2656.
25 K. Fukui, H. Masuda, H. Ohya-Nishiguchi and H. Kamada, Inorg.
Chim. Acta, 1995, 238, 73.
26 W. A. Spofford, P. Boldrini, E. L. Amma, P. Caefagno and P. S.
Gentile, Chem. Commun., 1970, 40.
27 W. A. Spofford and E. L. Amma, J. Cryst. Mol. Struct., 1976, 6, 235.
28 T. G. Fawcett, E. E. Fehskens, J. A. Potenza, H. J. Schugar and
R. A. Lalancette, Acta Crystallogr., Sect. B, 1979, 35, 1460.
References
1 D. A. Buckingham and C. R. Clark, in Comprehensive Coordination
Chemistry, ed. G. Wilkinson, Pergamon, Oxford, 1987, vol. 4, p. 870.
2 B. S. Manhas, B. C. Verma and S. B. Kalia, Polyhedron, 1995, 14,
3549.
3 R. Beckett and B. F. Hoskins, J. Chem. Soc., Dalton Trans., 1974,
622.
4 C. Silvestru, R. Rösler, I. Haiduc, R. Cea-Olivares and G. Espinosa-
Perez, Inorg. Chem., 1995, 34, 3352.
5 I. Haiduc and I. Silaghi-Dumitrescu, Coord. Chem. Rev., 1986, 74,
127.
6 T. S. Lobana, Prog. Inorg. Chem., 1989, 37, 495.
7 P. Bhattacharyya and J. D. Woollins, Polyhedron, 1995, 14, 3367.
8 M. R. Churchill, J. Cooke, J. P. Fennessey and J. Wormald, Inorg.
Chem., 1971, 10, 1031.
Received 16th July 1997; Paper 7/05086K
78
J. Chem. Soc., Dalton Trans., 1998, Pages 73–78