Facile one-step synthesis of MPHMes from MesPCl2 (M = Li, Na, K; Mes = 2,4,6-Me3C6H2)

Article abstract of DOI:10.1021/ic302759k

Reaction of alkali metals (Li, Na, K) with mesityldichlorophosphane (MesPCl₂, Mes = 2,4,6-Me₃C₆H₂) in ethereal solvents leads to formation of the corresponding mesitylphosphanides MPHMes in good purity and yield. ³¹P NMR spectroscopic studies in deuterated solvents strongly support a mechanism of the reaction that involves protonation/disproportionation steps in which the solvent is the only possible proton source. Li(thf)(tmeda)PHMes (1), [Na(tmeda)(μ-PHMes)] _∞ (2), and [K(pmdeta)(μ-PHMes)]₂ (3) (tmeda = N,N,N′,N′-tetramethylethylenediamine, pmdeta = N,N,N′, N″,N″-pentamethyldiethylenetriamine) were obtained; in the solid state, 2 forms zigzag chains while 3 is a dimeric compound.

Full text of DOI:10.1021/ic302759k

Article
pubs.acs.org/IC
Facile One-Step Synthesis of MPHMes from MesPCl2 (M = Li, Na, K;
Mes = 2,4,6-Me3C6H2)
Ivana Jevtovikj, Rebeca Herrero, Santiago Gomez-Ruiz, Peter Lonnecke, and Evamarie Hey-Hawkins*
́
̈
Institut fur Anorganische Chemie der Universitat Leipzig, Johannisallee 29, D-04103 Leipzig, Germany
̈
̈
S
* Supporting Information
ABSTRACT: Reaction of alkali metals (Li, Na, K) with mesityldichloro-
phosphane (MesPCl2, Mes = 2,4,6-Me3C6H2) in ethereal solvents leads to
formation of the corresponding mesitylphosphanides MPHMes in good
purity and yield. 31P NMR spectroscopic studies in deuterated solvents
strongly support a mechanism of the reaction that involves protonation/
disproportionation steps in which the solvent is the only possible proton
source. Li(thf)(tmeda)PHMes (1), [Na(tmeda)(μ-PHMes)]∞ (2), and
[K(pmdeta)(μ-PHMes)]2 (3) (tmeda = N,N,N′,N′-tetramethylethylenedi-
amine, pmdeta = N,N,N′,N″,N″-pentamethyldiethylenetriamine) were
obtained; in the solid state, 2 forms zigzag chains while 3 is a dimeric
compound.
solvent or in liquid ammonia or with the help of a strong base
INTRODUCTION
■
such as nBuLi.10 A common disadvantage of these procedures is
the use of primary or secondary phosphanes, which are
obtained mainly by reduction of the corresponding chloro-
phosphanes with LiAlH4,11 a reaction step that is not very
convenient in practice. In this work, we report a facile method
for preparation of alkali metal mesitylphosphanides MPHMes
directly from the alkali metal and MesPCl212 (M = Li, 10:4; M
= Na, K, 6:2) in ethereal solvents. The previously known
lithium salt Li(thf)(tmeda)PHMes (1), [Na(tmeda)(μ-
PHMes)]∞ (2), and [K(pmdeta)(μ-PHMes)]2 (3) were thus
obtained, and 2 and 3 were fully characterized. While reaction
of alkali metals with dichlorophosphanes is well investigated
and leads to different phosphanes and phosphanides,6,13,14 we
show here that variation of the stoichiometry and reaction
conditions leads in a clean, straightforward reaction to
monophosphanides MPHMes in high yields.
Alkali metal phosphanides are an important class of starting
materials with intriguing structural chemistry.1,2 In recent years
the structural principles governing this class of compounds have
been further unraveled. Thus, the motifs for alkali metal
phosphanides in the solid state range from monomers, dimers,
and trimers to polymeric and three-dimensional structures, and
their reactivity is dependent on the nature of the substituents
on the phosphorus atom, the solvating ligands, and the metal
itself. These developments have opened up a rich area of
transition metal3 and main group metal coordination
chemistry.4
Initially we were interested in finding more facile routes to
alkali metal polyphosphanides.5 Thus, we obtained M2(P4Mes4)
(M = Na and K), albeit in moderate yields,6 and employed
them in the preparation of a wide variety of main group and
transition metal complexes.5a−c,7 However, as some of the
target compounds were only obtained in low yield and many
others were difficult to prepare using these highly reactive Na
or K salts, lithium tetramesityltetraphosphane-1,4-diide seemed
to be a more promising starting material. In our search for a
facile synthesis of Li2(P4Mes4) we observed that, depending on
the stoichiometry, solvent, and reaction conditions, formation
of LiPHMes is favored, and we decided to explore the
analogous reactions with Na and K.
RESULTS AND DISCUSSION
■
Reactions with Lithium. We recently reported that
reaction of 4 equiv of MesPCl2 with 10 equiv of alkali metal
in refluxing THF (48 h for Na and 6 h for K) leads to
M2(P4Mes4) (M = Na, K) in moderate yields.6 We thus
decided to explore the same reaction using lithium sand in
order to synthesize Li2(P4Mes4). However, after 6 h formation
of the (PHMes)− ion as the only P-containing product was
To date, several procedures for preparation of alkali metal
phosphanides have been described in the literature.2b,8−10 The
most common method is direct metalation of a primary or
secondary phosphane with a strong deprotonating agent such
as an alkyl lithium or alkali metal hydride.8 Other methods
include direct metalation of a primary or secondary phosphane
with a heavier alkali metal9 and P−Caryl cleavage of an aryl-
substituted tertiary phosphane with an alkali metal in a donor
confirmed by the appearance of a doublet at −157 ppm (1JPH
=
162 Hz) in the 31P NMR spectrum.
Further experiments using different reaction times and
temperatures showed that formation of cyclo-P4Mes4 and
Received: December 15, 2012
© XXXX American Chemical Society
A
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Scheme 1
cyclo-P3Mes3 occurred in just 5 min, while formation of
Li2(P4Mes4) was observed after only 30 min at room
temperature (characteristic AA′XX′ spin system in the
31P{1H} NMR spectrum at ca. −12 and −115 ppm).15
while a proton and an electron are liberated. Most likely, a
redox reaction occurs in which 1,2-dimesityldiphosphane-1,2-
diide M2(P2Mes2) is reductively cleaved to form two molecules
of MPHMes, while two THF molecules are oxidatively coupled
to form a THF dimer.19 The latter could be detected by ESI
mass spectrometry (m/z = 143 [M + H]+), but polymerization
of THF could not be excluded.20 Finally, reaction of 1 equiv of
MesPCl2 and 10 equiv of sodium or potassium in refluxing
THF gave MPHMes and traces of MesPH2 in 6 h for sodium
and 3 h for potassium (according to the 31P NMR spectrum).
Furthermore, other dichlorophosphanes (tBuPCl2 and PhPCl2)
also react with alkali metals in ethereal solvents in a 6:2
(M:RPCl2) ratio with formation of the expected alkali metal
phosphanides, MPHtBu21 and MPHPh,22 indicating that this
method is quite general and mostly independent of the
substituents on the phosphorus atom.
In view of these results, formation of LiPHMes was studied.
We observed that reaction of 1 equiv of MesPCl2 and 10 equiv
of lithium in refluxing THF led to LiPHMes as the only P-
containing compound in 3 h (according to the 31P NMR
spectrum). Assuming that Li2(P4Mes4) is formed first,
subsequent protonation may occur to give M(P4HMes4),16
which is very unstable and disproportionates in solution to give
a mixture of phosphanes and phosphanides which may react
further with lithium to give LiPHMes as the final product.
Evaporation of the solvent, successive extractions of the residue
with Et2O, filtration, and recrystallization from THF/TMEDA
gave the previously known Li(thf)(tmeda)PHMes (1).17 When
the reaction was carried out in noncoordinating solvents such
as toluene or n-hexane, only formation of small amounts of
cyclo-P3Mes3 and cyclo-P4Mes4 was observed.
31P NMR Spectroscopic Studies in [D8]THF. Further
support for the suggested mechanism was provided by an NMR
spectroscopic study of the reaction of elemental potassium with
MesPCl2 (6:2) in [D8]THF, which showed that the solvent is
the only proton (deuterium) source in this reaction. The
proton-coupled 31P NMR spectrum of the reaction mixture
obtained after 3 h of reflux showed two major species: A broad
singlet for KPDMes at −142 ppm, and a broad singlet for
MesPD2 at −158 ppm. As expected, no phosphorus−proton
coupling was observed, but both singlets are broadened due to
the coupling between phosphorus and deuterium.23 This result
confirms the assumptions stated above and shows the
importance of the solvent in the outcome of this reaction.
Molecular Structures of [Na(tmeda)(μ-PHMes)]∞ (2)
and [K(pmdeta)(μ-PHMes)]2 (3). Yellow crystals of 2 were
obtained from a concentrated TMEDA solution at room
temperature. The compound crystallizes in the monoclinic
space group P21/c with four molecules per unit cell, Figure 1. In
the solid state, 2 is polymeric and forms infinite zigzag chains
along the c axis, Figure 2. Each phosphorus atom bridges two
sodium atoms with a Na−P−Na angle of 114.9(1)°, which is
significantly smaller than the essentially linear Li−P−Li angle
(176.9(1)°) found in the zigzag structure of [Li(DME)(μ-
Reactions with Sodium and Potassium. Similar behavior
was observed in reactions of MesPCl2 with sodium and
potassium. Thus, our attempts to synthesize the dianion
M2(P2Mes2) by reaction of 2 equiv of MesPCl2 and 6 equiv of
sodium sand or elemental potassium in refluxing THF gave
MPHMes in high yield. After addition of TMEDA (N,N,N′,N′-
tetramethylethylenediamine) for the Na salt or PMDETA
(N,N,N′,N″,N″-pentamethyldiethylenetriamine) for the K salt,
products [Na(tmeda)(μ-PHMes)]∞ (2) and [K(pmdeta)(μ-
PHMes)]2 (3) were obtained. In solution ([D8]THF) both
compounds exhibit a doublet in the 31P NMR spectrum at
1
−142.3 (M = K, JPH = 169.5 Hz) and −161.0 ppm (M = Na,
1JPH = 162.7 Hz).
A proposal for formation of 2 and 3 is shown in Scheme 1.
We assume with respect to the stoichiometry that 1,2-
dimesityldiphosphane-1,2-diide M2P2Mes2 is formed first and,
subsequently, a protonation takes place, followed by formation
of M(P2HMes2) as an intermediate for this reaction.18 This
disproportionates further to form MPHMes as a final product.
A possible explanation for the protonation and reduction step is
that CH2 groups in the ethereal solvents (in this case THF)
which are located next to the oxygen atom can form a radical,
24
PH2)]∞ but comparable with the infinite chain of alternating
25
Li and P atoms in [Li(diglyme)(μ-PHMe)]∞ (Li−P−Li
132.1(1)°, diglyme = 1-methoxy-2-(2-methoxyethoxy)ethane).
B
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Table 1. Selected Bond Lengths (picometers) and Angles
(degrees) for [Na(tmeda)(μ-PHMes)]∞ (2)
P(1)−Na(1)
P(1)′−Na(1)
P(1)−H(1P)
Na(1)−N(1)
Na(1)−N(2)
286.4(5)
284.6(5)
149.0(1)
245.3(1)
247.8(1)
P(1)−Na(1)−P(1)′
Na(1)−P(1)−H(1P)
N(1)−Na(1)−N(2)
N(1)−Na(1)−P(1)
N(2)−Na(1)−P(1)
P(1)−Na(1)−P(1)′
128.5(2)
95.7(4)
75.7(3)
112.0(2)
110.9(3)
114.9(1)
Figure 1. Asymmetric unit of [Na(tmeda)(μ-PHMes)]∞ (2). H atoms
(except at P1) were omitted for clarity. Thermal ellipsoids are at the
50% level.
Na−P distances [286.4(5) and 284.6(5) pm] are comparable to
those found in other structurally characterized sodium
phosphanides, e.g., [Na(thf)2(PMes)(SiFtBu2)] (289.0(1)
pm)26 and [Na(pmdeta)(μ-PHCy)]2 (291.0(8) pm).27 The
coordination sphere of sodium is completed by two nitrogen
atoms from a bidentate TMEDA ligand, and an unusual
coordination number of four is achieved by each sodium
atom.7e,h28 The average Na−N distance of 246.6(1) pm is
slightly shorter than the values of 254.0(2) pm in [Na-
23
Figure 3. Molecular structure of [K(pmdeta)(μ-PHMes)]2 (3). H
atoms (except at P1 and P2) were omitted for clarity. Thermal
ellipsoids are at the 50% level.
(pmdeta)(μ-PHCy)]2 and 265.6(3) pm in [Na(pmdeta)(μ-
Ph)]2,29 Table 1.
Large red crystals of [K(pmdeta)(μ-PHMes)]2 (3) were
obtained from a PMDETA/n-hexane solution at room
temperature. Compound 3 crystallizes in the triclinic space
Table 2. Selected Bond Lengths (picometers) and Angles
(degrees) for [K(pmdeta)(μ-PHMes)]2 (3)
group P1 with two formula units in the unit cell and forms
̅
dimers in which two (MesPH)− anions bridge two PMDETA-
solvated potassium cations, Figure 3. Mesityl substituents at
phosphorus have a trans arrangement. The central P2M2 ring is
nearly planar (torsion angle P(1)−K(1)−P(2)−K(2) 9.5(1)°),
Table 2. Both K+ ions achieve a coordination number of 6 via
M···C interaction with the ipso-carbon atom at phosphorus
[K(1)−C(1) 340.1(1), K(2)−C(19) 331.2(1) pm]. K−P
distances [325.1(6)−330.0(6) pm] are in the range of
structurally characterized potassium phosphanides.2c,22,29,30
K−N distances of the NMe2 group opposite the mesityl
group [K(1)−N(1) 281.2(1) pm, K(2)−N(6) 282.8(1) pm]
are shorter than the other K−N distances (range 286.5(1)−
288.8(1) pm), but all lie within the range of typical K−N
distances for compounds in which potassium is coordinated by
tertiary amines. For example, K−N distances are 285.3(3),
281.6(3), and 279.9(3) pm for the monomeric naphthyl-
substituted phosphanide K(pmdeta){P(C10H6-8-NMe2)(CH-
(SiMe3)2)},31 285.7(2), 286.0(2), and 287.3(2) pm for the
P(1)−H(1P)
P(2)−H(2P)
K(1)−N(1)
K(1)−N(2)
K(1)−N(3)
K(1)−P(1)
P(1)−K(1)−P(2)
P(1)−K(2)−P(2)
K(2)−P(1)−K(1)
K(2)−P(2)−K(1)
139.8(9)
139.0(1)
281.2(1)
287.1(1)
288.3(1)
330.0(6)
90.7(1)
91.6(1)
88.4(1)
87.6(1)
K(1)−P(2)
K(2)−N(6)
K(2)−N(4)
K(2)−N(5)
K(2)−P(1)
K(2)−P(2)
K(2)−P(1)−H(1P)
K(1)−P(1)−H(1P)
K(2)−P(2)−H(2P)
K(1)−P(2)−H(2P)
330.0(5)
282.8(1)
286.5(1)
288.8(1)
325.1(6)
329.9(5)
125.6(9)
106.0(8)
111.0(1)
127.0(2)
amino-functionalized mononuclear adduct K(pmdeta){P-
(C6H4-2-NMe2)(CH(SiMe3)2)},32 and 293.6(6), 286.5(6),
and 289.4(7) pm for the dimeric [K(pmdeta){μ-PtBuP(H)
tBu)}]2.33
Figure 2. Polymeric zigzag chain of [Na(tmeda)(μ-PHMes)]∞ (2) along the c axis. H atoms (except at P1) were omitted for clarity.
C
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Synthesis of Li(thf)(tmeda)PHMes (1). MesPCl2 (6.6 g, 30.0
mmol) was dissolved in 150 mL of THF and added to freshly prepared
lithium sand (2.08 g, 300.0 mmol, prepared using a Heidolph
SilentCrusher M dispersant machine). The mixture was heated to
reflux for 6 h and stirred for an additional 16 h at room temperature.
The red suspension was then analyzed by 31P NMR spectroscopy
(THF/C6D6): δ = −157 ppm (1JPH = 162 Hz). The solvent of the
mixture was removed in vacuo, and the deep red solid residue was
extracted with Et2O (3 × 200 mL) and filtered (to remove LiCl and
unconsumed Li). Solvent was evaporated, the oily residue dissolved in
THF (30 mL), and then 3 mL of TMEDA added. The mixture was
stored at −28 °C to give crystals of Li(thf)(tmeda)PHMes (1) over 1
week. Yield: 2.53 g, 37%. Spectroscopic data of 1 are in agreement
with those reported previously.17
CONCLUSIONS
■
Alkali metal mesitylphosphanides are readily obtained in a one-
step synthesis from alkali metal and MesPCl2 in ethereal
solvents. 31P NMR studies in [D8]THF corroborate the
assumption that this reaction occurs by initial protonation of
oligophosphanediides by the solvent followed by disproportio-
nation to give MPHMes as the final product. This new
synthetic route is an interesting alternative to alkali metal
phosphanides compared to those in the literature and offers
much potential for further exploration of the solid-state
structures of alkali metal mesitylphosphanides. Furthermore,
analogous reactions using alternative precursors, such as
tBuPCl2 and PhPCl2, also gave the corresponding alkali metal
phosphanide, indicating the generality of this method. In
addition, while the known procedures usually include reduction
of chlorophosphanes to the corresponding primary or
secondary phosphanes, the newly developed method described
here omits this unpleasant reaction step.
Synthesis of [Na(tmeda)(μ-PHMes)]∞ (2). MesPCl2 (1.6 g, 7.2
mmol) was dissolved in 50 mL of THF and added to freshly prepared
sodium sand (0.5 g, 21.7 mmol, prepared from Na in boiling toluene).
The mixture was heated to reflux for 4 h and stirred for an additional
16 h at room temperature. A red suspension formed and was filtered.
The solvent of the filtrate was completely removed in vacuum. The
remaining yellow solid was washed with 3 × 10 mL of n-hexane and
dissolved in 10 mL of TMEDA, and the orange solution was layered
with 30 mL of n-hexane. Yellow crystals of [Na(tmeda)(μ-PHMes)]∞
(2) formed at room temperature within a few days. Yield: 1.7 g (82%).
EXPERIMENTAL SECTION
General Remarks. All experiments were carried out under dry
nitrogen. Solvents were dried and freshly distilled under nitrogen and
■
1
Mp: 139−142 °C, 230 °C decomposition to dark red oil. H NMR
([D8]THF): δ 2.15 (br s, 4H, CH2CH2 in TMEDA), 2.25 (s, 3H, p-
Me in 2,4,6-Me3C6H2), 2.35 (s, 12H, NMe2 in TMEDA), 2.37 (s, 6H,
o-Me in 2,4,6-Me3C6H2), 6.61 (s, 2H, 2,4,6-Me3C6H2). 13C{1H} NMR
([D8]THF): δ = 20.19 (s, p-CH3 in 2,4,6-Me3C6H2), 25.03 (s, o-CH3
in 2,4,6-Me3C6H2), 45.39 (s, N(CH3)2 in TMEDA), 58.11 (s, CH2N),
122.53 (s, p-C in 2,4,6-Me3C6H2), 126.11 (s, m-C in 2,4,6-Me3C6H2),
Table 3. Crystallographic Data of [Na(tmeda)(μ-PHMes)]∞
(2) and [K(pmdeta)(μ-PHMes)]2 (3)
[Na(tmeda)(μ-
PHMes)]∞ (2)
[K(pmdeta)(μ-
PHMes)]2 (3)
a
2
empirical formula
M
C15H28N2NaP
290.35
C36H70K2N6O0.22P2
730.64
134.13 (d, o-C in 2,4,6-Me3C6H2, JPC 9.6 Hz), 153.67 (d, ipso-C in
1
2,4,6-Me3C6H2, JPC 54.7 Hz). 31P NMR ([D8]THF): δ −161.0 (d,
1JPH 162.7 Hz). IR (KBr) cm−1: 2359−2293 m, br (P−H). Anal. Calcd
for C15H28N2NaP (290.35): C, 62.05; H, 9.72; N, 9.65. Found: C,
60.72; H, 9.67; N, 9.45.
T (K)
130(2)
130(2)
cryst syst
space group
a (pm)
b (pm)
c (pm)
monoclinic
P21/c
triclinic
P1
̅
Synthesis of [K(pmdeta)(μ-PHMes)]2 (3). Small pieces (ca. 5 × 5
× 5 mm) of potassium (0.5 g, 12.7 mmol) were added to a solution of
MesPCl2 (0.94 g, 4.3 mmol) in 50 mL of THF. The mixture was
heated to reflux for 3 h. The resulting dark red suspension was filtered,
and the solvent was evaporated. The remaining red solid was washed
three times with 10−20 mL of n-hexane. The solid was then dissolved
in 10 mL of toluene, 2 mL of PMDETA was added, and the dark red
solution was layered with 30 mL of n-hexane. Red crystals of
[K(pmdeta)(μ-PHMes)]2 (3) formed in 1 week at room temperature.
Yield: 2.3 g (76%). Mp: 330−332 °C, decomposition to dark brown
844.88(2)
2459.77(5)
868.42(2)
90
922.34(3)
1365.03(5)
1818.38(6)
96.795(3)
93.756(3)
103.777(3)
2.1975(1)
2
α (deg)
β (deg)
γ (deg)
V (nm3)
Z
90.522(2)
90
1.80468(7)
4
ρcalcd (Mg m−3
)
1.069
1.104
1
oil. H NMR (C6D6): δ 1.96 (s, 3H, NMe in pmdeta), 2.04 (s, 12H,
θmin−θmax (deg)
total data
2.87−30.51
19 675
2.65−30.51
24 110
NMe2 in pmdeta), 2.15 (m, 8H, CH2CH2 in pmdeta), 2.20 (s, 3H, p-
Me in 2,4,6-Me3C6H2), 2.65 (s, 6H, o-Me in 2,4,6-Me3C6H2), 6.85 (s,
2H, 2,4,6-Me3C6H2). 13C{1H} NMR (C6D6): δ 20.70 (s, p-CH3 in
unique data (Rint)
params, restraints
GOF on F2
5499 (0.0258)
284, 6
13404 (0.0329)
528, 4
2
2,4,6-Me3C6H2), 25.34 (d, o-CH3 in 2,4,6-Me3C6H2, JPC 12.7 Hz),
0.918
0.794
41.66 (s, NCH3 in pmdeta), 45.18 (s, N(CH3)2 in pmdeta), 56.00 (s,
CH2N), 57.35 (s, CH2N), 125.34 (s, p-C in 2,4,6-Me3C6H2), 128.97
(s, m-C in 2,4,6-Me3C6H2), 134.12 (d, o-C in 2,4,6-Me3C6H2, 2JPC 9.0
R1, wR2 [I > 2σ(I)]
R1, wR2 (all data)
residual electron density (e
0.0325, 0.0794
0.0539, 0.0834
0.352 and −0.139
0.0407, 0.0723
0.0938, 0.0793
0.531 and −0.379
1
Hz), 152.62 (d, ipso-C in 2,4,6-Me3C6H2, JPC 50.3 Hz). 31P NMR
Å−3
)
(C6D6): δ −142.3 (d, 1JPH 169.5 Hz). IR (KBr) cm−1: 2355−2296 m,
br (P−H). Anal. Calcd for C36H70K2N6P2 (727.12): C, 59.47; H, 9.70;
N, 11.56. Found: C, 58.25; H, 9.66; N, 11.79.
a
Apparently, partial oxidation occurred during mounting of the
crystals, while all NMR spectra showed only the unoxidized product.
Test Reaction in [D8]THF. Potassium sand (0.04 g, 1.02 mmol,
prepared from K in boiling THF) was added to a solution of MesPCl2
(0.07 g, 0.34 mmol) in 2 mL of [D8]THF. The mixture was heated to
reflux for 3 h. A dark red suspension formed, which was filtered.
Filtrate was concentrated to 0.6 mL and transferred into an NMR
tube, which was sealed under vacuum for measurement. 31P NMR
([D8]THF, 25 °C): δ −142 (br s, KPDMes), −158 (br s, MesPD2).
Data Collection and Structure Determination of [Na(tmeda)-
(μ-PHMes)]∞ (2) and [K(pmdeta)(μ-PHMes)]2 (3). Data for 2 and 3
were collected with an Oxford GEMINI CCD diffractometer (λ(Mo
Kα) = 71.073 pm). Semiempirical absorption corrections from
equivalents were carried out with SCALE3 ABSPACK.34 Structures
kept over a potassium mirror. TMEDA and PMDETA were acquired
commercially, dried over Na, and stored under argon. MesPCl2 was
synthesized according to a literature procedure.12
NMR spectra were recorded at 25 °C with a Bruker AVANCE DRX
400 spectrometer (1H NMR 400.13 MHz, internal standard TMS; 13
C
NMR 100.16 MHz, internal standard TMS; 31P NMR 161.97 MHz,
external standard 85% H3PO4). IR spectra were recorded with a
Perkin-Elmer Spektrum 2000 FT-IR spectrometer between 4000 and
400 cm−1 (as KBr pellets). Melting points (Gallenkamp) were
determined in sealed capillaries under argon and are uncorrected.
D
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were solved by direct methods using SHELXS-97.35 Structure
refinement was carried out using full-matrix least-squares routines
against F2 with SHELXL-97.35 All non-hydrogen atoms were refined
anisotropically; hydrogen atoms of the methyl substituents and
hydrogen atoms bonded to the partially oxidized phosphorus atoms
in structure 3 are calculated on idealized positions; for all other
hydrogen atoms a difference-density Fourier map was used to locate
them. Table 3 summarizes the crystallographic data of 2 and 3.
Structure figures were generated with DIAMOND-3.36 CCDC 914064
(2) and 914065 (3) contain supplementary crystallographic data for
this paper. These data can be obtained free of charge via www.ccdc.
cam.ac.uk/conts/retrieving.html (or from the Cambridge Crystallo-
graphic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax:
(+44)1223-336-033; or deposit@ccdc.cam.uk).
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ASSOCIATED CONTENT
* Supporting Information
This material is available free of charge via the Internet at
http://pubs.acs.org.
■
S
AUTHOR INFORMATION
Corresponding Author
*E-mail: hey@rz.uni-leipzig.de.
■
Notes
(5) (a) Gom
255, 1360 and references therein. (b) Gom
E. New J. Chem. 2010, 34, 1525 and references therein. (c) Gom
́
ez-Ruiz, S.; Hey-Hawkins, E. Coord. Chem. Rev. 2011,
ez-Ruiz, S.; Hey-Hawkins,
ez-
The authors declare no competing financial interest.
́
́
ACKNOWLEDGMENTS
Ruiz, S.; Hey-Hawkins, E. Metal Complexes with Anionic Poly-
phosphorus Chains as Potential Precursors for the Synthesis of Metal
Phosphides. In Phosphorus Chemistry: Catalysis and Material Science
Applications; Peruzzini, M., Gonsalvi, L., Eds.; Springer: New York,
2011; Vol. 37, pp 85−120 and references therein.
■
Financial support from the Deutsche Forschungsgemeinschaft
(He 1376/22-3), the German Academic Exchange Service
(doctoral grant for I.J.), the Alexander von Humboldt
Foundation (postdoctoral grant for S.G.-R.), and the EU-
COST Action CM0802 PhoSciNet is gratefully acknowledged.
We thank Chemetall GmbH and BASF SE for generous
donations of chemicals.
(6) (a) Wolf, R.; Schisler, A.; Lonnecke, P.; Jones, C.; Hey-Hawkins,
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E. Eur. J. Inorg. Chem. 2004, 3277. (b) Wolf, R.; Hey-Hawkins, E. Z.
Anorg. Allg. Chem. 2006, 632, 727.
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Angew. Chem., Int. Ed. 2005, 44, 6241. (b) Wolf, R.; Hey-Hawkins, E.
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