Solvent-free mesityllithium: Solid-state structure and its reactivity towards white phosphorus

Article abstract of DOI:10.1039/c0dt00161a

The donor-free mesityllithium was prepared from the reaction of MesBr with n-BuLi in diethyl ether at -78°C. The solid-state structure of unsupported mesityllithium consists of C₂Li₂-rings composed of two LiMes units, which interact with adjacent dimers [LiMes]₂, forming a polymeric infinite chain along the crystallographic c-axis (monoclinic space group, P2₁/n). The structure of donor-free mesityllithium reveals short contacts between the C atoms of the mesityl rings and the lithium atoms of neighbouring [LiMes]₂ units. The structure determination of LiMes was performed by X-ray powder diffraction. In addition we have investigated the reaction of LiMes with Me₃SnCl and P₄ for our understanding of the reactivity of donor-free mesityllithium. The heterogeneous reaction of donor-free mesityllithium with Me₃SnCl produces conveniently the stannylated mesitylene Me₃SnMes (triclinic, space group P1). White phosphorus reacts with three equivalents of unsupported mesityllithium in benzene to give Li₃P₄Mes₃. In this context it should be noted that a tetraphosphide with an identical LiP-core as in Li₃P₄Mes₃ had been formed in the 1:3 reaction of P₄ with the silanide Li[SitBu₃]. The tetraphosphide Li₃P₄Mes₃ was analyzed using X-ray crystallography (monoclinic, space group C2/c).

Full text of DOI:10.1039/c0dt00161a

View Article Online / Journal Homepage / Table of Contents for this issue
PAPER
www.rsc.org/dalton | Dalton Transactions
Solvent-free mesityllithium: solid-state structure and its reactivity towards
white phosphorus†
Alexander H u¨ bner, Thomas Bernert, Inge S a¨ nger, Edith Alig, Michael Bolte, Lothar Fink, Matthias Wagner and
Hans-Wolfram Lerner*
Received 18th March 2010, Accepted 1st June 2010
First published as an Advance Article on the web 8th July 2010
DOI: 10.1039/c0dt00161a
The donor-free mesityllithium was prepared from the reaction of MesBr with n-BuLi in diethyl ether at
◦
-
78 C. The solid-state structure of unsupported mesityllithium consists of C
2
2
Li -rings composed of
two LiMes units, which interact with adjacent dimers [LiMes]
along the crystallographic c-axis (monoclinic space group, P2
2
, forming a polymeric infinite chain
/n). The structure of donor-free
1
mesityllithium reveals short contacts between the C atoms of the mesityl rings and the lithium atoms of
neighbouring [LiMes] units. The structure determination of LiMes was performed by X-ray powder
diffraction. In addition we have investigated the reaction of LiMes with Me SnCl and P for our
understanding of the reactivity of donor-free mesityllithium. The heterogeneous reaction of donor-free
mesityllithium with Me SnCl produces conveniently the stannylated mesitylene Me SnMes (triclinic,
space group P1). White phosphorus reacts with three equivalents of unsupported mesityllithium in
benzene to give Li Mes . In this context it should be noted that a tetraphosphide with an identical
LiP-core as in Li had been formed in the 1 : 3 reaction of P with the silanide Li[SitBu ]. The
was analyzed using X-ray crystallography (monoclinic, space group C2/c).
2
3
4
3
3
¯
3
P
4
3
3
P
4
Mes
3
4
3
tetraphosphide Li
3
P
4
Mes
3
Introduction
Organyllithium compounds have gained prominence in wide areas
1
of application in research laboratories and industry. Generally,
the solid-state structures of lithium organyls are important for
1–3
our understanding of their reactivity. Despite the long existence
and common usage of lithium organyls, the structures of donor-
free lithium aryls are not as well investigated as their alkyl
3
counterparts. There have only been a few crystal structures of
4–7
donor-free lithium aryls reported in the literature.
A characteristic feature of solvent-free lithium aryls with the
exception of [Li(3,5-tBu )] is the strong interaction of the
2
C
6
H
3
6
p-electrons with the lithium cations. In summary, donor-free
4
lithium aryls feature four structural motifs: A ([LiPh]
2
), B ([Li(2,6-
5
6
Dipp
2
C
6
H
3
)]
2
, Dipp = 2,6-iPr
2
C
6
H
3
), C ([Li(2,4,6-iPr
) in the solid state, as shown in Fig. 1.
3
C
6
H
2
)]
4
),
7
and D ([Li(3,5-tBu
2
C
6
H
3
)]
6
In this context it should be noted that the presence of donors
can cause problems in nucleophilic substitution reactions by
coordinating to electrophilic centres like B, Si, or Sn atoms and by
solubilizing lithium halide salts formed in the course of such reac-
tions. Thus, it is of importance to apply pure, solvent-free lithium
organic compounds. In this paper we report, for the first time, the
structure of solvent-free, unsupported mesityllithium. In addition
we present here the reactivity of donor-free mesityllithium towards
white phosphorus.
Fig. 1 Structural motifs of unsupported lithium aryls.
Results and Discussion
The successful synthesis of unsupported LiCH
2
SMe from SMe
2
8
with 3 equivalents of n-BuLi, raised the question whether the
donor-free mesityllithium can be prepared by analogous reaction
with mesitylene and n-BuLi. The NMR spectra of this reaction,
however, indicate that it is not practical to prepare unsupported
mesityllithium by the same routes as applied for LiCH
2
SMe.
Institut f u¨ r Anorganische Chemie, Goethe-Universit a¨ t, Max-von-Laue-Str.
However, we could synthesize solvent-free mesityllithium when
7
, D-60438, Frankfurt, Germany. E-mail: lerner@chemie.uni-frankfurt.de;
MesBr was treated with one equivalent of n-BuLi in Et
2
O at
Fax: +49 69 79829260; Tel: +49 69 79829152
CCDC reference numbers 768792 (1), 768408 (2), 768409 {[8]
For crystallographic data in CIF or other electronic format see DOI:
0.1039/c0dt00161a
◦
-
78 C, as shown in Scheme 1. Thereby we have obtained
†
2
}.
microcrystalline, donor-free mesityllithium as a precipitate. The
formation of solvent-free mesityllithium indicates that the Li
1
7
528 | Dalton Trans., 2010, 39, 7528–7533
This journal is © The Royal Society of Chemistry 2010

View Article Online
supersilylated tetraphosphides M
by the reaction of P
3
[5] (M = Li, Na) was achieved
4
with the silanides M[SitBu
3
] (M = Li, Na) in a
3
1
: 3 stoichiometry in benzene, however, in thf M
are unstable and thereby (iv) M[6] and M [PSitBu
were formed, and (v) at last the pentaphosphide M
synthesized by degradation of the corresponding octaphosphides
[5] (M = Li, Na)
] (M = Li, Na)
[7] could be
2
3
14
2
M
4
[4] with M[SitBu
3
] (M = Na, K) or was directly accessible by
18,19
2 3
treating P
4
with 4 equivalents of Na(thf)
[SitBu
] in benzene.
20
21
In addition we have prepared Cs[6], {Ag
2
[PSitBu
3
]}
8
,
and
18
{
Ag
2
[7]}
2
,
respectively, by metathesis reaction from the corre-
sponding sodium phosphides.
Now we have discovered that white phosphorus reacts with
three molar equivalents of 1 in benzene forming an analogous
phosphide that had been formed in the 1 : 3 reactions of P
with the silanides M[SitBu
] (M = Li, Na) and Na[SiPhtBu
see Scheme 2). Treatment of P
at room temperature resulted in an immediate reaction, and
pure Li Mes (8) was precipitated. The tetraphosphide 8 was
separated by filtration. After dissolving the obtained solid, single
crystals of the tetraphosphide dimer [8] as a solvate were grown
from a thf solution by gas-phase diffusion of diethyl ether.
In the end the reactivity of the donor-free 1 towards P , as
shown in Scheme 2, is analogous to that of donor-free silanides
M[SitBu ]. By contrast, the thf-
] (M = Li, Na) and Na[SiPhtBu
complexed mesityllithium reacts with white phosphorus forming
4
3
2
]
(
4
with donor-free 1 in benzene
3
P
4
3
Scheme 1 Synthesis of donor-free mesityllithium (1) and stannylated
mesitylene Me SnMes (2).
2
3
4
cation in 1 exhibits apparently a stronger affinity to the mesityl
ring than to the O atoms of Et O molecules.
2
3
2
We have found that slurries of donor-free 1 react spontaneously
withelectrophiles. For example solvent-free1 underwentareaction
22
quite different products.
9
with Me
3
SnCl to give stannylated mesitylene 2 in high yield
(
see Scheme 1). In addition, we have investigated the reaction
of mesityllithium with P
Previously we have reported that product formation of P
4
.
4
1,12
1
activation with the silanides M[SitBu
3
] (M = Li, Na, K)
depends strongly on the stoichiometry and
Using the reactants in molar ratios from 1 : 2 to 1 : 4,
different phosphides were formed, as depicted in Fig. 2: (i) the
tri-tert-butylsilylated (supersilylated) tetraphosphenediides M [3]
and
13
and Na[SiPhtBu ]
2
14–19
solvent.
2
(
M = Li, Na, K) were obtained from the reaction of P
4
1
4–16
M[SitBu
3
] (M = Li, Na, K) in a molar ratio of 1 : 2 in thf,
[4] (M = Na, K), however,
were also synthesized in a 1 : 2 stoichiometry but in weakly polar
(ii)
the supersilylated octaphosphides M
4
16,17
solvents (heptane, tBuOMe etc.),
(iii) the synthesis of the
Scheme 2 Reaction of three equivalents of donor-free LiMes with one
equivalent of P in benzene at r.t.
4
3
1
The P NMR spectrum of 8 is somewhat different from that
14
of M
contrast to well-resolved signals of M
Na (SiPhtBu those of 8 are very broad in the P NMR
spectrum. Another difference between the phosphide 8 on the
one hand and the silyl phosphides M
[5] (M = Li, Na) and
Na (SiPhtBu on the other hand is manifested in a significant
3
[5] (M = Li, Na) and Na
3
P
4
(SiPhtBu
2
)
3
.
However, in
3
[5] (M = Li, Na) and
3
1
3
P
4
)
2 3
3
3
P
4
2 3
)
3
1
downfield shift of the corresponding P resonances in 8.
Partial protonation of 8 surprisingly gives the diphosphanide
9
, as shown in Scheme 3. Obviously, a degradation reaction of
the P -core had taken place. The diphosphanide 9 was identified
unambiguously by P NMR spectroscopy. In addition 9 could
be transformed with CF CO H into the literature-known diphos-
4
3
1
Fig. 2 Products of P
Na, K).
4
activation with the silanides M[SitBu
3
] (M = Li,
3
3
2
2
phane MesPH-PHMes.
This journal is © The Royal Society of Chemistry 2010
Dalton Trans., 2010, 39, 7528–7533 | 7529

View Article Online
Table 1 Bond lengths and bond angles of unsupported lithium aryls
Li–Cipso [ A˚ ]
Li–Li [ A˚ ]
C–C [ A˚ ]
[
[
[
[
[
[
[
LiMes]
Li(thf)
2
(1)
Mes]
2.16 av
2.28 av
2.14 av
2.07 av
2.12
2.17 av
2.19 av
2.13
2.49
2.39
3.66
3.86
2.27
2.52 av
1.40 av
1.41 av
1.39 av
1.40 av
1.39 av
1,40 av
1.40 av
2
6
2
2
4
LiPh]
Li(2,6-Dipp
Li(2,4,6-iPr
Li(2,6-Mes
Li(3,5-tBu
2
5
2
6 3 2
C H )]
6
3
C H )]
6 2 4
6
2
C
6
H
3
)]
2
7
2
6 3 6
C H )]
Scheme 3 Partial protonation of 8.
The solid-state structures of donor-free mesityllithium and
[
LiPh] resemble each other. The unit cell of 1 contains four
2
formula units of LiMes located on general positions (Wyckoff
position 4e). Two LiMes units are related to each other by a centre
of inversion. Therefore the solid-state structure of 1 consists of
[
LiMes]
of 1 reveals short contacts between the C atoms of the mesityl
rings and the lithium atoms of neighbouring [LiMes] units. As a
result, the mesityllithium crystallizes as an infinite zigzag-chain
of [LiMes] dimers along the crystallographic c-axis (Fig. 4).
In contrast to that, the polymeric chains of [LiPh] -dimers in
2
-dimers, as its fundamental unit (Fig. 3). The structure
2
2
Fig. 4 The structural motif of 1 in the solid state: infinite chains of
2
[LiMes] dimers along the c-axis.
2
phenyllithium are orientated along the crystallographic b-axis. In
in solvate-free lithium aryls and the thf-complexed mesityllithium
listed in Table 1.
this context it should be noted that such a ladder motif is known
24
in organolithium chemistry. Due to the space group symmetry,
the chains of [LiMes] -dimers feature a herringbone arrangement.
X-Ray quality crystals of 2 were grown from a pentane solution
at ambient temperature. The stannane 2 crystallizes in the triclinic
2
Apparently, the Li cation in LiMes exhibits a strong affinity to the
mesityl ring. It is interesting to note that in the mesityl cuprates
¯
space group P1 (Fig. 5; for selected bond lengths and angles see
25
25
caption of Fig. 5). The Sn–C bond length between the mesityl
substituent and the Sn atom is comparable with the lengths of the
[Cu
2
Li
2
Mes
4
]
and [Cu
3
LiMes
4
]
the p-electrons of the mesityl
rings interact also with the lithium atoms.
Fig. 3 Molecular structure of mesityllithium (1) in the solid state. Selected
◦
bond lengths [ A˚ ] and bond angles [ ]: C(1)–C(7) 1.491(2), C(1)–C(6)
1
.407(3), C(1)–C(2) 1.367(2), C(2)–C(3) 1.440(2), C(3)–C(4) 1.389(3),
C(3)–C(8) 1.555(2), C(4)–Li(1) 2.146(9), Li(1)–C(4) 2.172(8), C(5)–C(9)
.550(3), C(5)–C(4) 1.372(3), C(6)–C(5) 1.418(2), Li(1)–Li’(1) 2.13(1),
Li(1)–C(4)–Li’(1) 59.0(3), Li(1)–C(4)–C(5) 117.6(3), Li(1)–C(4)–C(3)
1
1
18.1(2).
Fig. 5 Molecular structure of MesSnMe (2) in the solid state. The
3
In Table 1 the metrical parameters of the donor-free mesityl-
displacement ellipsoids are drawn at the 50% probability level. Se-
lithium are compared with those of other solvate-free lithium aryls
◦
lected bond lengths [ A˚ ] and bond angles [ ]: Sn(1)–C(10) 2.151(17),
26
and the thf-complexed mesityllithium [Li(thf)
2
Mes] . The Li–Li
2
Sn(1)–C(1) 2.154(13), Sn(1)–C(12) 2.158(15), Sn(1)–C(11) 2.169(15),
C(1)–C(6) 1.40(2), C(1)–C(2) 1.42(2), C(2)–C(3) 1.38(3), C(2)–C(7)
˚
distance of 2.13 A in 1 is on the low end of the range of values
26
4
5
found in [Li(thf)
2
Mes]
2
,
[LiPh]
2
, [Li(2,6-Dipp
2
C
6
H
3
)]
2
(Dipp
1
1
.53(2), C(3)–C(4) 1.41(3), C(10)–Sn(1)–C(1) 117.5(7), C(10)–Sn(1)–C(12)
04.8(7), C(1)–Sn(1)–C(12) 109.4(7), C(10)–Sn(1)–C(11) 106.6(7),
6
6
=
2,6-iPr
2
C
6
H
3
), [Li(2,4,6-iPr
)]
3
C
6
H
2
)]
4
, [Li(2,6-Mes
2
C
6
H
3
)]
2
, and
7
[
Li(3,5-tBu
2
C
6
H
3
6
, respectively (Table 1). The averaged C=C
C(1)–Sn(1)–C(11) 109.0(7), C(12)–Sn(1)–C(11) 109.3(6), C(6)–C(1)–Sn(1)
125.0(11), C(2)–C(1)–Sn(1) 117.1(11).
˚
bond length of 1.40 A is within the range of lengths observed
7
530 | Dalton Trans., 2010, 39, 7528–7533
This journal is © The Royal Society of Chemistry 2010

View Article Online
◦
Table 2 Bond lengths and bond angles of lithium tetraphosphides
Li (Li [5]))
(R = Mes (8), SitBu
residue at -78 C the crude product was extracted into pentane.
3
P
4
R
3
3
3
Single crystals were grown from this pentane solution at room
temperature. Yield: 0.193 g (86%). 2: d
H
(250 MHz; C
6
D
6
; Me Si)
4
1
4
14
Li
3
[5]
Li
3
[5](C
6
H
6
)
[8]
2
2
2
0
.31 (9 H, s, SnMe
3
, JSn(119)H 53 Hz, JSn(117)H 51 Hz), 2.15 (3 H, s,
4
P–P [ A˚ ]
Li–P [ A˚ ]
Li–Li [ A˚ ]
2.283(1) av
2.51(1) av
2.82(1) av
101.1(1) av
2.300(6) av
2.53(4) av
2.91(3) av
100.3(2) av
2.217(5) av
2.59(3) av
3.07(3) av
104.9(2) av
para-Me), 2.29 (6 H, s, ortho-Me, JSn(117/119)H 6 Hz), 6.68 (2 H, s,
meta-H, JSn(117/119)H 16 Hz). d
-5.1 (SnMe , J
Me, JSn(117/119)C 5.2 Hz), 25.7 (ortho-Me, JSn(119)C 31.4 Hz, JSn(117)C
4
1
C
{ H} (75.45 MHz; CDCl
3
; Me Si)
4
1
1
3
Sn(119)C
340.7 Hz, J
Sn(117)C
3
325.6 Hz), 21.1 (para-
◦
P–P–P [ ]
5
3
3
3
30.1 Hz), 127.7 (meta-Mes, JSn(119)C 42.0 Hz, JSn(117)C 40.1 Hz),
1
1
terminal Sn–CH
3
bonds. All other structural parameters of 2 are
138.0 (ipso-Mes, J
Mes, J
34.1 Hz, J
503.2 Hz, J
481.2 Hz), 138.5 (para-
Sn(119)C
4
Sn(117)C
2
7
4
2
in the expected range.
X-Ray quality crystals of the tetraphosphide [8]
9.9 Hz, J
9.5 Hz), 145.2 (ortho-Mes, J
Sn(119)C
2
Sn(117)C
Sn(119)C
1
2
(monoclinic,
Sn(117)C
32.6 Hz). d { H} (93.275 MHz; CDCl ; Me Sn)
Sn
3
4
C2/c) were grown from a thf solution by gas-phase diffusion of
diethyl ether. The tetraphosphide 8 displays a dimer containing
-48.4 (Me SnMes). Found: C, 50.75; H, 7.05. C H Sn requires
3
12 20
C, 50.93; H, 7.12.
8
P and 6 Li atoms in the solid state. The LiP-core consists
of a trigonal-antiprismatic Li -cluster which is capped by two
the six lithium atoms are arranged in
6
Reaction of 1 with P4
3
-
[P
4
Mes
3
]
anions. In [8]
2
14
1 (0.189 g, 1.5 mmol) was added to a solution of P (0.5 mmol) in 5
4
a distorted trigonal-antiprismatic fashion like in Li
3
[5]. The
3
cm benzene at ambient temperature and stirred for 4 days during
tetraphosphide 8 features for every Li atom three P–Li contacts
˚
which a yellow precipitate formed. After filtration the residue was
(
P–Li distance: 2.59(3) A, average). Apart from these P atoms,
3
dissolved in 2 cm thf. Single crystals of the tetraphosphide 8
the Li atoms are surrounded by three other Li atoms like in the
1
4
were grown from the thf solution by gas-phase diffusion of diethyl
ether. The tetraphosphide 8 was formed in 60% yield. 8: dH (250
molecular structure of Li
3
[5]. The central P atom has a pyramidal
14
geometry similar to that in Li
P bonds have an average length of 2.217(5) A. This distance is
3
[5]. As shown in Table 2, the P–
˚
MHz; D
8
-thf; Me
4
Si) 2.05–2.10 (br, para-Me), 2.15–2.30 (br, ortho-
Me), 6.50–6.60 (br, meta-H). d
P
(162.03 MHz; D -thf; H PO , P
8
3
4
somewhat shorter than the P–P bond length in Li
3
[5] (averaged
14
numbering see Fig. 6) -125.3 (br, mult, P(1), P(3), P(4)), 57.5 (br,
mult, P(2)).
˚
P–P bond length: 2.2826(12) A) and in Li
3
[5](C
6
H ) (averaged
6
˚
P–P bond length: 2.300(6) A).
Experimental
General procedures
All experiments were carried out under dry argon or nitro-
gen with strict exclusion of air and moisture using standard
Schlenk techniques or a glove box. The solvents (benzene,
diethyl ether, hexane, pentane, tetrahydrofuran) were distilled from
sodium/benzophenone prior to use.
The triphosphenide Li
3
P
4
Mes is extremely moisture and oxygen
3
sensitive. Therefore, the analysis is limited to NMR and X-ray
structure determination. The NMR spectra were recorded on a
Bruker AM 250, a Bruker DPX 250, a Bruker Avance 300 and a
Bruker Avance 400 spectrometer. Abbrevations: s = singlet; d =
doublet; t = triplet; q = quartet; mult = multiplet; br = broad.
Synthesis of 1
3
A solution of n-BuLi in hexane (27.1 cm , 1.55 M, 40 mmol)
was added to a solution of MesBr (8.00 g, 40 mmol) in diethyl
3
◦
ether (80 cm ) at -78 C. The reaction mixture was stirred for
2
Fig. 6 Core structure of {[Li(thf)] P Mes } {[8] } in the solid state. The
3
4
3
2
2
◦
h at -78 C and for 16 h at room temperature, during which
a colourless precipitate formed. After filtering and washing the
precipitate with hexane (2 ¥ 5 cm ), analytically pure 1 remained
as a white microcrystalline solid in 35% yield.
displacement ellipsoids are drawn at the 50% probability level. Mesityl
and thf rings have been omitted for clarity. Selected bond lengths [A
˚
]
◦
3
and bond angles [ ]: P(1)–P(2) 2.209(5), P(2)–P(4)#1 2.219(5), P(2)–P(3)
2
.220(5), P(4)–P(2)#1 2.219(5). Symmetry transformation used to generate
equivalent atoms: #1 -x + 1/2, -y + 1/2, -z + 1.
Reaction of 1 with Me
3
SnCl
Remark: due to traces of water in D
protonated which gives the diphosphanide 9. 9: d
-thf; Me Si) 2.02 (3 H, br, para-Me), 2.04 (3 H, br, para-Me),
2.16 (6 H, br, ortho-Me), 2.18 (6 H, br, ortho-Me), 5.03 (1 H,
8
-thf, 8 was partially
Me SnCl (0.628 g, 3.15 mmol) was added to a slurry of 1 (0.100
3
H
(250 MHz;
3
◦
g, 0.79 mmol) in hexane (10 cm ) at -20 C. The reaction mixture
was stirred for 1 h at 0 C and for 16 h at room temperature. After
filtration all volatiles were removed in vacuo. After cooling of the
D
8
4
◦
1
3
dd, JPH 207.20 Hz, JPH 9.84 Hz, PH), 6.49 (2 H, meta-H), 6.52
This journal is © The Royal Society of Chemistry 2010
Dalton Trans., 2010, 39, 7528–7533 | 7531

View Article Online
1
(
3
2
2 H, meta-H). d
P
(162.03 MHz; D
8
-thf; H
3
PO
4
) -144.1 (dd, JPP
Crystal data and experimental details for LiMes (1): formula:
3
1
1
˚
˚
80.52 Hz, JPH 9.84 Hz, MesPLi), -87.2 (dd, JPP 380.52 Hz, JPH
C
˚
9
H
11Li; a = 15.27957(61) A, b = 10.61806(43) A, c = 4.74612(19)
◦
3
˚
07.20 Hz, MesPH).
A; b = 96.5964(17) , V = 764.910(53) A , Z = 4; space
-
1
-3
group: P2
1
/n; m = 0.43 mm ; r = 1.095 g cm ; diffractometer:
◦
STOE Stadi-P; scan method: step (increment in 2q = 0.01 ),
Crystal structure determinations of 1, 2 and [8]
2
˚
transmission mode; radiation: CuK
a
(l = 1.54056 A), X-ray
Indexing with DICVOL led to the monoclinic unit cell. The
structure solution was carried out using simulated annealing
with DASH based on a modified molecular structure model of
mesitylene. The Rietveld refinement was carried out with TOPAS
Rietveld plot of 1 see Fig. 7). The mesitylene ring was restrained
to be flat. All methyl groups were restrained to be tetrahedrons.
All C–C and C–H angles of the benzene ring were restrained to
tube; monochromator: primary focussing, Ge (111); detector
type: linear position sensitive detector; sample was sealed in a
◦
◦
borosilicate glass capillary; T = 298 K; 2q range: 2 to 100 ;
total number of measured points = 9800; R = 0.01604; Rwp
= 0.009115; Goodness-of-Fit =
p
(
= 0.02062; Rexp = 0.01360: R
I
1.516; 112 parameters; 39 restraints; 3 constraints; profile func-
tion: modified Thompson–Cox–Hastings pseudo-Voigt; weighting
scheme: based on measured s.u., w = 1/s; data collection:
STOE & Cie (2004). WinXPOW. STOE and Cie, Darmstadt,
◦
be 120 except the angle C(3)–C(4)–C(5). Thermal parameters of
non-hydrogen atoms with the exception of those of Li atoms were
refined combined. Thermal parameters of hydrogen atoms were
constrained to those of the non-hydrogen atoms.
28
Germany.
Data collections for 2 and [8]
2
were performed on a STOE
IPDS-II two-circle diffractometer with graphite-monochromated
˚
MoK
a
-radiation (l = 0.71073 A). The structures were solved with
2
direct methods and refined against F by full-matrix least-squares
calculations (Table 3). The crystallographic figures of merit for 2
and [8]
2
are higher than usual because both samples crystallized in
, two
very thin plates and these plates diffracted only weakly. In [8]
2
thf rings are disordered over two positions with site occupation
factors of 0.69(3) and 0.70(5) for the main components. The disor-
dered atoms were just isotropically refined. As a result of that, the
geometric parameters of these moieties adopt unusual values. The
application of restraints was unsuccessful. Absorption corrections
were performed with the MULABS option in PLATON. All non-
H atoms except the disordered ones have been refined anisotrop-
ically, whereas the H atoms have been treated with a riding
29
model.
Fig. 7 Rietveld plot of mesityllithium 1.
Table 3 Crystal data and experimental details for 2 and [8]
2
2
[8]
2
Empirical formula
Formula weight
Temperature/K
Crystal size/mm
Crystal system
C
282.97
173(2)
0.22 ¥ 0.19 ¥ 0.07
Triclinic
P1
7.3483(16)
8.4221(17)
10.901(3)
76.145(19)
75.504(19)
86.082(17)
634.1(3)
2
12
H
20Sn
78 6 6 8
C H114Li O P
1437.09
173(2)
0.18 ¥ 0.16 ¥ 0.07
Monoclinic
C2/c
26.261(6)
15.843(3)
21.951(5)
3
¯
Space group
a/A˚
b/A˚
c/A˚
◦
a/
90
◦
b/
99.096(18)
90
9018(3)
4
1.058
0.198
◦
g /
V/A˚
3
Z
-3
Calcd. density/Mg m
1.482
1.975
-
1
m/mm
Index ranges
q-range/
-8≤ h ≤8, -10≤ k ≤10, -13≤ l ≤13
-31≤ h ≤28, -18≤ k ≤18, -26≤ l ≤26
◦
3.52 to 25.65
3.30 to 25.03
No. of reflns. collected
No. of indep. reflns.
8002
2369
31 782
7927
R
int
0.1374
1.012
0.4168
0.807
2
Goodness-of-fit (F )
R1, wR2 [I > 2s(I)]
R1, wR2 indices (all data)
Largest diff. peak and hole/e A˚ -
R1 = 0.1166, wR2 = 0.2870
R1 = 0.1355, wR2 = 0.3017
4.003 and -2.413
R1 = 0.1123, wR2 = 0.2082
R1 = 0.3505, wR2 = 0.3158
0.575 and -0.312
1
7
532 | Dalton Trans., 2010, 39, 7528–7533
This journal is © The Royal Society of Chemistry 2010

View Article Online
Conclusions
7 R. J. Wehmschulte and P. P. Power, J. Am. Chem. Soc., 1997, 119,
2
847.
8
9
K. Ruth, R. E. Dinnebier, S. W. T o¨ nnes, E. Alig, I. S a¨ nger, H.-W. Lerner
and M. Wagner, Chem. Commun., 2005, 3442.
The donor-free mesityllithium was prepared from the reaction
of MesBr with n-BuLi in diethyl ether at -78 C. The solid-
◦
Me
0.
10 F. J a¨ kle and I. Manners, Organometallics, 1999, 18, 2628.
3 3
SnMes can also be prepared from CuMes and Me SnCl, see ref.
state structure of unsupported mesityllithium 1 consists of C
rings composed of two LiMes units, which interact with adjacent
dimers [LiMes] , forming a polymeric infinite chain along the
crystallographic c-axis. The p-electrons of each mesityl ring
interact with the lithium atoms of neighbouring [LiMes] units.
2
Li
2
-
1
1
1
1 H.-W. Lerner, Coord. Chem. Rev., 2005, 249, 781.
2 N. Wiberg, K. Amelunxen, H.-W. Lerner, H. Schuster, H. N o¨ th, I.
Krossing, M. Schmidt-Amelunxen and T. Seifert, J. Organomet. Chem.,
1997, 542, 1.
3 H.-W. Lerner, S. Scholz, M. Bolte and M. Wagner, Z. Anorg. Allg.
Chem., 2004, 630, 443; H.-W. Lerner, S. Scholz and M. Bolte, Z. Anorg.
Allg. Chem., 2001, 627, 1638.
2
2
1
The structure determination of 1 was performed by X-ray powder
diffraction. In addition we examined the reaction of LiMes
with Me
3
SnCl and P
4
for our understanding of the reactivity of
SnCl gave
1
4 H.-W. Lerner, M. Wagner and M. Bolte, Chem. Commun., 2003, 990.
15 N. Wiberg, A. W o¨ rner, H.-W. Lerner, K. Karaghiosoff, D. Fenske, G.
donor-free mesityllithium. The reaction of 1 with Me
3
Baum, A. Dransfeld and P. von Ragu e´ Schleyer, Eur. J. Inorg. Chem.,
conveniently the stannylated mesitylene 2 in high yield. White
phosphorus reacts with three equivalents of 1 in benzene to give
the tetraphosphide 8. In this context it should be noted that an
1
998, 833.
1
6 H.-W. Lerner, M. Bolte, K. Karaghiosoff and M. Wagner,
Organometallics, 2004, 23, 6073.
analogous product had been formed in the 1 : 3 reactions of P
with the silanides M[SitBu
] (M = Li, Na). The comparison of
the reactions of white phosphorus between 1 and Li[SitBu ] shows
activation is exclusively
determined by the reaction conditions namely the solvent and
stoichiometry.
4
17 A. Lorbach, A. Nadj, S. T u¨ llmann, F. Dornhaus, F. Sch o¨ del, I. S a¨ nger,
G. Margraf, J. W. Bats, M. Bolte, M. C. Holthausen, M. Wagner and
H.-W. Lerner, Inorg. Chem., 2009, 48, 1005.
3
3
1
1
2
2
8 H.-W. Lerner, G. Margraf, L. Kaufmann, J. W. Bats, M. Bolte and M.
Wagner, Eur. J. Inorg. Chem., 2005, 1932.
9 N. Wiberg, A. W o¨ rner, H.-W. Lerner, K. Karaghiosoff and H. N o¨ th,
Z. Naturforsch., 1998, 53b, 1004.
0 H.-W. Lerner, I. S a¨ nger, F. Sch o¨ del, A. Lorbach, M. Bolte and M.
Wagner, Dalton Trans., 2008, 787.
1 H.-W. Lerner, G. Margraf, J. Bats and M. Wagner, Chem. Commun.,
30
in an exemplary manner how the P
4
Notes and references
2
005, 4545.
22 Treatment of P
compounds a species which reveals P resonances in the range of PP
1
T. Stey and D. Stalke, in The Chemistry of Organolithium Compounds,
ed. Z. Rappoport and I. Marek, Wiley, New York, 2004, pp. 47–120.
V. H. Gessner, C. D a¨ schlein and C. Strohmann, Chem.–Eur. J., 2009, 15,
4
with LiMes in thf gives along with other P-containing
31
1
2
double bonds [d
P
(162.03 MHz, D
137.4 (d)]. Further investigations into the reaction of P
thf are currently under way.
8
-thf, H
3
PO
4
) = 224.1 (d, JPP 451.8),
3
320; C. Strohmann, T. Seibel and K. Strohfeldt, Angew. Chem., 2003,
15, 4669; C. Strohmann, T. Seibel and K. Strohfeldt, Angew. Chem.,
4
with LiMes in
1
Int. Ed., 2003, 42, 4531; C. Strohmann, T. Seibel and D. Schildbach, J.
Am. Chem. Soc., 2004, 126, 9876; C. Strohmann and V. H. Gessner,
Angew. Chem., Int. Ed., 2007, 46, 8281; C. Strohmann and V. H.
Gessner, J. Am. Chem. Soc., 2007, 129, 8952.
23 S. Kurz, H. Oesen, J. Sieler and E. Hey-Hawkins, Phosphorus, Sulfur
Silicon Relat. Elem., 1996, 117, 189.
24 R. E. Mulvey, Chem. Soc. Rev., 1998, 27, 339; D. R. Armstrong, D.
Barr, R. Snaith, W. Clegg, R. E. Mulvey, K. Wade and D. Reed, J.
Chem. Soc., Dalton Trans., 1987, 1071.
3
H. Dietrich, Acta Crystallogr., 1963, 16, 681; E. A. C. Lucken and E.
Weiss, J. Organomet. Chem., 1964, 2, 197; T. Kottke and D. Stalke,
Angew. Chem., Int. Ed. Engl., 1993, 32, 580; U. Siemeling, T. Redecker,
B. Neumann and H.-G. Stammler, J. Am. Chem. Soc., 1994, 116, 5507;
R. Zerger, W. Rhine and G. Stucky, J. Am. Chem. Soc., 1974, 96, 6048;
A. Maercker, M. Bsata, W. Buchmeier and B. Engelen, Chem. Ber.,
25 R. P. Davies, S. Hornauer and A. J. P. White, Chem. Commun., 2007,
304.
26 M. A. Beno, H. Hope, M. M. Olmstead and P. P. Power,
Organometallics, 1985, 4, 2117.
27 Cambridge Structural Database (CSD), Version 5.29 with three up-
dates, January 2008; Allen, 2002 F. H. Allen, Acta Crystallogr., Sect.
B: Struct. Sci., 2002, 58, 380.
28 A. Boultif and D. Lou e¨ r D., J. Appl. Crystallogr., 1991, 24, 987; A.
A. Coelho, TOPAS Academic, 2007, User Manual. Coelho Software,
Brisbane, Australia; W. I. F. David, K. Shankland, J. Van de Streek,
E. Pidcock and S. Motherwell, DASH, 2007, Version 3.0. Cambridge
Crystallographic Data Centre, 12 Union Road, Cambridge, England;
R. M. Ibberson, S. Parsons, I. Natkaniec and K. Holderna-Natkaniec,
Z. Kristallogr., Suppl., 2007, 26, 575.
1
984, 117, 2547; M. Veith and H. B a¨ rninghausen, Acta Crystallogr.,
Sect. B: Struct. Crystallogr. Cryst. Chem., 1974, 30, 1806; D. Seebach,
R. Amstutz, T. Laube, W. B. Schweizer and J. D. Dunitz, J. Am. Chem.
Soc., 1985, 107, 5403; R. Boese and D. Bl a¨ ser, J. Appl. Crystallogr.,
1
989, 22, 394; H. Hope, Acta Crystallogr., Sect. B: Struct. Sci., 1988,
4, 22; D. Stalke, J. Appl. Crystallogr., 1993, 26, 615; Kottke and D.
4
Stalke, Chem. Soc. Rev., 1998, 27, 171.
4
5
6
R. E. Dinnebier, U. Behrens and F. Olbrich, J. Am. Chem. Soc., 1998,
1
20, 1430.
B. Schiemenz and P. P. Power, Angew. Chem., Int. Ed. Engl., 1996, 35,
29 G. M. Sheldrick, Acta Crystallogr., Sect. A: Found. Crystallogr., 2008,
64, 112.
2
150.
K. Ruhlandt-Senge, J. J. Ellison, R. J. Wehmschulte, F. Pauer and P. P.
4
30 Very recently a review about P activation has been published. M.
Power, J. Am. Chem. Soc., 1993, 115, 11353.
Scheer, G. Balazs and A. Seitz, Chem. Rev., DOI: 10.1021/cr100010e.
This journal is © The Royal Society of Chemistry 2010
Dalton Trans., 2010, 39, 7528–7533 | 7533