The reactivity of cyclo-(P5tBu4) - towards group 13, 14 and 15 metal chlorides: Complexation and formation of cyclooligophosphanes, {cyclo-(P5tBu 4)}2 and {cyclo-(P<su

Article abstract of DOI:10.1039/b407736a

[Na(THF)₄][cyclo-(P₅^tBu₄)] (1) reacts with Et₂AlCl and GeCl₄ to give Et ₂Al{cyclo-(P₅^tBu₄)}(THF) (2) and, in low yield, GeCl₃{cyclo-(P

Full text of DOI:10.1039/b407736a

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F U L L P A P E R
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The reactivity of cyclo-(P5 Bu4)− towards group 13, 14 and 15 metal
chlorides: complexation and formation of cyclooligophosphanes,
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{cyclo-(P5 Bu4)}2 and {cyclo-(P4 Bu3)PtBu}2, by reductive
elimination
Andrea Schisler,a Peter Lönnecke,a Thomas Gelbrichb and Evamarie Hey-Hawkins*a
a
Institut für Anorganische Chemie der Universität Leipzig, Johannisallee 29, D-04103 Leipzig,
Germany. E-mail: hey@rz.uni-leipzig.de; Fax: +(0049)3419739319; Tel: +(0049)3419736151
EPSRC National Crystallography Service, University Southampton, Dept. of Chemistry,
b
Highfield, Southhampton, UK SO17 1BJ
Received 21st May 2004, Accepted 3rd August 2004
First published as an Advance Article on the web 20th August 2004
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[Na(THF)4][cyclo-(P5 Bu4)] (1) reacts with Et2AlCl and GeCl4 to give Et2Al{cyclo-(P5 Bu4)}(THF) (2) and, in low yield,
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GeCl3{cyclo-(P5 Bu4)}, respectively, while the reaction of 1 with SnCl2, PbCl2 or BiCl3 results in the formation of the
structural isomers {cyclo-(P5 Bu4)}2 (3) and {cyclo-(P4 Bu3)PtBu}2 (4) (besides other cyclic phosphanes) and elemental
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metal.
1
(161 MHz): external 85% H3PO4; H NMR (400 MHz): internal
Introduction
TMS; 13C NMR (100 MHz): internal TMS. The IR spectra were
recorded as Nujol mulls on a Perkin-Elmer Spektrum 2000 spectro-
meter in the range 400–4000 cm−1. The FAB mass spectra were
obtained on a ZAB-HSQ-VG Analytical Manchester. The coupling
constants of the 31P{1H} NMR spectra were calculated with the
program SPINWORKS.17
Cyclooligophosphanes1 cyclo-(PR)n, which are isolobal to cycloal-
kanes, have long attracted the interest of chemists. While the first
example of this class of compounds, cyclo-(PPh)5, was synthesised
as early as 1877,2 the number of bicyclic compounds obtained in
pure form, mainly by Baudler et al., is still small,3–6 and only three
structurally characterised examples are known to date: {cyclo-
(P3R2)}2 (R = tBu, Cp)4 and {cyclo-(P4 Bu3)}2.6 Theoretical studies
performed on oligocyclic Pn molecules and clusters (n = 2, 4, 6,…,
28) indicate that these compounds should be thermodynamically
stable at low temperatures.7
Bicyclic oligophosphanes should be accessible by oxidative cou-
pling of cyclooligophosphanide anions cyclo-(PnRn−1)−,8–10 and this
method was already employed in the preparation of {cyclo-(P3R2)}2
(R = tBu, Cp).4 The first cyclooligophosphanide anions cyclo-
(PnRn−1)− were reported in 1987,8,9,11,12 and even today, the number of
readily accessible, pure compounds is still small.10 Most compounds
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Preparations
Reaction of 1 with Et2AlCl. A solution of 0.29 g (2.39 mmol)
Et2AlCl in 10 ml n-pentane was added to a vigorously stirred solu-
tion of 0.97 g (2.39 mmol) 1 in 20 ml n-pentane. A colour change
from yellow–orange to light yellow was observed. After 30 min
the solution was filtered and the solvent evaporated in vacuo. The
pale yellow oily residue consists of Et2Al{cyclo-(P5 Bu4)}(THF) (2)
(72%) and cyclo-(P5 Bu4H)18 (28%) (by 31P NMR spectroscopy). 2
could not be obtained in pure form; traces of cyclo-(P5 Bu4H) were
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were only obtained in inseparable mixtures and characterised by 31
NMR spectroscopy. Recently, we reported the targeted high-yield
synthesis of Na[cyclo-(P5 Bu4)] and preliminary results on its use in
coordination chemistry.13
P
always present.
1H NMR (C6D6):  0.18 (q, JHH = 8.3 Hz, 4H, CH2), 1.27–1.53
3
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(m, 46H, tBu, CH3 and THF), 3.49 (s, 4H, THF). 13C NMR (C6D6):
1
2
 0.36 (br, CH2), 8.67 (qt, JCH = 124.5 Hz, JCH = 5.0 Hz, CH3),
1
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Although linear and cyclic oligophosphanides are of interest as
ligands in main group and transition metal chemistry, there are only
few reports of the use of linear oligophosphanide ligands (PnRn)2−
in main group metal and coordination chemistry. Examples of the
former include the synthesis of the germatetraphospholanes14 cyclo-
24.34 (t, JCH = 134.8 Hz, THF), 30.58–32.82 (m, Bu), 71.08 (t,
1JCH = 153.0 Hz, THF). 27Al NMR (C6D6):  68.4 (br, W = 3040 Hz).
31P{1H} NMR (C6D6): ABB′CC′ spin system, A −110.6(1)
1
(m, JAB = −324.9(1) Hz = 1JAB′
,
2JAC = +13.3(1) Hz = 2JAC′),


B,B′ +47.1(1) (m, 1JBC = −298.3(2) Hz = 1JB′C′, 2JBB′ = −15.9(2) Hz),
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1
2
(P4 Bu4GeR2) (R = Et, Ph) and cyclo-{P4tBu4Ge(2-P2 Bu2)} and the
C,C′ +51.7(1) (m, JCC′ = −311.4(1) Hz, JBC′ = −6.2(1) Hz = 2JB′C).
stannatetraphospholanes15 cyclo-(P4 Bu4SnR2) (R = tBu, Bu, Ph)
FAB-MS, THF-free 2 (matrix: 3-NBA, m/z (%)): 469.5 (2.9)
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n
and cyclo-{P4tBu4Sn(Cl)nBu}. In addition, we have shown that the
[M+ + H], 383.4 (2.1) [M+ − Al − 2Et = P5 Bu4], 352.2 (10.1)
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cyclic oligophosphanide anion cyclo-(P5 Bu4)− exhibits a rich and
[M+ Al − P − 2Et = P4 Bu4], 351.1 (24.9) [M+ − Al − P − 2Et − H],
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unprecedented transition metal chemistry.13,16
239.5 (6.4) [M+ − 4tBu = Et2AlP5], 235.7 (5.8) [M+ − 2P − 3tBu],
However, in main group metal chemistry, redox reactions play an
important role besides salt-elimination reactions. We now report the
reaction of [Na(THF)4][cyclo-(P5 Bu4)] (1) with Et2AlCl and GeCl4,
233.8 (100.0) [M+ − 4tBu − 6H], 210.3 (19.4) [M+ − 4tBu − Et],
209.3
(2.3)
[M+ − P − 4tBu = Et2AlP4],
204.5
(13.6)
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[M+ −3P −3tBu],178.0(2.6)[M+ −2P−4tBu=Et2AlP3],177.0(10.0)
[M+ − 2P − 3tBu − 2Et], 155.4 (3.8) [M+ − Al − 4tBu − 2Et = P5],
150.7 (16.7) [M+ − P − 4tBu − 2Et], 147.7 (24.8) [M+ − 3P −
4tBu = Et2AlP2], 120.4 (5.5) [M+ − 2P − 4tBu − 2Et], 116.4 (15.5)
[M+ − 4P − 4tBu = Et2AlP].
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which give Et2Al{cyclo-(P5 Bu4)}(THF) (2) and, in low yield,
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GeCl3{cyclo-(P5 Bu4)}, respectively, while the reaction of 1 with
SnCl2, PbCl2 or BiCl3 results in the formation of the structural iso-
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mers {cyclo-(P5 Bu4)}2 (3) and {cyclo-(P4 Bu3)PtBu}2 (4) (besides
other cyclic phosphanes) and elemental metal.
Reaction of 1 with GeCl4. A solution of 0.13 g (0.62 mmol)
GeCl4 in 10 ml petroleum ether (bp 45–70 °C) was added slowly
to a solution of 0.5 g (1.23 mmol) 1 in 10 ml petroleum ether (bp
45–70 °C) at −70 °C. A colour change from colourless to light yel-
low and finally orange was observed. After 3 h at r.t. the solution
was filtered and concentrated. The 31P NMR spectrum (C6D6) of
Experimental
General
All manipulations were carried out under an inert atmosphere.
NMR spectra: AVANCE DRX 400 (Bruker), standards: 31P NMR
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 2 0 0 4
D a l t o n T r a n s . , 2 0 0 4 , 2 8 9 5 – 2 8 9 8
2 8 9 5

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this inseparable mixture showed the presence of the following P-
containing compounds:
(11.7%), cyclo-(P5 Bu4H)18 (13.0%), cyclo-(P4 Bu3)PtBuH21–23
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(19.7%), {cyclo-(P5 Bu4)}2 (3) (29.6%) and {cyclo-(P4 Bu3)PtBu}2
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cyclo-(P4 Bu4)19 (7.6%)
(4) (14.5%).
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1
cyclo-(P3 Bu3)20 (14.9%): A −108.4 (t, JA,B = ±201.5 Hz),
B −70.0
X-Ray data collection, structure determination, and re-
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cyclo-(P5 Bu4H)18 (43.7%): A −56.3 (m), B +67.9 (m), C
finement crystallography. Crystal data25 for C32H72P10 {cyclo-
1
1
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+39.0 (m), D +60.3 (m), E +80.2 (m); JAB = −317.5 Hz, JAC
=
(P5 Bu4)}2 (3): M = 766.60, orthorhombic, space group Aba2,
−270.1 Hz, 1JBD = −279.4 Hz, 1JCE = −325.7 Hz, 1JDE = −305.2 Hz,
a = 13.1781(8), b = 12.5258(7), c = 26.3187(11), V = 4344.3(4) Å3,
T = −153 °C; Z = 4, Dc = 1.172 g cm−3; (Mo-K) = 0.416 mm−1;
11341 reflections measured of which 3598 were independent. Final
R = 0.1225, Rw = 0.2311 for 1184 reflections with F2 > 2(F2).
Intensity data were recorded using a Nonius Kappa CCD area-
detector diffractometer mounted at the window of a rotating-anode
FR591 generator with a molybdenum anode ( = 0.71073 Å).  and
 scans were carried out to fill the Ewald sphere. An empirical ab-
sorption correction was applied using SORTAV. The structure was
solved by direct methods and refined on F2 by full-matrix least-
squares refinements.26 Disorder over two positions of the atoms P3
and P4 is imposed by the two-fold axis parallel to the c axis.
Crystal data for C32H72P10 (4); M = 766.60, monoclinic, space
group C2/c, a = 22.763(5), b = 14.679(3), c = 16.629(3) Å,
 = 126.54(3)°, V = 4464(1) Å3, T = −73 °C; Z = 4, Dc = 1.141 g
cm−3; (Mo-K) = 0.404 mm−1; 5291 independent reflections.
Final R = 0.0433 and Rw = 0.1104 for reflections with F2 ≥ 2(I)
and R = 0.0543 and Rw = 0.1161 for all reflections. X-Ray diffrac-
tion data were obtained with a Stoe IPDS using φ scan rotation. The
structures were solved by direct methods using SHELXS-97 and
SHELXL-97 for structure refinement.26 Anisotropic refinement of
all non-hydrogen and isotropic refinement of the hydrogen atoms.
CCDC reference numbers 237083 and 238064.
2JAE = +0.1 Hz, JAD = −11.7 Hz, JBC = +0.2 Hz, JBE = −11.3 Hz,
2
2
2
2JCD = −12.2 Hz
cyclo-(P4 Bu3)PtBuH21–23 (5.1%): A −5.3 (m, JAE = ±219.3 Hz,
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1
2JAB = ±44.5Hz), B −31.9(m, 1JBC = ±154.1Hz, 2JAD = ±207.4 Hz),
1
2
C −42.3 (m, JBE = ±142.2 Hz, JBD = ±14.8 Hz), D −46.1 (m,
1JCD = ±148.1 Hz, 2JCE = ±8.9 Hz), E −143.2 (m, 1JDE = ±106.7 Hz,
3JAC = ±8.9 Hz)
cyclo-(P4 Bu3)PtBuCl9,18 (14.4%): A +141.1 (dddd, JAE
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1
=
2
1
±227.6 Hz, JAB = ±181.9 Hz), B −55.4 (dddd, JBD = ±147.7 Hz,
2JAC = ±101.1 Hz), C −52.5 (dddd, JBE = ±120.2 Hz, JBC
=
1
2
1
2
±11.2 Hz), D −30.0 (ddd, JCD = ±145.8 Hz, JED = ±7.3 Hz), E
−109.4 (dddd, 1JCE = ±142.3 Hz, 3JAD = ±11.1 Hz)
GeCl3{cyclo-(P4 Bu3)}24 (2.4%): A −14.6 (td, 1JAM = ±145.2 Hz),
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M −57.6 (dd, 1JBM = ±115.6 Hz), B −93.3 (td, 2JAB = ±20.7 Hz)
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GeCl3{cyclo-(P5 Bu4)} (5.3%): A −110.8 (m), BB′ −33.1 (m),
CC′ −28.2 (m).
Reaction of 1 with SnCl2. A suspension of 0.17 g (0.94 mmol)
SnCl2 in 10 ml n-pentane was added to a solution of 0.76 g
(1.87 mmol) 1 in 20 ml n-pentane at −50 °C. A grey solid (Sn and
NaCl) formed immediately. The colour of the solution (yellow) did
not change. The solution was filtered and concentrated. At room
temperature yellow cubes of {cyclo-(P5 Bu4)}2 (3) were obtained.
Yield: 0.3 g, 42%.
31P{1H} NMR (C6D6): AA′BB′CC′DD′EE′ spin system,
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See http://www.rsc.org/suppdata/dt/b4/b407736a/ for crystallo-
graphic data in CIF or other electronic format.


A,A′ +28.8 (m), B,B′ −27.2 (m), C,C′ −1.0 (m), D,D′ −4.7 (m),
E,E′ −33.9 (m). FAB-MS (matrix 3-NBA; m/z (%)): 766.1 (23.0)
Results and discussion
Our attempts to obtain main group metal complexes of the cyclo-
[M+], 709.0 (21.1) [M+ − tBu], 652.0 (10.6) [M+ − 2tBu], 595.0 (2.8)
[M+ − 3tBu], 538.0 (7.0) [M+ − 4tBu], 507.0 (3.3) [M+ − P − 4tBu],
481.1 (4.5) [M+ − 5tBu], 476.0 (3.3) [M+ − 2P − 4tBu], 445.1
(7.1) [M+ − 3P − 4tBu], 424.0 (9.2) [M+ − 6tBu], 414.1 (10.3)
[M+ − 4P − 4tBu], 383.1 (13.2) [M+ − 5P − 4tBu = M+/2], 367.1
oligophosphanide anion cyclo-(P5 Bu4)− starting from Na[cyclo-
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(P5 Bu4)] (1) and Et2AlCl, GeCl4, SnCl2, PbCl2 or BiCl3 were only
successful in the case of Al and Ge, while the last three reactions
failed regardless of the solvent (n-pentane, THF, diethyl ether,
toluene) or temperature employed. In these cases the formation
of elemental metal (Sn, Pb, or Bi) was observed even at low temp-
erature.
(6.7) [M+ − 7tBu], 352.8 (6.8) [M+ − 6P − 4tBu = P4 Bu4], 310.1
t
(10.4) [M+ − 8tBu = P10], 295.1 (10.2) [M+ − 6P − 5tBu], 279.1
(100.0) [M+ − 1P − 8tBu = P9], 248.1 (7.3) [M+ − 2P − 8tBu = P8],
238.1 (10.2) [M+ − 6P − 6tBu], 207.0 (13.6) [M+ − 7P − 6tBu],
217.1 (13.7) [M+ − 3P − 8tBu = P7]. IR (KBr, cm−1): 2934s, 2888s,
2854s, 2704w, 1468m, 1457s, 1386m, 1358s, 1261s, 1167s, 1097s,
1019s, 934w, 866m, 804s, 701w, 669w, 601w, 566w, 527w, 467w,
418w, 403w.
Aluminium and germanium cyclopentaphosphanides
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More successful was the reaction of Na[cyclo-(P5 Bu4)] (1) with
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Et2AlCl, which gave Et2Al{cyclo-(P5 Bu4)}(THF) (2) and cyclo-
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(P5 Bu4H)18 (28%); the latter is probably formed by protolysis
31P NMR spectrum (C6D6) of the reaction mixture showed
of 1. In the 31P NMR spectrum (in C6D6) 2 exhibits signals of an
A
the presence of the following P-containing compounds besides 3:
ABB′CC′ spin system (ratio 1:2:2). The nuclei PB,B′ and PC,C′
cyclo-(P5tBu4H)18 (24.9%), cyclo-(P4tBu3)PtBuH21–23 (3.7%), {cyclo-
fulfill the requirement for a higher order spectrum, |B − C|/JBC
<
(P4 Bu3)PtBu}2 (4) (15.1%), cyclo-(P4 Bu4)19 (3.9%).
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10.3,4 The chemical shifts of PB, PB′, PC, PC′ are in the range of tert-
butyl-substituted cyclopentaphosphanes;5 however, compared to 1,
high-field shifts ( = 35.6 (PB, PB′), 23.3 (PC, PC′), 5.0 (PA)) are
observed in 2.
Reaction of 1 with PbCl2. A suspension of 0.09 g (0.35 mmol)
PbCl2 in 10 ml n-pentane was added to a solution of 0.28 g
(0.70 mmol) 1 in 10 ml n-pentane at r.t. A grey solid (Pb and NaCl)
formed immediately. The colour of the solution changed from yel-
low to green–yellow. The solution was stirred at r.t. for 3 h and
filtered. The 31P NMR spectrum (C6D6) of this solution showed the
presence of the following P-containing compounds:
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cyclo-(P5 Bu4H)18 (32.4%), {cyclo-(P5 Bu4)}2 (3) (55.2%) and
{cyclo-(P4 Bu3)PtBu}2 (4) (11.4%).
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Reaction of 1 with BiCl3. A suspension of 0.33 g (1.06 mmol)
BiCl3 in 10 ml petroleum ether (bp 45–70 °C) was added slowly
to a solution of 0.43 g (1.06 mmol) 1 in 10 ml petroleum ether (bp
45–70 °C) at r.t. A black solid (Bi and NaCl) formed slowly. The
colour of the solution changed from yellow to dark green. The so-
lution was filtered and the solvent evaporated in vacuo. The dark
green solid was studied by 31P NMR spectroscopy (C6D6), which
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Coordination of the cyclo-(P5 Bu4)− anion via the phosphorus
atom PA to Al results in smaller 1JAB and 1JAB′ (−324.9(1) Hz; cf. 1:
379.2(1) Hz) and similar 1JBC, 1JB′C′ and 1JCC′ coupling constants.
In the 27Al NMR spectrum (C6D6) a signal at 68.4 ppm
(W = 3040 Hz) is observed for 2.
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showed the presence of cyclo-(P4 Bu4)19 (11.5%), cyclo-(P3 Bu3)20
2 8 9 6
D a l t o n T r a n s . , 2 0 0 4 , 2 8 9 5 – 2 8 9 8

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The mass spectrum (FAB-MS) of THF-free 2 shows the molecu-
lar ion peak at m/z = 469.5 (2.9%; [M+ + H]) as well as the expected
fragmentation products.
Elimination of BuCl, which reacts with 1 with formation of
cyclo-(P5 Bu4H) and isobutene (Scheme 1(b)),13 was already
observed in the reaction of 1 with [NiCl2(PEt3)2].27 In a comparable
reaction, K2(P4 Bu4) reacts with tert-butyl chloride with elimination
of KCl and isobutene and formation of H2P4 Bu4.28 The reaction of 1
with SnCl2 was also carried out in deuterated THF to prove that the
formation of cyclo-(P5 Bu4H) is not due to ether cleavage. No cyclo-
(P5 Bu4D) was observed in the 31P NMR spectrum.
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The reaction of 1 with GeCl4 in petroleum ether at −70 °C in a
ratio of 2:1 gave numerous products, which could only be iden-
tified by 31P NMR spectroscopy, but not isolated and purified.
These include cyclo-(P4tBu4),19 cyclo-(P3tBu3),20 cyclo-(P5tBu4H),18
cyclo-(P4tBu3)PtBuH,21,22,23 cyclo-(P4tBu3)PtBuCl,9,18 GeCl3{cyclo-
(P4tBu3)}24 and GeCl3{cyclo-(P5tBu4)}. The last-named is formed in
only 5.3% yield. Signals at  +88.7 and +57.6 could not be assigned.
When an excess of GeCl4 was employed, only one Ge-contain-
ing product was obtained, which we assume to be GeCl3{cyclo-
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The formation of the structural isomers {cyclo-(P5 Bu4)}2 (3) and
{cyclo-(P4 Bu3)PtBu}2 (4) occurs via reductive elimination from the
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corresponding Sn complexes. The formation of elemental Sn (and
NaCl) was shown by powder diffraction and elemental analysis (no
P present, which rules out the formation of tin phosphides, SnxPy).
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(P5 Bu4)} (by 31P{1H} NMR spectroscopy). Three multiplets are
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observed for the complicated higher-order ABB′CC′ spin system
(ratio 1:2:2; −110.8 (PA), −33.1 and −28.2 ppm; the last two corre-
spond to PB, PB′, PC and PC′, which bear tert-butyl groups). However,
this product could not be obtained in pure form.
{cyclo-(P4 Bu3)PtBu}2 (4) was previously obtained by dehaloge-
nating tBuPCl2 with magnesium in the presence of P4, purified by
HPLC (30 mg starting from 0.33 mol tBuPCl2) and characterised by
31P NMR spectroscopy.4
The structural isomer 3 was characterised by IR, NMR spectro-
scopy, MS (FAB) and by X-ray structure determination.
In the 31P NMR spectrum at room temperature (in C6D6) com-
pound 3 showed a complicated higher order AA′BB′CC′DD′EE′
spin system consisting of five signals at  +28.8, −1.0, −4.7, −27.2
and −33.9 (ratio 1:1:1:1:1). A two-dimensional 31P31P spectrum
yielded the constitution of the P10 framework, showing a direct
linkage between PA and PB, PA and PE, PB and PC, PD and PE, as
well as between PC and PD. The proton-coupled 31P NMR spectrum
showed that PA bears no tert-butyl group. The dimeric nature of 3
is also apparent from the mass spectrum and the X-ray structure
determination.
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The structural isomers {cyclo-(P5 Bu4)}2 (3) and {cyclo-
t
(P4 Bu3)PtBu}2 (4)
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In the reactions of Na[cyclo-(P5 Bu4)] (1) with SnCl2 (2:1), PbCl2
(2:1) or BiCl3 (1:1) the formation of elemental metal (Sn, Pb, or
Bi) was observed even at low temperature.
31P NMR spectroscopy showed the formation of the dimer
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{cyclo-(P5 Bu4)}2 (3) as the main product (ca. 50% for SnCl2 and
PbCl2, ca. 30% for BiCl3) as well as of {cyclo-(P4 Bu3)PtBu}2 (4)
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(ca. 11–15%). Other P-containing products are cyclo-(P5 Bu4H),18
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cyclo-(P4 Bu3)PtBuH21,22,23 and cyclo-(P4 Bu4).19 As these com-
pounds show similar solubility in all common solvents, separation
was only achieved by fractional crystallisation of 3 and 4.
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In the mass spectrum, a molecular ion peak is observed for 3 at
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m/z = 766.1 (23.0%) as well as the fragment cyclo-(P5 Bu4) (M+/2)
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We assume that the corresponding [M{cyclo-(P5 Bu4)}x] are
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at m/z = 383.1 (13.2%). Interestingly, a signal for the Bu-free
formed initially, which, however, are unstable even at low tempera-
ture and decompose with formation of different cyclic phosphorus
products. Scheme 1(a) shows the proposed decomposition pathway
for the reaction of 1 with SnCl2.
molecule P10 is also observed at m/z = 310.1 (10.4%). Theoretical
studies performed on oligocyclic Pn molecules and clusters showed
them to be thermodynamically stable at low temperatures.7 Thus,
compound 3 could be a suitable precursor for such a novel Pn
(n = 10) modification.
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Molecular structures of {cyclo-(P5 Bu4)}2 (3) and {cyclo-
t
(P4 Bu3)PtBu}2 (4)
Crystals of 3 suitable for X-ray diffraction were obtained from a
saturated n-pentane solution. The crystals were rather small and
systematically twinned; thus, the observed cubes were in fact
intergrown platelets, which could, however, not be separated me-
chanically due to their small size. The diffraction pattern was thus
contaminated by the signals of at least one other individuum, with
apparent overlap of signals at low diffraction angles. This problem
was also apparent during the structure refinement. The molecule is
disordered statistically with the atoms P3 and P4 occupying alterna-
tive positions (Fig. 1). This disorder generates a twofold symmetry
for the crystal structure. Compound 3 crystallises in the orthorhom-
bic space group Aba2 with four molecules in the unit cell.
The two non-planar chiral ring systems have envelope conforma-
tions in which the atoms P3 and P4 deviate from the plane formed
by P2′–P1′–P1–P2 and P5′–P6′–P6–P5, respectively. The P2–P3
Fig. 1 ORTEP plot of the molecular structure of compound 3; H atoms
Scheme 1
are omitted for clarity.
D a l t o n T r a n s . , 2 0 0 4 , 2 8 9 5 – 2 8 9 8
2 8 9 7

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Z. Anorg. Allg. Chem., 1989, 578, 7; (i) M. Baudler, J. Hellmann,
P. Bachmann, K. F. Tebbe, R. Fröhlich and M. Feher, Angew. Chem.,
1981, 93, 415; M. Baudler, J. Hellmann, P. Bachmann, K. F. Tebbe,
R. Fröhlich and M. Feher, Angew. Chem., Int. Ed. Engl., 1981, 20, 406;
(j) M. Baudler and H. Jachow, Z. Naturforsch., Teil B, 1994, 49, 1755;
(k) M. Baudler, M. Michels, J. Hahn and M. Pieroth, Angew. Chem.,
1985, 97, 514; M. Baudler, M. Michels, J. Hahn and M. Pieroth, Angew.
Chem., Int. Ed. Engl., 1985, 24, 504.
and P4–P5 bond lengths (213.7(6) and 211.4(6) pm) are smaller
than the other P–P bond lengths (219.9(6)–226.5(6) pm), which are
in the typical range for single bonds. Similarly, one of the P–PtBu
distances in 1 is shorter (213.2(1) pm) than the other P–P bonds
(220.4(1)–222.9(1) pm).16
t
{cyclo-(P4 Bu3)PtBu}2 (4) crystallises in the monoclinic space
group C2/c with four molecules in the unit cell. The centre of the
P5–P5′ bond coincides with a twofold axis (Fig. 2).
4 M. Baudler, M. Schnalke and Ch. Wiaterek, Z. Anorg. Allg. Chem.,
1990, 585, 7.
5 N. Wiberg, A. Wörner, H.-W. Lerner, K. Karaghiosoff, D. Fenske,
G. Baum, A. Dransfeld and P. von Rague Schleyer, Eur. J. Inorg. Chem.,
1998, 6, 833.
6 M. Feher, R. Fröhlich and K. F. Tebbe, Z. Kristallogr., 1982, 158, 241.
7 (a) M. Häser and O. Treutler, J. Chem. Phys., 1995, 102, 3703;
(b) M. Marco, U. Schneider and R. Ahlrichs, J. Amer. Chem. Soc., 1992,
114, 9551.
8 M. Baudler, Ch. Gruner, G. Fürstenberg, B. Kloth, F. Saykowski and
U. Özer, Z. Anorg. Allg. Chem., 1978, 446, 169.
9 M. Baudler and B. Makowka, Z. Anorg. Allg. Chem., 1985, 528, 7.
10 A. Schmidpeter and G. Burget, Phosphorus Sulfur, 1985, 22, 323.
11 G. Fritz and K. Stoll, Z. Anorg. Allg. Chem., 1986, 538, 78.
12 G. Fritz, R. Biastoch, K. Stoll, T. Vaahs, D. Hanke and H. W. Schneider,
Phosphorus Sulfur, 1987, 30, 385.
13 A. Schisler, U. Huniar, P. Lönnecke, R. Ahlrichs and E. Hey-Hawkins,
Angew. Chem., 2001, 113, 4345; A. Schisler, U. Huniar, P. Lönnecke,
R. Ahlrichs and E. Hey-Hawkins, Angew. Chem., Int. Ed., 2001, 40,
4217.
14 (a) M. Baudler and H. Suchomel, Z. Anorg. Allg. Chem., 1983, 503,
7; (b) H. Binder, B. Schuster, W. Schwarz and K. W. Klinkhammer,
Z. Anorg. Allg. Chem., 1999, 625, 699; (c) M. Baudler, L. Riese-Meyer
and U. Schings, Z. Anorg. Allg. Chem., 1984, 519, 24.
15 (a) M. Baudler and H. Suchomel, Z. Anorg. Allg. Chem., 1983, 505,
39; (b) D. Bongert, G. Heckmann, W. Schwarz, H.-D. Hausen and
H. Binder, Z. Anorg. Allg. Chem., 1995, 621, 1358; (c) D. Bongert,
H.-D. Hausen, W. Schwarz, G. Heckmann and H. Binder, Z. Anorg.
Allg. Chem., 1996, 622, 1167.
Fig. 2 ORTEP plot of the molecular structure of compound 4; H atoms
are omitted for clarity.
The molecule consists of two cyclotetraphosphanes, which have
a butterfly conformation, with one exocyclic PtBu group. The dihe-
dral angle between the planes P1–P2–P4 and P2–P3–P4 is 40.59(4)°.
The P–P distances range from 220.39(8) to 224.29(9) pm and are
typical for P–Psingle bonds.29 The P4 chain P1–P5–P5′–P1 has a syn
arrangement. The torsion angle between the planes P1–P5–P5′ and
P1′–P5′–P5 is only 4.9(1)°.
16 A. Schisler, Dissertation, Leipzig, 2003; A. Schisler, P. Lönnecke
and E. Hey-Hawkins, Dalton Trans.; to be submitted; A. Schisler,
P. Lönnecke and E. Hey-Hawkins, Inorg. Chem., to be submitted;
A. Schisler, P. Lönnecke and E. Hey-Hawkins, Chem. Eur. J., to be
submitted.
Conclusion
While the reaction of [Na(THF)4][cyclo-(P5tBu4)] (1) with Et2AlCl or
17 A negative sign was generally used for the coupling constants 1JPP and
the remaining signs and coupling constants were calculated with the
program SPINWORKS (K. Marat, SPINWORKS, version 2000 05 10,
University of Manitoba).
t
GeCl4 gives the substitution products, Et2Al{cyclo-(P5 Bu4)}(THF)
t
(2) and GeCl3{cyclo-(P5 Bu4)}, 1 reacts with SnCl2, PbCl2 or BiCl3
t
with formation of the structural isomers {cyclo-(P5 Bu4)}2 (3) and
t
{cyclo-(P4 Bu3)PtBu}2 (4) (besides other cyclic phosphanes) and
18 A. Schisler, Diplomarbeit, Leipzig, 1999.
19 K. Issleib and M. Hoffmann, Chem. Ber., 1966, 99, 1320.
20 M. Baudler, J. Hahn, H. Dietsch and G. Fürstenberg, Z. Naturforsch.,
Teil B, 1976, 31, 1305.
elemental metal.
Acknowledgements
21 M. Baudler and H. Tschäbunin, Z. Anorg. Allg. Chem., 1984, 511, 77.
22 M. Baudler and Ch. Gruner, Chem. Ber., 1982, 115, 1739.
23 M. Baudler, J. Hellman and T. Schmidt, Z. Naturforsch., Teil B, 1983,
38, 537.
A. S. thanks the Saxonian Ministry of Science and Art for a PhD
grant.
24 M. Karnop, W.-W. du Mont, P. G. Jones and J. Jeske, Chem. Ber., 1997,
130, 1611.
References
25 Data collection and cell refinement: D. Z. Otwinowski and W. Minor,
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26 Structure solution and refinement: SHELXS and SHELXL97:
G. M. Sheldrick 1997, University of Göttingen, Germany.
27 K. A. Jensen, Z. Anorg. Allg. Chem., 1936, 229, 265.
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2 8 9 8
D a l t o n T r a n s . , 2 0 0 4 , 2 8 9 5 – 2 8 9 8