COMMUNICATIONS
P2,3) 320.9 Hz, 2J(P1, P4,5) 25.8 Hz, 1P), À237.1 (td, 1J(P4,5, P2,3)
148.7Hz, 2J(P4,5, P1) 25.8 Hz, 2P).
À
The very weakly basic Al[OC(CF3)3]4 ion stabilizes, in 1
À
and 2, the first binary phosphorus-rich P X cation (X hal-
ogen, H, organyl) and shows that this class of cations is
accessible if a suitable weakly basic and nonoxidizing counter-
Received: July 13, 2001 [Z17496]
ion is provided. In the course of this reaction PX2 ions (X
[1] a) T. P. Martin, Z. Phys. 1986, D 3, 211; b) R. Huang, H. Li, Z. Lin, S.
Yang, J. Phys. Chem. 1995, 99, 1418; c) R. B, Huang, Z. Y. Liu, P.
Zhang Y. B. Zhu, F. C. Lin, J. H. Zhao, L. S. Zheng, Chin. J. Struct.
Chem. 1993, 180; d) Z. Y. Liu, R. B. Huang, L. S. Zheng, Z. Phys. D
1996, 38, 171; e) M. D. Chen, J. T. Li, R. B. Huang, L. S. Zheng, C. T.
Au, Chem. Phys. Lett. 1999, 305, 439.
Br, I), which are isoelectronic to silylene SiX2 and an
interesting class of compounds in their own right, were
formed as intermediates and may be used in further reactions
with other simple inorganic or organic substrates.
[2] J. A. Zimmerman, S. B. H. Bach, C. H. Watson, J. R. Eyler, J. Phys.
Chem. 1990, 95, 98.
[3] O. A. Mazyar, T. Baer, Chem. Phys. Lett. 1998, 288, 327.
[4] a) L. Latifzadeh-Masoudipour, K. Balasubramanian, Chem. Phys.
Lett. 1997, 267, 545; b) L. Latifzadeh, K. Balasubramanian, Chem.
Phys. Lett. 1996, 258, 393; c) L. Latifzadeh, K. Balasubramanian,
Chem. Phys. Lett. 1995, 241, 13.
Experimental Section
All manipulations were performed using grease-free Schlenk or dry box
techniques and a dinitrogen or argon atmosphere. All apparatus were
closed by Young valves and the solvents were rigorously dried over P2O5
and degassed prior to use and stored under N2 on molecular sieves (4 ä).
Yellow phosphorus was sublimed prior to use. Full details are disclosed in
the Supporting Information.
[5] D. Gudat, Eur. J. Inorg. Chem. 1998, 1087.
[6] a) J. Passmore, J. Chem. Soc. Dalton Trans. 1978, 1251; b) C. Aubauer,
M. Kaupp, T. M. Klapˆtke, H. Nˆth, H. Pietrowski, W. Schnick, J.
Senker, J. Chem. Soc. Dalton Trans. 2001, 1880, and references therein.
[7] S. Pohl, Z. Anorg. Allg. Chem. 1983, 498, 20.
[8] C. Aubauer, G. Engelhardt, T. M. Klapˆtke, A. Schulz, J. Chem. Soc.
Dalton Trans. 1999, 1729.
In situ synthesis of 2: Ag(P4)2 [AÀ] (0.151 g, 0.114 mmol) was weighed into
an NMR tube connected to a valve. I2 (0.101 g, 0.399 mmol) was sublimed
onto the solid at 77 K after which CD2Cl2 (0.9 mL) was condensed onto the
mixture. The NMR tube was sealed and then placed in a dry ice/2-propanol
bath and activated with ultrasound at À788C for about 10 min. The initial
31P NMR spectra were run 30 min later and the 13C and 27Al NMR spectra
[9] M. Baudler, K. Glinka, Chem. Rev. 1993, 93, 1623.
À
[10] The very high P E bond energies (E F, O) led to the decomposition
of the weakly basic counteranions MnF5n1À (n 1 4, M As, Sb) or
SO3FÀ. Reactions of P4 with S2O6F2 furnished elemental sulfur and
P,F,O species. The sulfur was then oxidized by excess S2O6F2 to give
after storage at À808C one week later (no decomposition visible in the 31
P
NMR spectrum). 13C NMR (63 MHz, CD2Cl2, À908C): d 122.4 (q,
J(C,F) 290.1 Hz; CF3); 27Al NMR (78 MHz, CD2Cl2, À908C): d 39.5 (s,
n1/2 27Hz); 31P NMR (101 MHz, CD2Cl2, À908C): d 168.2 (dt,
1J(P2,3,P1) 278.5 Hz, 1J(P2,3, P4,5) 152.6 Hz, 2P), À89.0 (tt,
1J(P1,P2,3) 278.5 Hz, 2J(P1, P4,5) 26.7Hz, 1P), À193.9 (td, 1J(P4,5,
P2,3) 152.6 Hz, 2J(P4,5, P1) 26.7Hz, 2P). Upon warming the sample to
polysulfur cations. Attempts to prepare P2I5 (cf. [P2I5][AlI4]) by
À
reacting I3 MF6 with P2I4 in various solvents at À788C only led to
decomposition and formation of PF3, MI3, and elemental iodine (M
As, Sb).[8]
[11] I. Krossing, Chem. Eur. J. 2001, 7, 490.
[12] S. M. Ivanova, B. G. Nolan, Y. Kobayashi, S. M. Miller, O. P. Ander-
son, S. H. Strauss, Chem. Eur. J. 2001, 7, 503.
À408C, the P5I2 signals vanish quickly and, apart from other unassigned
signals of lower intensity, those of P3I6 appear as the major P-containing
peaks 31P NMR (À808C): d 89.2 (d, 1J(P,P) 385.5 Hz, 2P), À4.6 (t,
[13] I. Krossing, J. Am. Chem. Soc. 2001, 123, 4603.
1J(P,P) 385.5 Hz, 1P).
[14] ™Superweak Complexes of tetrahedral P4 Molecules with the Silver
Cation of Innocent Anions∫: I. Krossing, Chem. Eur. J. 2002, in press.
[15] ™Reactions of P4 and I2 with Ag[Al(OC(CF3)3)4]: From Elusive
Synthesis of 2: Ag(P4)2 [AÀ] (1.020 g, 0.765 mmol) was weighed into a two
bulbed vessel incorporating a sintered glass frit and stopped by Young
valves. I2 (0.697 g, 2.746 mmol) was sublimed onto the solid at 77 K after
which CH2Cl2 (5 mL) was condensed onto the mixture. The apparatus was
placed in a dry ice/2-propanol bath until the solvent had thawed and was
then stored in a À808C freezer and heavily shaken every 30 minutes for
about one minute (10 Â ). After four days at À808C the yellow solution
over yellow-orange precipitate was filtered at À808C. All volatiles were
then quickly removed at about 08C (expected weight of the material:
1.717 g, found: 1.737 g) and the apparatus immediately transferred into a
glove box. Soluble yellow 2 ((0.963 g, 0.700 mmol), expected: 1.052 g; yield:
92%) and insoluble material (0.611 g; expected: 0.665 g) were isolated,
while 0.140 g were not accessible within the flask (total: 0.963 g 0.611 g
0.140 g 1.714 g; expected: 1.717 g). Raman spectra of 2 (Table 2) and
the insoluble material (P4, PI3, and traces of P2I4) were recorded
immediately after the sample preparation. A 31P NMR sample of yellow
2 in CD2Cl2 gave the same spectrum as the one observed in the in situ
reaction described above.
Polyphosphorous Cations to Subvalent P3I6 and Phosphorus Rich
P5I2 ∫: I. Krossing, Dalton Trans., accepted.
[16] B. W. Tattershall, N. L. Kendall, Polyhedron 1994, 13, 1517.
[17] A. Klamt, G. Sch¸rmann, J. Chem. Soc. Perkin. Trans. 1993, 2, 799.
[18] Including the zero-point energy and thermal corrections to the free
energy at 298 K.
[19] The position of the signal of the P(X2) atom in P5X2 is shifted
considerably from d(31P) 23 (X Br) to d(31P) À89 (X I) due
to an effective Fermi-contact mechanism[20] which is also responsible
for the extreme upfield shift of the PI4 ion (d(31P) À475[6, 20, 21]).
[20] M. Kaupp, C. Aubauer, G. Engelhardt, T. M. Klapˆtke, O. Malkina, J.
Chem. Phys. 1999, 110, 3897.
[21] This is the value of PI4 [AÀ] (I. Krossing, unpublished results). The
signal for solid PI4[MF6] appeared at d(31P) À517(M As) and
À519 (M Sb).[20]
[22] Crystal structure determination of 3: IPDS (Stoe), graphite-mono-
chromated MoKa radiation, T 200(2) K, unit cell determination:
5000 reflections, corrections: Lorentz, polarization, and numerical
absorption correction, m 2.61 cmÀ1, direct methods with SHELXS-
97, refinement againstF 2 with SHELXL-97. Space group:P2/n, Z 2,
a 13.536(3), b 9.554(2), c 14.508(3) ä, b 90.15(3)8, V
Synthesis of 3: Ag (CH2Cl2)[AÀ] (0.848 g, 0.731 mmol) was weighed into a
two-bulbed glass vessel incorporating a fine sintered glass frit and two
Young valves. P4 (0.086 g, 0.694 mmol) was added to the solid. PBr3
(0.188 g, 0.066 mL, 0.695 mmol) was added to it at 77 K and CH2Cl2 (ca.
10 mL) was condensed onto the mixture and allowed to stir at À788C for
8 h. For completion of the reaction the vessel was stored in a À808C freezer
for 10 days and occasionally heavily shaken. After filtration from the
insoluble AgBr a clear colorless solution was obtained. The volume of the
solvent was quickly reduced to about 1 mL at 08C. Salt 3 crystallized as
colorless blocks almost quantitatively from the cooled concentrated filtrate
(À308C). Yield: 0.752 g (85%).13C NMR (63 MHz, CD2Cl2, À708C): d
121.5 (q, J(C,F) 292.0 Hz; CF3); 27Al NMR (78 MHz, CD2Cl2, À708C):
d 38.7(s, n1/2 12 Hz); 31P NMR (101 MHz, CD2Cl2, À808C): d 162.0
(dt, 1J(P2,3, P1) 320.9 Hz, 1J(P2,3, P4,5) 148.7Hz, 2P), 20.0 (tt, 1J(P1,
1876.2(6) ä3, 1calcd 2.269 gcmÀ1
2qmax. 528, reflections: 14525
,
collected, 3469 unique, 2323 observed (4s), 322 parameters, 48 SADI
restraints (to fix the anion), R1 0.0957, wR2 (all data) 0.2823,
GooF 1.082. Upon further cooling a phase transition occurred and
all of the 10 tested crystals cracked even when cooled very slowly.
Therefore, the rotation of the 12 CF3 groups could not be frozen out
and the agreement factor remained relatively high. Moreover the
P5Br2 ion occupies two different positions with a 50% occupation
each (see Supporting Information). Crystallographic data (excluding
4408
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Angew. Chem. Int. Ed. 2001, 40, No. 23