Preparation of cationic [(R2N)P5Cl]+-cage compounds from [(R2N)PCl]+ and P4

Article abstract of DOI:10.1002/zaac.201200123

The reaction of several amino-substituted mono- and dichlorophosphanes (R₂N)_nPCl_3-n (n = 2, R = i-Pr; n = 1, R = i-Pr, Cy) with GaCl₃ to form phosphenium cations [(i-Pr₂N) ₂P]⁺ (

Full text of DOI:10.1002/zaac.201200123

ARTICLE
DOI: 10.1002/zaac.201200123
Preparation of Cationic [(R2N)P5Cl]+-Cage Compounds from [(R2N)PCl]+
and P4
Michael H. Holthausen[a] and Jan J. Weigand*[a]
Dedicated to Professor Wolfgang Beck on the Occasion of His 80th Birthday
Keywords: P4 activation; Phosphorus; Cations; Main group elements; Structure elucidation
Abstract. The reaction of several amino-substituted mono- and dichlo-
rophosphanes (R2N)nPCl3–n (n = 2, R = i-Pr; n = 1, R = i-Pr, Cy) with sponding P5+-cages 15a,b+. No reaction was observed for the less elec-
chloro-substituted phosphenium cations 14a,b+ readily form the corre-
GaCl3 to form phosphenium cations [(i-Pr2N)2P]+ (13+) and [(R2N)
PCl]+ (14a,b+) has been investigated. The isolation and fully charac-
terization of the first amino- and chloro-substituted phosphenium cat-
ion 14b[GaCl4] was accomplished. The insertion of these phosphen-
ium ions into P–P bonds of dissolved P4 was examined. Amino- and
trophilic diamino-substituted phosphenium cation 13+. The molecular
structures of [14b][GaCl4] and [15b][Ga2Cl7] are presented and,
furthermore, the intriguing NMR spectra of the P5+-cations 15a,b+ are
discussed.
+
P5 -cage compounds has been extended to zwitterionic and
Introduction
cationic P5-cages from four–membered phosphorus–nitrogen
(8+, 92+)[9] and phosphorus–nitrogen–metal heterocycles (10+,
11)[10] by P–P bond insertion reactions of the respective phos-
phenium cations (Scheme 2). Unstabilized phosphenium cat-
ions [R2P]+ (2+, R = aryl, alkyl) are elusive because of their
highly electrophilic nature[9], and only N-stabilized phosphen-
ium cations (e.g. R = NCy2, Ni-Pr2) have been reported to
form stable salts in which the phosphorus atom is indeed di-
valent.[10]
A plethora of anionic and neutral phosphorus cage and ring
compounds have been discovered and described in literature.[1]
However, the field of cationic polyphosphorus derivatives is
still underdeveloped and mostly limited to catenated and cyclic
compounds.[2] Only recently, the first structurally characterized
cationic phosphorus cages [P5X2]+ (X = Br, I, Cl) (1+) were
reported obtainable from the reaction of P4 and PX3 in the
presence of the silver salt Ag[Al(OR)4] (OR = perfluorinated
aliphatic alkoxide).[3] Similar to other carbene like main group
compounds[4] phosphenium cations are anticipated to undergo
P–P bond insertion reactions because of their amphiphilic na-
ture.[5] Therefore, we investigated room temperature molten
media obtained from various stoichiometric combinations of
Ph2PCl and GaCl3. These mixtures can be used as sources of
the elusive phosphenium cation [R2P]+ (2+, R = Ph).[6] Thus,
dissolution of P4 in such melts at elevated temperatures re-
sulted in the stepwise formation of cationic cage compounds
[Ph2P5]+ (3+), [Ph4P6]2+ (42+), and [Ph6P7]3+ (53+, Scheme 1).[7]
In addition, we also examined mixtures of dichlorophosphanes
RPCl2 (R = aryl, alkyl) and Lewis acids ECl3 (E = Al, Ga) in
fluorobenzene solution. These mixtures are suitable sources of
[RPCl]+ (6+) ions and provide access to a multitude of asym-
metrically substituted cationic cage compounds [RP5Cl]+ (7+)
(Scheme 1).[8] This approach can be applied to various chloro-
phosphanes, thus, the number of highly functionalized cationic
Scheme 1. Cationic phosphorus cages and phosphenium cations.
In our present contribution we report on the reactions of
amino-substituted mono- and dichlorophosphanes (R2N)nPCl3–n
(n = 2, R = i-Pr; n = 1, R = i-Pr, Cy) with the Lewis acid
GaCl3. Both types of derivatives react with GaCl3 to form the
corresponding phosphenium cations [(i-Pr2N)2P]+ (13+) and
[(R2N)PCl]+ (14a,b+) (a: R = i-Pr, b: R = Cy; Scheme 3).
* Dr. J. J. Weigand
Fax: +49-251-83-33108
E-Mail: jweigand@uni-muenster.de
[a] Institut für Anorganische und Analytische Chemie
Universität Münster
Corrensstraße 30, 48149 Münster, Germany
Z. Anorg. Allg. Chem. 2012, 638, (7-8), 1103–1108
© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
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M. H. Holthausen, J. J. Weigand
ARTICLE
i-Pr; RЈ = Mes[16], ortho-(CF3)2C6H3[17]) are known and struc-
turally characterized. We were interested if cation 13+ can in-
sert into P–P bonds of the P4 tetrahedron. The formation of
cation 13+ is achieved upon addition of GaCl3 to (i-Pr2N)2PCl
in almost quantitative yield.[17] However, the 31P{1H} NMR
spectrum of the reaction mixture of P4, (i-Pr2N)2PCl and GaCl3
in a 1:1:1 ratio in fluorobenzene showed only the formation of
cation 13+ (Scheme 4) and unreacted P4 (δ = –521.0 ppm), the
formation of cation 16+ was not observed. The outcome of this
reaction was found to be independent of the reaction stoichi-
ometry of (i-Pr2N)2PCl and GaCl3 (see experimental section).
This might be explained with the decreased electrophilicity of
cation 13+ attributed to the optimal overlap of the lone pairs
of electrons at the nitrogen atoms with the empty p-type orbital
of the divalent phosphorus atom.[18] This is in sharp contrast to
the related four-membered phosphenium cations derived from
[DippNPCl]2 which give cations 8+ and 92+ upon reaction with
P4 in the presence of GaCl3 in various stoichiometries.[9] In
order to increase the electrophilicity of phosphenium cations,
replacement of one substituent in [(R2N)2P]+ by a chloride
should result in a pronounced reactivity. Thus, the correspond-
ing dichlorophosphanes (i-Pr2N)PCl2 and (Cy2N)PCl2 should
yield the phosphenium cations 14a,b+ which are expected to
display an enhanced electrophilicity. Cations 14a,b+ are known
and have been used for the syntheses of phospholes and nitro-
gen-phosphorus heterocycles.[19] However, their isolation has
not been reported so far. Therefore, we investigated the reac-
tions of (i-Pr2N)PCl2 and (Cy2N)PCl2 with GaCl3 in 1 : 1 and
1 : 2 stoichiometries (Figure 1). The addition of one equivalent
GaCl3 to a C6H5F solution of (i-Pr2N)PCl2 or (Cy2N)PCl2 in-
duced the formation of the expected phosphenium cations 14a+
and 14b+. This is indicated by remarkable low field shifts ob-
served in 31P{1H} NMR spectra of the reaction mixtures (n =
1; 14a+: δ = 292.4 ppm, ν1/2 = 105 Hz; 14b+: δ = 309.8 ppm,
ν1/2 = 110 Hz, Figure 1) compared to the chemical shifts of the
corresponding phosphanes (i-Pr2N)PCl2: δ = 167.7 ppm, ν1/2
= 105 Hz; (Cy2N)PCl2: δ = 167.7 ppm, ν1/2 = 90 Hz).[20] The
increased low-field shift of 14b+ might be best explained by
the less favored overlap of the free lone pair of electrons at
the more sterically demanding Cy2N-substituent compared to
the i-Pr-substituted species 14a+.[21] In addition, the chemical
shifts of the phosphenium ions strongly depend on the amount
of Lewis acid added to the reaction mixture. A second equiva-
lent of GaCl3 leads to the formation of [Ga2Cl7]– anions[22]
accompanied with a significant low field shift of the respective
phosphenium cations 14a,b+ (n = 2; 14a+: δ = 340.0 ppm, ν1/2
= 145 Hz; 14b+: δ = 350.1 ppm, ν1/2 = 514 Hz; Figure 1). A
comparable reliance of the 31P{1H} NMR resonances of phos-
Scheme 2. Cationic phosphorus cages from four-membered heterocy-
cles.
However, only cations 14a,b+ undergo insertion reactions into
one P–P bond of the P4 tetrahedron to yield the corresponding
cationic cages [(R2N)P5Cl]+ (15a,b+). In course of our investi-
gations, we also succeeded in the isolation and characterization
of the first amino- and chloro-substituted phosphenium cation
(14b+) as tetrachlorogallate salt. The dependency of the chemi-
cal shift of the phosphenium cations in response to the stoi-
chiometric combination of GaCl3 and chlorophosphanes is also
discussed.
Scheme 3. Amino-substituted phosphenium cations and phosphorus
cages.
Results and Discussion
The reaction of chlorophosphanes of the type R2PCl and
RPCl2 (R = aryl, alkyl) with halide abstracting agents such as
Me3SiOTf or AgOTf or Lewis acids (ECl3, E = Ga, Al) yields
a variety of products, involving phosphanylphosphonium cat-
ions and Lewis acid-base adducts between the phosphane and
ECl3.[13] Other structural variations are also discussed.[8, 13b]
Related reactions of amino-substituted chlorophosphanes and
Lewis acids or halide abstracting agents have been investigated
previously and do not show the structural variety as observed
for the alkyl- or aryl-substituted chlorophosphanes.[14] How-
ever, a series of phosphenium ions [(R2N)2P]+ (13+) were iso-
lated and utilized for example as NHP ligands (N-Heterocyclic
Phosphenium) in transition metal chemistry.[15] Very few ex-
Scheme 4. Attempted reaction of P4 with chlorophosphane 13 in the
amples of phosphenium ions of the form [(R2N)2PRЈ]+ (R = presence of Lewis acid GaCl3.
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Preparation of Cationic [(R2N)P5Cl]+-Cage Compounds from [(R2N)PCl]+ and P4
phenium cations on the nature of the corresponding anions has
been reported for cyclodiphosphadiazenium salts.[23]
Scheme 5. Reaction of P4 with dichlorophosphanes (R2N)PCl2 (R = i-
Pr, Cy) in the presence of the Lewis acid GaCl3.
Figure 1. 31P{1H} NMR investigation of mixtures of (i-Pr2N)PCl2 or
(Cy2N)PCl2 with GaCl3 in fluorobenzene in various stoichiometries
(C6D6 capillary, C6H5F).
Figure 2. Cut-out of the crystal structure of compound 14b[GaCl4].
Thermal ellipsoids at 50% probability (hydrogen atoms are omitted
for clarity). Selected bond lengths /Å and angles /°: P1–Cl1 2.0026(8),
P1–N1 1.608(2), N1–C1 1.496(3), N1–C7 1.525(3), P1–Cl2i 3.291(1),
P1–Cl4i 3.207(1); N1–P1–Cl1 104.50(7), N1–P1–Cl4i 132.68(6), Cl1–
P1–Cl4i 88.79(3), Cl2–P1–Cl2i 166.27(3), C1–N1–P1 129.0(1), C7–
N1–P1 113.3(1), C1–N1–C7 129.0(1); i) –1+x, y, z.
The additional increase in line broadening of the resonances
can be explained by the dynamic equilibrium dissociation of
[Ga2Cl7]– to [GaCl4]– and GaCl3.[8] The salt 14b[GaCl4] was
obtained as analytically pure colorless solid in excellent yield
(81%) by the slow addition of n-hexane to the fluorobenzene
solution of the 1:1 reaction of (Cy2N)PCl2 and GaCl3. Com-
pound 14b[GaCl4] was fully characterized and a section of
the crystal structure is depicted in Figure 2. This compound
crystallizes in the orthorhombic space group P212121 as a race-
mic twin with four formula units in the unit cell. 14b[GaCl4]
represents the first structural characterized chloro-substituted
phosphenium cation. The P1–N1 bond length (1.608(2) Å),
which is comparable to known diamino-substituted phosphen-
ium cations,[17, 24] is substantially shorter than a typical P–N
single bond (dcov(P–N) = 1.8 Å; dcov(P=N) = 1.6 Å)[25] indicat-
ing double bond character. The nitrogen atom exhibits a planar
arrangement (angular sum 359.9(1)°) indicating sp2 hybridiza-
tion and is located in the plane spanned by the atoms P1, Cl1
and the ipso-carbon atoms of the cyclohexyl groups (dihedral
angles 6.7(2)°, 177.2(1)°). The angle involving the phosphorus
atom is rather acute (Cl1–P1–N1: 104.50(7)°) compared to
known phosphenium cations of type 13+ (e.g. in [((i-Pr)2N)
2P][GaCl4]: 117.07(7)°),[17] and is indicative of the higher
electrophilicity of chloro-substituted phosphenium cations.
The molecular structure of 14b[GaCl4] shows two very short
interatomic Cl···P contacts (P1···Cl2 3.060(1) Å, P1···Cl4i
3.207(9) Å) (symmetry operation i = –1+x, y, z) between the
anions and cations which are close to the sum of the van der
Waals radii (rA(P) + rD(Cl) = 3.55 Å)[26]. This interaction leads
to the formation of one-dimensional strands along the [100]
axis ((Cl2–P1–Cl2i: 166.27(3) °, P1–Cl2–P1i: 166.27(3) °; Fig-
ure 2). Considering the second interatomic contact involving
Cl4i, the phosphorus atom shows a distorted bisphenoidal ge-
ometry (N1–P1–Cl4i: 166.27(3)°, Cl1–P1–Cl4i: 88.79(3)°).
The reaction of P4, (Cy2N)PCl2 and GaCl3 in a 1:1:1 ratio in
C6H5F solution has been performed to investigate the ability of
cation 14b+ to insert in one of the P–P bonds of P4 (Scheme 5).
31P{1H}-NMR investigation of the reaction mixture exhibits
+
incomplete conversion to the corresponding cationic P5 -cage
15b+ in an approximate yield of 60% (Figure 3). Remaining P4
and phosphenium cation 14b+ can be observed in the reaction
mixture. The separation of compound 15b[GaCl4] from the re-
action mixture was difficult, since cation 15b+ is in equilib-
rium with cation 14b+ and P4. Similar results were obtained
employing a second equivalent GaCl3 or using (i-Pr2N)PCl2
(Scheme 5; see experimental section). However, layering the
reaction mixture of the 1:1:2 stoichiometry with n-hexane at
–35 °C yields crystalline 15b[Ga2Cl7], suitable for X-ray dif-
fraction, as a conglomerate including 14b[GaCl4]. A view of
the molecular structure of the cation 15b+ in 15b[Ga2Cl7] is
+
depicted in Figure 3. The P5 -cage in cation 15b+ displays
nearly identical bond lengths and angles compared to other
reported [RP5Cl]+-cations (2.151(9) to 2.258(5) Å).[9] Simi-
larly to the latter cages, the bonds between the bridging (P2,
P3) and tetracoordinate phosphorus atoms (P1) and the P4–P5
bond in cation 15b+ are slightly shorter by approximately 0.07
Å (2.1573(6) to 2.1981(6) Å) than the remaining P–P bonds
(2.2385(6) to 2.2460(6) Å). The short P4–P5 bond length is
typical for the bridgehead bond in related bicyclo[1.1.0]-tetra-
phosphane moieties.[27] Likewise, the P1–N1 bond in 15b+ is
shortened (1.612(2) Å) because of electrostatic interaction. In
accordance to the molecular structure of 15b+ an ABMX2 spin
system is observed within the 31P{1H} NMR spectra of the
reaction mixtures (Figure 3).[28] This is the result of the CS-
+
symmetry of the P5 -moiety. The chemical shifts and coupling
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M. H. Holthausen, J. J. Weigand
ARTICLE
Figure 3. a) left: 31P{1H} NMR spectrum of the 1:1:1 reaction of P4, (Cy2N)PCl2 and GaCl3. (C6H5F, C6D6 capillary, 300 K; insets show
experimental (upwards) and fitted spectra (downwards); * marks small amounts of unidentified side products; 15b+ exhibits an ABMX2 spin
system: δA = –271.8 ppm, δΒ = –264.8 ppm, δM = 33.7 ppm, δX = 116.2 ppm, 1J(PAPX) = –152.7 Hz, 1J(PBPX) = –145.9 Hz, 1J(PAPB) = –
167.1 Hz, 1J(PMPX) = –277.8 Hz, 2J(PAPM) = 17.8 Hz, 2J(PBPM) = 23.1 Hz; b) right: ORTEP plot of the molecular structure of the cation in
15b[Ga2Cl7]. Thermal ellipsoids at 50% probability (hydrogen atoms and anion are omitted for clarity). Selected bond lengths /Å and angles /°:
P1–Cl1 2.0523(5), P1–N1 1.612(2), N1–C1 1.500(2), N1–C7 1.500(2), P1–P2 2.1621(6), P1–P3 2.1573(6), P2–P4 2.2385(6), P2–P5 2.460(6),
P3–P4 2.2424(6), P3–P5 2.2394(6), P4–P5 2.1981(6); C7–N1–C1 119.4(1), N1–P1–Cl1 110.99(5), P3–P1–P2 91.42(2), P1–P2–P4 83.73(2), P1–
P3–P5 82.38(2), P2–P4–P3 87.27(2), P4–P2–P5 58.70(2), P5–P4–P2 60.82(2).
constants of 15b+ exhibit some interesting characteristics com- insertion reactions to form the amino-substituted cations
pared to other CS-symmetric [RP5Cl]+-cations (R = alkyl, [(R2N)P5Cl]+ (15a,b+) no reaction was observed for the di-
aryl).[8] Within alkyl- and aryl-substituted [RP5Cl]+-cage com- amino-substituted phosphenium cation [(i-Pr2N)2P] (13+). This
pounds the chemical shifts of the phosphonium moiety shift to study gives an insight into the properties relevant for phos-
higher field with decreasing electronegativity of the corre- phenium cations to undergo reactions with P4 and extends the
+
sponding substituents (ranging from 99 ppm (R = t-Bu) to number of cationic P5 -cage compounds to amino-substituted
26 ppm (R = C6F5)).[8] An opposite trend was described for the derivates. This will help to design appropriate chlorophos-
phosphorus atoms adjacent to the phosphonium moiety (rang- phane precursor for the transformation of P4 into cationic poly-
ing from 44 ppm (R = t-Bu) to 83 ppm (R = C6F5)).[8] Thus, phosphorus compounds.
the resonance of the phosphonium moiety of 15b+
(δM = 33.7 ppm) and the resonance of the adjacent phosphorus
atoms (δX = 116.2 ppm) emphasize the electronegative charac-
ter of the amino-substituent. Between the phosphonium moiety
and the bridgehead phosphorus atoms (P4/P5) two different
2JPP coupling constants are observed (2J(PAPM) = 17.8 Hz,
Experimental Section
All reactions were carried out in either a glove box or using standard
Schlenk techniques under an inert Ar atmosphere. Dry, oxygen-free
solvents were employed. P4 was dried with (CH3)3SiCl and recrys-
tallized from CS2 prior to use. Reagent grade GaCl3 and (i-Pr2N)2PCl
were used as received from commercial suppliers. (i-Pr2N)PCl2 and
(Cy2N)PCl2 were prepared according to the previously described meth-
ods.[29] NMR spectra were measured at 300 K on a Bruker AVANCE
III 400 or a Bruker AVANCE II 200 spectrometer, and spectra were
referenced either to residual solvent (1H, 13C) or externally [31P
(H3PO4), 27Al (Al(NO3)3), 71Ga (Ga(NO3)3)]. Chemical shifts are re-
ported in ppm. J values are reported in Hz. CD2Cl2 was purchased
from Sigma-Aldrich and stored over 3 Å molecular sieves prior to use.
To obtain 31P{1H} NMR spectra of reaction mixtures, a C6D6-capillary
was inserted into the NMR tube. For compounds which give rise to a
higher order spin systems in their 31P{1H} NMR spectra, the resolu-
tion-enhanced 31P{1H} spectra were transferred to the software pro-
gram gNMR, version 5.0, by Cherwell Scientific.[30] The full lineshape
iteration procedure of gNMR was applied to obtain the best match of
the calculated to the experimental spectra along with the assignment
of all the peaks revealed in the resolution-enhanced spectra. The signs
1
2J(PBPM) = 23.1 Hz). Also the JPP coupling constants from
the bridgehead phosphorus atoms to the neighbouring ones ex-
1
hibit different values (1J(PAPX) = –152.7 Hz, J(PBPX) = –
145.9 Hz). By comparison of these values with known
[RP5Cl]+-, [R2P5]+- and [P5X2]+-cations (R = alkyl, aryl; X =
Cl, Br, I) the A part of the spin system can be assigned to the
phosphorus atom in closer proximity to the Cl-substitutent due
to the set of smaller coupling constants.[3, 7, 8]
Conclusions
The reactions of amino-substituted mono- and dichlorophos-
phanes (R2N)nPCl3–n (n = 2, R = i-Pr; n = 1, R = i-Pr, Cy)
with various amounts of the Lewis acid GaCl3 have been in-
vestigated. In all cases the formation of phosphenium ions
(13+, 14a,b+) was observed. The isolation and characterization
of the first amino- and chloro-substituted phosphenium cation
[14b][GaCl4] was achieved. The ability of insertion reactions
into P–P bonds of the P4 tetrahedron was examined. Whereas
1
for the J(31P,31P) coupling constants were set negative and all other
signs obtained accordingly.[31] Melting points were recorded on an
electrothermal melting point apparatus in sealed capillaries under Ar-
gon atmosphere and are uncorrected. Infrared (IR) spectra were re-
chloro-substituted phosphenium cations 14+ undergo P–P bond corded using a Bruker Vertex 70 spectrometer. Elemental analyses
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Preparation of Cationic [(R2N)P5Cl]+-Cage Compounds from [(R2N)PCl]+ and P4
were performed on a Vario EL III CHNS elemental analyzer at the (vw), 1064 (s), 1014 (w), 947 (w), 894 (m), 610 (w), 550 (m), 504
IAAC, University of Münster.
(vw), 430 (vw); 1H NMR (CD2Cl2, 25 °C): δ = 1.16–1.28 (2H, m,
CH2), 1.37–1.50 (4H, m, CH2), 1.70–1.85 (6H, m, CH2), 1.90–1.98
(4H, m, CH2), 2.02–2.09 (4H, m, CH2), 4.11–4.23 (2H, m, CH);
13C{1H} NMR (CD2Cl2, 25 °C): δ = 25.0 (2C, s, CH2), 26.3 (4C, s,
CH2), 34.6 (4C, d, JPC = 6.9 Hz), 65.8 (2C, d, CH, JPC = 6.4 Hz);
71Ga{1H} NMR (CD2Cl2, 25 °C): δ = 250.7 (1 Ga, s(br), ν1/2
= 5000 Hz); 31P{1H} NMR (CD2Cl2, 25 °C,): δ = 294.0 (1P, s, v1/2
= 113 Hz); elemental analysis for C12H22Cl5GaNP (458.27): calcd. N:
3.1 C: 31.4, H 4.8; found: N: 2.8 C 30.8, H 4.7 %.
Recrystallization of [14b][GaCl4] from fluorobenzene by n-hexane dif-
fusion gave single crystals suitable for X-ray diffraction. Layering
1:1:2 reaction mixtures of (Cy2N)PCl2, P4 and GaCl3 with n-hexane
gave single crystals of [15b][Ga2Cl7] suitable for X-ray analysis. Sin-
gle crystals of [14b][GaCl4] and [15b][Ga2Cl7] were mounted in Para-
tone oil and transferred to the cold N2 gas stream of a Bruker AXS
APEX CCD diffractometer equipped with a rotation anode at 153(1)
K (graphite-monochromated Mo-Kα radiation with λ = 0.71073 Å).
Crystal data: [14b][GaCl4], C12H22Cl5GaNP, FW = 458.25, ortho-
rhombic, space group P212121, Z = 4, a = 6.9315(4) Å, b = 16.584(1)
Å, c = 16.734(1) Å, α= 90°, β= 90°, γ= 90°, V = 1923.7(2) Å3, F(000)
= 928, T = 153(1), μ= 2.198, 9161 reflections collected, 5159 reflec-
tions unique (Rint = 0.0283), 4620 reflections observed (F Ͼ 2σ (F)).
The final was R1 = 0.0344 and wR2 = 0.0662 (all data). CCDC-871709;
[15b][Ga2Cl7], C12H22Cl8Ga2NP5, FW = 758.20, monoclinic, space
group P21/n, Z = 4, a = 9.2899(5) Å, b = 25.734(1) Å, c = 11.9087(7)
Å, V = 2786.3(3) Å3, F(000) = 1496, T = 153(1), μ= 2.992, 29837
reflections collected, 7198 reflections unique (Rint = 0.0234), 6360 re-
flections observed (F Ͼ 2σ (F)). The final was R1 = 0.0265 and wR2
= 0.0494 (all data) CCDC-871709. For crystallographic data in CIF or
other electronic format see DOI: 10.1039/b000000x
3
3
Acknowledgement
We gratefully acknowledge the Fonds der Chemischen Industrie (FCI)
(fellowship for M.H.H.), the European Phosphorus Science Network
(PhoSciNet CM0802) and the Deutsche Forschungsgemeinschaft
(DFG) (WE 4621/2–1). J.J.W. thanks Prof. F. Ekkehardt Hahn (WWU
Münster) for his generous support.
References
[1] a) M. Baudler, Angew. Chem. 1982, 94, 520; b) M. Baudler, An-
gew. Chem. 1987, 99, 428; c) M. Baudler, Chem. Rev. 1994, 94,
1273.
[2] C. A. Dyker, N. Burford, Chem. Asian J. 2008, 3, 28.
[3] a) I. Krossing, I. Raabe, Angew. Chem. Int. Ed. 2001, 40, 4406;
b) A. Bihlmeier, M. Gonsior, I. Raabe, N. Trapp, I. Krossing,
Chem. Eur. J. 2004, 10, 5041; c) I. Krossing, J. Chem. Soc., Dal-
ton Trans. 2002, 500; d) M. Gonsior, I. Krossing, L. Müller, I.
Raabe, M. Jansen, L. van Wüllen, Chem. Eur. J. 2002, 8, 4475.
[4] a) C. Dohmeier, H. Schnöckel, C. Robl, U. Schneider, R.
Ahlrichs, Angew. Chem. 1994, 106, 225; Angew. Chem. Int. Ed.
Engl. 1994, 33, 199; b) Y. Peng, H. Fan, H. Zhu, H. W. Roesky,
J. Magull, C. E. Hughes, Angew. Chem. Int. Ed. 2004, 43, 3443;
c) M. B. Power, A. R. Barron, Angew. Chem. Int. Ed. Engl. 1991,
30, 1353; d) W. Uhl, M. Benter, Chem. Commun. 1999, 771; e)
A. R. Fox, R. J. Wright, E. Rivard, P. P. Power, Angew. Chem. Int.
Ed. 2005, 44, 7729; f) N. Wiberg, A. Wörner, K. Karaghiosoff,
D. Fenske, Chem. Ber./Recueil 1997, 130, 135; g) H.-W. Lerner,
M. Bolte, K. Karaghiosoff, M. Wagner, Organometallics 2004,
23, 6073; h) W. T. K. Chan, F. García, A. D. Hopkins, L. C. Mar-
tin, M. McPartlin, D. S. Wright, Angew. Chem. Int. Ed. 2007, 46,
3084; i) Y. Xiong, S. Yao, M. Brym, M. Driess, Angew. Chem.
Int. Ed. 2007, 46, 4511.
31P{1H} NMR Experiments of (i-Pr2N)2PCl/GaCl3/P4 Mixtures: A
suspension of P4 (0.5 mmol) in a solution of (i-Pr2N)2PCl (0.5 mmol)
and GaCl3 (0.5(i)/1.0(ii) mmol) in CH2Cl2 ((i), 2 mL or C6H5F ((ii),
2 mL),[32] respectively) was stirred for 12 h at room temperature after
which 31P{1H} spectra were recorded ((i), CH2Cl2, C6D6-capillary,
25 °C): δ = 304.7 ([(i-Pr2N)2P][GaCl4], ν1/2 = 50 Hz), 521.5 (P4); ((ii),
C6H5F, C6D6-capillary, 25 °C,): δ = 315.7 ([(i-Pr2N)2P][Ga2Cl7], ν1/2
= 35 Hz), 521.5 (P4)).
31P{1H} NMR Experiments of (R2N)PCl2/GaCl3 Mixtures: (R = i-
Pr, Cy). A solution of (R2N)PCl2 (0.5 mmol) and GaCl3 (0.5/
1.0 mmol) in C6H5F (2 mL) was stirred for 15 min at room temperature
after which 31P{1H} NMR spectra were recorded (Figure 1).
31P{1H} NMR Experiments of (Cy2N)PCl2/GaCl3/P4 Mixtures: A
suspension of P4 (0.5 mmol) in a solution of (Cy2N)PCl2 (0.5 mmol)
and GaCl3 (0.5(i)/1.0 mmol(ii)) in C6H5F (2 mL) was stirred for 12 h
at room temperature after which 31P{1H} spectra were recorded ((i):
Figure 3, (ii): 31P{1H} NMR spectrum was found to be similar to (i)).
[5] D. Gudat, Eur. J. Inorg. Chem. 1998, 1087.
[6] J. J. Weigand, N. Burford, A. Decken, Eur. J. Inorg. Chem. 2008,
31P{1H} NMR Experiments of (i-Pr2N)PCl2/GaCl3/P4 Mixtures: A
suspension of P4 (0.5 mmol) in a solution of (i-Pr2N)PCl2 (0.5 mmol)
and GaCl3 (0.5(i)/1.0 mmol(ii)) in C6H5F (2 mL) was stirred for 12 h
at room temperature after which 31P{1H} spectra were recorded. The
31P{1H} NMR spectra of (i) and (ii) were found to be similar to the
data obtained for (Cy2N)PCl2. [(i-Pr2N)P5Cl]+ (15a+) (C6H5F, C6D6-
capillary, 25 °C): ABMX2 spin system: (δA = –274.6 ppm, δB =
–266.6 ppm, δM = 33.1 ppm, δX = 118.0 ppm, 1J(PAPX) = –152.9 Hz,
4343.
[7] J. J. Weigand, M. H. Holthausen, R. Fröhlich, Angew. Chem. Int.
Ed. 2009, 48, 295.
[8] M. H. Holthausen, K.-O. Feldmann, S. Schulz, A. Hepp, J. J. Wei-
gand, Inorg. Chem. 2012, 51, 3374.
[9] M. H. Holthausen, J. J. Weigand, J. Am. Chem. Soc. 2009, 131,
14210.
[10] M. H. Holthausen, C. Richter, A. Hepp, J. J. Weigand, Chem.
Commun. 2010, 46, 6921.
[11] J. M. Slattery, S. Hussein, Dalton Trans. 2012, 41, 1808.
[12] A. H. Cowley, R. A. Kemp, Chem. Rev. 1985, 85, 367.
[13] a) F. S. Shagvaleev, T. V. Zykova, R. I. Tarasova, T. S. Sitdikova,
V. V. Moskva, J. Gen. Chem. USSR (Engl. Trans.) 1990, 60, 1585;
Z. Obshch. Khim. 1990, 60, 1775; b) N. Burford, T. S. Cameron,
D. J. LeBlanc, P. Losier, S. Sereda, G. Wu, Organometallics 1997,
4712; c) Y. Carpenter, N. Burford, M. Lumsden, R. McDonald,
Inorg. Chem. 2011, 50, 3342.
[14] S. Burck, D. Gudat, Inorg. Chem. 2008, 47, 315.
[15] a) D. Gudat, Top. Heterocycl. Chem. 2010, 21, 63; b) H. Nakaz-
awa, J. Organomet. Chem. 2000, 611, 349; c) R. W. Reed, Z. Xie,
C. A. Reed, Organometallics 1995, 14, 5002.
1
1J(PBPX) = –144.4 Hz, J(PAPB) = –161.3 Hz, 1J(PMPX) = –278.3 Hz,
2
2J(PAPM) = 18.1 Hz, J(PBPM) = –24.0 Hz.
Synthesis of [14b][GaCl4]: To a solution of (Cy2N)PCl2 (1.0 mmol)
in C6H5F (5 mL) GaCl3 (1.0 mmol) was added. The reaction mixture
was stirred for 1 h at room temperature accompanied by the formation
of small amounts of a white precipitate. n-Hexane (2 mL) was slowly
added to complete precipitation. The white solid was isolated, washed
with n-hexane (3 x 2 mL) and dried in vacuo. [14b][GaCl4] Yield:
81%(370 mg,0.8 mmol);m.p.110.0–110.6 °C;IR(KBr,25 °C,(cm–1)):
2937 (vs), 2857 (w), 1447 (s), 1386 (vw), 1257 (vw), 1165 (w), 1144
Z. Anorg. Allg. Chem. 2012, 1103–1108
© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.zaac.wiley-vch.de
1107

M. H. Holthausen, J. J. Weigand
ARTICLE
[16] A. Dumitrescu, H. Gornitzka, W. W. Schoeller, D. Bourissou, G.
Bertrand, Eur. J. Inorg. Chem. 2002, 1953.
[17] N. Burford, P. Losier, C. MacDonald, V. Kyrimis, P. K. Bakshi,
Wiberg, A. F. Holleman, Lehrbuch der Anorganischen Chemie,
102. Aufl., Walter de Gruyter, Berlin, 2007, Anhang IV.
[26] A. Bondi, J. Phys. Chem. 1964, 68, 441.
[27] M. Donath, E. Conrad, P. Jerabek, G. Frenking, R. Fröhlich, N.
Burford, J. J. Weigand, Angew. Chem. Int. Ed. 2012, 51, 2964.
[28] Designation of the spin system by convention. Furthest downfield
resonance is denoted by the latest letter in the alphabet, and fur-
thest upfield by the earliest: Δδ(PiPii)/J(PiPii) Ͼ 10 (resonance
considered to be pseudo first order and the assigned letters are
separated) Ͻ 10 (consecutive letters are assigned).
[29] a) (Cy)2NPCl2: G. Markl, B. Alig, J. Organomet. Chem. 1984,
273, 29; b) (i-Pr)2NPCl2: A. H. Cowley, R. A. Kemp, J. G. Lasch,
N. C. Norman, C. A. Stewart, B. R. Whittlesey, T. C. Wright, In-
org. Chem. 1986, 25, 740.
T. S. Cameron, Inorg. Chem. 1994, 33, 1434.
[18] D. Gudat, Coord. Chem. Rev. 1997, 163, 71.
[19] a) M.-R. Marr, M. Sanchez, R. Wolf, J. Chem. Soc., Chem. Com-
mun. 1984, 566; b) S. A. Weissmann, S. G. Baxter, A. M. Arif,
A. H. Cowley, J. Chem. Soc., Chem. Commun. 1986, 1082; c) C.
Roques, M.-R. Mazieres, J.-P. Majoral, M. Sanchez, Inorg. Chem.
1989, 28, 3991; d) V. D. Romanenko, T. V. Sarina, M. Sanchez,
A. N. Chernega, A. B. Rozhenko, M.-R. Mazieres, M. I. Povolot-
ski, J. Chem. Soc., Chem. Commun. 1993, 963; e) J. Hydrio, M.
Gouygou, F. Dallemer, G. G. A. Balavoine, J.-C. Daran, Eur. J.
Org. Chem. 2002, 675.
[30] P. H. M. Budzelaar, gNMR for Windows (5.0.6.0) NMR Simula-
tion Program, IvorySoft 2006.
[20] 31P{1H} NMR measurements of (i-Pr)2NPCl2 and (Cy)2NPCl2 in
C6H5F solutions with C6D6 capillary.
[21] A. H. Cowley, M. Lattman, J. C. Wulburn, Inorg. Chem. 1981,
20, 515.
[31] a) H. C. E. McFarlane, W. McFarlane, J. A. Nash, J. Chem. Soc.,
Dalton Trans. 1980, 240; b) S. Aime, R. K. Harris, E. M.
McVicker, M. Fild, J. Chem. Soc., Dalton Trans. 1976, 2144; c)
M. A. M. Forgeron, M. Gee, R. E. Wasylishen, J. Phys. Chem.
2004, 108, 4895; d) J. E. Del Bene, J. Elguero, I. Alkorta, J. Phys.
Chem. 2004, 108, 3662.
[22] S. Ulvenlund, A. Whaetley, L. A. Bengtsson, J. Chem. Soc., Dal-
ton Trans. 1995, 2, 245.
[23] R. Kuzora, A. Schulz, A. Villinger, R. Wustrack, Dalton Trans.
2009, 9304.
[32] Performing the 1:1:1 reaction in C6H5F leads to the precipitation
of [(i-Pr2N)2P][GaCl4].
[24] A. H. Cowley, M. C. Cushner, J. S. Szobota, J. Am. Chem. Soc.
1978, 100, 7784.
Received: March 20, 2012
[25] Sum of covalent radii: r(P) = 1.1 and r(N) = 0.7; N. Wiberg, E.
Published Online: May 15, 2012
1108
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© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Z. Anorg. Allg. Chem. 2012, 1103–1108