m-Terphenylaluminum and -gallium compounds: Synthesis and conversion into low-coordinate organogallium cations

Article abstract of DOI:10.1002/ejic.200601049

The reaction of two or 3 equiv. of m-terphenyllithium with MCl₃ or AlH₃·NMe₃ (M = Al, Ga) affords the bis(terphenyl)-aluminum and -gallium chloride compounds [{2,6-(4-tBuC ₆H₄)₂C₆H₃} ₂GaCl] (1), [{2,6-(3,5-Me₂C₆H₃) ₂C₆H₃}₂GaCl] (2), [{2,6-(4-tBuC ₆H₄)₂C₆H₃}₃Ga] (3), [(2,6-Mes₂C₆H₃)₂AlCl] (5), and [(2,6-Mes₂C₆H₃)2AlH] (7; Mes = 2,4,6-Me ₃C₆H₂). While the gallium compounds can be obtained at room temperature, heating is required for the aluminum derivatives. The dibutyl compounds [(2,6-Mes₂C₆H₃)GaBu ₂] (8) and [(2,6-Dipp₂C₆H₃)GaBu ₂] (9; Dipp = 2,6-iPr₂C₆H₃) have also been synthesized by the reaction of m-terphenyllithium with ClGaBu ₂. A metathesis reaction of 2 with Li[Al{OCH(CF₃) ₂}₄] gives the ionic species [(2,6-Mes₂C ₆H₃)₂Ga]⁺[Li[Al-[OCH(CF ₃)₂]₄}₂]- (11). The cationic butyl(terphenyl)gallium compounds [(2,6-Mes₂C₆H ₃)GaBu]⁺ ([13]⁺) and [(2,6-Dipp ₂C₆H₃)GaBu]⁺ ([14]⁺) have been prepared by butanide abstraction with the trityl salts of the weakly coordinating anions [B(C₆F₅)₄]^-, [CHB₁₁Br₆Me₅]^-, and [CHB ₁₁Cl₁₁]^-. These ionic species are stable at room temperature for days or weeks, although their combinations with the borate anion [B-(C₆F₅)₄]^- suffer from C₆F₅ migration, which is slow at room temperature and faster at elevated temperatures. The compound [14]⁺[CHB ₁₁Cl₁₁]^- is stable at 70°C for at least 23 h. Addition of 1-octene to a solution of [14]⁺[CHB ₁₁Cl₁₁]^_ in C₆D₆ results in olefin exchange and formation of the octyl species [(2,6-Dipp ₂C₆H₃)Ga(octyl)]⁺ ([17] ⁺), and a slow alkylation of the solvent to afford various octylbenzenes. Hydrolysis of 8 and [13]⁺[CHB₁₁Br ₆Me₅]^- gives the compounds [{(2,6-Mes ₂C₆H₃)GaBu(μ-OH)}₂] (10) and [(BuGa)₄(μ-OH)₆]²⁺[CHBnBr₆Me ₅]^-₂ (16). All compounds have been characterized by ¹H and ¹³C{¹H} NMR spectroscopy and mass spectrometry, and compounds 3, 5, 7, 10, and 16·4.5C₆H₆ have also been characterized by single-crystal X-ray crystallography. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.

Full text of DOI:10.1002/ejic.200601049

FULL PAPER
DOI: 10.1002/ejic.200601049
m-Terphenylaluminum and -gallium Compounds: Synthesis and Conversion into
Low-Coordinate Organogallium Cations
Jackie D. Young,[a] Masood A. Khan,[a] Douglas R. Powell,[a] and Rudolf J. Wehmschulte*[b]
Keywords: Aluminum / Cations / Gallium / Lewis acids / Low coordination
The reaction of two or 3 equiv. of m-terphenyllithium with
MCl3 or AlH3·NMe3 (M = Al, Ga) affords the bis(terphenyl)-
aluminum and -gallium chloride compounds [{2,6-(4-
tBuC6H4)2C6H3}2GaCl] (1), [{2,6-(3,5-Me2C6H3)2C6H3}2GaCl]
(2), [{2,6-(4-tBuC6H4)2C6H3}3Ga] (3), [(2,6-Mes2C6H3)2AlCl]
(5), and [(2,6-Mes2C6H3)2AlH] (7; Mes = 2,4,6-Me3C6H2).
While the gallium compounds can be obtained at room tem-
perature, heating is required for the aluminum derivatives.
The dibutyl compounds [(2,6-Mes2C6H3)GaBu2] (8) and
[(2,6-Dipp2C6H3)GaBu2] (9; Dipp = 2,6-iPr2C6H3) have also
been synthesized by the reaction of m-terphenyllithium with
ClGaBu2. A metathesis reaction of 2 with Li[Al{OCH(CF3)2}4]
gives the ionic species [(2,6-Mes2C6H3)2Ga]+[Li{Al-
[OCH(CF3)2]4}2]– (11). The cationic butyl(terphenyl)gallium
compounds [(2,6-Mes2C6H3)GaBu]+ ([13]+) and [(2,6-
Dipp2C6H3)GaBu]+ ([14]+) have been prepared by butanide
abstraction with the trityl salts of the weakly coordinating
anions [B(C6F5)4]–, [CHB11Br6Me5]–, and [CHB11Cl11]–. These
ionic species are stable at room temperature for days or
weeks, although their combinations with the borate anion [B-
(C6F5)4]– suffer from C6F5 migration, which is slow at room
temperature and faster at elevated temperatures. The com-
–
pound [14]+[CHB11Cl11
]
is stable at 70 °C for at least 23 h.
Addition of 1-octene to a solution of [14]+[CHB11Cl11
] in
–
C6D6 results in olefin exchange and formation of the octyl
species [(2,6-Dipp2C6H3)Ga(octyl)]+ ([17]+), and a slow alky-
lation of the solvent to afford various octylbenzenes. Hydro-
lysis of 8 and [13]+[CHB11Br6Me5]– gives the compounds
[{(2,6-Mes2C6H3)GaBu(µ-OH)}2]
(10)
and
[(BuGa)4(µ-
OH)6]2+[CHB11Br6Me5]– (16). All compounds have been
2
characterized by 1H and 13C{1H} NMR spectroscopy and
mass spectrometry, and compounds 3, 5, 7, 10, and
16·4.5C6H6 have also been characterized by single-crystal X-
ray crystallography.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2007)
cationic aluminum center.[7] In an effort to increase the re-
activity of the cationic species, we have begun to investigate
methods to achieve two-coordination that do not rely on
excessive steric protection, which tends to decrease and
change reactivity patterns. Based on the observed close sec-
ondary Al···C contacts in [(2,6-Mes2C6H3)2Al]+ involving
the ipso- and ortho-carbon atoms of the flanking mesityl
groups,[7] we speculate that a single m-terphenyl substituent
in conjunction with the least-coordinating anions should be
sufficient for the stabilization of a low-coordinate cationic
center. The bulky substituents are expected to prevent close
anion···cation contacts such as those observed in [Et2Al]-
[CB11H6X6] (X = Cl, Br)[13] and to stabilize the electron-
poor center through secondary M···C contacts. Ideally, the
internal stabilization would be sufficiently labile to allow
facile cation···substrate interactions (Scheme 1).
Introduction
The enormous progress in the development of weakly co-
ordinating anions during the past 10–15 years has invigor-
ated the research of previously inaccessible, often highly re-
active, cationic species.[1–4] Some recent examples in main
group chemistry include a three-coordinate stannylium cat-
ion [(Trip)3Sn]+ (Trip = 2,4,6-iPr3C6H2),[5] two-coordinate
gallium and aluminum cations [(2,6-Mes2C6H3)2M]+ (M =
Ga,[6] Al;[7] Mes = 2,4,6-Me3C6H2), monosubstituted group
14 cations [Cp*Si]+[8] and [(2,6-Trip2C6H3)Pb]+,[9] or the
interesting phosphorus-based cations [P2X5]+ and
[P5X2]+.[10] On the more applied side, there have been sev-
eral studies of the potential of low-coordinate cationic or-
ganoaluminum compounds as catalysts for olefin oligomer-
ization and polymerization.[11–14] Three-coordinate species
have been obtained using monoanionic bidentate li-
gands,[15,16] and quasi-two-coordination has been achieved
by employing two large m-terphenyl substituents at a single
Here, we report the synthesis of a series of terphenylalu-
minum and -gallium precursor molecules and the conver-
sion of a selection of these into cationic species.
[a] Department of Chemistry and Biochemistry,
University of Oklahoma,
620 Parrington Oval, Room 208, Norman, OK 73019, USA
[b] Department of Chemistry, Florida Institute of Technology,
150 West University Blvd., Melbourne, FL 32901, USA
Fax: +1-321-674-8951
Results and Discussion
A series of mono- and diterphenylgallium halides and
alkyl derivatives has been prepared from standard organo-
E-mail: rwehmsch@fit.edu
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J. D. Young, M. A. Khan, D. R. Powell, R. J. Wehmschulte
FULL PAPER
tBuC6H4)2C6H3}2GaMe] by methylation of 1 with meth-
yllithium. Ligand migration in arylgallium compounds is
not uncommon and has been described previously.[17] The
systematic reaction involving 3 equiv. of 2,6-(4-tBuC6H4)2-
C6H3Li gave 3 in 34% yield as a colorless, high-melting
(m.p. 281 °C), crystalline solid. Its structure (Figure 1) fea-
tures a slightly distorted trigonal-planar gallium center
[Σ(C–Ga–C) = 359.3°] that is efficiently protected by three
m-terphenyl substituents. The Ga–C bond lengths
[1.989(2)–2.010(2) Å] fall within the upper range observed
previously for diterphenylgallanes.[18–21] The slightly elon-
gated Ga(1)–C(16) bond [2.010(2) Å] and the correspond-
ing widening of the C(38)–Ga(1)–C(68) angle to 122.57(10)°
may be attributed to the steric demands of the m-terphenyl
substituents. The substituents are arranged in the typical
propeller fashion,[18,22,23] and the planes of the central arene
rings are rotated out of the GaC3 plane by 39° [C(38) ring],
47° [C(16) ring], and 64° [C(68) ring]. Some minor distor-
tions are found for the C(38) substituent. The central C(38)
ring is bent away from the normal linear arrangement by
18.6°, as judged from the angle between the Ga(1)–C(38)
and C(38)–C(41) vectors. Similarly, there is a 6.6° angle be-
tween the C(39)–C(43) and C(43)–C(46) vectors of the
flanking C(43) ring. The shortest C···C contacts between
neighboring arene rings are 3.22 Å for C(38)···C(18) and
3.24 Å for C(16)···C(70). Overall, the structure of 3 bears
close resemblance to that of the indium analogue [{2,6-(4-
tBuC6H4)2C6H3}3In].[18]
Scheme 1.
metallic procedures.[17] Selected examples have been con-
verted into cationic species either by salt elimination or alk-
anide abstraction. Most of the latter reactions were per-
formed on a small (ca. 50 µmol) scale, and the products
were characterized by multinuclear NMR spectroscopy and
mass spectrometry.
Diterphenylgallium Compounds
The diterphenylgallium chloride species [{2,6-(4-
tBuC6H4)2C6H3}2GaCl] (1) and [{2,6-(3,5-Me2C6H3)2-
C6H3}2GaCl] (2) were obtained in moderate yields by the
metathesis reaction of 2 equiv. of the coresponding terphen-
yllithium compound with GaCl3 at room temperature in
hexane solution according to Equation (1). Compounds 1
and 2 were isolated as colorless microcrystalline solids that
are readily soluble in aromatic solvents or CH2Cl2 but prac-
tically insoluble in hexanes. The synthesis of 1 under
slightly different conditions and its X-ray crystal structure
have been reported independently.[18] Crystals of 1 obtained
from toluene solution are essentially identical to those crys-
tallized from Et2O solution described by Robinson et al.
after taking low-temperature effects in the present data set
into consideration.[18]
Figure 1. Thermal ellipsoid plot (50% probability ellipsoids) show-
ing the molecular structure of 3. Hydrogen atoms have been omit-
ted for clarity.
Diterphenylaluminum Compounds
Whereas the synthesis of the di- and triterphenylgallium
(1) compounds 1–3 as well as the more crowded species [(2,6-
Mes2C6H3)2GaCl][24] (4) proceeds at room temperature, the
preparation of the aluminum analogue [(2,6-Mes2C6H3)2-
AlCl] (5) was complicated by the formation of a stable in-
termediate tentatively characterized as the alanate [(2,6-
Triterphenylgallium
The very crowded compound [{2,6-(4-tBuC6H4)2- Mes2C6H3)AlCl3]Li. A closely related compound has been
C6H3}3Ga] (3) was initially obtained in small amounts dur- previously observed in the reaction of 2,6-Mes2C6H3Li with
ing an attempt to prepare the methyl derivative [{2,6-(4- AlBr3.[25] The reaction of 2 equiv. of 2,6-Mes2C6H3-
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m-Terphenylaluminum and -gallium Compounds
FULL PAPER
Li with AlCl3 at room temperature for 20 h resulted in the be seen in the crystal structure (Figure 3). The overall struc-
formation of a new m-terphenyl compound (the alanate) tural features are similar to those of 5 and 6, although the
and unreacted 2,6-Mes2C6H3Li in an approximately 1:1 ra- distortions are less pronounced than in the structure of 5.
1
tio according to H NMR spectroscopy. The introduction The Al–H distance is 1.436(18) Å and the Al–C distances
of the second terphenyl substituent requires refluxing in average 1.990 Å. As was found for the corresponding gal-
benzene solution. Inadvertent Al–C bond hydrolysis during lium compounds 4 and 6, the C–Al–C angle in 7, with a
reflux reduced the yield significantly, and it was difficult to value of 137.62(5)°, is also significantly smaller than in the
isolate pure 5. Its crystal structure (Figure 2) is isostructural chloride 5 [147.52(13)°, see above]. The terphenyl substitu-
with that of the gallium congener,[24] but features a signifi- ents display a staggered arrangement with respect to each
cantly shorter Al–Cl bond with a value of 2.1098(12) Å other to minimize steric repulsion. The angles between the
[2.177(5) Å for 4], which indicates the higher Lewis acidity Al(1)–C(15) and C(15)–C(12) vectors and the Al(1)–C(39)
of aluminum. The Al–C bond lengths, with average values and C(39)–C(36) vectors are 11.7° and 12.8°, respectively,
of 1.978 Å, are identical with the Ga–C distances observed and there are only minor distortions within the terphenyl
for 4. The shorter Al–Cl distance results in a slight decrease substituents, thus indicating less steric crowding than for 5.
of the C–M–C angle from 153.5(5)° in 4 to 147.52(13)°.
Evidence for the steric crowding brought about by two large
m-terphenyl substituents is apparent in some distortions.
For example, as in 3, the central rings of the substituents
are bent away from the ideal linear alignment by 16.2°
[C(15) ring] and 12.9° [C(39) ring]. Furthermore, the flank-
ing mesityl groups are pushed out of the plane of the C(15)
ring by 12.8° [C(9) mesityl] and 10.4° [C(16) mesityl].
Figure 3. Thermal ellipsoid plot (50% probability ellipsoids) show-
ing the molecular structure of 7. Hydrogen atoms, with the excep-
tion of the hydrogen atom bound to the aluminum atom, have been
omitted for clarity.
Dibutylgallium Compounds
The dibutyl(terphenyl)gallanes [(2,6-Mes2C6H3)GaBu2]
Figure 2. Thermal ellipsoid plot (50% probability ellipsoids) show-
(8) and [(2,6-Dipp2C6H3)GaBu2] (9) (Dipp = 2,6-iPr2C6H3)
ing the molecular structure of 5. Hydrogen atoms have been omit-
were synthesized by the reaction of terphLi with ClGaBu2
[Equation (3)].
ted for clarity.
The hydride derivative [(2,6-Mes2C6H3)2GaH] (6) has
been prepared by the reaction of the chloride 4 with LiH-
BEt3.[21] Because 5 could only be isolated in moderate
yields, a different route was selected for the preparation of
the aluminum hydride [(2,6-Mes2C6H3)2AlH] (7). Thus, re-
action of 2,6-Mes2C6H3Li with [(2,6-Mes2C6H3)AlH2]·
[26]
OEt2
[Equation (2)] at 70 °C for 30 min afforded 7 in
moderate to good yields in the form of well-shaped color-
less crystals.[7]
(3)
The presence of the flexible n-butyl groups apparently
prevents the formation of crystals of sufficient quality for
(2)
Compound 7 is only the second example of an aluminum X-ray diffraction. In fact, 8 could only be obtained as fine
hydride that is three-coordinate in the solid state.[27] Similar colorless needles, and 9 was initially isolated as a colorless
to [Mes*2AlH][27] (Mes* = 2,4,6-tBu3C6H2), the monomeric oil, which eventually solidified after a month at room tem-
character of 7 is also due to steric protection, as can clearly perature. Despite several attempts, compounds 8 and 9
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J. D. Young, M. A. Khan, D. R. Powell, R. J. Wehmschulte
FULL PAPER
could not be obtained analytically pure. Both compounds relative intensity corresponding to eight hydrogen atoms in
are readily soluble in aliphatic and aromatic solvents. Their the 1H NMR spectra. In addition, mass spectrometric
composition was confirmed by 1H and 13C{1H} NMR analysis of the solution showed the presence of the cation
spectroscopy as well as the isolation of a hydrolysis product [{2,6-(3,5-Me2C6H3)2C6H3}2Ga]+. Chlorobenzene solu-
of 8, namely [{(2,6-Mes2C6H3)GaBu(µ-OH)}2] (10). The tions of 11 remain unchanged at room temperature for days,
latter compound was isolated during an attempt to grow which suggests a surprising stability of this cationic species
X-ray quality crystals by slow concentration of a 1-octene considering that the related electron-deficient diterphenyl-
solution of 8 inside a dry box. Its structure (Figure 4) boranes (2,6-Ar2C6H3)2BH undergo C–H activation below
closely resembles those of the related dimeric hydroxy- room temperature to give 9-borafluorenes and H2.[28]
bridged compounds [{(2,6-Mes2C6H3)GaMe(µ-OH)}2] and
Conversion of the dibutyl(terphenyl)gallanes 8 and 9 into
[{(2,6-Mes2C6H3)GaCl(µ-OH)}2].[21] The terphenyl substit- the cationic species [(2,6-Mes2C6H3)GaBu]+ ([13]+) and
uents in the centrosymmetric molecule are positioned in a [(2,6-Dipp2C6H3)GaBu]+ ([14]+), was accomplished by
mutual trans orientation. The Ga–O bond lengths are es- treatment with the trityl salts [CPh3]+[A]– [A = B(C6F5)4,[29]
[31]
sentially identical [1.947(5) and 1.952(5) Å] and are close to CHB11Br6Me5,[30] CHB11Cl11
those found in the above-mentioned methyl derivatives and tion (4).
chlorides.[21]
] according to Equa-
(4)
These reactions were performed in NMR tubes sealed
with J. Young valves or in small Schlenk flasks. The progress
of the reactions was monitored by recording the signals due
Figure 4. Thermal ellipsoid plot (50% probability ellipsoids) show-
ing the molecular structure of 10. Hydrogen atoms, with the excep-
tion of those bound to oxygen atoms, have been omitted for clarity.
1
to CHPh3 and CH2CHCH2CH3 in the H NMR spectrum.
The reactions are relatively fast: they are complete within a
few hours when both reactants are soluble in the chosen
solvent. Otherwise, the reaction rate is dependent on the
solubility of the trityl salt, with [CPh3]+[CHB11Cl11]– being
the least soluble. Despite the small scale, all reactions are
Cation Formation
We have shown previously that the two-coordinate cat- readily reproducible. It has not been possible to isolate any
ionic species [(2,6-Mes2C6H3)2Ga]+ and [(2,6-Mes2C6H3)2- of the products in pure or crystalline form so far due to
Al]+ can be prepared by chloride abstraction[6] with the lith- their tendency to form oils. Nevertheless, the identities of
ium alanate Li[Al{OCH(CF3)2}4] or by alkanide or hydride the products have been established by multinuclear NMR
abstraction with the trityl salt [Ph3C]+[B(C6F5)4]–.[7,21] spectroscopy and ESI mass spectrometry. The best general
Chloride abstraction with 2 equiv. of Li[Al{OCH(CF3)2}4] strategy for obtaining the highest-purity samples involves
also converted the sterically less encumbered diterphenyl- performing the reaction in benzene solution followed by
gallium chloride 2 cleanly into the cationic species [(2,6- phase separation and washing of the dense phase contain-
Ar2C6H3)2Ga]+[Li(Al{OCH(CF3)2}4)2]– (11; Ar = 3,5- ing the product with benzene. All ionic products are soluble
Me2C6H3). Interestingly, the analogous reaction with com- in chlorobenzene, bromobenzene, or their mixtures with
pound 1 to afford 12 (Ar = 4-tBuC6H4) did not proceed. benzene. Only [13]+[CHB11Br6Me5]– is readily soluble in
1
Monitoring of the reaction in C6D5Cl by H NMR spec- benzene. The other combinations of [13]+[A]– and [14]+[A]–
troscopy showed broadening of some of the aromatic sig- form dense liquid phases, so-called liquid clathrates.[32] The
nals (δ = 7.4–7.0 ppm), but no further reaction was ob- solubility of [13]+[CHB11Cl11]– lies between these extremes:
served even after prolonged heating at 70 °C. Although a liquid clathrate separates at high concentrations (ca.
attempts to isolate crystals of 11 have not yet been success- 0.08 ) which can be redissolved upon dilution with C6D6.
ful, the stoichiometry of the products is supported by the Clathrate formation has been observed previously in our
presence of the methine hydrogen signal of the anion in a laboratory for the compounds [(2,6-Mes2C6H3)2M]+-
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m-Terphenylaluminum and -gallium Compounds
FULL PAPER
[B(C6F5)4]– (M = Al, Ga), which exist as separate ions.[7,21]
Hence, we propose clathrate formation as supporting evi-
dence for anion/cation separation in [13]+[A]– and [14]+-
[A]–. Additional evidence is found in the 19F NMR chemi-
cal shifts of [13]+[B(C6F5)4]– and [14]+[B(C6F5)4]–, which are
close to the values reported for the “free” anion.[16] How-
ever, a weak cation···XC6H5 (solvent) contact (X = Cl, Br)
cannot be ruled out. Such interactions have been described
for [(iPr2-ATI)MR][B(C6F5)4](ClPh) (M = Al, Ga, In; iPr2-
ATI = N,NЈ-diisopropylaminotroponiminate).[33]
The 1H NMR spectrum of a C6D6 solution of [13]+-
[CHB11Br6Me5]– shows two sets of signals for the o- and
oЈЈ-methyl groups and the m- and mЈЈ-hydrogen atoms of
the flanking mesityl groups of the m-terphenyl ligand due
to a loss of symmetry. This, together with the fact that [13]+-
[CHB11Br6Me5]– is soluble in benzene, may be viewed as
good evidence for its existence as a tight ion-pair with close
Ga···Br contacts similar to those observed for [Et2Al]+-
[CB11H6X6]– (X = Cl, Br).[13] In keeping with an intermedi-
Figure 5. Thermal ellipsoid plot (30% probability ellipsoids) show-
ing the molecular structure of the dication in 16.
1
ate behavior, the H NMR spectrum of [13]+[CHB11Cl11]–
in C6D6 solution does not display an analogous broaden-
ing.
Reaction of [14]+ with 1-Octene
All ionic compounds described here are stable in solution
at room temperature for days if not weeks. The [B(C6F5)4]–
salts are susceptible to C6F5 migration at elevated tempera-
One of the goals of the preparation of low-coordinate
tures, a common occurrence for this anion in combination aluminum and gallium cations was the investigation of their
with strong Lewis acids.[34] For example, heating of a solu- interactions with olefins. The NMR spectra obtained dur-
tion of [14]+[B(C6F5)4]– at 60 °C for 16 h results in the clean ing the monitoring of the syntheses of the various cation/
formation of a 1:1 mixture of [(2,6-Dipp2C6H3)GaBu- anion combinations [13]+[A]– and [14]+[A]– indicated a
(C6F5)] (15) and B(C6F5)3. These compounds were iden- rather slow reaction with 1-butene. Since [14]+[CHB11-
tified by 1H and 19F NMR spectroscopy, the latter by com- Cl11]– is thermally stable, its interaction with 1-octene was
parison with an authentic sample and published data[35] investigated more closely. Approximately 1.2 equiv. of 1-oc-
and the former by the similarity of its 19F NMR signals tene was added to a solution of [14]+[CHB11Cl11]– in a 6:1
with those of the related (pentafluorophenyl)aluminum spe- mixture of C6D6 and C6D5Cl, and the progress of the reac-
cies [MenAl(C6F5)3–n].[34] On the other hand, no change of tion was monitored by 1H NMR spectroscopy. About
the NMR spectra of the carborane salt [14]+[CHB11Cl11]– 15 min after the 1-octene addition, the H NMR spectrum
1
was observed after heating at 68–70 °C for 23 h, thereby showed a broadening of the α-CH2 signal, and signals of
indicating a surprisingly high stability of this compound.
free 1-octene and 1-butene in an approximately 2:1 ratio
The difficulty of obtaining pure samples of any of the were discernible. After 48 h at room temperature, the ole-
new ionic compounds may be illustrated by the fact that finic signals had almost completely disappeared, and an ad-
repeated attempts to crystallize [13]+[CHB11Br6Me5]– only ditional 2.4 equiv. of 1-octene was added after a reaction
afforded a few crystals of the hydrolysis product [(BuGa)4- time of 54 h. This time, only a small amount of free 1-but-
(µ-OH)6]2+[CHB11Br6Me5]– (16), whose structure consists ene was generated, and most of the signals due to the butyl
2
of layers of [(BuGa)4(µ-OH)6]2+ dications and compound [14]+ were replaced by similar signals that were
[CHB11Br6Me5]– anions separated by benzene molecules. slightly shifted from their previous positions. Two more ad-
The cations and anions are well separated, but are kept in ditions of 1-octene were undertaken after the olefin had
contact through hydrogen bonding between the hydroxy hy- been almost completely consumed. After a total reaction
drogen atoms of the cations and bromine atoms of the time of 21 d at room temperature, no more olefin signals
anions. These contacts can be as close as 2.44 Å for H(3)··· were present, and the spectrum was dominated by octyl sig-
Br(3A). The dications are cage molecules with a distorted nals, although a slightly broadened multiplet at δ =
adamantane Ga4O6 framework (Figure 5). The neutral ana- 0.21 ppm indicated the presence of a Ga-CH2 group. Analy-
logue [{(Me3Si)3Ga}4(µ-OH)4(µ-O)2] has been reported pre- sis of the mixture by ESI mass spectrometry and GC-MS
viously.[36] The metric parameters of both compounds are showed the presence of the octyl species [(2,6-Dipp2C6H3)-
comparable, with average Ga–O and Ga–C bond lengths of Ga(octyl)]+ ([17]+) and various octylbenzenes. These pre-
1.897(6) and 1.933(1) Å and O–Ga–O and Ga–O–Ga liminary results suggest a facile olefin/alkyl exchange fol-
angles of 96.9(1.8)° and 130.8(1.0)° in 16 (Table 3) vs. 1.895 lowed by octene isomerization and benzene alkylation.
and 1.998 Å and 100.46 and 125.42°, respectively, in Scheme 2 shows a proposed reaction mechanism. Further
[{(Me3Si)3Ga}4(µ-OH)4(µ-O)2].
work in this area is in progress.
Eur. J. Inorg. Chem. 2007, 1671–1681
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1675

J. D. Young, M. A. Khan, D. R. Powell, R. J. Wehmschulte
FULL PAPER
and MeLi (1.6  in Et2O) were obtained from commercial suppli-
ers. Compounds 2,6-(4-tBuC6H4)2C6H3Br,[37] 2,6-(4-tBuC6H4)2-
C6H3Li,[38] 2,6-(3,5-Me2C6H3)2C6H3Li,[28] [(2,6-Mes2C6H3)2AlH]
(7),[7] ClGaBu2,[39] 2,6-Mes2C6H3Li,[40] 2,6-Dipp2C6H3Li,[41] and
[Ph3C][B(C6F5)4][29] were synthesized according to literature meth-
ods. The carborane compounds [Ph3C][CHB11Br6Me5] and
[Ph3C][CHB11Cl11] were supplied by Prof. Christopher A. Reed and
Dr. Kee-Chan Kim from the University of California, Riverside.
NMR spectra were recorded with a Varian Mercury 300 MHz, a
Varian Unity Plus 400 MHz, a Bruker AMX 360, or a Bruker Av-
1
ance 400 MHz spectrometer. H NMR chemical shift values were
determined relative to the residual protons in C6D6 or CDCl3 as
internal reference (δ = 7.15 or 7.26 ppm). 13C NMR spectra were
referenced to the solvent signal (δ = 128.0 or 77.0 ppm). 19F NMR
spectra were referenced to an external solution of C6H5CF3 in
C6D6 (δ = –63.72 ppm). IR spectra were recorded in the range
4000–400 cm–1 with a Nicolet Nexus 470 FTIR spectrometer. Elec-
tron impact mass spectra were recorded with a Finnigan MAT Pol-
aris spectrometer and electrospray mass spectra with a Micromass
Q-ToF or a JEOL AccuTOF DART spectrometer. Melting points
were determined in Pyrex capillary tubes sealed under nitrogen
with a Mel-Temp apparatus and are uncorrected. Elemental analy-
ses were performed by Desert Analytics in Tucson, AZ.
[{(4-tBuC6H4)2C6H3}2GaCl] (1):
A solution of (4-tBuC6H4)2-
C6H3Br (1.00 g, 2.4 mmol) in hexanes (60 mL) was treated with a
hexane solution of n-butyllithium (0.97 mL, 2.78 ) at –78 °C. The
reaction mixture was warmed to room temperature and stirred
overnight. The volatile material was removed from the cloudy sus-
pension under reduced pressure. GaCl3 (0.21 g, 1.2 mmol) was
added to a suspension of the resulting colorless to beige solid in
hexanes (50 mL) at –78 °C. Warming to room temperature and stir-
ring overnight afforded a suspension of 1 and LiCl. Decanting of
the mother liquor, washing with hexanes and extraction with ben-
zene gave 1 as a fine colorless solid after removal of the solvent in
vacuo. Yield: 0.54 g (57%). Crystals suitable for X-ray diffraction
were grown from a concentrated toluene solution at –24 °C. M.p.
202–208 °C. 1H NMR (300 MHz, C6D6, 25 °C): δ = 7.32 (d, J =
7.5 Hz, m-H, 4 H), 7.28 (s, 4-tBuC6H4, 16 H), 7.19 (t, J = 7.5 Hz,
p-H, 2 H), 1.16 (s, CH3, 36 H) ppm. 13C{1H} NMR (90.567 MHz,
C6D6, 25 °C): δ = 150.89, 149.51, 147.05 (i-C), 142.96; 129.75 (p-C),
Scheme 2.
Conclusion
Diterphenylaluminum and -gallium compounds have
been prepared by the treatment of 2 equiv. of terphenylli-
thium with MCl3 or H3Al·NMe3; the synthesis of the alu-
minum species requires more forcing conditions. Dibutyl(ter-
phenyl)gallanes have also been obtained by treating ter-
phenyllithium with ClGaBu2. The best method for the prep-
aration of cationic gallium species [(terph)GaR]+ is treat-
ment with trityl salts of weakly coordinating anions, al-
though chloride abstraction with a fluorinated lithium tet-
raalkoxidoalanate can also be used for selected gallium 128.65 [o-C(4-tBuC6H4)], 127.93 (m-C), 126.30 [p-C(4-tBuC6H4)],
34.45 [C(CH3)3], 31.29 [C(CH3)3] ppm. MS (DART, C6D6 solu-
chloride precursors. The ionic compounds are at least mod-
erately stable in aromatic solvents at room temperature,
with the compound [14]+[CHB11Cl11]– being thermally
stable up to 70 °C. All ionic compounds, with the exception
of [13]+[CHB11Br6Me5]–, form clathrates in benzene solu-
tion, which suggests the presence of only weak ion-pairing
or even “free” ions. A preliminary study on the interaction
of [14]+[CHB11Cl11]– with 1-octene has found facile alkyl/
tion): calcd. for [M+ – Cl] 751.3794, found 751.3595.
[{(3,5-Me2C6H3)2C6H3}2GaCl] (2): GaCl3 (0.39 g, 2.2 mmol) was
added through an addition funnel for solids to a suspension of 2,6-
(3,5-Me2C6H3)2C6H3Li (1.37 g, 4.7 mmol) in hexanes at –78 °C.
After 15 min, the reaction mixture was allowed to slowly warm to
room temperature to give a cream-colored suspension and a dark
grey solid on the bottom of the flask. After 3 d at room tempera-
olefin exchange at the cationic gallium center and slow oc- ture, the dark solid was consumed. The insoluble material (1.09 g),
which is a mixture of 2 and LiCl, was collected on a glass frit.
Redissolution in CH2Cl2 (20 mL), followed by separation of LiCl
by decantation, concentration of the clear yellow solution to ca.
2 mL and cooling at 4 °C for 2 d afforded a fine crystalline solid
(0.2 g). A second batch (0.05 g) was obtained from the concen-
trated mother liquor at 4 °C after 3 d. Yield: 0.25 g (17%). M.p.
tene isomerization and benzene alkylation.
Experimental Section
General Procedures: All work was performed under anaerobic and
anhydrous conditions by using either modified Schlenk techniques
or an Innovative Technologies or Vacuum Atmospheres drybox.
Solvents were freshly distilled under N2 from sodium, potassium,
sodium/potassium alloy, or calcium hydride and degassed twice
prior to use, or they were dispensed from an MBraun Solvent Puri-
fication System. AlCl3, GaCl3, n-butyllithium (1.6  in hexanes),
1
softens at 178 °C, melts at 188–192 °C. H NMR (400 MHz C6D6,
25 °C): δ = 7.43 (d, J = 7.6 Hz, m-H, 4 H), 7.31(s, J = 7.6 Hz, p-
H, 2 H), 7.00 [s, o-H(3,5-Me2C6H3), 8 H], 6.66 [s, p-H(3,5-
Me2C6H3), 4 H], 1.93 (s, CH3, 24 H) ppm. 13C{1H} NMR
(100.13 MHz, C6D6, 25 °C): δ = 149.00, 148.22, 145.82, 139.26,
129.82, 129.80, 128.31, 126.85, 21.14 (CH3) ppm.
1676
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Eur. J. Inorg. Chem. 2007, 1671–1681

m-Terphenylaluminum and -gallium Compounds
[{(4-tBuC6H4)2C6H3}3Ga] (3): GaCl3 (0.18 g, 1.0 mmol) was added perature and stirred overnight. The cloudy, pale-yellow solution
FULL PAPER
to a suspension of 4-(tBuC6H4)2C6H3Li (1.07 g, 3.1 mmol) in hex-
anes (50 mL) at –78 °C through an addition funnel for solids. The
mixture was warmed to room temperature and stirred for 20 h. The
resulting fine, colorless precipitate was separated by filtration, and
the product was obtained by crystallization of the colorless super-
natant liquid at –24 °C for several days. Yield: 0.64 g (58%). Crys-
was filtered through a sintered glass frit, and the pale-yellow filtrate
was concentrated to 5 mL and cooled to –40 °C for 4 d. As no
crystals had formed, the volatile material was removed under re-
duced pressure to give crude 9 as a pale-yellow oil, which solidified
after a month at room temperature. The main impurity was iden-
tified as the arene 2,6-Dipp2C6H3I in amounts of approximately
tals suitable for X-ray diffraction were grown from a concentrated 5%. 1H NMR (300 MHz, C6D6, 25 °C): δ = 7.25 (m, 5 H), 7.16
1
toluene solution at –24 °C. M.p. 281–283 °C. H NMR (300 MHz,
(m, 4 H), 3.09 [sept, J = 6.9 Hz, 4 H, CH(CH3)2], 1.27 [d, J =
C6D6, 25 °C): δ = 7.19 [d, J = 8.4 Hz, 12 H, o- or p-(4-tBuC6H4)], 6.9 Hz, 12 H, CH(CH3)2], 1.14 (m, 8 H, β-, γ-CH2), 1.07 [d, J =
6.97 [d, J = 8.1 Hz, 12 H, o- or p-(4-tBuC6H4)], 6.97 (s, 9 H, m-
6.9 Hz, 12 H, CH(CH3)2], 0.84 (t, J = 7.2 Hz, 6 H, δ-CH3), 0.45
and p-H), 1.22 (s, 54 H, CH3) ppm. 13C{1H} NMR (75.45 MHz,
(m, 4 H, α-CH2) ppm. 13C{1H} NMR (75.45 MHz, C6D6, 25 °C):
C6D6, 25 °C): δ = 151.06 (i-C), 148.86, 148.60, 142.71, 129.80 [o- δ = 156.31, 147.10, 145.64, 141.89, 128.72, 127.80, 126.98, 123.36,
(4-tBuC6H4)], 127.93 (m- or p-C), 124.85 [p-(4-tBuC6H4)], 34.49 30.54 [CH(CH3)2], 28.24 (β- or γ-CH2), 27.46 (β- or γ-CH2), 26.22
[C(CH3)3], 31.53 [C(CH3)3] ppm. C78H87Ga (1094.3): calcd. C [CH(CH3)2], 22.66 [CH(CH3)2], 19.93 (α-CH2), 14.00 (δ-CH3) ppm.
85.61, H 8.01; found C 84.35, H 8.21.
[{(2,6-Mes2C6H3)GaBu(µ-OH)}2] (10):
A solution of crude 8
[(2,6-Mes2C6H3)2AlCl] (5): AlCl3 (0.25 g, 1.9 mmol) was added to a (30 mg) in C6D6 (1 mL) was placed in a small vial inside a
solution of 2,6-Mes2C6H3Li (1.28 g, 4.0 mmol) in benzene (10 mL)
through an addition funnel for solids with cooling in an ice bath.
After warming to room temperature, the mixture was stirred for
14 h and heated to reflux for another 2 h. After cooling to room
temperature, the clear yellow solution was decanted off the fine
colorless precipitate, and the volatile material was distilled off un-
der reduced pressure to give a pale-yellow foamy solid. Addition
of hexanes (5–6 mL) afforded the precipitation of 5 as a fine pale-
yellow powder (0.32 g) which was found to be contaminated with
22% 2,6-Mes2C6H4. Crystals of a quality suitable for X-ray diffrac-
tion were obtained by crystallization from a saturated toluene solu-
glovebox, and the solvent was allowed to slowly evaporate through
the partially tightened lid over a period of two weeks to afford a
pale-yellow glass. Redissolution in 1-octene (1 mL) and subsequent
slow concentration over a period of six weeks gave fine colorless
1
needles of 10 of sufficient quality for X-ray diffraction. H NMR
(400 MHz, C6D6, 25 °C): δ = 7.21 (t, J = 7.2 Hz, 2 H, p-H), 6.91
(d, J = 7.2 Hz, 4 H, m-H), 6.87 [s, 8 H, m-H(Mes)], 2.35 (s, 12 H,
p-Me), 2.08 (s, 24 H, o-Me), 1.21 (m, 4 H, β-, γ-CH2), 0.88 (t, J =
6.8 Hz, 6 H, δ-CH3), 0.13 (“t”, J = 8.1 Hz, 4 H, α-CH2), 0.09 (s, 2
H, OH) ppm. 13C{1H} NMR (100.75 MHz, C6D6, 25 °C): δ =
148.30, 141.76, 136.38, 136.14, 128.59, 128.42, 126.95, 28.38 (β-or
γ-CH2), 28.24 (β-or γ-CH2), 21.51 (p-CH3), 21.32 (o-CH3), 15.82
tion at –20 °C for 7 d, although an analytically pure bulk sample
1
could not be isolated. H NMR (400 MHz, C6D6, 25 °C): δ = 7.05 (α-CH2), 14.00 (δ-CH3) ppm. FTIR (thin film between CsI plates):
(t, J = 7.6 Hz, 2 H, p-H), 6.85 [s, 8 H, m-H(Mes)], 6.63 (d, J =
7.6 Hz, 4 H, m-H), 2.25 (s, 12 H, p-CH3), 1.83 (s, 24 H, o-CH3)
ppm. 13C{1H} NMR (100.61 MHz, C6D6, 25 °C): δ = 150.68,
143.73 (i-C), 141.78, 137.58 [o-C(Mes)], 136.99, 130.21 (p-C),
129.13 [m-C(Mes)], 128.43 (m-C), 21.91 (o-CH3), 21.29 (p-CH3)
ppm. MS (DART, solid): calcd. for [M + H+] 689.3495, found
689.3583.
ν = 3642 [m, ν(OH)] cm–1.
˜
[{2,6-(3,5-Me2C6H3)2C6H3}2Ga]+[Li(Al{OCH(CF3)2}4)2]– (11):
A
solution of 2 (32 mg, 47 µmol) in C6D5Cl (1.0 mL) was added to
finely powdered LiAl[OCH(CF3)2]4 (70 mg, 0.1 mmol) in an NMR
tube fitted with a J. Young valve. The NMR tube was shaken for
1 min and then rotated for 16 h around its long axis using a stan-
dard overhead stirrer lying on its side. The fine colorless precipitate
was allowed to settle, and the clear colorless supernatant liquid
containing essentially pure 11 was pipetted off. 1H NMR
(400 MHz, C6D5Cl, 25 °C): δ = 7.58 (t, J = 8.0 Hz, 2 H, p-H), 7.53
(d, J = 8.0 Hz, 4 H, m-H), 6.72 [s, 4 H, p-H of xylyl], 6.40 [s, 8 H,
o-H of xylyl], 4.84 [sept, JH,F = 5.4 Hz, 8 H, CH(CF3)2], 1.95 (s,
24 H, CH3) ppm. 13C{1H} NMR (100.61 MHz, C6D5Cl, 25 °C): δ
= 148.23, 146.74, 144.42, 131.51, 125.68, 122.34 (q, 1JC,F = 285 Hz,
[(2,6-Mes2C6H3)GaBu2] (8): A suspension of a 9:1 mixture of 2,6-
Mes2C6H3Li/2,6-Mes2C6H4 (2.27 g, 6.4 mmol 2,6-Mes2C6H3Li) in
hexanes (30 mL) was added slowly to a solution of ClGaBu2
(1.40 g, 6.4 mmol) in hexanes (20 mL) at –78 °C. The mixture was
kept at –78 °C for 30 min, then warmed to room temperature and
stirred overnight. The pale-yellow solution was decanted off the
fine colorless precipitate, concentrated to 5 mL, and cooled to
–40 °C for 2 d. As no crystals had formed, the solution was further
concentrated to about 1 mL and cooled to –40 °C for 5 d to afford
fine, colorless needles (1.21 g). A second batch was obtained from
the concentrated mother liquor after cooling at –40 °C for 4 d
(0.81 g). Yield: 2.02 g (58%). The needles were contaminated with
approximately 13% 2,6-Mes2C6H4. 1H NMR (300 MHz, C6D6,
25 °C): δ = 7.31 (t, J = 7.5 Hz, 1 H, p-H), 7.02 (d, J = 7.5 Hz, 2
H, m-H), 6.81 [s, 4 H, m-H(Mes)], 2.16 (s, 12 H, o-Me), 2.13 (s, 6
H, p-Me), 1.23 (m, 4 H, β-CH2), 1.04 (m, 4 H, γ-CH2), 0.83 (t, J
= 6.9 Hz, 6 H, δ-CH3), 0.54 (“t”, J = 7.8 Hz, 4 H, α-CH2) ppm.
13C{1H} NMR (75.45 MHz, C6D6, 25 °C): δ = 155.61, 147.00,
140.98, 137.01, 136.17, 128.88 [m-C(Mes)], 128.45 (p-C), 126.04 (m-
C), 28.32 (β- or γ-CH2), 28.13 (β- or γ-CH2), 21.11 (o-CH3), 21.05
(p-CH3), 19.33 (α-CH2), 14.24 (δ-CH3) ppm.
2
CF3), 121.14, 70.86 [sept, JC,F = 33 Hz, CH(CF3)2], 20.67 (CH3)
ppm. MS (DART, C6D5Cl solution): calcd. 639.2542, found
639.2497; (neg. ion): calcd. for [Al{OCH(CF3)2}4]– 694.9542, found
694.9511.
[(2,6-Mes2C6H3)GaBu]+[B(C6F5)4]– {[13]+[B(C6F5)4]–}: An NMR
tube equipped with a J. Young valve was charged with 8 (27 mg,
50 µmol), [Ph3C][B(C6F5)4] (43 mg, 47 µmol), and C6D6 (0.7 mL),
and the resulting mixture was shaken for 1 min to give a pale-yel-
low solution above a dense red layer (ca. 0.1 mL). The mixture was
rotated at room temperature for 5 h to afford a dense, dark orange-
yellow layer (0.1 mL) and a pale-yellow top layer. The top layer
was pipetted off, and the bottom layer was washed with C6D6
(2ϫ0.25 mL) and then dissolved in C6D5Br (0.35 mL) to give a
yellow solution. The solution contained mainly [13]+[B(C6F5)4]–,
which was contaminated with 15% of an unknown 2,6-Mes2C6H3-
containing species. 1H NMR [400.13 MHz, C6D6/C6D5Br (1:3),
[(2,6-Dipp2C6H3)GaBu2] (9): A suspension of 2,6-Dipp2C6H3Li
(2.51 g, 6.2 mmol) in hexanes (30 mL) was added slowly to a solu-
tion of ClGaBu2 (1.30 g, 5.9 mmol) in hexanes (20 mL) at –78 °C. 25 °C]: δ = 7.48 (t, J = 7.6 Hz, 1 H, p-H), 7.10 (d, J = 7.6 Hz, 2
The mixture was kept at –78 °C for 30 min, warmed to room tem- H, m-H), 6.88 [s, 4 H, m-H(Mes)], 2.22 (s, 6 H, p-CH3), 1.96 (s, 12
Eur. J. Inorg. Chem. 2007, 1671–1681
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J. D. Young, M. A. Khan, D. R. Powell, R. J. Wehmschulte
FULL PAPER
H, o-CH3), 0.65 (m, 2 H, β-CH2), 0.56 (s, 5 H, γ-CH2, δ-CH3), 0.25 Ph3CH could be detected by 1H NMR spectroscopy. The sample
(t, J = 7.5 Hz, 2 H, α-CH2) ppm. 13C{1H} NMR [100.61 MHz, was rotated slightly off axis for 18 h, after which time the 1H NMR
C6D6/C6D5Br (1:3); signals referenced to δ = 122.45 ppm for i-
spectrum showed the consumption of 9. The yellow upper phase
was pipetted off, and the dense red oily phase was washed with
C6D6 (0.6 mL and 1.2 mL). The remaining red oily liquid was dis-
solved in a mixture of C6D6/C6D5Cl (4.5:1.5). 1H NMR (300 MHz,
C6D6/C6D5Cl (4.5:1.5), 25 °C): δ = 7.26 (t, J = 6.9 Hz, 1 H, p-H),
7.24 (t, J = 7.8 Hz, 2 H, p-H of Dipp), 7.14 (d, J = 6.9 Hz, 2 H,
1
C(C6D5Br), 25 °C]: δ = 148.83 (br. d, JC,F = 243 Hz), 146.57,
1
140.47, 138.71 [br. d, JC,F = 243 Hz, p-C(C6F5)], 138.24, 136.82
(br. d, 1JC,F = 246 Hz), 135.81 [o-C(Mes)], 133.77 (p-C), 130.71 [m-
C(Mes)], 27.28 (γ-CH2), 25.66 (β-CH2), 21.97 (br., α-CH2), 20.94
(p-CH3), 20.82 (o-CH3), 13.32 (δ-CH3) ppm. 19F NMR
(284.34 MHz, C6D6/C6D5Cl (1:1), 25 °C): δ = –132.15 (br. d, J = m-H), 7.07 (d, J = 7.8 Hz, 4 H, m-H of Dipp), 2.52 [sept, J =
9.9 Hz, 8 F, o-F), –162.28 (t, J = 20.9 Hz, 4 F, p-F), –166.24 (br. s, 6.8 Hz, 4 H, CH(CH3)2], 0.95, [d, J = 6.8 Hz, 12 H, CH(CH3)2],
8 F, m-F) ppm. MS (DART, C6D6/C6D5Br (1:3) solution): calcd. 0.92, [d, J = 6.8 Hz, 12 H, CH(CH3)2], 0.41 (br. s, 7 H, β-, γ-CH2,
439.1916, found 439.1919.
δ-CH3), 0.04 (“t”, J = 6.8 Hz, 2 H, α-CH2) ppm. 13C{1H} NMR
1
(75.45 MHz, C6D6/C6D5Cl (4.5:1.5), 25 °C): δ = 149.1 (br. d, JC,F
[(2,6-Mes2C6H3)GaBu]+[CHB11Cl11]– {[13]+[CHB11Cl11]–}: An
NMR tube equipped with a J. Young valve was charged with 8
(24 mg, 45 µmol), [Ph3C][CHB11Cl11]·0.8C7H8 (33 mg, 39 µmol)
and C6D6 (0.6 mL), and the resulting mixture was shaken for 1 min
to give a pale-yellow solution above a fine yellow solid. The mixture
was rotated at room temperature for 26 h to afford a dense orange-
yellow layer (0.06 mL) and a yellow top layer. In order to ensure
complete consumption of the trityl salt, an additional 5 mg of 8
was added, and the tube was rotated for another 4 h. This resulted
in a significant fading of the color of both layers. The top layer
was pipetted off, and the bottom layer (ca. 0.03 mL) was dissolved
in C6D6 (0.6 mL). The NMR spectra are in agreement with the
formation of [13]+[CHB11Cl11]–, which still contained around 22%
Ph3CH. No further purification was attempted. The NMR spectro-
1
= 238 Hz), 147.83, 145.81, 133.54 (p-C), 138.8 (br. d, JC,F
=
1
249 Hz, p-CF), 138.05, 137.0 (br. d, JC,F = 249 Hz), 131.77 [m-
C(Dipp)], 129.22 (m-C), 125.63 [m-C(Dipp)], 30.95 [CH(CH3)2],
27.44 (β- or γ-CH2), 25.38 (β- or γ-CH2), 24.95 [CH(CH3)2], 23.43
[CH(CH3)2], 21.58 (α-CH2), 13.28 (δ-CH3) ppm. 19F NMR
(284.34 MHz, C6D6/C6D5Cl (4.5:1.5), 25 °C): δ = –133.12 (br. d, J
= 7.7 Hz, 8 F, o-F), –163.93 (t, J = 20.8 Hz, 4 F, p-F), –167.72 ppm
(br. t, J = 18.9 Hz, 8 F, m-F).
[(2,6-Dipp2C6H3)GaBu]+[CHB11Cl11]– {[14]+[CHB11Cl11]–}: An
NMR tube equipped with a J. Young valve was charged with 9
(36 mg, 62 µmol, 30% excess) and [Ph3C][CHB11Cl11]·0.8C7H8
(40 mg, 47 µmol), and C6D6 (0.75 mL) was added. The sample was
rotated horizontally slightly off axis at room temperaturefor 5 d
scopic data are given for [13]+[CHB11Cl11]–. 1H NMR during which time a dense orange liquid layer formed (ca. 0.1 mL).
(400.13 MHz, C6D6, 25 °C): δ = 7.15 (obscured by C6D5H, p-H),
6.85 (d, J = 7.6 Hz, 2 H, m-H), 6.79 [s, 4 H, m-H(Mes)], 2.08 (s,
12 H, o-CH3), 2.05 (s, 6 H, p-CH3), 1.24 (m, 2 H, β-CH2), 1.12 (br.
The pale-yellow upper layer was pipetted off, and the lower layer
was washed twice with C6D6 (0.5 and 0.3 mL). C6D5Cl (0.45 mL)
was added to the remaining liquid to give a clear yellow orange
s, 2 H, α-CH2), 0.97 (sext, J = 7.2 Hz, 2 H, γ-CH2), 0.71 (t, J = solution of [14]+[CHB11Cl11]–. 1H NMR (400.13 MHz, C6D5Cl/
7.2 H, 3 Hz, δ-CH3) ppm. 13C{1H} NMR (100.61 MHz, C6D6,
25 °C): δ = 147.48, 139.39, 138.53, 136.50 [o-C(Mes)], 131.98,
C6D6 (3:1), 25 °C): δ = 7.55 (t, J = 7.6 Hz, 1 H, p-H), 7.48 (t, J =
7.8 Hz, 2 H, p-H of Dipp), 7.39 (d, J = 7.6 Hz, 2 H, m-H), 7.27 (d,
130.16 [m-C(Mes)], 48.03 (br., CHB11Cl11), 26.76 (γ-CH2), 26.47 J = 7.8 Hz, 4 H, m-H of Dipp), 2.86 (br. s, 1 H, CHB11Cl11), 2.66
(β-CH2), 21.55 (o-CH3), 20.92 (p-CH3), 13.51 (δ-CH3) ppm.
[sept, J = 6.8 Hz, 4 H, CH(CH3)2], 1.11 [d, J = 6.8 Hz, 12 H,
CH(CH3)2], 1.07 [d, J = 6.8 Hz, 12 H, CH(CH3)2], 0.69 (quint, J
= 6.8 Hz, 2 H, β-CH2), 0.55 (t, J = 7.6 Hz, 2 H, α-CH2), 0.49 (br.
s, 5 H, γ-CH2, δ-CH3) ppm. 13C{1H} NMR [100.61 MHz, C6D5Cl/
C6D6 (3:1); signals referenced to δ = 133.69 ppm for i-C(C6D5Cl),
25 °C]: δ = 149.14 (i-C), 147.27 [o-C(Dipp)], 145.40, 137.79, 133.46
(p-C), 131.58, 128.51, 125.49 [m-C(Dipp)], 46.76 (br., CHB11Cl11),
30.52 [CH(CH3)2], 24.60 [CH(CH3)2], 23.46 [CH(CH3)2], 13.20 (δ-
CH3) ppm. MS (ESI, acetonitrile solution): calcd. for [C34H46Ga+]
523.286, found 523.3; calcd. for [M+ + CH3CN] 564.312, found
564.4.
[(2,6-Mes2C6H3)GaBu]+[CHB11Br6Me5]– {[13]+[CHB11Br6Me5]–}:
A small tube equipped with a Teflon valve was charged with 8
(28 mg,
52 µmol),
[Ph3C][CHB11Br6Me5]·2.3C7H8
(60 mg,
52 µmol), and C6D6 (1.5 mL), and the resulting mixture was ro-
tated at room temperature for 16 h to afford a clear, orange solu-
tion. The volatile material was distilled off in vacuo, and the re-
sulting orange-red oil was dissolved in hexanes (1 mL). The slightly
cloudy solution was cooled to –20 °C for 2 h to precipitate Ph3CH.
The yellow-orange supernatant liquid was pipetted off, and the sol-
vent was allowed to evaporate slowly inside a drybox. The resulting
yellow glass was investigated by 1H NMR spectroscopy, and the
spectra were found to be in agreement with the formulation [13]+-
Thermal Stability of [14]+[B(C6F5)4]–: A solution of [14]+[B-
(C6F5)4]– (ca. 5 µmol) in C6D6/C6D5Cl (ca. 12:1 ratio, 0.6 mL) in
an NMR tube equipped with a J. Young valve was heated at 60 °C
[CHB11Br6Me5]–. Small amounts of 2,6-Mes2C6H4, Ph3CH and n-
1
hexane were also present. H NMR (400 MHz, C6D6, 25 °C): δ = for 16 h. During that time, the phase separation disappeared and a
6.95 (br. s, w1/2 = 6.9 Hz, 2 H, m-H of Mes), 6.73 (br. s, w1/2
7.6 Hz, 2 H, m-H of Mes), 2.49 (br. s, w1/2 = 6.4 Hz, 6 H, o-CH3), are in accordance with the presence of two compounds, namely
2.06 (s, 6 H, p-CH3), 1.94 (br. s, w1/2 = 6.4 Hz, 6 H, o-CH3), 1.50
[(2,6-Dipp2C6H3)GaBu(C6F5)] (15)[34] and B(C6F5)3.[35] 1H NMR
(m, 4 H, α-, β-CH2), 1.21 [m, 2 H, γ-CH (obscured by hexane (300 MHz, C6D6/C6D5Cl (12:1), 25 °C): δ = 7.26 (br. s, 3 H, m-, p-
=
pale-yellow solution was obtained. The NMR spectroscopic data
CH2)], 0.80 (t, J = 7.5 Hz, 3 H, δ-CH3), 0.25 (s, 15 H, B-CH3) ppm.
Further attempts at purification were unsuccessful and eventually
led to the formation of 16 (vide infra).
H), 7.00 [d, J = 7.5 Hz, 4 H, m-H of Dipp], 2.99 [sept, J = 6.8 Hz,
4 H, CH(CH3)2], 1.15, [d, J = 6.8 Hz, 12 H, CH(CH3)2], 0.99, [d,
J = 6.8 Hz, 12 H, CH(CH3)2], 0.68 (“t”, J = 6.0 Hz, 3 H, δ-CH3),
0.45 (“t”, J = 8.0 Hz, 2 H, α-CH2) ppm. 19F NMR [284.34 MHz,
C6D6/C6D5Cl (12:1), 25 °C]: 15: δ = –121.90 (m, o-F), –155.18 (t,
J = 19.9 Hz, p-F), –162.18 (m, m-F) ppm; B(C6F5)3: δ = –129.89
(m, o-F), –142.86 (m, p-F), –161.18 (m, m-F) ppm.
[(2,6-Dipp2C6H3)GaBu)]+[B(C6F5)4]– {[14]+[B(C6F5)4]–}: A solution
of
9 (39 mg, 67 µmol) in C6D6 (0.8 mL) was added to
[Ph3C][B(C6F5)4] (62 mg, 67 µmol) in an NMR tube equipped with
a J. Young valve at room temperature. The mixture was shaken,
and a dense red liquid phase separated after standing for a few
[(BuGa)4(µ-OH)6]2+[CHB11Br6Me5]– (16): The solution of [13]+-
2
minutes. After 2 h at room temperature, only a small amount of [CHB11Br6Me5]– that was used to measure the H NMR spectrum
1
1678
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© 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2007, 1671–1681

m-Terphenylaluminum and -gallium Compounds
FULL PAPER
was transferred to a small vial inside the glove box, and the solvent
carbon oil inside a drybox. A suitable crystal was selected, attached
to a glass fiber, and immediately placed in the low-temperature
nitrogen stream. Crystals of 16 experienced a phase transition
around 170 K, and the data were collected at 178 K. The data were
collected with a Bruker Apex diffractometer using Mo-Kα (λ =
0.71073 Å) radiation. Absorption corrections using a multi-scan
method from equivalent reflections were applied for 1, 3, 5, 7, and
10; a semi-empirical method was used for 16.[43] The structures
were solved by direct methods using the SHELXTL program suite
(version 6.1[44]) and refined by full-matrix least squares on F2 in-
cluding all reflections. All non-hydrogen atoms were refined aniso-
tropically, and all hydrogen atoms were included in the refinement
with idealized parameters. The OH hydrogen atoms in compounds
10 and 16 were not observed, but were placed into calculated posi-
tions using riding and distance restraints, respectively. The X-ray
crystal structure of 1 at room temperature was reported recently.[18]
Its parameters are very similar to the ones given here with the ex-
ception of a slightly larger unit cell. The structure of 16 displayed
some serious disorder problems. The structure includes one dicat-
ion, two monoanions, and four and one half benzene molecules.
One of the solvent molecules was severely disordered and was best
modeled using the Squeeze program.[45] Three of the n-butyl groups
on the cation were disordered and each was modeled in two orien-
tations. The occupancies of atoms C(1)–C(4), C(5)–C(8), and
C(13)–C(16) refined to 0.689(12) and 0.311(12), 0.627(11) and
0.373(11), and 0.797(9) and 0.203(9) for the unprimed and primed
atoms, respectively. Restraints were placed on the positional and
displacement parameters of the disordered atoms and the solvent
atoms as well as the positional parameters of the hydrogen atoms
bonded to the oxygen atoms and the hydrogen atoms on C(1A)
and C(1B). Some details of the crystal data and refinement are
given in Table 1, and selected bond lengths and angles are listed in
was allowed to slowly evaporate. The resulting colorless crystals
[42]
were analyzed by X-ray diffraction as Ph3CH·C6H6
16·4.5C6D6.
and
Reaction of [14]+[CHB11Cl11]– with 1-Octene:
A solution of
[14]+[CHB11Cl11]– (11 mg, 12 µmol) in a 6:1 mixture of C6D6/
C6D5Cl (0.6 mL) was treated with 1-octene (14 µmol, 2.4 µL) at
1
room temperature. The reaction was monitored by H NMR spec-
troscopy. After most of the free olefin had been consumed, ad-
ditional olefin was added at various intervals starting after 54 h
(5 µL), then after an additional 8 d (5 µL), and finally after further
4 d (10 µL). The last olefin added had been consumed at room
temperature after 7 d. Two drops of the reaction mixture were used
for ESI mass spectrometry. The rest was poured into a vial in air,
the solvent was allowed to evaporate, and the remaining oil was
investigated by GC/MS. MS (ESI, acetonitrile solution): calcd. for
C38H54Ga [M+] 579.35; found 579.6; calcd. for C40H57GaN [M+
+
MeCN] 620.37; found 620.6. GC/MS: tR = 11.62 min (16%), calcd.
for C14H16D6 (4-octylbenzene) 196.21, found 196.1; 11.73 min
(25%), calcd. for C14H16D6 (3-octylbenzene) 196.21, found 196.1;
11.97 min (59%), calcd. for C14H16D6 (2-octylbenzene) 196.21,
found 196.1. Assignments were made based on the fragmentation
patterns.
X-ray Crystallography: Crystals of 1, 3, and 5 were obtained by
crystallization from concentrated toluene solutions at –24 °C, crys-
tals of 7 were obtained from a concentrated benzene solution at 3–
4 °C, and crystals of 10 and 16 at room temperature from a 1-
octene or benzene solution of 8 or [13]+[CHB11Br6Me5]–, respec-
tively, by slow evaporation of the solvents inside a drybox. Crystals
of 1, 3, 5, and 7 were removed from the Schlenk tube under a
stream of N2 and immediately covered with a layer of hydrocarbon
oil, and crystals of 10 and 16 were covered with a layer of hydro-
Table 1. Crystal data and structural refinement details for 1, 3, 5, 7, 10, and 16·4.5C6H6.
1
3
5
7
10
16·4.5C6H6
Empirical formula
Formula mass
T [K]
Wavelength [Å]
Crystal system
Space group
a [Å]
b [Å]
c [Å]
α [°]
β [°]
C52H58ClGa
788.15
100(2)
0.71073
monoclinic
P21/n
17.1401(9)
13.7377(7)
19.7484(10)
90
110.2180(10)
90
4363.6(4)
4
1.200
0.725
C78H87Ga
1094.2
100(2)
0.71073
monoclinic
P21/c
9.9494(8)
33.470(3)
18.6120(15)
90
94.3920(10)
90
6179.6(9)
4
1.176
0.489
2344
C48H50AlCl
689.31
130(2)
0.71073
monoclinic
P21/n
11.9518(16)
20.391(3)
16.157(2)
90
100.167(2)
90
3875.9(9)
4
1.181
0.154
1472
C48H51Al
654.87
120(2)
0.71073
orthorhombic
P212121
11.9283(5)
15.8012(7)
20.3941(9)
90
90
90
3843.9(3)
4
1.132
C56H70Ga2O2
914.56
110(2)
0.71073
triclinic
¯
P1
9.010(6)
12.163(7)
12.211(7)
67.407(7)
78.940(8)
82.428(7)
1210.1(13)
1
C55H101B22Br12Ga4O6
2333.98
178(2)
0.71073
monoclinic
C2/c
33.122(5)
18.094(2)
31.434(4)
90
112.014(5)
90
17465(4)
8
1.775
0.71073
9064
γ [°]
V [Å3]
Z
Dcalcd. [Mgm–3
]
1.255
1.153
484
µ(Mo-Kα) [mm–1
F(000)
]
0.085
1408
1672
Crystal size [mm]
Crystal color and habit
2Θmax [°]
0.16ϫ0.12ϫ0.06 0.38ϫ0.22ϫ0.20 0.26ϫ0.18ϫ0.04 0.28ϫ0.22ϫ0.18 0.48ϫ0.08ϫ0.02
0.24ϫ0.22ϫ0.14
colorless prism
52.0
colorless prism
54.3
colorless plate
52.8
colorless prism
52.2
colorless prism
54.0
colorless needle
52.0
No. of obsd. recflections
No. of variables
9643
499
0.0347
0.0803
1.005
12644
760
0.0509
0.1155
1.006
7663
463
0.0625
0.1081
1.011
8384
458
0.0332
0.0906
1.026
4581
271
0.0859
0.2364
1.068
17168
983
0.0671
0.1772
1.027
1.804
[a]
R1 [I Ͼ 2σ(I)]
[b]
wR2 [I Ͼ 2σ(I)]
Goodness-of-fit on F2
Largest diff. peak [eÅ–3
]
0.418
0.648
0.301
0.280
1.842
[a] R1 = Σ||Fo| – |Fc||/Σ|Fo|. [b] wR2 = (Σw||Fo| – |Fc||2/Σw|Fo|2)1/2
.
Eur. J. Inorg. Chem. 2007, 1671–1681
© 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
1679

J. D. Young, M. A. Khan, D. R. Powell, R. J. Wehmschulte
FULL PAPER
Tables 2 and 3. CCDC-626538 to -626542 and 626654 contain the
supplementary crystallographic data for this paper. These data can
be obtained free of charge from The Cambridge Crystallographic
Data Centre via www.ccdc.cam.ac.uk/datarequest/cif.
[1]
[2]
[3]
[4]
[5]
S. H. Strauss, Chem. Rev. 1993, 93, 927.
C. A. Reed, Acc. Chem. Res. 1998, 31, 133.
E. Y.-X. Chen, T. J. Marks, Chem. Rev. 2000, 100, 1391.
I. Krossing, I. Raabe, Angew. Chem. Int. Ed. 2004, 43, 2066.
J. B. Lambert, L. Lin, S. Keinan, T. Mueller, J. Am. Chem. Soc.
2003, 125, 6022.
R. J. Wehmschulte, J. M. Steele, J. D. Young, M. A. Khan, J.
Am. Chem. Soc. 2003, 125, 1470.
J. D. Young, M. A. Khan, R. J. Wehmschulte, Organometallics
2004, 23, 1965.
Table 2. Selected bond lengths [Å] and angles [°] for 1, 3, 5, and 7.
1
3
5 (M = Al;
7 (M = Al;
[6]
[7]
[8]
(M = Ga) (M = Ga)
X = Cl)
X = H)
M–C
1.9701(16)
1.9816(17)
2.010(2)
1.989(2)
1.996(3)
1.976(3)
1.979(3)
1.9936(13)
1.9864(13)
P. Jutzi, A. Mix, B. Rummel, W. W. Schöller, B. Neumann, H.-
G. Stammler, Science 2004, 305, 849.
M–X
C–M–C
2.1786(5)
138.26(7)
2.1098(12)
147.52(13)
1.436(18)
137.62(5)
117.64(10)
119.05(10)
122.57(10)
[9] S. Hino, M. Brynda, A. D. Phillips, P. P. Power, Angew. Chem.
Int. Ed. 2004, 43, 2655.
[10]
[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
[21]
[22]
[23]
M. Gonsior, I. Krossing, L. Müller, I. Raabe, M. Jansen, L.
van Wüllen, Chem. Eur. J. 2002, 8, 4475.
M. P. Coles, D. C. Swenson, R. F. Jordan, V. G. Young Jr, Or-
ganometallics 1997, 16, 5183.
A. V. Korolev, E. Ihara, I. A. Guzei, V. G. Young Jr, R. F. Jor-
dan, J. Am. Chem. Soc. 2001, 123, 8291.
K.-C. Kim, C. A. Reed, G. S. Long, A. Sen, J. Am. Chem. Soc.
2002, 124, 7662.
P. H. M. Budzelaar, G. Talarico, Struct. Bonding (Berlin) 2003,
105, 141.
C. E. Radzewich, I. A. Guzei, R. F. Jordan, J. Am. Chem. Soc.
1999, 121, 8673.
S. Dagorne, I. A. Guzei, M. P. Coles, R. F. Jordan, J. Am.
Chem. Soc. 2000, 122, 274.
C. Elschenbroich, Organometallics, 3rd ed., Wiley-VCH,
Weinheim, Germany, 2006.
B. Quillian, Y. Wang, P. Wei, A. Handy, G. H. Robinson, J.
Organomet. Chem. 2006, 691, 3765.
R. C. Crittendon, X.-W. Li, J. Su, G. H. Robinson, Organome-
tallics 1997, 16, 2443.
R. C. Crittendon, B. C. Beck, J. Su, X.-W. Li, G. H. Robinson,
Organometallics 1999, 18, 156.
R. J. Wehmschulte, J. M. Steele, M. A. Khan, Organometallics
2003, 22, 4678.
O. T. Beachley Jr, M. R. Churchill, J. C. Pazik, J. W. Ziller, Or-
ganometallics 1986, 5, 1814.
M. A. Petrie, P. P. Power, H. V. R. Dias, K. Ruhlandt-Senge,
K. M. Waggoner, R. J. Wehmschulte, Organometallics 1993, 12,
1086.
X.-W. Li, W. T. Pennington, G. H. Robinson, Organometallics
1995, 14, 2109.
X.-W. Li, J. Su, G. H. Robinson, Chem. Commun. 1998, 1281.
R. J. Wehmschulte, W. J. Grigsby, B. Schiemenz, R. A. Bartlett,
P. P. Powe r, Inorg. Chem. 1996, 35, 6694.
A. H. Cowley, H. S. Isom, A. Decken, Organometallics 1995,
14, 2589.
R. J. Wehmschulte, A. A. Diaz, M. A. Khan, Organometallics
2003, 22, 83.
E. Ihara, V. G. Young Jr, R. F. Jordan, J. Am. Chem. Soc. 1998,
120, 8277.
D. Stasko, C. A. Reed, J. Am. Chem. Soc. 2002, 124, 1148.
Z. Xie, C.-W. Tsang, E. T.-P. Sze, Q. Yang, D. T. W. Chan,
T. C. W. Mak, Inorg. Chem. 1998, 37, 6444.
J. L. Atwood, in Coordination Chemistry of Aluminum (Ed.:
G. H. Robinson), VCH, New York, 1993, pp. 197.
A. V. Korolev, F. Delpech, S. Dagorne, I. A. Guzei, R. F. Jor-
dan, Organometallics 2001, 20, 3367.
M. Bochmann, M. J. Sarsfield, Organometallics 1998, 17, 5908.
T. Beringhelli, D. Maggioni, G. D’Alfonso, Organometallics
2001, 20, 4927.
C. Schnitter, H. W. Roesky, T. Albers, H.-G. Schmidt, C. Ri-
ipken, E. Parisini, G. M. Sheldrick, Chem. Eur. J. 1997, 3, 1783.
R. J. Wehmschulte, M. A. Khan, B. Twamley, B. Schiemenz,
Organometallics 2001, 20, 844.
C–M–X
107.04(5)
114.52(5)
105.22(10)
107.26(9)
113.8(7)
108.6(7)
Table 3. Selected bond lengths [Å] and angles [°] for 10 and 16.
Compound 10
Ga(1)–O(1)
Ga(1)–O(1A)
Ga(1)–C(1)
Ga(1)–C(25)
1.947(5)
1.952(5)
1.992(6)
1.967(7)
O(1)–Ga(1)–O(1A) 78.4(2)
O(1)–Ga(1)–C(1) 111.0(2)
O(1A)–Ga(1)–C(1) 110.8(3)
O(1)–Ga(1)–C(25) 108.1(3)
O(1A)–Ga(1)–C(25) 107.0(3)
C(25)–Ga(1)–C(1)
129.7(3)
Compound 16
Ga(1)–O(1)
Ga(1)–O(2)
Ga(1)–O(3)
Ga(2)–O(1)
Ga(2)–O(4)
Ga(2)–O(6)
Ga(3)–O(2)
Ga(3)–O(4)
O(1)–Ga(1)–O(2)
O(1)–Ga(1)–O(3)
O(2)–Ga(1)–O(3)
O(1)–Ga(2)–O(4)
O(1)–Ga(2)–O(6)
O(4)–Ga(2)–O(6)
O(2)–Ga(3)–O(4)
O(2)–Ga(3)–O(5)
O(4)–Ga(3)–O(5)
1.889(6)
1.903(5)
1.898(5)
1.901(6)
1.893(5)
1.907(5)
1.903(5)
1.896(5)
97.0(3)
97.2(2)
96.8(3)
98.3(2)
96.0(2)
97.3(2)
93.1(3)
100.4(3)
98.1(2)
Ga(3)–O(5)
Ga(4)–O(3)
Ga(4)–O(5)
Ga(4)–O(6)
Ga(1)–C(1)
Ga(2)–C(5)
Ga(3)–C(9)
Ga(4)–C(13)
O(3)–Ga(4)–O(5)
O(3)–Ga(4)–O(6)
O(5)–Ga(4)–O(6)
Ga(1)–O(1)–Ga(2)
Ga(1)–O(2)–Ga(3)
Ga(1)–O(3)–Ga(4)
Ga(2)–O(4)–Ga(3)
Ga(3)–O(5)–Ga(4)
Ga(2)–O(6)–Ga(4)
1.890(5)
1.887(5)
1.901(5)
1.898(5)
1.932(5)
1.933(5)
1.932(4)
1.934(5)
95.1(2)
97.5(2)
96.4(2)
129.5(3)
130.1(3)
132.5(3)
130.9(3)
130.6(3)
131.1(3)
[24]
[25]
[26]
[27]
[28]
[29]
Acknowledgments
[30]
[31]
Financial support for this work from the University of Oklahoma,
the Florida Institute of Technology, and the donors of the Petro-
leum Research Fund, administered by the American Chemical So-
ciety, is gratefully acknowledged. We also thank Prof. Christo-
pher A. Reed and Dr. Kee-Chan Kim from the University of Cali-
fornia, Riverside, for valuable discussions and the donation of the
carborane trityl salts used in this study. We are also grateful to Dr.
Li Zhang for the ESI mass spectra collected at the University of
Oklahoma and to Prof. Nasri Nesnas for the DART mass spectra
collected at the Florida Institute of Technology. We are further-
more grateful to the National Science Foundation for the purchase
of the Bruker Avance 400 NMR spectrometer (CHE 03422510).
[32]
[33]
[34]
[35]
[36]
[37]
1680
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© 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2007, 1671–1681

m-Terphenylaluminum and -gallium Compounds
FULL PAPER
[38] R. J. Wehmschulte, M. A. Khan, S. I. Hossain, Inorg. Chem.
2001, 40, 2756.
[42] A. Allemand, R. Gerdil, Acta Crystallogr., Sect. A 1975, 31,
S130.
[39] R. A. Kovar, G. Loaris, H. Derr, J. O. Callaway, Inorg. Chem. [43] G. M. Sheldrick, University of Göttingen, Germany, 2002.
1974, 13, 1476.
[44] G. M. Sheldrick, Bruker AXS, Madison, WI, 2000.
[45] P. van der Sluis, A. L. Spek, Acta Crystallogr., Sect. A 1990,
46, 194.
[40] K. Ruhlandt-Senge, J. J. Ellison, R. J. Wehmschulte, F. Pauer,
P. P. Powe r, J. Am. Chem. Soc. 1993, 115, 11353.
[41] B. Schiemenz, P. P. Power, Angew. Chem. Int. Ed. Engl. 1996,
35, 2150.
Received: November 8, 2006
Published Online: March 6, 2007
Eur. J. Inorg. Chem. 2007, 1671–1681
© 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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