Syntheses, characterization, and X-ray crystal structures of β-diketiminate group 13 hydrides, chlorides, and fluorides

Article abstract of DOI:10.1021/ic0517826

A series of organometallic compounds of group 13 metals supported by the sterically encumbered β-diketiminate ligand containing hydrides, fluorides, chlorides, and bromide have been synthesized and structurally characterized. The synthetic strategy applie

Full text of DOI:10.1021/ic0517826

Inorg. Chem. 2006, 45, 1853−1860
Syntheses, Characterization, and X-ray Crystal Structures of
-Diketiminate Group 13 Hydrides, Chlorides, and Fluorides
â
Sanjay Singh, Hans-Ju1rgen Ahn, Andreas Stasch, Vojtech Jancik, Herbert W. Roesky,* Aritra Pal,
Mariana Biadene, Regine Herbst-Irmer, Mathias Noltemeyer, and Hans-Georg Schmidt
Institut fu¨r Anorganische Chemie der Georg-August-UniVersita¨t Go¨ttingen, Tammannstrasse 4,
D-37077 Go¨ttingen, Germany
Received October 14, 2005
A series of organometallic compounds of group 13 metals supported by the sterically encumbered
â-diketiminate
ligand containing hydrides, fluorides, chlorides, and bromide have been synthesized and structurally characterized.
The synthetic strategy applied utilizes halide metathesis and reduction of metal chlorides to the corresponding
hydrides. Thus, the reaction of LLi
(4) with GaBr3. Reduction of LGa(Me)Cl with LiH
LGaH2 (12) has been accomplished by reacting LGaI2 (8) with LiH
converted to LAl(Me)F (5) and LAlF2 (7), respectively. The former was obtained in a reaction of LAl(Me)Cl with
Me3SnF while the latter was isolated in a reaction of LAlH2 with BF3 OEt2. Similarly reaction of LGaI2 (8) with
‚
OEt2 with MeMCl2 affords LM(Me)Cl (M
BEt3 leads to the formation of LGa(Me)H (10). Synthesis of
BEt3. LAl(Me)Cl (1) and LAlH2 (6) have been
) Al (1), Ga (2), In (3)) and LGaBr2
‚
‚
‚
Me3SnF affords LGaF2 (9). Compounds reported herein have been characterized by elemental analyses, IR, NMR,
EI-MS, and single-crystal X-ray diffraction techniques.
Introduction
to stabilize low coordination numbers at the metal centers,
rare coordination geometries, or low oxidation states owing
to their ability to tune properly between the steric and
electronic factors.6,7,12,13 Some of these complexes act as
olefin polymerization catalysts,3,4,8,9,15 as models for active
sites in metalloproteins,6,7 and also as complexes with unusual
chemical properties.12
Sterically encumbered â-diketiminate ligands offer a
negative, bidentate chelating mode1,2 to a wide range of
transition metals,2-7 main group elements,8-13 and lanthanide
systems.14 A noticeable point is the ability of these ligands
* To whom correspondence should be addressed. E-mail: hroesky@
gwdg.de.
A number of M(III) derivatives with the â-diketiminate
ligand L have been previously reported and structurally
characterized [L ) HC{(CMe)(2,6-iPr2C6H3N)}2]. These
include the cation [LAlMe]+,9 the dimethyl derivative
LMMe2,9,10 the dichloride LMCl2, and the diiodide LMI2 (M
(1) Bradley, W.; Wright, I. J. Chem. Soc. 1956, 640-648.
(2) Laurence, B.-M.; Lappert, M. F.; Severn, J. R. Chem. Rev. 2002, 102,
3031-3065 and references therein.
(3) Feldman, J.; McLain, S. J.; Parthasarthy, A.; Marshall, W. J.; Calabrese,
J. C.; Arthur, S. D. Organometallics 1997, 16, 1514-1516.
(4) Kim, W.-K.; Fevola, M. J.; Liable-Sands, L. M.; Rheingold, A. L.;
Theopold, K. H. Organometallics 1998, 17, 4541-4543.
(5) Qian, B.; Scanlon, W. J.; Smith, M. R., III; Motry, D. H. Organo-
metallics 1999, 18, 1693-1698.
10
) Al, Ga, or In).16 Synthesis of LAlMe2 was reported by
Smith et al. whereas other complexes were reported by Power
and co-workers.16 Preparation of LMCl2 was accomplished
by the reaction of LLi‚OEt2 with MCl3.16 Reaction of “GaI”
with LLi‚OEt2 yields LGaI2 and LGa,16 whereas LInI2 was
(6) Holland, P. L.; Tolman, W. B. J. Am. Chem. Soc. 1999, 121, 7270-
7271.
(7) Holland, P. L.; Tolman, W. B. J. Am. Chem. Soc. 2000, 122, 6331-
6332.
(8) Radzewich, C. E.; Coles, M. P.; Jordan, R. F. J. Am. Chem. Soc. 1998,
120, 9384-9385.
10
prepared by the reaction of LLi‚OEt2 with InI3.16 LAlMe2
16
(9) Radzewich, C. E.; Guzei, G. T.; Jordan, R. F. J. Am. Chem. Soc. 1999,
121, 8673-8674.
and LGaMe2 were isolated by the reaction of the corre-
sponding trimethyls with the LH. LInMe2 was prepared by
(10) Qian, B.; Ward, D. L.; Smith, III, M. R. Organometallics 1998, 17,
3070-3076.
(11) Bailey, P. J.; Dick, C. M. E.; Fabre, S.; Parsons, S. Dalton Trans.
2000, 1655-1661.
(14) Driess, D.; Magull, J. Z. Anorg. Allg. Chem. 1994, 620, 814-818.
(15) Gibson, V. C.; Maddox, P. J.; Newton, C.; Redshaw, C.; Solan, G.
A.; White, A. J. P.; Williams, D. J. Chem. Commun. 1998, 1651-
1652.
(16) Stender, M.; Eichler, B. E.; Hardman, N. J.; Power, P. P.; Prust, J.;
Noltemeyer, M.; Roesky, H. W. Inorg. Chem. 2001, 40, 2794-2799.
(12) Cui, C.; Roesky, H. W.; Schmidt, H.-G.; Noltemeyer, M.; Hao, H.;
Cimpoesu, F. Angew. Chem., Int. Ed. 2000, 39, 4274-4276.
(13) Hardman, N. J.; Eichler, B. E.; Power, P. P. Chem. Commun. 2000,
1991-1992.
10.1021/ic0517826 CCC: $33.50
Published on Web 01/20/2006
© 2006 American Chemical Society
Inorganic Chemistry, Vol. 45, No. 4, 2006 1853

Singh et al.
Scheme 1. Preparation of Group 13 Methyl Chlorides Supported by
the â-Diketiminate Ligand
Scheme 2. Preparation of â-Diketiminate Gallium Dibromide
Scheme 3. Preparation of the â-Diketiminate Methylaluminum
Fluoride
the metathesis of LInCl2 with 2 equiv of MeMgBr.16 It is
noticeable that all these complexes have symmetrical sub-
stituents around the metal atom. Presently, there is a growing
interest in the chemistry of such complexes where the metal
atom has at least two different substituents.
On the basis of our longstanding interest in the synthesis
of â-diketiminate complexes of group 13 metals, we have
contributed to a whole new range of compounds.17-25 Some
of these are useful catalysts,23,25 compounds with syntheti-
cally useful functional groups,17-21,23-25 and compounds with
the metal in a low oxidation state.12 We have reported
recently that the sterically encumbered neutral LAl(Me)Cl
can be utilized as a starting material to prepare the mono-
hydroxide LAl(Me)OH, which in turn can again be used as
a synthon to assemble a range of homo- and heterobimetallic
derivatives23-25 some of which have found applications in
ethylene polymerization23 and polymerization of ꢀ-caprolac-
tone.25 Therefore, it was our primary interest to prepare other
derivatives of LAl(Me)Cl where the Al atom will have at
least two different substituents and also to extend it to the
congeners of group 13.
are thermally stable solids with melting points of 190 and
185 °C, respectively, and are sensitive to moisture. 1H NMR
of 2 reveals the Ga-Me to resonate at δ -0.31 ppm and
two septets at δ 3.15 and 3.87 ppm corresponding to the
CH protons of the iPr moieties of the ligand, characteristics
of asymmetrically substituted metal center in complexes with
the â-diketiminate ligand. The corresponding protons of 3
appear at δ -0.28 ppm, and septets, at δ 3.15 and 3.83 ppm.
The most intense peak in the EI-MS spectra of 2 and 3
corresponds to the loss of one Me group from the molecular
ion and was observed at m/z 523 and 567, respectively.
LGaBr2 (4) was synthesized by the reaction of LLi‚OEt2 with
GaBr3 in diethyl ether (Scheme 2). LGaBr2 (4) melts at 236
°C. The base peak in the EI-MS spectrum of 4 at m/z 567
corresponds to the loss of one bromine atom from 4.
Moreover, the molecular ion was observed at m/z 646 albeit
in low intensity.
Trimethyltin fluoride has proved to be a versatile fluori-
nating agent particularly in the conversion of groups 4-6
and also main group chlorides to the corresponding
fluorides.27-29 Trimethyltin chloride generated during the
metathesis is readily removed in vacuo. Thus, the reaction
of LAl(Me)Cl (1) with Me3SnF in THF results in the
complete conversion of 1 to LAl(Me)F (5) (Scheme 3) which
was characterized by its 19F NMR where the Al-F resonates
at δ 8.6 ppm. Methyl protons of Al-Me are coupled to the
F atom and are observed as a doublet (δ -0.82 ppm). EI-
MS of 5 exhibits [M+ - Me] as the base peak at m/z 463.
When LAlH2 (6) was treated with BF3‚OEt2 at low
temperature and allowed to warm to room temperature, the
difluoride derivative LAlF2 (7) was isolated (Scheme 4). A
singlet in the 19F NMR of 7 (δ 6.8 ppm) confirms the
formation of Al-F bonds. The EI-MS spectrum shows [M+]
as the base peak at m/z 482. The corresponding gallium
Results and Discussion
Synthesis of LM(Me)Cl (M ) Al (1), Ga (2), In (3)) has
been accomplished by the reaction of LLi‚OEt2 with MeMCl2
(Scheme 1). It was observed that the reaction of LH with
Me2MCl leads to a mixture of products which are difficult
to separate. Compounds 1-3 are examples of novel â-di-
ketiminate metal complexes which are X-ray structurally
characterized with metals having two different substituents.
Spectroscopic properties of LAl(Me)Cl have already been
reported.26 Compounds LGa(Me)Cl (2) and LIn(Me)Cl (3)
(17) Bai, G.; Peng, Y.; Roesky, H. W.; Li, J.; Schmidt, H.-G.; Noltemeyer,
M. Angew. Chem., Int. Ed. 2003, 42, 1132-1135.
(18) Bai, G.; Roesky, H. W.; Li, J.; Noltemeyer, M.; Schmidt, H.-G. Angew.
Chem., Int. Ed. 2003, 42, 5502-5506.
(19) Jancik, V.; Pineda, L. W.; Pinkas, J.; Roesky, H. W.; Neculai, D.;
Neculai, A. M.; Herbst-Irmer, R. Angew. Chem., Int. Ed. 2004, 43,
2142-2145.
(20) Jancik, V.; Pineda, L. W.; Stu¨ckl, A. C.; Roesky, H. W.; Herbst-Irmer,
R. Organometallics 2005, 24, 1511-1515.
(21) Pineda, L. W.; Jancik, V.; Roesky, H. W.; Neculai, D.; Neculai, A.
M. Angew. Chem., Int. Ed. 2004, 43, 1419-1421.
(22) Roesky, H. W.; Singh, S.; Jancik, V.; Chandrasekhar, V. Acc. Chem.
Res. 2004, 37, 969-981.
(23) Bai, G.; Singh, S.; Roesky, H. W.; Noltemeyer, M.; Schmidt, H.-G.
J. Am. Chem. Soc. 2005, 127, 3449-3455.
(26) Zhu, H.; Chai, J. F.; He, C.; Bai, G.; Roesky, H. W.; Jancik, V.;
Schmidt, H.-G.; Noltemeyer, M. Organometallics 2005, 24, 380-384.
(27) Pinkas, J.; Roesky, H. W. J. Fluorine Chem. 2003, 122, 125-150.
(28) Roesky, H. W.; Keller, K. J. Fluorine Chem. 1999, 100, 217-226.
(29) Hohmeister, H.; Wessel, H.; Lobinger, P.; Roesky, H. W.; Mu¨ller, P.;
Uso´n, I.; Schmidt, H.-G.; Noltemeyer, M.; Magull, J. J. Fluorine Chem.
2003, 120, 59-64.
(24) Singh, S.; Kumar, S. S.; Chandrasekhar, V.; Ahn, H.-J.; Biadene, M.;
Roesky, H. W.; Hosmane, N. S.; Noltemeyer, M.; Schmidt, H.-G.
Angew. Chem., Int. Ed. 2004, 43, 4940-4943.
(25) Chai, J. F.; Jancik, V.; Singh, S.; Zhu, H.; He, C.; Roesky, H. W.;
Schmidt, H.-G.; Noltemeyer, M.; Hosmane, N. S. J. Am. Chem. Soc.
2005, 127, 7521-7528.
1854 Inorganic Chemistry, Vol. 45, No. 4, 2006

â-Diketiminate Group 13 Hydrides and Halides
Scheme 4. Preparation of the â-Diketiminate Aluminum Difluoride
Scheme 6. Preparation of the â-Diketiminate Gallium Methyl Hydride
Scheme 5. Preparation of â-Diketiminate-Supported Gallium
Difluoride
Scheme 7. Preparation of â-Diketiminate-Supported Gallium
Dihydride
compound LGaF2 (9) was synthesized by the reaction of
LGaI2 (8) with Me3SnF (Scheme 5). 19F NMR of 9 exhibits
the Ga-F to resonate at δ 38.3 ppm. The mass spectrum of
9 reveals the base peak as [M+ - F] at m/z 505 and the
molecular ion at m/z 523 [M+] in low intensity.
On the contrary reaction of LiH‚BEt3 with LAl(Me)Cl (1)
affords a mixture of products which could not be separated
and characterized. Other attempts to prepare LAl(Me)H (11)
including reaction of LH with MeAlH2‚NMe343 or reduction
of LAl(Me)Cl (1) with LiAlH4 were not successful. Com-
pound 10 is a stable solid with a melting point of 177 °C. In
A number of hydrides of aluminum have been prepared
ranging from mono-,30,33 di-,30-34 and trihydrides.35-38 The
latter has been a very strong and useful reducing agent in
the form of alane and aluminates. The corresponding gallium
compounds33,38,39 are also known but their stability is lower
than the aluminum derivatives. Attempts have been devoted
to increase the stability of these compounds by coordination
of an ancillary ligand to the gallium atom. These are among
the most easily accessible, more stable, and, usually, more
malleable than the parent hydrides.33,39,40 Most common are
the Lewis base adducts of group 13 metal hydrides.38,41 Thus,
GaH3‚NMe3 is stable below room temperature but its shelf
life is considerably lower at room temperature. Therefore, it
is a synthetic challenge to prepare stable mono- and
dihydrides of gallium. An obvious route is the reduction of
the corresponding chlorides with a suitable reducing agent.42
The reduction of LGa(Me)Cl with LiH‚BEt3 in toluene
smoothly affords LGa(Me)H (10) in good yield (Scheme 6).
1
the H NMR spectrum of 10 Ga-Me protons resonate at δ
5.49 ppm as a broad signal, whereas the base peak in the
EI-MS spectrum of 10 at m/z 487 corresponds to [M+
-
Me]. The IR spectrum of 10 shows a strong band at ν˜ 1825
cm-1 which can be attributed to the Ga-H stretching
frequency.
Similarly, the synthesis of dihydride of gallium LGaH2
(12) involves the conversion of LGaI2 (8) to LGaH2 with
LiH‚BEt3 (Scheme 7). In the 1H NMR spectrum the Ga-H
resonates at δ 4.58 ppm. The IR spectrum of 12 shows two
strong bands at ν˜ 1893 and 1861 cm-1 which can be
attributed to the asymmetric and symmetric stretch of the
Ga-H bonds, respectively. The EI-MS spectrum exhibits the
base peak at m/z 487, which corresponds to [M+ - H].
X-ray Structural Characterization of Complexes 1-5,
7, 9, 10, and 12. All complexes 1-5, 7, 9, 10, and 12
crystallize in the monoclinic system in P21/n (1-4, 7, 9, and
12) or in P21/c (5 and 10) with one molecule in the
asymmetric unit. These compounds can be divided into three
groups containing isomorphic species. The first group
contains complexes 1-4 (two approximately similar sub-
stituents are attached to the metal center), the second include
compounds 7, 9, and 12 (two small atoms (H or F) bound to
the metal center), and the species 5 and 10 belong to the
third one (two substituents with different size on the metal
atom), respectively. Molecular structures of these complexes
are depicted in Figures 1-9, respectively. The crystal data
and structure refinement details of all complexes are sum-
marized in Table 1, and selected bond lengths and angles
(30) Wehmschulte, R. J.; Power, P. P. Inorg. Chem. 1996, 35, 3262-3267.
(31) Wehmschulte, R. J.; Power, P. P. Inorg. Chem. 1994, 33, 5611-5612.
(32) Wehmschulte, R. J.; Grigsby, W. J.; Schiemenz, B.; Bartlett, R. A.;
Power, P. P. Inorg. Chem. 1996, 35, 6694-6702.
(33) Isom, H. S.; Cowley, A. H.; Decken, A.; Sissingh, F.; Corbelin, S.;
Lagow, R. J. Organometallics 1995, 14, 2400-2406.
(34) Contreras, L.; Cowley, A. H.; Gabba¨ı, F. P.; Jones, R. A.; Carrano,
C. J.; Bond, M. R. J. Organomet. Chem. 1995, 489, C1-C3.
(35) Downs, A. J.; Pulham, C. R.; Chem. Soc. Rev. 1994, 23, 175-184.
(36) Ruff, J. K. Inorg. Synth. 1967, 9, 30-37.
(37) Twamley, B.; Hardman, N. J.; Power, P. P. Acta Crystallogr. 2001,
E57, m227-m228.
(38) Pulham, C. R.; Downs, A. J.; Goode, M. J.; Rankin, D. W. H.;
Robertson, H. E. J. Am. Chem. Soc. 1991, 113, 5149-5162.
(39) Cowley, A. H.; Gabba¨ı, F. P.; Atwood, D. A. J. Am. Chem. Soc. 1994,
116, 1559-1560.
(40) Wehmschulte, R. J.; Ellison, J. J.; Ruhlandt-Senge, K.; Power, P. P.
Inorg. Chem. 1994, 33, 6300-6303.
(41) Storr, A.; Wiebe, V. G. Can. J. Chem. 1969, 47, 673-679.
(42) Cowley, A. H.; Gabba¨ı, F. P.; Isom, H. S.; Decken, A. J. Organomet.
Chem. 1995, 500, 81-88.
(43) Peters, F. M.; Bartocha, B.; Bilbo, A. J. Can. J. Chem. 1963, 41, 1051-
1058.
Inorganic Chemistry, Vol. 45, No. 4, 2006 1855

Singh et al.
Figure 1. Molecular structure of LAl(Me)Cl (1) with 50% thermal
ellipsoids. All hydrogen atoms are omitted for clarity.
Figure 4. Molecular structure of LGaBr2 (4) with 50% thermal ellipsoids.
All hydrogen atoms are omitted for clarity.
Figure 2. Molecular structure of LGa(Me)Cl (2) with 50% thermal
ellipsoids. All hydrogen atoms are omitted for clarity.
Figure 5. Molecular structure of LAl(Me)F (5) with 50% thermal
ellipsoids. All hydrogen atoms are omitted for clarity.
Figure 3. Molecular structure of LIn(Me)Cl (3) with 50% thermal
ellipsoids. All hydrogen atoms are omitted for clarity.
are listed in Tables 2-4. The most common feature among
the structures is that the four atoms C(1), C(3), N(1), and
N(2) are almost coplanar, whereas the position of the metal
and C(2) atoms depends strongly on the substituents attached
to the metal center. If the substituents are small (H, F or
electron lone pair), the C3N2M ring is planar or nearly planar
(observed in LAl,12 LAlH2,37 7, 9, and 12), and an elongation
of the anisotropic displacement parameter perpendicular to
the plane of the metal and the substituents is observed
indicating vibration perpendicular to the plane but larger
substituents attached to the metal atom cause its significant
deviation out of the plane. The C(2) atom is in this case
also deviated from the C2N2 plane, but the deviation is not
so large as in the case of the metal center. This boat
Figure 6. Molecular structure of LAlF2 (7) with 50% thermal ellipsoids.
All hydrogen atoms are omitted for clarity.
conformation of the C3N2M ring can also be found in many
other derivatives of these ligands from group 13 metals and
from different elements of the periodic table. In the com-
plexes 1-5, 7, 9, 10, and 12 the C-C and C-N distances
of the C3N2M ring lie within the narrow ranges 1.394-1.410
and 1.325-1.346 Å, respectively, which are indicative of
considerable multiple bond character and delocalization in
these bonds. It is noteworthy that within the C3N2M (M )
Al, Ga, In) rings the N-M-N angle is invariably the
narrowest, smallest for LIn(Me)Cl (3) at 90.9(1)° and widest
for LGaF2 (9) at 100.8(1)°, depending on the covalent radii
1856 Inorganic Chemistry, Vol. 45, No. 4, 2006

â-Diketiminate Group 13 Hydrides and Halides
Figure 7. Molecular structure of LGaF2 (9) with 50% thermal ellipsoids.
All hydrogen atoms are omitted for clarity.
Figure 8. Molecular structure of LGa(Me)H (10) with 50% thermal
ellipsoids. All hydrogen atoms except that on Ga(1) are omitted for clarity.
Figure 9. Molecular structure of LGaH2 (12) with 50% thermal ellipsoids.
All hydrogen atoms except those on Ga(1) are omitted for clarity.
of the metal and on the size of the substituents, respectively.
In all complexes, the substituents are coordinated to the metal
atom in the form of distorted tetrahedron.
In complexes 1-3 the metal atoms are surrounded by the
chlorine atom, methyl group, and nitrogen atoms of the
chelating â-diketiminate ligand (Figures 1-3). The bite
angles of the â-diketiminate ligands N(1)-M(1)-N(2),
which are 97.6(1), 97.1(1), and 90.9(1)° for 1-3, respec-
tively, are smaller than the regular tetrahedral bond angles
(109.28°) and follow the trend in the size of covalent radii
Inorganic Chemistry, Vol. 45, No. 4, 2006 1857

Singh et al.
Table 2. Selected Bond Distances (Å) and Angles (deg) for
Compounds 1-4a
Cl(1) bond length in 2 is 2.223(1) Å, which is the same as
that found in LGaCl2 (2.228(1) and 2.218(1) Å, average
2.223 Å).16 The C(6)-Ga(1)-Cl(1) angle is 114.5(1)° (Table
2), which lies between the angles of C(30)-Ga(1)-C(31)
param
1
2
3
4
M(1)-Cl(1)
M(1)-Br(1)
M(1)-Br(2)
M(1)-C(6)
M(1)-N(1)
M(1)-N(2)
2.158(1)
2.223(1)
2.402(1)
16
2.286(1)
2.330(1)
at 122.44(9)° in LGaMe2 and Cl(1)-Ga(1)-Cl(2) at
110.20(4)° in LGaCl2.16
1.905(5)
1.906(2)
1.887(2)
1.956(2)
1.949(1)
1.936(1)
2.138(2)
2.148(2)
2.133(2)
1.925(3)
1.908(2)
The In(1)-C(6) bond length in LIn(Me)Cl (3) (2.138(2)
Å) is almost similar to those observed in LIn(Me)2 (2.148-
(1) and 2.168(1) Å, average 2.158 Å).16 The In(1)-Cl(1)
bond length (2.402(1) Å) is comparable to that of LInCl2
(2.387(1) and 2.404(3) Å, average 2.396 Å).16 The C(6)-
In(1)-Cl(1) angle is 119.1(1)° (Table 2), which is wider than
the Cl(1)-In(1)-Cl(2) 108.99(8)° in LInCl216 but narrower
than the C(30)-In(1)-C(31) 130.94(6)° in LInMe2.16
The molecular structure of LGaBr2 (4) has also been
determined by single-crystal X-ray techniques. A perspective
view of the molecular structure of 4 is shown in Figure 4,
and relevant bond lengths and angles are listed in Table 2.
The Ga-Br bond lengths (2.286(1) and 2.330(1) Å) are
shorter than those found in [PyGaBr2]2 (2.350(2) Å)45 and
tBu3SiGaBr2‚THF (2.360(1) Å)46 and [(3,5-Me2C6H3CH2)2-
GaBr2]2 (average 2.519 Å).47 The Br(1)-Ga(1)-Br(2) angle
is 112.2(1)° and is considerably wider than the corresponding
angles in [PyGaBr2]2 (105.8(1)°)45 and tBu3SiGaBr2‚THF
(105.6(1)°)46 and [(3,5-Me2C6H3CH2)2GaBr2]2 (92.1(1)°).47
The N(1)-Ga(1)-N(2) angle within the chelating ring of
the â-diketiminate ligand is 99.8(1)°, which is slightly wider
than that found in LGa(Me)Cl (97.1(1)°).
The Al(1)-C(6) bond distance in LAl(Me)F (5) (1.944-
(2) Å) is slightly shorter than that found in LAlMe2 (average
1.964 Å).10 The Al-F bond length (1.679(1) Å) is slightly
longer than that observed in LAlF2 (7) (1.656(1) and 1.650-
(1) Å) and identical in [OCMeCHCMeN(2,6-iPr2C6H3)]2AlF
(1.678(1) Å).48 However, the Al-F bond lengths in 5 and 7
are typical for terminal bonds and are comparable to terminal
Al-F bonds in [{(Me3Si)3CAlF2}3] (average 1.669 Å) but
are significantly shorter than the bridging ones (average 1.805
Å).49 F(1)-Al(1)-C(6) angle in 5 is 144.7(1)°, which is
wider than the F(1)-Al(1)-F(2) angle of 107.8(1)° in 7,
probably due to the smaller size of the F atom compared to
that of the Me group. Ga-F distances observed in LGaF2
(9) are 1.755(2) and 1.773(2) Å, which are considerably
shorter than those found in Ga(pc)F (1.936(1) Å) (pc )
phthalocyanato),50 [Mes2Ga(F)(tBuNH2)] (1.838(3) Å)51
[{(Me3Si)2HC}2GaF]2 (average 1.966 Å),52 and [Mes2GaF]2
(1.947(2) Å).53 The F(1)-Ga(1)-F(2) angle in 9 is 103.7-
(1)°, which is identical with the average F-Ga-F bond angle
Cl(1)-M(1)-C(6)
Br(1)-M(1)-Br(2)
N(1)-M(1)-N(2)
N(1)-M(1)-Cl(1)
N(1)-M(1)-Br(1)
N(1)-M(1)-Br(2)
N(1)-M(1)-C(6)
N(2)-M(1)-Cl(1)
N(2)-M(1)-Br(1)
N(2)-M(1)-Br(2)
N(2)-M(1)-C(6)
114.9(4)
114.5(1)
119.1(1)
112.2(1)
99.8(1)
97.6(1)
105.4(1)
97.1(1)
103.1(1)
90.9(1)
100.9(1)
116.0(1)
107.2(1)
117.2(4)
106.8(1)
119.3(1)
104.0(1)
122.4(1)
101.3(1)
112.9(1)
107.9(1)
113.2(4)
116.3(1)
117.0(1)
a M ) Al (1), Ga (2, 4), In (3).
Table 3. Selected Bond Distances (Å) and Angles (deg) for
Compounds 5, 7, and 9
param
5
7
9
M(1)-F(1)
M(1)-F(2)
M(1)-C(6)
M(1)-N(1)
M(1)-N(2)
1.679(1)
1.655(1)
1.650(1)
1.773(2)
1.755(2)
1.944(2)
1.897(1)
1.885(1)
1.865(1)
1.866(1)
1.895(2)
1.899(2)
F(1)-M(1)-C(6)
F(1)-M(1)-F(2)
N(1)-M(1)-N(2)
N(1)-M(1)-F(1)
N(1)-M(1)-F(2)
N(1)-M(1)-C(6)
N(2)-M(1)-F(1)
N(2)-M(1)-F(2)
N(2)-M(1)-C(6)
144.7(1)
107.8(1)
99.3(1)
112.1(1)
113.2(1)
103.7(1)
100.8(1)
114.0(1)
111.9(1)
97.1(1)
105.7(1)
115.8(1)
107.8(1)
112.8(1)
111.6(1)
112.4(1)
114.5(1)
114.1(1)
a M ) Al (5, 7), Ga (9).
Table 4. Selected Bond Distances (Å) and Angles (deg) for
Compounds 10 and 12
param
10
12
Ga(1)-H(1)
Ga(1)-H(2)
Ga(1)-C(6)
Ga(1)-N(1)
Ga(1)-N(2)
1.75(2)
1.54(2)
1.52(2)
1.955(2)
1.968(2)
1.976(2)
1.960(1)
1.963(1)
H(1)-Ga(1)-H(2)
H(1)-Ga(1)-C(6)
N(1)-Ga(1)-N(2)
N(1)-Ga(1)-C(6)
N(2)-Ga(1)-C(6)
N(1)-Ga(1)-H(1)
N(1)-Ga(1)-H(2)
N(2)-Ga(1)-H(1)
N(2)-Ga(1)-H(2)
118(1)
118.3(6)
94.3(1)
111.2(1)
112.7(1)
109.5(6)
95.7(1)
110.7(8)
109.0(9)
110.2(8)
110.4(9)
108.3(7)
(44) For covalent atomic radii, see the Web page of the Cambridge
Structural Database: http://www.ccdc.cam.ac.uk/products/csd/radii/.
(45) Small, R. W. H.; Worrall, I. J. Acta Crystallogr. 1982, B38, 86-87.
(46) Wiberg, N.; Blank, T.; Westerhausen, M.; Schneiderbauer, S.;
Schno¨ckel, H.; Krossing, I.; Schnepf, A. Eur. J. Inorg. Chem. 2002,
351-356.
for these metals (1.35 Al, 1.22 Ga, 1.63 Å In).44 The Al-
(1)-Cl(1) bond length (2.158(1) Å) in 1 is similar to that
found in LAlCl2 (2.134(1) and 2.119(1) Å, average 2.126
Å).16 The C(6)-Al(1)-Cl(1) angle 114.9(4)° lies between
the angles of C(1)-Al(1)-C(2) 115.4(2)° in LAlMe210 and
Cl(1)-Al(1)-Cl(2) 108.0(1)° in LAlCl2 (Table 2).16
The Ga(1)-C(6) bond length in LGa(Me)Cl (2) (1.956-
(2) Å) is comparable to that observed in LGaMe2 (1.970(2)
and 1.979(2) Å, average 1.975 Å).16 Similarly, the Ga(1)-
(47) Kopp, M. R.; Neumu¨ller, B. Z. Naturforsch. 1998, 53B, 545-551.
(48) Yu, R.-C.; Hung, C.-H.; Huang, J.-H.; Lee, H.-Y.; Chen, J.-T. Inorg.
Chem. 2002, 41, 6450-645.
(49) Schnitter, C.; Klimek, K.; Roesky, H. W.; Albers, T.; Schmidt, H.-
G.; Ro¨pken, C.; Parisini, E. Organometallics 1998, 17, 2249-2257.
(50) Wynne, K. J. Inorg. Chem. 1985, 24, 1339-1343.
(51) Kra¨uter, T.; Neumu¨ller, B. Z. Anorg. Allg. Chem. 1995, 621, 597-
606.
1858 Inorganic Chemistry, Vol. 45, No. 4, 2006

â-Diketiminate Group 13 Hydrides and Halides
standard, and 19F NMR spectra were recorded with C6F6 as external
standard. Mass spectra were recorded on a Finnigan MAT 8230
mass spectrometer using the EI-MS method. The most intense peak
of an isotopic distribution is tabulated. IR spectra were recorded
on Bio-Rad Digilab FTS-7 spectrometer as a Nujol mull between
KBr plates. Melting points were obtained in sealed capillaries on
a Bu¨chi B540 instrument. Elemental analyses were performed at
the Analytical Laboratory of the Institute of Inorganic Chemistry,
University of Go¨ttingen.
52
in [{(Me3Si)2HC}2GaF]2 but wider than that observed in
[Mes2GaF]2 (78.9(1)°).53 The N(1)-Ga(1)-N(2) angle within
the C3N2Ga ring in 9 is 100.8(1)°, which is wider than the
similar angles found in LGa(Me)Cl (2) (97.1(1)°) but
comparable to that observed in LGaBr2 (4) (99.8(1)°).
The structures of the complexes LGa(Me)H (10) and
LGaH2 (12) are analogous to their parent compounds LGa-
(Me)Cl (2) and LGaI2, respectively. The Ga(1)-C(6) bond
length in LGa(Me)H (10) (1.955(2) Å) was found to be
identical with 1.956(2) Å observed in LGa(Me)Cl (2). The
Ga-H distances in 12 (1.54(2) and 1.52(2) Å) are shorter
than in 10 but are in agreement with Ga-H distances
reported earlier, for example in [(tBuO)2GaH)]2 (1.53(7) Å).54
Furthermore, there is a residual density peak (0.61 e.Å-3)
close to the hydrogen of 10 caused by an unmodeled disorder
(either ca. 6% methyl or 3.5% chlorine). This leads to an
artificial elongation of the Ga-H bond.
Synthesis of LGa(Me)Cl (2). LLi‚OEt2 (1.49 g, 3.00 mmol)
dissolved in toluene (30 mL) was cooled to -78 °C, and MeGaCl2
(0.47 g, 3.00 mmol) dissolved in toluene (20 mL) was added with
continuous stirring. The solution was allowed to warm to room
temperature and stirred overnight. After removal of all volatiles,
the residue was extracted with n-hexane (50 mL). Partial removal
of the solvent and storage at -26 °C afforded colorless crystals of
LGa(Me)Cl. An additional crop of LGa(Me)Cl was obtained from
the mother liquor. Total yield: 1.26 g (78%). Mp: 190 °C. Anal.
Calcd for C30H44ClGaN2 (Mr ) 537.86): C, 66.99; H, 8.25; N,
1
5.21. Found: C, 66.87; H, 8.32; N, 5.18. H NMR (C6D6, 200
Conclusion
MHz): δ -0.31 (s, 3 H, GaMe), 1.04 (d, 6 H, JH-H ) 6.8 Hz,
CHMe2), 1.19 (two overlapped d, 12 H, JH-H ) 6.8 Hz, CHMe2),
1.48 (d, 6 H, JH-H ) 6.8 Hz, CHMe2), 1.57 (s, 6 H, CMe), 3.15
(sept, 2 H, JH-H ) 6.8 Hz, CHMe2), 3.87 (sept, 2 H, JH-H ) 6.8
Hz, CHMe2), 4.90 (s, 1 H, γ-CH), 7.01-7.14 (m, 6 H, Ar). MS
[EI; m/z (%)]: 538 (12) [M+], 523 (100) [M+ - Me], 501 (34)
[M+ - Cl], 485 (14) [M+ - Me - Cl]. IR (Nujol, cm-1): ν˜ 1532,
1468, 1441, 1385, 1302, 1262, 1179, 1100, 1056, 1023, 934, 872,
797, 778, 759, 726, 646, 584, 532, 450.
Synthesis of LIn(Me)Cl (3). The preparation of LIn(Me)Cl was
carried out by using a procedure similar to that for LGa(Me)Cl.
The quantities of the reactants used are 1.00 g (2.00 mmol) for
LLi‚OEt2 and 0.40 g (2.00 mmol) for MeInCl2. Yield: 0.75 g
Herein, we have described the syntheses and X-ray
structures of group 13 hydrides, chlorides, bromide, and
fluorides supported by a â-diketiminate ligand. This proce-
dure utilizes the reaction of metal chlorides with super
hydride to prepare metal hydride and reaction of metal
chlorides with Me3SnF or BF3‚OEt2 to prepare metal
fluorides. The resulting compounds are excellent starting
materials and can be used to prepare interesting compounds;
an example has already been demonstrated in preparing
terminal hydroxides of Al23 and Ga20 as well as in the
synthesis of tetranuclear alumoxane hydride and alumoxane
gallium hydride.24 Similarly we anticipate that other deriva-
tives reported here would allow further elaboration of these
synthons.
(65%). Mp: 185 °C. Anal. Calcd for C30H44ClInN2 (Mr
)
582.95): C, 61.81; H, 7.61; N, 4.81. Found: C, 61.79; H, 7.58; N,
1
4.82. H NMR (C6D6, 200 MHz): δ -0.28 (s, 3 H, InMe), 1.09
(d, 6 H, JH-H ) 6.8 Hz, CHMe2), 1.23 (two overlapped d, 12 H,
JH-H ) 6.8 Hz, CHMe2), 1.46 (d, 6 H, JH-H ) 6.8 Hz, CHMe2),
1.58 (s, 6 H, CMe), 3.15 (sept, 2 H, JH-H ) 6.8 Hz, CHMe2), 3.83
(sept, 2 H, JH-H ) 6.8 Hz, CHMe2), 4.80 (s, 1 H, γ-CH), 7.10-
7.14 (m, 6 H, Ar). MS [EI; m/z (%)]: 582 (12) [M+], 567 (100)
[M+ - Me]. IR (Nujol, cm-1): ν˜ 1526, 1383, 1317, 1268, 1254,
1177, 1163, 1107, 1099, 1055, 1043, 1021, 933, 859, 796, 778,
758, 720, 635, 518, 446.
Synthesis of LGaBr2 (4). GaBr3 (1.00 g, 3.23 mmol) dissolved
in diethyl ether (40 mL) was cooled to -78 °C, and a solution of
LLi‚Et2O (1.61 g, 3.23 mmol), dissolved in diethyl ether and cooled
to -78 °C was added. The reaction mixture was allowed to warm
to room temperature and stirred for 12 h. After removal of all
volatiles, 4 was extracted with n-hexane (50 mL). After removal
of n-hexane, 4 was dissolved in diethyl ether and colorless crystals
were obtained at -27 °C. Yield: 1.71 g (82%). Mp: 236 °C. Anal.
Calcd for C29H41Br2GaN2 (Mr ) 647.18): C, 53.82; H, 6.39; Br,
24.69; Ga, 10.77; N, 4.33. Found: C, 53.91; H, 6.42; Br, 24.32;
Ga, 10.53, N, 4.39. 1H NMR (200 MHz, CDCl3): δ 1.20 (d, 12 H,
JH-H ) 6.8 Hz, CHMe2), 1.31 (d, 12 H, JH-H ) 6.8 Hz, CHMe2),
1.90 (s, 6 H, CMe), 3.37 (sept, 4 H, JH-H ) 6.8 Hz, CHMe2), 5.31
(s, 1 H, γ-CH), 7.20-7.30 (m, 6 H, Ar). MS [EI; m/z (%)]: 646
(38) [M+], 567 (100) [M+ - Br], 486 (7) [M+ - 2Br]. IR (Nujol,
cm-1): ν˜ 1877, 1654, 1522, 1261, 1149, 1099, 1021, 934, 875,
799, 722, 638, 535.
Experimental Section
General Comments. All manipulations were carried out under
an atmosphere of purified nitrogen using standard Schlenk tech-
niques. Samples prepared for spectral measurements as well as for
reactions were manipulated in a glovebox. Solvents were dried using
conventional procedures, distilled under nitrogen, and degassed prior
to use. Deuterated NMR solvents were treated with Na/K alloy,
distilled, and stored under nitrogen. MeGaCl2,55 MeInCl2,56 LH,3
LLi‚OEt2,57 LGaCl2,16 LGaI2,16 MeAlH2‚NMe3,43 and Me3SnF58
were prepared as described in the literature. MeAlCl2, BF3‚OEt2,
and LiH‚BEt3 were purchased from Aldrich and were used without
purification.
1
Physical Measurements. The H NMR spectra were recorded
on Bruker AM 200 NMR spectrometer with SiMe4 as external
(52) Uhl, W.; Graupner, R.; Hahn, I.; Spies, T.; Frank, W. Eur. J. Inorg.
Chem. 1998, 355-360.
(53) Neumu¨ller, B.; Gahlmann, F. Angew. Chem., Int. Ed. Engl. 1993, 32,
1701-1702.
(54) Veith, M.; Faber, S.; Wolfgang, H.; Huch, V. Chem. Ber. 1996, 129,
381-384.
(55) Beachley, O. T., Jr.; Rosenblum, D. B.; Macrae, D. J. Organometallics
2001, 20, 945-949.
(56) MeInCl2 was prepared in a reaction of Me3In and InCl3 in 1:2
stoichiometric ratio by using the procedure similar to that reported
for MeGaCl2.55
(57) Stender, M.; Wright, R. J.; Eichler, B. E.; Prust, J.; Olmstead, M. M.;
Roesky, H. W.; Power, P. P. J. Chem. Soc., Dalton Trans. 2001, 3465-
3469.
Synthesis of LAl(Me)F (5). THF (40 mL) was added to a
mixture of LAl(Me)Cl (0.99 g, 2.00 mmol) and Me3SnF (0.37 g,
(58) Roesky, H. W.; Keller, K. J. Fluorine Chem. 1998, 89, 3-4.
Inorganic Chemistry, Vol. 45, No. 4, 2006 1859

Singh et al.
JH-H ) 7.2 Hz, CHMe2), 1.30 (two overlapped d, 12 H, JH-H
6.8 Hz, CHMe2), 1.57 (s, 6 H, CMe), 3.43 (sept, 4 H, JH-H ) 6.8
Hz, CHMe2), 4.81 (s, 1 H, γ-CH), 5.49 (s broad, 1 H, GaH), 7.04-
7.13 (m, 6 H, Ar). MS [EI; m/z (%)]: 502 (28) [M+], 487 (100)
[M+ - Me]. IR (Nujol, cm-1): ν˜ 1825, 1559, 1523, 1495, 1442,
1404, 1388, 1319, 1261, 1232, 1196, 1178, 1104, 1055, 1022, 935,
865, 796, 766, 644, 608, 590, 564, 523, 440.
2.00 mmol). The mixture was then stirred at room temperature until
a clear solution was obtained (ca 24 h). After removal of all the
volatiles, LAl(Me)F was extracted with n-hexane (50 mL). Partial
removal of the solvent and storage at 0 °C for 2 d afforded colorless
crystals of 5. Yield: 0.81 g (85%). Mp: 202 °C. Anal. Calcd for
C30H44AlFN2 (Mr ) 478.66): C, 75.28; H, 9.27; N, 5.85. Found:
)
1
C, 75.32; H, 9.31; N, 5.83. H NMR (200 MHz, C6D6): δ -0.82
(d, 3 H, JH-F ) 2.0 Hz, AlMe), 1.08 (d, 6 H, JH-H ) 6.8 Hz,
CHMe2), 1.19 (two overlapped d, 6 H, JH-H ) 6.8 Hz, CHMe2),
1.29 (d, 6 H, JH-H ) 6.8 Hz, CHMe2), 1.44 (d, 6 H, JH-H ) 6.8
Hz, CHMe2), 1.56 (s, 6 H, CMe), 3.16 (sept, 2 H, JH-H ) 6.8 Hz,
CHMe2), 3.64 (sept, 2 H, JH-H ) 6.8 Hz, CHMe2), 4.98 (s, 1 H,
γ-CH), 7.05-7.12 (m, 6 H, Ar). 19F NMR (188 MHz, C6D6): δ
8.6 (s, Al-F). MS [EI; m/z (%)]: 478 (10) [M+], 463 (100) [M+
- Me], 444 (8) [M+ - Me - F]. IR (Nujol, cm-1): ν˜ 1624, 1550,
1531, 1444, 1384, 1318, 1256, 1191, 1177, 1105, 1055, 1023, 941,
879, 806, 797, 757, 720, 663, 629, 448.
Synthesis of LGaH2 (12). LGaI2 (1.00 g, 1.35 mmol) dissolved
in benzene (50 mL) was treated with a solution of LiH‚BEt3 in
THF (2.7 mL, 2.7 mmol, 2 equiv). The mixture was stirred at room
temperature for 12 h. After removal of all volatiles 12 was extracted
with n-hexane and the insoluble LiI was filtered off. After the
removal of n-hexane the compound was dissolved in diethyl ether
and colorless crystals were obtained at -27 °C. Yield: 0.70 g
(80%). Mp: 135 °C. Anal. Calcd for C29H43GaN2 (Mr ) 489.39):
C, 71.17; H, 8.86; Ga, 14.25; N, 5.72. Found: C, 71.25; H, 8.89;
Ga, 14.19, N, 5.73. 1H NMR (300 MHz, CDCl3): δ 1.19 (d, 12 H,
JH-H ) 6.8 Hz, CHMe2), 1.23 (d, 12 H, JH-H ) 6.8 Hz, CHMe2),
1.72 (s, 6 H, CMe), 3.20 (sept, 4 H, JH-H ) 6.8 Hz, CHMe2), 4.58
(s, broad, 2 H, GaH), 4.85 (s, 1 H, γ-CH), 7.10-7.24 (m, 6 H,
Ar). MS [EI; m/z (%)]: 488 (65) [M+], 487 (100) [M+ - H], 486
(8) [M+ - 2H]. IR (KBr, Nujol): ν˜ 1893, 1861, 1562, 1526, 1405,
1320, 1263, 1253, 1233, 1176, 1101, 1055, 1023, 965, 935, 869,
799, 763, 743, 722, 713, 666, 638, 596, 545, 526, 500, 441.
X-ray Crystal Structure Determination of Complexes 1-5,
7, 9, 10, and 12. Data for the structures were collected on a Bruker
three-circle diffractometer equipped with a SMART 6000 CCD
detector and with a mirror-system-monochromated Cu KR source
(for 1-3, 5, 7, and 10) and Stoe IPSD2 system with monochromated
Mo KR radiation (for 4, 9, and 12). Intensity measurements were
performed on a rapidly cooled crystal. The structures were solved
by direct methods (SHELXS-97)59 and refined against all data by
full-matrix least squares on F2 using anisotropic displacement
parameters for all non-hydrogen atoms.60 The two hydrogen atoms
bonded to Ga in 12 were refined with similar distance restraints,
while the other hydrogen atoms were included in the refinement at
geometrically ideal positions and refined with a riding model except
the hydrogen atom bonded to Ga in 10, which was refined freely
with U-value fixed to 1.2Ueq(Ga). In 1 the positions of the methyl
group and the chlorine are disordered. The occupancy of the second
position refined to 0.11(3). Distance restraints and equal atomic
displacement parameters of the two atoms of one position were
used for the refinement. The disorder in 10 as mentioned above
was not modeled because the occupancy of the second position
was too small. The crystal data are summarized in Table 1. Further
details are provided in the Supporting Information.
Synthesis of LAlF2 (7). BF3‚OEt2 (0.43 g, 0.38 mL, 3.0 mmol,
1.34 equiv) was added dropwise to a cooled (-78 °C) solution of
LAlH2 (1.00 g, 2.24 mmol) in toluene (10 mL). The solution was
stirred at this temperature for 10 min, slowly warmed to room
temperature, and stirred overnight. All volatiles were removed in
vacuo, and the residue was crystallized from n-hexane/toluene (1:
1) to give large colorless crystals of LAlF2 (7). Yield: 0.88 g (82%).
Mp: 235 °C. Anal. Calcd for C29H41AlF2N2 (Mr ) 482.63): C,
1
72.17; H, 8.56; N, 5.80. Found: C, 72.20; H, 8.58; N, 5.85. H
NMR (300 MHz, C6D6): δ 1.10 (d, 12 H, JH-H ) 6.9 Hz, CHMe2),
1.41 (d, 12 H, JH-H ) 6.9 Hz, CHMe2), 1.53 (s, 6 H, CMe), 3.30
(sept, 4 H, JH-H ) 6.9 Hz, CHMe2), 4.94 (s, 1 H, γ-CH), 7.03-
7.18 (m, 6 H, Ar). 19F NMR (188 MHz, C6D6): δ 6.8 (s, Al-F).
27Al NMR (78.2 MHz, C6D6, TMS): δ 66.9 (s, w1/2 ) 1350 Hz).
MS [EI; m/z (%)]: 482 (100) [M+], 467 (41) [M+ - Me], 447
(18) [M+ - MeH - F]. IR (Nujol, cm-1): ν˜ 1539, 1318, 1255,
1177, 1102, 1030, 937, 900, 817, 803, 758, 719, 448, 412.
Synthesis of LGaF2 (9). Benzene (60 mL) was added to a
mixture of LGaI2 (1.00 g, 1.35 mmol) and Me3SnF (0.494 g, 2.70
mmol). The suspension was stirred at room temperature until all
the Me3SnF dissolved to give a clear solution (ca. 4 weeks). After
removal of all volatiles under vacuum, the compound was extracted
with diethyl ether (30 mL). Partial removal of the ether and keeping
the solution at 4 °C afforded colorless crystals. Yield: 0.63 g (90%).
Mp: 237 °C. Anal. Calcd for C29H41F2GaN2 (Mr ) 525.37): C,
66.30; H, 7.87; F, 7.23; Ga, 13.27; N, 5.33. Found: C, 66.42; H,
1
7.90; F, 7.19; Ga, 13.10; N, 5.38. H NMR (500 MHz, C6D6): δ
1.09 (d, 12 H, JH-H ) 6.8 Hz, CHMe2), 1.44 (d, 12 H, JH-H ) 6.8
Hz, CHMe2), 1.52 (s, 6 H, CMe), 3.30 (sept, 4 H, JH-H ) 6.8 Hz,
CHMe2), 4.87 (s, 1 H, γ-CH), 7.05-7.13 (m, 6 H, Ar). 19F NMR
(188 MHz, C6D6): δ 38.34 (s, GaF). MS [EI; m/z (%)]: 524 (13)
[M+], 505 (100) [M+ - F], 486 (33) [M+ - 2 F]. IR (Nujol, cm-1):
ν˜ 1653, 1533, 1349, 1307, 1263, 1177, 1149, 1103, 1056, 1029,
970, 953, 937, 891, 880, 803, 789, 759, 722, 624, 532, 442.
Synthesis of LGa(Me)H (10). LGa(Me)Cl (1.07 g, 2.00 mmol)
dissolved in toluene (20 mL) was cooled to -78 °C, and a solution
of LiH‚BEt3 in THF (2.0 mL, 2.00 mmol, 1 equiv) was added
dropwise. The solution was allowed to warm to room temperature
and stirred overnight. After removal of all volatiles the residue was
extracted with n-hexane (40 mL). Partial removal of the solvent
and storage at -26 °C afforded colorless crystals of LGa(Me)H.
An additional crop of LGa(Me)H was obtained from the mother
liquor. Total yield: 0.72 g (72%). Mp: 177 °C. Anal. Calcd for
C30H45GaN2 (Mr ) 503.41): C, 71.58; H, 9.01; N, 5.56. Found:
Acknowledgment. This work was supported by the
Go¨ttinger Akademie der Wissenschaften. S.S. thanks the
Graduiertenkolleg (GRK 782) Spektroskopie und Dynamik
molekularer Aggregate, Ketten und Kna¨uel for a graduate
student fellowship.
Supporting Information Available: Detailed X-ray structural
data including a summary of crystallographic parameters, atomic
coordinates, bond distances and angles, anisotropic thermal param-
eters, and H atom coordinates for 1-5, 7, 9, 10, and 12 (CIF).
This material is available free of charge via the Internet at
http://pubs.acs.org.
IC0517826
(59) Sheldrick, G. M. SHELXS-97, Program for Structure Solution. Acta
Crystallogr., Sect. A 1990, 46, 467-473.
(60) Sheldrick, G. M. SHELXL-97, Program for Crystal Structure Refine-
ment; University of Go¨ttingen: Go¨ttingen, Germany, 1997.
1
C, 71.60; H, 9.03; N, 5.60. H NMR (200 MHz, C6D6): δ -0.45
(d, 3 H, JH-H ) 0.8 Hz, GaMe), 1.16 (two overlapped d, 12 H,
1860 Inorganic Chemistry, Vol. 45, No. 4, 2006