A stable aluminacyclopropene LAl(η2-C2H 2) and its end-on azide insertion to an aluminaazacyclobutene

Article abstract of DOI:10.1002/anie.200500899

Not all down-to-Earth: A stable aluminacyclopropene Lal(η²- C₂H₂) 1 was isolated from the reaction of LAl with C ₂H₂. Further reaction of 1 with C₂H₂ results in terminal C≡CH and

Full text of DOI:10.1002/anie.200500899

Communications
Metallacycle
ers.[5d–e] The IR and ESR spectroscopic data on matrix-
isolated products from the reaction of AlCl with C2H2 confirm
the results.[5e] Herein, we show the reaction of the aluminum(i)
monomer LAl[8] directly with C2H2 in the temperature range
from low to room temperature and the successful isolation of
the first stable aluminacyclopropene LAl(h2-C2H2) 1. The
subsequent reaction of 1 with C2H2 results in the product 2:
DOI: 10.1002/anie.200500899
A Stable Aluminacyclopropene LAl(h2-C2H2) and
Its End-On Azide Insertion to an
Aluminaazacyclobutene**
ꢁ
=
LAl(C CH)(CH CH2) (Scheme 1). The reaction of 1 with a
Hongping Zhu, Jianfang Chai, Hongjun Fan,
Herbert W. Roesky,* Cheng He, Vojtech Jancik,
Hans-Georg Schmidt, Mathias Noltemeyer,
William A. Merrill, and Philip P. Power
Dedicated to Kit Cummins
Scheme 1. The stepwise reaction of LAl with C2H2 to 1 and 2;
L=HC(C(Me)NAr)2; Ar=2,6-iPr2C6H3
The MC2 rings of cyclopropene derivatives substituted with
heavier main-group elements have a highly strained structure
and indicate a remarkable reactivity. They are often involved
in such reactions as ring opening, insertion, substitution,
dimerization, and hydrogen [1,2] sigmatropic shifts.[1] There-
fore, they are of great interest in syntheses, especially in the
preparation of larger heterocycles that contain main-group
large bulky organic azide leads to the unusual aluminaazacy-
=
=
clobutene insertion product 3: LAl(CH CHN(N NAr*))
(Ar* = 2,6-Ar02C6H3, Ar’ = 2,4,6-Me3C6H2) (Scheme 2).
ꢀ
elements and C C unsaturated bonds.
Such three-membered heterocyclic compounds with
organic substituents at the two olefinic carbon atoms have
been reported previously.[1–4] However, species with the
simplest M(h2-C2H2) moiety are either discussed on the
basis of theoretical calculations,[5] or observed in metal-vapor
deposition reactions at 12 K.[6] Among the AlC2 ring com-
pounds, Et(solvent)Al(h2-C2Ph2) (solvent = Et2O, THF) and
ClAl(h2-C2R2) (R = Me, Et) were assumed to be the respec-
Scheme 2. The end-on insertion of N3Ar* into 1 to form 3; L=HC-
(C(Me)NAr)2; Ar=2,6-iPr2C6H3; Ar*=2,6-Ar02C6H3; Ar’=2,4,6-Me3C6H2
The reaction of LAl with an excess of carefully dried C2H2
in toluene was initially carried out in the temperature range of
ꢀ788C to room temperature. The instant color change of the
solution from red to orange and then the slow change to
almost colorless was easily observed, and compound 2 was
formed. Clearly, the formation of 2 indicates that LAl reacted
with two molecules of C2H2. When this reaction was
controlled in the temperature range between ꢀ78 and
ꢀ508C, the red solution only changed to orange (this color
change occurred even if the reaction was performed at
ꢂ ꢀ1008C). By removal of unreacted C2H2, the 1:1 adduct
LAl(h2-C2H2) 1 was isolated. Notably, when this reaction was
continued without the removal of excess C2H2, the corre-
tive intermediates in the formation of 1,4-(dialumina)cyclo-
[7]
ꢁ
hexadiene and (ClAl·RC CR)4. The bulky b-diketiminato
ligand L (L = HC(C(Me)NAr)2; Ar= 2,6-iPr2C6H3) was sub-
sequently found to stabilize the ring of the Al(h2-C2R1R2)
species (R1, R2: SiMe3, Ph). Such compounds have been
prepared by the reductive coupling of LAlI2 and potassium in
1
the presence of R C CR2.[3] Species with the formula XAl(h2-
ꢁ
C2H2) (X = H, Cl) are supported in calculations, yet are
considered unstable in comparison with the acyclic isom-
[*] Dipl.-Chem. H. Zhu, Dr. J. Chai, Prof. Dr. H. W. Roesky, Dr. C. He,
Dr. V. Jancik, H.-G. Schmidt, Dr. M. Noltemeyer
Institut für Anorganische Chemie
1
sponding H NMR spectrum showed the formation of small
amounts of 2, whereas the reaction solution remained orange
in color.
Georg-August Universität Göttingen
Tammannstrasse 4, 37077 Göttingen (Germany)
Fax: (+49)551-39-3373
Compound 1 was obtained as an orange crystalline solid in
quantitative yield and is extremely air-sensitive. Upon expo-
sure to air, the orange color of the solution of 1 immediately
becomes colorless. However, 1 is stable in an inert gas
atmosphere. It is readily soluble in aromatic solvents and
sparingly soluble in nonbranched hydrocarbons. Compound 2
is a colorless crystalline solid and is highly soluble in hydro-
carbons. Compounds 1 and 2 were characterized by MS, 1H and
13C NMR spectroscopy, and by X-ray crystallography.[9a–b]
The structural analyses clearly reveal that compound 1
contains the simple Al(h2-C2H2) moiety (Figure 1), whereas 2
ꢁ
E-mail: hroesky@gwdg.de
Dr. H. Fan
Labor für Physikalische undTheoretische Chemie
Universität Siegen
57068 Siegen (Germany)
W. A. Merrill, Prof. P. P. Power
Department of Chemistry
University of California, Davis
One Shields Avenue, Davis, CA 95616 (USA)
[**] This work was supported by the Göttinger Akademie der Wissen-
schaften. C.H. thanks the Alexander von Humboldt Foundation for
a fellowship.
=
contains terminal C CH and CH CH2 groups at the Al cen-
5090
ꢀ 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2005, 44, 5090 –5093

Angewandte
Chemie
close to those in 2 (1.895(1), 1.910(2) Š), and are similar to
those observed in compounds with four-coordinate b-diket-
iminato aluminum(iii) (1.888(2)–1.935(2) Š).[10] However,
ꢀ
they are shorter than the Al N bonds in LAl (1.957(2) Š)
as a result of the AlI center[8] having a larger radius than that
of AlIII.
ꢀ
ꢀ
In 2, the Al C bond lengths (Al CCꢁC = 1.941(14) Š (av);
ꢀ
Al CC C = 1.954(14) Š (av)) are similar to those in related
=
compounds LAlMe2 (1.955(4)–1.961(3) Š) and L’AlMe2
(1.958(3)-1.970(3) Š, in which L’ = HC(C(Me)N-p-tolu-
ene)2).[11] The C C (1.170(14) Š (av)) and C C bond lengths
ꢁ
=
(1.323(18) Š (av)) are indicative of characteristic C-C triple
ꢁ
ꢀ
and double bonds, whereas the Al C C (175.4(19)8 (av)) and
ꢀ =
Al C C (124.6(14)8 (av)) bond angles deviate from the ideal
1808 and 1208, respectively.[12] The 1H and 13C NMR spectra of
ꢁ
=
2 confirm the functional CH CH2 and C CH groups at the
ꢀ
=
Al center. In the Al CH CH2 moiety, the corresponding
Figure 1. Molecular structure of LAl(h2-C2H2) 1. Protons in L are
omittedfor clarity. Selectedbondlengths [Š] andangles [ 8]: Al(1)–N(1)
1.875(1), Al(1)–N(2) 1.884(1), Al(1)–C(6) 1.885(2), Al(1)–C(7)
1.878(2), C(6)–C(7) 1.358(2), C(6)–H(6) 1.000, C(7)–H(7) 1.021;
N(1)-Al(1)-N(2) 97.98(5), C(6)-Al(1)-C(7) 42.30(7), Al(1)-C(6)-C(7)
68.57(10), Al(1)-C(7)-C(6) 69.13(10), H(6)-C(6)-C(7) 126.4,
H(7)-C(7)-C(6) 127.1.
protons resonate at d = 5.70–6.20 ppm; carbon resonances are
1
=
ꢀ
=
at d = 125.4 ( CH2) and 138.0 ppm (br, Al CH ); both H
and 13C NMR resonances are within the typical range for
alkenyl groups. Furthermore, three groups of double doublets
are observed and are indicative for these three protons in a
ꢁ
ꢀ
nonequivalent steric environment. The Al C CH group
exhibits proton resonance at d = 1.55 ppm (s) and carbon
ꢁ
ꢁ
ꢀ
resonances at d = 94.6 (br, CH) and 137.3 ppm (br, Al C ).
ter (Figure 2). The latter is the first crystallographically
The absorptions at 1996 and 3270 cmꢀ1 in the IR spectrum of 2
ꢁ
ꢁ
=
authenticated example of terminal C CH and CH CH2
are tentatively assigned to the stretching frequencies of C C
ꢁ
ꢀ
groups attached to the same Al center. In 2, the X-ray
and C H bonds.
2
ꢁ
=
ꢀ
reflection data indicate that both CH CH2 and C CH groups
are disordered in two positions (C(6)H(6)C(7)H(7)H(8),
C(8)C(9)H(9), 62.2%; C(6A)H(6A)C(7A)H(7A)H(8A),
C(8A)C(9A)H(9A), 37.8%). Thus, the central Al ion appears
to have a disordered tetrahedral geometry with a = 96.99(6)8
In 1, the parameters within the Al(h -C2H2) moiety (Al C
ꢀ
ꢀ
ꢀ
1.882(2) Š (av), C C 1.358(2) Š, C H 1.010 Š (av); aC
Al C 42.30(7)8, aAl C C 68.85(10)8 (av), aH C C 126.68
ꢀ
ꢀ ꢀ
ꢀ ꢀ
(av)) fit well in comparison with those of Al(h2-C2) in LAl(h2-
1
2
1
2
ꢀ
C2R R ) (R = SiMe3, R = Ph) (Al C 1.889(2)–1.899(3) Š,
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ ꢀ
for N Al N, and a = 111.6(5)8 for C Al C bond angles
C C 1.356(5)–1.382(4) Š; C Al C a42.02(14)–42.57(11)8,
Al C C a68.39(15)–68.80(19)8),[3] and are also much closer
ꢀ
ꢀ ꢀ
(av). The Al N bond lengths in 1 (1.875(1), 1.884(1) Š) are
2
ꢀ
to those of the calculated HAl(h -C2H2) (Al C 1.844–
ꢀ
ꢀ
ꢀ ꢀ
1.852 Š, C C 1.362–1.384 Š, C H 1.076–1.089 Š; H C C
a126.8–127.38).[5d] Notably, in the AlC2 ring of 1 the average
ꢀ
ꢀ
Al C bond length is shorter than that of 2, whereas the C C
bond length is longer (standard deviations of 0.072 and
0.036 Š, respectively). This may indicate a conjugated ring
system in AlC2. Furthermore, the H and 13C NMR spectra
1
recorded in C6D6 show that the proton (d = 8.82 ppm (s)) and
carbon resonances (177.2 ppm (br)) of the Al(h2-C2H2)
moiety are in the low-field region characteristic for the
alkenyl system. These results indicate a certain aromatic
character of the AlC2 ring in 1.
The reaction of 1 with a large bulky azide N3Ar* shows an
end-on azide insertion, resulting in the four-membered
=
=
aluminaazacyclobutene
LAl(CH CHN(N NAr*))
3
(Scheme 2). A handful of reactions between monovalent
Group 13 compounds and organic azides have been
reported.[13] The initial N2 elimination is generally accepted,
and supported by experimental observations.[13e–f] The for-
mation of a five-membered AlN4 ring in LAl((NSiMe3)2N2)
ꢁ
=
Figure 2. Molecular structure of LAl(C CH)(CH CH2) 2, with both
ꢁ
=
C CH andCH CH2 groups in 62.2% occupation. Protons in L are
omittedfor clarity. Selectedbondlengths [Š] andangles [ 8]: Al(1)–N(1)
1.910(2), Al(1)–N(2) 1.895(1), Al(1)–C(6) 1.944(11), Al(1)–C(8)
1.962(11), C(6)–C(7) 1.325(17), C(8)–C(9) 1.173(11); N(1)-Al(1)-N(2)
96.99(6), C(6)-Al(1)-C(8) 110.8(4), Al(1)-C(6)-C(7) 124.6(12), Al(1)-
C(8)-C(9) 173.9(13).
was suggested to proceed through a [2+3] cycloaddition of an
[13d]
=
Al N intermediate and N3SiMe3,
whereas the disubsti-
tuted aluminacyclopropene LAl(h2-C2(SiMe3)2) reacted
under disassociation and N2 elimination with a similar bulky
Angew. Chem. Int. Ed. 2005, 44, 5090 –5093
ꢀ 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
5091

Communications
[3]
=
1: A toluene solution (30 mL) of LAl (0.22 g, 0.5 mmol) at
decreased pressure was cooled to ꢀ788C and exposed to dried C2H2.
This mixture was kept in the temperature range of ꢀ788C to ꢀ508C
for 2 h. An instant color change of the solution from red to orange was
observed. All volatiles were removed, and an orange crystalline solid
of 1 was afforded (> 95%); m.p. 2198C; IR (Nujol): n˜ = 442.7(w),
529.1(w), 589.8(m), 613.5(w), 647.4(w), 712.7(m), 748.3(w), 758.5(w),
778.2(w), 801.0(s), 867.7(w), 893.9(w), 936.7(w), 1026.0(m),
1055.6(w), 1100.6(m), 1177.4(w), 1260.7(m), 1304.9(w), 1318.7(w),
azide to an Al N compound. Accordingly, the end-on
ꢀ
N3Ar* insertion into the Al C bond unambiguously reveals
the initial interaction between an Al center and the terminal
N atom of the azide group. This type of reaction is, to the best
of our knowledge, so far unknown. Compound 3 has been
well-characterized by spectroscopic, analytical, and X-ray
crystallographic measurements.[9c] The molecular structure of
3 is shown in Figure 3.
1410.5(s),
1485.6(s),
1532.8(m),
1653.7(w) cmꢀ1
;
1H NMR
3
(500.13 MHz, [D6]benzene, 258C, TMS): d = 1.12 (d, J = 6.9 Hz, 4 ”
3
3H, CH(CH3)2), 1.46 (d, J = 6.9 Hz, 4 ” 3H, CH(CH3)2), 1.53 (s, 2 ”
3H, b-CH3), 3.33 (sept, 3J = 6.9 Hz, 4 ” 1H, CH(CH3)2), 4.89 (s, 1H, g-
CH), 7.02–7.12 (m, 6H, Ar-H), 8.82 ppm (s, 2 ” 1H, Al-h2-C2H2);
13C NMR (125.77 MHz, C6D6, 258C, TMS): d = 23.4, 24.4, 24.6, 28.9
(CH(CH3)2, b-CH3), 96.5 (g-C), 124.4, 138.8, 143.9 (Ar-C), 172.8
(CN), 177.2 ppm (broad, Al-h2-C2); 27Al NMR (77.13 MHz, C6D6,
258C, AlCl3): signal too broad to be observed. 27Al NMR (77.13 MHz,
[D8]toluene, ꢀ708C, AlCl3): signal too broad to be observed. MS: m/z
(%): 469.3 (20) [M+ꢀ1], 455.3 (30) [M+ꢀMe], 429.3 (100)
[M+ꢀMeꢀC2H2]; elemental analysis (%) calcd for C31H43AlN2
(470.68): C 79.10, H 9.21, N 5.95; found: C 79.43, H 9.18, N 6.03.
Single crystals of 1 were obtained by keeping the n-hexane/toluene
solution of 1 at ꢀ268C for one week. TMS = tetramethylsilane.
2: The initial procedure (LAl (0.22 g, 0.5 mmol), C2H2 (excess),
and toluene (30 mL)) is the same as the synthesis of 1. At ꢀ508C, the
mixture was stirred and warmed to ambient temperature within 48 h,
the color of the solution slowly turned to almost colorless. All
volatiles were removed in vacuum and the residue was washed with n-
=
=
Figure 3. Molecular structure of LAl(CH CHN(N NAr*)) (3). Protons
in L are omittedfor clarity. Selectedbondlengths [Š] andangles [ 8]:
Al(1)–N(1) 1.866(2), Al(1)–N(2) 1.867(2), Al(1)–N(3) 1.892(2), Al(1)–
C(6) 1.932(3), C(6)–C(7) 1.342(4), C(7)–N(3) 1.410(3), N(3)–N(4)
1.320(3), N(4)–N(5) 1.284(3); N(1)-Al(1)-N(2) 99.8(1), C(6)-Al(1)-N(3)
72.6(1), Al(1)-N(3)-C(7) 88.2(2), Al(1)-C(6)-C(7) 88.5(2), C(6)-C(7)-
N(3) 110.7(2), N(3)-N(4)-N(5) 112.4(2).
hexane (2 mL) to afford a colorless crystalline solid of 2 (0.22 g,
ꢀ1
ꢁ
ꢁ
90%); m.p. 1638C; IR (Nujol): n˜ = 1992 (C C), 3277 cm ( CH);
1H NMR (500.13 MHz, [D8]toluene, 258C, TMS): d = 1.08 (d, 3J =
6.8 Hz, 2 ” 3H, CH(CH3)2), 1.25 (d, J = 6.8 Hz, 2 ” 3H, CH(CH3)2),
1.28 (d, J = 6.8 Hz, 2 ” 3H, CH(CH3)2), 1.44 (d, J = 6.8 Hz, 2 ” 3H,
3
3
3
ꢁ
CH(CH3)2), 1.55 (s, 2 ” 3H, b-CH3), 1.73 (s, 1H, C CH), 3.23 (sept,
3J = 6.8 Hz, 2 ” 1H, CH(CH3)2), 3.81(sept, 3J = 6.8 Hz, 2 ” 1H, CH-
(CH3)2), 4.91(s, 1H, g-CH), 5.79 (dd, 3J(trans) = 20.9 Hz, 2J = 6.4 Hz,
In summary, we have isolated the stable aluminacyclo-
propene LAl(h2-C2H2) 1 from the reaction of LAl with one
equivalent C2H2. Further reaction of 1 with another equiv-
3
1H), 6.04 (dd, 3J(cis) = 16.5 Hz, 2J = 6.4 Hz, 1H), 6.12 (dd, J(trans)
=
20.9 Hz, 3J(cis) = 16.5 Hz, 1H), (CH CH2), 6.97–7.12 ppm (m, 6H, Ar-
=
H); 13C NMR (125.76 MHz, [D8]toluene, 258C, TMS): d = 23.4, 24.5,
ꢁ
=
alent of C2H2 yields LAl(C CH)(CH CH2) 2. This may be
ꢁ
24.7, 24.8, 27.2, 28.2, 28.6 (CH(CH3)2, b-CH3), 94.6 (broad, CH), 98.4
considered as a prebiotic reaction owing to AlI species (AlF)
and acetylene having been detected spectroscopically in
dense interstellar clouds.[14] The crystallographic and NMR
spectral data of 1 indicate an electron-delocalized AlC2
heterocycle, which can be described as a Hückel 2p aromatic
system. The Schmidt degradation and Curtius rearrangement
(g-C), 124.1, 124.8, 127.5, 128.8, 129.2, 137.1, 140.3, 143.7, 145.4 (Ar-
ꢁ
=
=
C), 125.4, ( CH2), 137.3 (broad, Al-C ), 138.0 (broad, Al-C ),
170.6 ppm (CN); MS: m/z (%): 496.4 (15) [M+], 469.4 (100)
+
=
[M ꢀCH CH2]; elemental analysis (%) calcd for C33H45AlN2
(496.72): C 79.80, H 9.13, N 5.64; found: C 79.26, H 9.18, N 5.56.
Single crystals of 2 were grown from the n-hexane solution of 2 at 48C
within one week.
= =
of RC(O)N3 to RN C O with the elimination of N2 was
3: Toluene (25 mL) was added to a mixture of 1 (0.24 g, 0.5 mmol)
and N3Ar* (0.18 g, 0.5 mmol) at ꢀ508C. The suspension was stirred
and allowed to warm to room temperature. After stirring for 12 h,
removal of the solvent and washing with n-hexane (2 mL) afforded 3
as an orange crystalline solid (0.37 g, 90%); m.p. 2158C; 1H NMR
described 105 years ago,[15] and the Staudinger reaction in
which R3P interacts with N3R’ via the R3PNNNR’ intermedi-
=
ate to form R3P NR’ with the elimination of N2 was reported
in 1919.[16] The reaction of 1 with N3Ar* results in an end-on
3
(300.13 MHz, [D6]benzene, 258C, TMS): d = 1.02 (d, J = 6.8 Hz, 2 ”
=
azide insertion to yield an aluminaazacyclobutene LAl(CH
CHN(N NAr*)) 3: a novel finding in which degradation or
rearrangement of the N3 moiety is not observed. This reflects
the unusual trapping ability of 1. Current work is focused on
experimental confirmation by using 1 to trap small molecules
such as NO, N2O, and CO.
3H, CH(CH3)2), 1.05 (d, 3J = 6.8 Hz, 2 ” 3H, CH(CH3)2), 1.16 (d, 3J =
6.8 Hz, 4 ” 3H, CH(CH3)2), 1.50 (s, 2 ” 3H, b-CH3), 2.23 (s, 2 ” 3H),
2.27 (s, 4 ” 3H, Me(in Ar’)), 2.83 (sept, 3J = 6.8 Hz, 2 ” 1H, CH-
=
(CH3)2), 3.03 (sept, 3J = 6.8 Hz, 2 ” 1H, CH(CH3)2), 4.92 (s, 1H, g-
3
CH), 5.03 (d, J(cis) = 7.6 Hz, 1H), 7.51 (d, 3J(cis) = 7.6 Hz, 1H), (HC
=
CH), 6.83, 6.97–7.12 (m), 7.15 ppm (14H, Ar-H, Ar*-H, Ar’-H);
13C NMR (75.47 MHz, [D6]benzene, 258C, TMS): d = 21.3, 22.3, 23.0,
23.2, 24.4, 24.7, 25.0, 25.8, 26.7, 29.1, 31.9 (CH(CH3)2, b-CH3,
=
Experimental Section
Me(Ar’)), 100.5 (g-C), 114.8 (broad, Al-C ), 123.5, 123.8, 125.1,
130.9, 134.2, 136.0, 138.5, 141.6, 146.2, 147.3 (Ar-C, Ar*-C, Ar’-C),
All manipulations were carried out under a purified nitrogen
atmosphere using Schlenk techniques or inside a glove box filled
with dry nitrogen in which the calibrated values of O2 and H2O were
strictly controlled to below 1ppm.
+
=
162.4 (N-C(H) ), 171.9 ppm (CN); MS: m/z (%): 825 (5) [M ꢀ1], 417
(100) [M+ꢀN3Ar*ꢀC2H2ꢀAl]; elemental analysis (%) calcd for
C55H68AlN5 (826.17): C 79.96, H 8.30, N 8.48; found: C 79.28,
5092 www.angewandte.org
ꢀ 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2005, 44, 5090 –5093

Angewandte
Chemie
H 8.38, N 8.42. Single crystals of 3·0.5 n-hexane were grown from the
n-hexane/toluene solution of 3 at 48C within 5 days.
wR2 = 0.1508 for all data. Fourier synthesis gave a min/max
residual electron density ꢀ0.437/ + 0.589 eŠ3. The crystallo-
graphic data for 1–3 were collected on a Stoe IPDS II-array
detector system using graphite-monochromated MoKa radiation
(l = 0.71073 Š). Intensity measurements were performed on a
rapidly cooled crystal with dimensions 0.40 ” 0.40 ” 0.30 mm3 in
the range 1.92 ꢃ q ꢃ 24.838 for 1, with 0.30 ” 0.30 ” 0.30 mm3 in
1.89 ꢃ q ꢃ 24.828 for 2, and with 0.20 ” 0.10 ” 0.10 mm3 in 1.84 ꢃ
q ꢃ 24.878 for 3. The structures were solved by direct methods
(SHELXS-97)[17] and refined with all data by full-least-squares
against F2.[18] The non-hydrogen atoms were located by differ-
ence Fourier synthesis and refined anisotropically, in which the
Received: March 10, 2005
Published online: July 14, 2005
Keywords: alkenes · alkynes · aluminum · azides · metallacycles
.
[1] E. Roskamp, C. Roskamp in Comprehensive Heterocyclic
Chemistry II, Vol. 2 (Eds.: A. R. Katritzky, C. W. Rees, E. F. V.
Scriven), Pergamon, Oxford, 1996, pp. 305 – 332.
ꢁ
=
C CH and CH CH2 groups in 2 are both disordered and located
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in two positions with the same occupation ratio of 0.622/0.378.
The hydrogen atoms except for H(6) and H(7) in 1 and 3 were
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model. H(6) and H(7) in 1 and 3 were located by difference
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ꢀ ꢀ
ꢀ ꢀ
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C H 1.061 Š, C C H 1 808: K. P. C. Vollhardt, N. E. Schore in
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[9] a) Crystal data for 1: C31H43AlN2, Mr = 470.65, monoclinic, space
group P21/n, a = 12.199(1), b = 16.932(1), c = 13.974(1) Š, b =
103.87(1)8,
F(000) = 1024,
V= 2802(1) Š3,
l = 0.71073 Š,
Z = 4,
T= 133(2) K,
1calcd = 1.116 Mgmꢀ3
m(MoKa) =
,
0.093 mmꢀ1; 29105 measured reflections, 4818 independent
(Rint = 0.0486). The final refinements converged at R1 = 0.0349
and wR2 = 0.0867 for I > 2s(I) and R1 = 0.0502 and wR2 =
0.0916 for all data. Fourier synthesis gave a min/max residual
electron density ꢀ0.255/ + 0.263 eŠ3; b) crystal data for 2:
C33H45AlN2, Mr = 496.69, monoclinic, space group P21/n, a =
18.844(4), b = 8.732(2), c = 20.080(4) Š, b = 112.61(1)8, V=
3050(1) Š3, Z = 4, 1calcd = 1.082 Mgmꢀ3
, F(000) = 1080, l =
0.71073 Š, T= 133(2) K, m(MoKa) = 0.089 mmꢀ1; 14544 mea-
sured reflections, 5145 independent (Rint = 0.0394). The final
refinements converged at R1 = 0.0364 and wR2 = 0.0820 for I >
2s(I) and R1 = 0.0582 and wR2 = 0.0877 for all data. Fourier
synthesis gave a min/max residual electron density ꢀ0.208/
+ 0.163 eŠ3; c) crystal data for 3: C58H75AlN5, Mr = 869.21,
monoclinic, space group P21/c, a = 22.289(5), b = 13.057(3), c =
[16] D. E. C. Corbridge in Phosphorus (An Outline of Its Chemistry,
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[17] SHELXS-90, Program for Structure Solution G. M. Sheldrick,
Acta Crystallogr. Sect. A 1990, 46, 467 – 473.
18.765(4) Š, b = 109.71(3)8, V= 5141(2) Š3, Z = 4, 1calcd
=
1.123 Mgmꢀ3, F(000) = 1884, l = 0.71073 Š, T= 133(2) K, m-
(MoKa) = 0.081mm ꢀ1; 53490 measured reflections, 8850 inde-
pendent (Rint = 0.0825). The final refinements converged at R1 =
0.0560 and wR2 = 0.1371 for I > 2s(I) and R1 = 0.0933 and
[18] SHELXL-97, Program for Crystal Structure Refinement G. M.
Sheldrick, University of Göttingen, Germany, 1997.
Angew. Chem. Int. Ed. 2005, 44, 5090 –5093
ꢀ 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
5093