Reactions of Iminophosphorano(8-quinolyl)methane with AlMe3: Unexpected Formation of Aluminum Iminophosphorano(2-methyl-8-quinolyl)methandiide Complex

Article abstract of DOI:10.1021/om034045v

Reaction of Ph₂P(8-CH₂C₉H ₆N)=NBu^t (1) with 2 equiv of AlMe₃ in toluene under reflux conditions afforded aluminum iminophosphorano(2-methyl-8-quinolyl)methandiide complex (2). The reaction proceeded via the intermediates of a coordination complex, [(AlMe ₃){Ph₂P-(8-CH₂C₉H ₆N)=NBu^t}] (3), and then an addition complex (4) of AlMes to the carbon-nitrogen double bond of the quinolyl ring of the neutral ligand. The coordination complex was converted to the singly deprotonated complex [(AlMe₂){CH(8-C₉H₆N)(Ph₂P=NBu ^t)}] (5) at 60 °C, which further reacted with AlMe₃ in toluene under reflux conditions to yield aluminum iminophosphorano(8-quinolyl)methandiide (6). The structures of complexes 2, 4, and 6 were proved by single-crystal X-ray diffraction techniques, and the five-coordinate complexes 3 and 5 were characterized by ²⁷Al NMR spectroscopy.

Full text of DOI:10.1021/om034045v

4900
Organometallics 2003, 22, 4900-4904
Rea ction s of Im in op h osp h or a n o(8-qu in olyl)m eth a n e w ith
AlMe3: Un exp ected F or m a tion of Alu m in u m
Im in op h osp h or a n o(2-m eth yl-8-qu in olyl)m eth a n d iid e
Com p lex
Zhong-Xia Wang* and Ye-Xin Li
Department of Chemistry, University of Science and Technology of China,
Hefei, Anhui 230026, People’s Republic of China
Received J uly 17, 2003
Reaction of Ph2P(8-CH2C9H6N)dNBut (1) with 2 equiv of AlMe3 in toluene under reflux
conditions afforded aluminum iminophosphorano(2-methyl-8-quinolyl)methandiide complex
(2). The reaction proceeded via the intermediates of a coordination complex, [(AlMe3){Ph2P-
(8-CH2C9H6N)dNBut}] (3), and then an addition complex (4) of AlMe3 to the carbon-nitrogen
double bond of the quinolyl ring of the neutral ligand. The coordination complex was
converted to the singly deprotonated complex [(AlMe2){CH(8-C9H6N)(Ph2PdNBut)}] (5) at
60 °C, which further reacted with AlMe3 in toluene under reflux conditions to yield aluminum
iminophosphorano(8-quinolyl)methandiide (6). The structures of complexes 2, 4, and 6 were
proved by single-crystal X-ray diffraction techniques, and the five-coordinate complexes 3
and 5 were characterized by 27Al NMR spectroscopy.
In tr od u ction
of the methylene of the ligand and the rare addition
complex of AlMe3 to the carbon-nitrogen double bond
of the quinolyl ring.
Organoaluminum compounds with nitrogen-contain-
ing ligands have attracted much attention in recent
years due to their use as precursors to nitride materials
and as catalysts.1 These compounds also show versatile
coordination modes and reactivities.2 For example, the
low-coordinate cationic aluminum compounds have
demonstrated enhanced activities in olefin polymeriza-
tion.3 For ligands, monofunctional amides, phosphin-
imides, chelating N,N-amidinates, guanidinates, and
diketiminates are most prevalent.4 We report here a
new functionalized iminophosphorane ligand, Ph2P(8-
CH2C9H6N)dNBut (C9H6N ) quinolyl), and its reactions
with AlMe3. The reactions formed coordination com-
plexes, both singly and doubly deprotonated complexes
Resu lts a n d Discu ssion
The neutral ligand 1 was prepared by deprotonation
of the phosphonium salt [Ph2(ButNH)(8-CH2C9H6N)P]+-
Br- (prepared by reaction of ButNHPPh2 with 8-bro-
5
momethylquinoline6) using NaH in THF. Treatment of
1 with 2 equiv of AlMe3 in toluene at 120 °C afforded
the bimetallic aluminum iminophosphorano(2-methyl-
8-quinolyl)methandiide complex (2) in 49% yield (Scheme
1). The reaction intermediate 4 was obtained in good
yield by action of 1 with over 1 equiv of AlMe3 at room
temperature or 60 °C. Reaction of 4 with 1 equiv of
AlMe3 at 120 °C produced 2 via elimination of HAlMe2
and methane as well as further elimination of H2.
However, no reaction occurred when heating 4 in the
absence of AlMe3. This showed that the elimination of
methane in the reaction of AlMe3 with 4 may be prior.
Apparently 4 is an addition product of AlMe3 to the
carbon-nitrogen double bond of the quinolyl ring of 1.
Usually addition of trialkylaluminum to a carbon-
nitrogen double bond of a nitrogen-containing hetero-
cyclic compound is difficult, although the additions of
AlMe3 to the carbon-nitrogen double bond of a Schiff
base are known.3b,7 In a control experiment we found
that the reaction between quinoline and 2 equiv of
AlMe3 in toluene under reflux conditions for 5 h yielded
only the coordination complex [AlMe3‚C9H7N] in high
* Corresponding author. E-mail: zxwang@ustc.edu.cn.
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10.1021/om034045v CCC: $25.00 © 2003 American Chemical Society
Publication on Web 10/23/2003

Reactions of Iminophosphorano(8-quinolyl)methane
Organometallics, Vol. 22, No. 24, 2003 4901
Sch em e 1
F igu r e 1. ORTEP diagram of complex 2 with 20% prob-
ability thermal ellipsoids. All hydrogen atoms have been
omitted for clarity. Selected bond lengths (Å) and bond
angles (deg): Al(1)-C(1) 2.126(4), Al(2)-C(1) 2.014(4), Al-
(1)-N(1) 1.920(3), Al(2)-N(2) 1.999(4), P(1)-C(1) 1.745-
(4), P(1)-N(1) 1.611(3); C(1)-Al(1)-N(1) 78.87(13), C(1)-
Al(2)-N(2) 85.54(15), Al(1)-C(1)-Al(2) 121.20(16), C(1)-
P(1)-N(1) 100.14.
yield. Hence it seems that an additional donor group,
an iminophosphorano group, promotes the addition
reaction of AlMe3 to 1. It was also observed that more
than 1 equiv of AlMe3 was necessary to carry out the
addition reaction. Action of an equimolar amount of
AlMe3 with 1 at room temperature formed a coordina-
tion complex, presumably 3 (Scheme 1), which further
reacted with AlMe3 to give complex 4 in 96% yield. In
fact, the addition reaction of 3 with AlMe3 can be
completed in the presence of a catalytic amount of
AlMe3. The extra AlMe3 could act as an external
alkylating agent. The reaction of the coordination
complex 3 with AlMe3 formed an equivalent of AlMe3
besides the addition complex 4, and the released AlMe3
may continue the addition reaction to the unreacted 3.
This was also proved by reaction of complex 3 with
AlEt3. Action of 3 with 1 equiv of AlEt3 gave a brownish-
bimetallic methandiide complex of aluminum, [(AlMe2)2-
{µ2-C(Ph2PdNSiMe3)2-κ4C,C′,N,N′}], has been reported.13
Other dialuminiomethane derivatives are also known.14
Compounds 1-6 have been characterized by elemen-
1
tal analysis and H, 13C, 31P, and 27Al (for 3 and 5) NMR
spectroscopy. To assist the assignments of the signals
1
of the H NMR spectrum of 4, a 2D H-H COSY NMR
spectrum was also run. The 13C signals of the quater-
nary methanediide carbon in 2 and 6 were not observed.
1
The H NMR spectrum of complex 4 showed that the
1
yellow oil. The H NMR spectrum showed that it was a
two protons of the methylene have different chemical
environments, the chemical shifts appearing at 2.51 and
4.66 ppm, respectively. The upfield signal may be due
to agostic interaction between the proton and the
aluminum atom. The 27Al NMR spectra of complexes 3
and 5 show resonances at 70.57 and 69.38 ppm, respec-
tively, consistent with the existence of five-coordinate
aluminum centers.15
mixture of 4 and 7 with impurities, while the reaction
of 3 with a catalytic amount of AlEt3 afforded complex
4. The above reaction provides a route of alkylation of
Complexes 2, 4, and 6 were further characterized by
X-ray crystallography. The molecular structure of com-
plex 2 is showed in Figure 1 along with selective bond
lengths and angles. The complex has a spirocyclic
skeleton that comprises a five-membered metallacyclic
ring and a four-membered metallacyclic ring fused at
C(1). The spiro carbon atom is distorted tetrahedral with
angles ranging from 84.67(16)° to 121.20(16)°. Each
aluminum atom has a distorted tetrahedral geometry.
The C(1)-Al(2)-N(2) bond angle [85.54(15)°] is wider
than that of C(1)-Al(1)-N(1) [78.87(13)°] due to differ-
ence of the ring sizes, and the latter is close to those
the quinoline ring. Some other metal-mediated alkyla-
tions of quinoline and pyridine are also known.8-12 In
the absence of AlMe3 3 was almost quantitatively
converted to 5 at 60 °C in 2 h either in a sealed NMR
tube in C6D6 or in a preparative scale in benzene or
toluene. Further reaction of 5 with 1 equiv of AlMe3 in
toluene under reflux conditions afforded another bime-
tallic aluminum methandiide complex, 6, in 92% yield
via elimination of methane. A structurally related
(13) Aparna, K.; McDonald, R.; Ferguson, M.; Cavell, R. G. Orga-
nometallics 1999, 18, 4241.
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J . Am. Chem. Soc. 1984, 106, 1291. (b) Deelman, B.-J .; Stevels, W.
M.; Teuben, J . H.; Lakin, M. T.; Spek, A. L. Organometallics 1994, 13,
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H.; Yao, C. F. J . Am. Chem. Soc. 1993, 115, 10596. (b) Russell, G. A.;
Guo, D.; Khanna, R. K. J . Org. Chem. 1985, 50, 3423.
(11) Sugiyama, H.; Aharonian, G.; Gambarotta, S.; Yap, G. P. A.;
Budzelaar, P. H. H. J . Am. Chem. Soc. 2002, 124, 12268.
(12) Grigg, R.; Savic, V. Tetrahedron Lett. 1997, 38, 5737.
(14) (a) Robinson, G. H.; Lee, B.; Pennington, W. T.; Sangokoya, S.
A. J . Am. Chem. Soc. 1988, 110, 6260. (b) Robinson, G. H.; Self, M. F.;
Pennington, W. T.; Sangokoya, S. A. Organometallics 1988, 7, 2424.
(c) Lee, B.; Sangokoya, S. A.; Pennington, W. T.; Robinson, G. H. J .
Coord. Chem. 1990, 21, 99. (d) Marek, I.; Normant, J .-F. Chem. Rev.
1996, 96, 3241.
(15) (a) Benn, R.; Rufinska, A. Angew. Chem., Int. Ed. Engl. 1986,
25, 861. (b) Benn, R.; Rufinska, A.; Lehmkuhl, H.; J anssen, E.; Kru¨ger,
C. Angew. Chem., Int. Ed. Engl. 1983, 22, 779. (c) Benn, R.; J anssen,
E.; Lehmkuhl, H.; Rufinska, A. J Organomet. Chem. 1987, 333, 155.
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37, 1655. (e) Lewilin´ski, J .; Zachara, J .; Man´k, B.; Pasynkiewicz, S. J .
Organomet. Chem. 1993, 454, 5.

4902 Organometallics, Vol. 22, No. 24, 2003
Wang and Li
F igu r e 3. ORTEP diagram of complex 4 with 20% prob-
ability thermal ellipsoids. All hydrogen atoms except that
on C(9) have been omitted for clarity. Selected bond lengths
(Å) and bond angles (deg): Al(1)-N(1) 1.988(2), Al(1)-N(2)
1.892(2), P(1)-C(1) 1.810(2), P(1)-N(1) 1.614(2), C(9)-N(2)
1.491(3), C(10)-N(2) 1.378(3); N(1)-Al(1)-N(2) 107.33(9),
N(1)-Al(1)-C(28) 107.97(11), C(28)-Al(1)-C(29) 106.98(14),
C(1)-P(1)-N(1) 107.50(11), P(1)-N(1)-Al(1) 116.60(11),
C(10)-N(2)-Al(1) 130.70(17), N(2)-C(9)-C(8) 112.1(3).
F igu r e 2. ORTEP diagram of complex 6 with 20% prob-
ability thermal ellipsoids. All hydrogen atoms have been
omitted for clarity. Selected bond lengths (Å) and bond
angles (deg): Al(1)-N(1) 1.925(3), Al(1)-C(1) 2.132(4),
Al(2)-N(2) 1.985(4), Al(2)-C(1) 2.006(4), P(1)-N(1) 1.620(3),
P(1)-C(1) 1.754(4), C(1)-C(2) 1.495(5); N(1)-Al(1)-C(1)
79.30(13), N(2)-Al(2)-C(1) 85.94(16), Al(2)-C(1)-Al(1)
121.69(17), N(1)-P(1)-C(1) 100.42(16), P(1)-N(1)-Al(1)
95.06(14).
Reaction of Ph2P(8-CH2C9H6N)dNBut with 2 equiv of
AlMe3 in toluene under reflux conditions afforded spiro-
cyclic aluminum iminophosphorano(2-methyl-8-quinolyl)-
methandiide (2), while stepwise reaction of Ph2P(8-CH2-
C9H6N)dNBut with AlMe3 gave spirocyclic aluminum
iminophosphorano(8-quinolyl)methandiide (6). Complex
2 was formed via the intermediates of a coordination
complex of AlMe3 with the neutral ligand and an
addition complex (4) of AlMe3 to the carbon-nitrogen
double bond of the quinolyl ring of Ph2P(8-CH2C9H6N)d
NBut, while complex 6 was yielded via the coordination
complex and then a singly deprotonated complex of the
ligand, [AlMe2{CH(8-C9H6N)(Ph2PdNBut)}]. Complex
4 also provides a rare example of addition of trialkyl-
aluminum to a carbon-nitrogen double bond of a nitro-
gen-containing heterocyclic compound.
found in [(AlMe2)2{µ2-C(Ph2PdNSiMe3)2-κ4C,C′N,N′}]
(av 80.0°).13 The Al(1)-C(1) distance of 2.216(4) Å is
longer than that of Al(2)-C(1), 2.014(4) Å, and both are
comparable to corresponding distances in [(AlMe2)2{µ2-
C(Ph2PdNSiMe3)2-κ4C,C′N,N′}], 2.117(3) and 2.121(3)
Å, respectively.13 The Al(2)-N(2) distance of 1.999(4)
Å is longer than that of Al(1)-N(1), 1.920(3) Å, and is
also longer than those in [(AlMe2)2{µ2-C(Ph2PdNSiMe3)2-
κ4C,C′N,N′}] (av 1.930 Å), but still within the usual
range.2d,4a,c,16
The monomeric crystalline complex 6 has a skeletal
structure very similar to 2 (Figure 2), and the bond
lengths and bond angles are also comparable to corre-
sponding ones in complex 2.
The molecular structure of complex 4 is shown in
Figure 3 along with selective bond lengths and angles.
The complex is a monomer in which the two nitrogen
atoms of the ligand chelate to an aluminum center to
form a seven-membered metallacyclic ring with Al(1),
N(1), P(1), C(1), C(2), C(10), and N(2) atoms adopting a
distorted boat conformation. The coordination geometry
at aluminum is distorted tetrahedral with angles rang-
ing from 105.60(12)° to 115.34(12)°. The distance of the
aluminum atom to the iminophosphorano-nitrogen atom
[1.988(2) Å] is significantly longer than that to the
formally negatively charged nitrogen atom [1.892(2) Å].
The bond angles at C(9) ranging from 110.1(3)° to
112.1(3)° reflect an sp3 hybrid of C(9). The sum of the
bond angles at N(2) is 359.48°, indicating that the atoms
N(2), Al(1), C(9), and C(10) lie in a plane.
Exp er im en ta l Section
Ger n er a l P r oced u r es. All experiments were performed
under nitrogen using standard Schlenk and vacuum line
techniques. Solvents were distilled under nitrogen over sodium
(toluene), sodium-benzophenone (benzene, THF, Et2O, and
n-hexane), or CaH2 (CH2Cl2) and degassed prior to use. CDCl3
and C6D6 were purchased from Acros Organics and degassed
and stored over activated molecular sieves (CDCl3) or Na/K
alloy (C6D6). LiBun and Ph2PCl were purchased from Acros
Organics and used as obtained. AlMe3 and AlEt3 was pur-
chased from Alfa Aesar and used as received. ButNHPPh25 and
8-bromomethylquinoline6 were prepared according to litera-
ture. NMR spectra were recorded on a Bruker av400 or av300
spectrometer at ambient temperature. The chemical shifts of
1H and 13C{1H} NMR spectra are referenced to internal solvent
resonances, the 31P{1H} NMR spectra are referenced to
external 85% H3PO4, and the 27Al NMR spectra are referenced
to external AlCl3. Infrared spectra were recorded on a Bruker
VECTOR-22 spectrometer. Elemental analyses were per-
formed by the Analytical Laboratory of Shanghai Institute of
Organic Chemistry and the Analytical Center of the University
of Science and Technology of China.
Su m m a r y
We have described the reactions of an iminophosphor-
ane-methylene-quinoline compound, Ph2P(8-CH2C9H6N)d
NBut, with AlMe3. The products formed are dependent
on the reaction conditions and the ratio of the reactants.
(16) (a) Robson, D. A.; Rees, L. H.; Mountford, P.; Schro¨der, M.
Chem. Commun. 2000, 1269. (b) Yamaguchi, I.; Tijima, T.; Yamamoto,
T. J . Organomet. Chem. 2002, 654, 229. (c) Styron, E. K.; Lake, C. H.;
Watkins, C. L.; Krannich, L. K. Organometallics 2000, 19, 3253.
P r ep a r a tion of [P h 2(8-CH2qu in olyl)(NHBu t)P ]+Br -. To
a solution of 8-bromomethylquinoline (7.22 g, 32.81 mmol) in

Reactions of Iminophosphorano(8-quinolyl)methane
Organometallics, Vol. 22, No. 24, 2003 4903
80 mL of CH2Cl2 was added Ph2PNHBut (8.40 g, 32.64 mmol)
at room temperature with stirring. The mixture was stirred
for 8 h and then the solvent removed under vacuum. Benzene
was added to the viscous residue to form a white crystalline
solid (13.45 g, 86%), mp 230-233 °C. 1H NMR (CDCl3): δ
(ppm) 1.17 (s, 9H, But), 5.29 (d, J ) 16.0 Hz, 2H, CH2), 7.20-
7.43 (m, 5H, Ar), 7.56 (t, J ) 6.8 Hz, 2H, Ar), 7.72 (dd, J )
7.7, 12.6 Hz, 5H, Ar), 7.99 (s, 1H, Ar), 8.12 (s, 1H, Ar), 8.47 (d,
J ) 3.5 Hz, 1H, Ar). 13C{1H} NMR (CDCl3): δ (ppm) 30.68 (d,
J ) 64.7 Hz, CH2), 32.09 (d, J ) 4.3 Hz, But), 55.70 (d, J ) 5.5
Hz, But), 121.63, 121.74, 123.01, 127.10, 127.66, 128.46 (d, J
) 2.6 Hz), 128.78 (d, J ) 4.1 Hz), 129.36 (d, J ) 12.8 Hz),
133.76 (d, J ) 10.4 Hz), 134.63 (d, J ) 2.9 Hz), 138.01, 145.77,
149.11. 31P{1H} NMR (CDCl3): δ (ppm) 37.35.
benzene, and dried under vacuum to give a white powder of 3
(0.33 g, 82%), mp 119-121 °C. H NMR (C6D6): δ (ppm) 0.39
1
(s, 9H, Al-Me), 1.49 (s, 9H, But), 5.48 (d, J ) 18.4 Hz, 2H, CH2),
6.54 (dd, J ) 4.1, 8.1 Hz, 1H, Ar), 6.72-6.84 (m, 4H, Ar), 6.92-
7.00 (m, 3H, Ar), 7.15-7.20 (m, 2H, Ar), 7.56-7.63 (m, 3H,
Ar), 7.80-7.86 (m, 2H, Ar), 8.10-8.15 (m, 1H, Ar). 13C{1H}
NMR (C6D6): δ (ppm) 0.84 (Al-Me), 33.35 (But), 33.74 (d, J )
65.8 Hz, CH2), 52.50 (But), 120.66, 122.79, 125.58, 126.17,
128.67, 129.33, 131.06, 131.46, 132.43, 133.16 (d, J ) 9.8 Hz),
133.65 (d, J ) 8.1 Hz), 134.08 (d, J ) 9.6 Hz), 135.12, 139.39,
147.47, 148.46, 149.31. 31P{1H} NMR (C6D6): δ (ppm) 33.21.
27Al NMR (C6D6): δ (ppm) 70.57 (w1/2 ) 3600 Hz). Anal. Calcd
for C29H36N2PAl: C, 74.02; H, 7.71; N, 5.95. Found: C, 73.82;
H, 7.83; N, 5.89.
P r ep a r a tion of P h 2P (8-CH2qu in olyl)dNBu t (1). A mix-
ture of [Ph2(8-CH2quinolyl)(NHBut)P]+Br- (1.55 g, 3.24 mmol)
and NaH (0.16 g, 6.67 mmol) in THF (20 mL) was stirred
overnight at room temperature and then refluxed for 2 h. The
mixture was filtered, and the solvent was removed from the
filtrate under vacuum. The residue was recrystallized in
hexane to give colorless crystalline 1 (1.08 g, 84%), mp 114-
P r ep a r a tion of Com p lex 4. (1) By Rea ction of P h 2P -
(8-CH2qu in olyl)dNBu t w ith 2 Equ iv of AlMe3. To a solu-
tion of 1 (0.57 g, 1.43 mmol) in toluene (10 mL) was added
AlMe3 (2.3 M solution in hexane, 1.24 mL, 2.85 mmol) at room
temperature. The mixture was stirred at room temperature
overnight and at 60 °C for 4 h. The mixture was filtered, and
the filtrate was concentrated under vacuum to afford pale
yellow crystals of 4 (0.50 g, 75%), mp 190 °C (dec). 1H NMR
(C6D6): δ (ppm) 0.00 (s, 3H, Al-Me), 0.22 (s, 3H, Al-Me), 1.19
(s, 9H, But), 1.25 (d, J ) 6.5 Hz, 3H, Me), 2.51 (dd, J ) 14.7,
7.6 Hz, 1H, P-CH), 4.56 (quintet, J ) 6.2 Hz, 1H, NCH), 4.66
(dd, J ) 14.7, 16.7 Hz, 1H, P-CH), 5.88 (dt, J ) 2.1, 7.4 Hz,
1H, Ar), 5.97 (dd, J ) 5.9, 9.2 Hz, 1H, CHdCH), 6.34 (td, J )
0.8, 7.4 Hz, 1H, Ar), 6.50 (d, J ) 9.3 Hz, 1H, CHdCH), 6.86-
6.96 (m, 2H, Ar), 6.98-7.02 (m, 2H, Ar), 7.06-7.09 (m, 3H,
Ar), 7.25-7.31 (m, 2H, Ar), 7.72-7.77 (m, 2H, Ar). 13C{1H}
NMR (C6D6): δ (ppm) -1.90 (Al-Me), 0.75 (Al-Me), 22.57 (Me),
33.79 (d, J ) 7.40 Hz, But), 37.54 (d, J ) 71.5 Hz, CH2), 48.83
(NCH), 57.06 (d, J ) 7.1 Hz, But), 113.59, 116.94 (d, J ) 10.2
Hz), 125.10, 126.05, 126.78, 128.74, 128.89, 129.11, 130.09,
130.69 (d, J ) 4.9 Hz), 131.16, 132.17, 132.38, 133.18 (d, J )
9.1 Hz), 133.65 (d, J ) 8.7 Hz), 150.95. 31P{1H} NMR (C6D6):
δ (ppm) 33.27. Anal. Calcd for C29H36N2PAl: C,74.02; H 7.71;
N, 5.95. Found: C,74.19; H, 7.99; N, 5.49.
1
116 °C. H NMR (C6D6): δ (ppm) 1.47 (s, 9H, But), 4.80 (d, J
) 13.7 Hz, 2H, CH2), 6.71 (dd, J ) 4.1, 8.2 Hz, 1H, Ar), 6.94-
6.96 (m, 6H, Ar), 7.12-7.17 (m, 2H, Ar), 7.43 (dd, J ) 1.5, 8.2
Hz, 1H, Ar), 7.77-7.84 (m, 4H, Ar), 8.11 (d, J ) 6.7 Hz, 1H,
Ar), 8.61-8.63 (m, 1H, Ar). 13C{1H} NMR (C6D6): δ (ppm)
32.26 (d, J ) 61.1 Hz, CH2), 36.17 (d, J ) 10.6 Hz, But), 52.42
(But), 120.94, 126.55 (dd, J ) 2.7, 9.7 Hz), 128.26, 130.49 (d,
J ) 2.6 Hz), 131.35 (d, J ) 5.2 Hz), 132.73 (d, J ) 9.1 Hz),
134.12 (d, J ) 6.8 Hz), 136.30, 136.68, 137.94, 147.81 (d, J )
5.4 Hz), 149.24. 31P{1H} NMR (C6D6): δ (ppm) 18.99. IR
(KBr): ν (cm-1) 1269vs (PdN). Anal. Calcd for C26H27N2P: C,
78.37; H, 6.83; N, 7.03. Found: C, 77.97; H, 6.82; N, 6.89.
P r ep a r a tion of [(AlMe2)2{C(P h 2P dNBu t)(2-Me-8-qu in -
olyl)] (2). (1) By Rea ction of Com p ou n d 1 w ith 2 Equ iv
of AlMe3 in Tolu en e a t 120 °C. To a solution of 1 (0.34 g,
0.85 mmol) in toluene (15 mL) was added AlMe3 (2.3 M
solution in hexane, 0.74 mL, 1.70 mmol) at room temperature
with stirring. The mixture was stirred at room temperature
overnight and at 120 °C (bath temperature) for 5 h. The solvent
was removed under vacuum. The residue was dissolved in Et2O
and then filtered. Concentration of the filtrate afforded yellow
(2) By Rea ction of P h 2P (8-CH2qu in olyl)dNBu t w ith 1.2
Equ iv of AlMe3. The same method as in (1) was used, but
the molar ratio of Ph2P(8-CH2quinolyl)dNBut to AlMe3 was
changed to 1:1.2. After similar workup, complex 4 was obtained
in 74% yield.
1
crystals of 2 (0.22 g, 49%), mp 256 °C (dec). H NMR (C6D6):
(3) By Reaction of [AlMe3{P h 2P (8-CH2qu in olyl)dNBu t}]
(3) w ith AlMe3. To a suspension of complex 3 (0.23 g, 0.49
mmol) in toluene (10 mL) was added AlMe3 (2.3 M solution in
hexane, 0.20 mL, 0.46 mmol) at room temperature. The
mixture was stirred at room temperature overnight and at 60
°C for 2 h. The mixture was filtered, and the filtrate was
concentrated under vacuum to give crystalline 4 (0.22 g, 96%).
P r ep a r a t ion of [AlMe2{CH (8-q u in olyl)(P h 2P dNBu t }]
(5). A suspension of complex 3 (0.27 g, 0.57 mmol) in toluene
(10 mL) was stirred at 60 °C for 2 h and then filtered. The
solvent was removed under vacuum to afford a pale yellow oil
identified as 5 (0.25 g, 96%). 1H NMR (C6D6): δ (ppm) 0.12 (s,
3H, Al-Me), 0.27 (s, 3H, Al-Me), 1.33 (s, 9H, But), 5.60 (d, J )
14.5 Hz, 1H, CH), 6.70-6.82 (m, 1H, Ar), 6.95-7.01 (m, 4H,
Ar), 7.08-7.16 (m, 5H, Ar), 7.51-7.57 (m, 3H, Ar), 8.09-8.15
(m, 2H, Ar), 8.82 (d, J ) 3.6 Hz, 1H, Ar). 13C{1H} NMR
(C6D6): δ (ppm) -5.48 (Al-Me), -4.83 (Al-Me), 26.66 (d, J )
58.8 Hz, CH), 33.36 (d, J ) 7.5 Hz, But), 52.54 (d, J ) 5.6 Hz,
But), 120.69, 122.77 (d, J ) 3.9 Hz), 126.16 (d, J ) 4.0 Hz),
128.54, 128.69, 129.26 (d, J ) 7.5 Hz), 130.42, 131.50, 132.42
(d, J ) 8.9 Hz), 133.16 (d, J ) 9.8 Hz), 133.75, 134.07 (d, J )
9.7 Hz), 134.65, 136.09, 139.35 (d, J ) 3.6 Hz), 147.69 (d, J )
8.7 Hz), 148.47. 31P{1H} NMR (C6D6): δ (ppm) 35.02. 27Al NMR
(C6D6): δ (ppm) 69.38 (w1/2 ) 3700 Hz). Anal. Calcd for
δ (ppm) -1.01 (s, 3H, Al-Me), -0.51 (s, 3H, Al-Me), 0.21 (s,
3H, Al-Me), 0.30 (s, 3H, Al-Me), 1.33 (s, 9H, But), 2.29 (s, 3H,
Ar-Me), 6.16 (d, J ) 8.3 Hz, 1H, Ar), 6.70 (d, J ) 7.9 Hz, 1H,
Ar), 6.89-6.95 (m, 4H, Ar), 7.06-7.14 (m, 5H, Ar), 7.85-7.91
(m, 2H, Ar), 8.03-8.10 (m, 2H, Ar). 13C{1H} NMR (C6D6): δ
(ppm) -7.14 (Al-Me), -5.94 (Al-Me), -4.23 (Al-Me), -1.72 (Al-
Me), 22.97 (Me), 34.00 (d, J ) 7.5 Hz, But), 52.85 (d, J ) 8.6
Hz, But), 118.03, 123.45, 126.91, 127.29, 128.98, 129.13, 130.39,
130.79, 131.12 (d, J ) 10.7 Hz), 131.34, 131.71 (d, J ) 9.6 Hz),
134.05 (d, J ) 9.5 Hz), 137.79, 138.93, 140.66, 145.73 (d, J )
17.7 Hz), 146.46. 31P{1H} NMR (C6D6): δ (ppm) 36.53. Anal.
Calcd for C31H39N2PAl2: C,70.98; H, 7.49; N, 5.34. Found: C,
71.36; H, 7.82; N, 5.59.
(2) By Rea ction of Com p lex 4 w ith 1 Equ iv of AlMe3
in Tolu en e a t 120 °C. To a solution of 4 (0.30 g, 0.64 mmol)
in toluene (10 mL) was added AlMe3 (2.3 M solution in hexane,
0.28 mL, 0.64 mmol) at room temperature. The mixture was
stirred at room temperature for 2 h and at 120 °C (bath
temperature) for 5 h. The solvent was removed under vacuum.
The residue was dissolved in Et2O and then filtered. Concen-
tration of the filtrate produced yellow crystals identified as 2
(0.17 g, 51%).
P r ep a r a t ion of [AlMe3{P h 2P (8-CH2q u in olyl)dNBu t }]
(3). To a benzene (10 mL) solution of compound 1 (0.34 g, 0.85
mmol) was added AlMe3 (2.3 M solution in hexane, 0.36 mL,
0.83 mmol) with stirring at room temperature. A white
precipitate was formed after a few minutes. The stirring was
continued for 3 h. The precipitate was filtered, washed with
C
28H32N2PAl: C,73.99; H 7.10; N, 6.16. Found: C, 73.67; H,
7.40; N, 6.02.
P r ep a r a tion of [(AlMe2)2{C(8-qu in olyl)(P h 2P dNBu t)}]
(6). To a solution of complex 5 (0.29 g, 0.64 mmol) in toluene

4904 Organometallics, Vol. 22, No. 24, 2003
Ta ble 1. Deta ils of th e X-r a y Str u ctu r e Deter m in a tion s of Com p lexes 2, 4, a n d 6
Wang and Li
2
4
6
empirical formula
fw
cryst syst
space group
a (Å)
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3)
C
31H39Al2N2P
C29H36AlN2P
470.55
triclinic
P1h
10.912(3)
11.610(4)
13.007(4)
88.417(5)
65.396(5)
63.159(5)
1310.4(7)
2
1.193
504
0.158
2.20 to 25.00
6810
C30H37Al2N2P
524.57
triclinic
P1h
510.55
monoclinic
P2(1)/n
9.998(3)
22.527(6)
13.184(4)
90
95.960(5)
90
2953.3(15)
4
1.148
1088
0.173
2.44 to 25.00
14 659
10.029(3)
12.015(3)
12.520(4)
89.232(5)
88.610(6)
88.114(6)
1507.3(8)
2
1.156
560
0.171
2.57 to 25.00
7776
Z
Dcalcd (g/cm3)
F(000)
µ (mm-1
)
θ range for data collecn (deg)
no. of reflns collected
no. of indep reflns (Rint
)
5219 (Rint ) 0.0473)
4585 (Rint ) 0.0434)
5177 (Rint ) 0.0913)
no. of data/restraints/params
5219/0/333
4585/0/304
5177/0/323
goodness of fit on F2
0.989
0.979
0.986
final R indicesa [I > 2σ(I)]
R indices (all data)
R1 ) 0.0661, wR2 ) 0.1101
R1 ) 0.1462, wR2 ) 0.1377
0.330 and -0.262
R1 ) 0.0458, wR2 ) 0.1030
R1 ) 0.0833, wR2 ) 0.1195
0.268 and -0.245
R1 ) 0.0676, wR2 ) 0.1152
R1 ) 0.1545, wR2 ) 0.1369
0.254 and -0.295
largest diff peak and hole [e‚Å-3
]
R1 ) ∑||Fo| - |Fc||/∑|Fo|; wR2 ) [∑w(Fo - Fc2)2/∑w(Fo4)]1/2
.
a
2
(10 mL) was added AlMe3 (2.3 M solution in hexane, 0.28 mL,
0.64 mmol) at room temperature with stirring. The mixture
was stirred at 120 °C (bath temperature) for 5 h and filtered
after cooling to rt. The filtrate was concentrated under vacuum
to give orange crystals (0.30 g, 92%), mp 254-256 °C. 1H NMR
(C6D6): δ (ppm) -0.97 (s, 3H, Al-Me), -0.45 (s, 3H, Al-Me),
0.29 (s, 3H, Al-Me), 0.37 (s, 3H, Al-Me), 1.41 (s, 9H, But), 6.38
(dd, J ) 4.8, 8.2 Hz, 1H, Ar), 6.77 (d, J ) 8.0 Hz, 1H, Ar),
7.00-7.06 (m, 4H, Ar), 7.13-7.33 (m, 5H, Ar), 7.88 (dd, J )
1.5, 4.8 Hz, 1H, Ar), 7.93-8.00 (m, 2H, Ar), 8.13-8.19 (m, 2H,
Ar). 13C{1H} NMR (C6D6): δ (ppm) -6.10 (Al-Me), -5.81 (Al-
Me), -2.09 (Al-Me), 33.93 (d, J ) 7.7 Hz, But), 52.86 (d, J )
8.5 Hz, But), 117.71, 120.56, 127.92, 128.24, 129.25 (d, J )
12.2 Hz), 130.16 (d, J ) 12.4 Hz), 130.91, 131.35, 131.48,
134.03 (d, J ) 9.7 Hz), 138.08, 139.22, 140.27, 144.32, 145.66,
145.90, 147.42. 31P{1H} NMR (C6D6): δ (ppm) 35.59. Anal.
Calcd for C30H37N2PAl2: C, 70.57; H, 7.30; N, 5.49. Found: C,
70.28; H, 7.61; N, 5.32.
radiation (λ ) 0.71073 Å). Semiempirical absorption correc-
tions were applied to the data for 2 and 6. The structures were
solved by direct methods (SHELXS-97)17 and refined against
F2 by full-matrix least-squares using SHELXL-97.18 Hydrogen
atoms were placed in calculated positions. Crystal data and
experimental details of the structure determinations are listed
in Table 1.
Ack n ow led gm en t. This research was supported by
The National Natural Science Foundation of China
(Project Code 20072035) and The Excellent Young
Teachers Program of MOE, People’s Republic of China.
We thank Prof. H.-G. Wang and Dr. H.-B. Song for X-ray
structure determinations.
Su p p or tin g In for m a tion Ava ila ble: X-ray crystallo-
graphic files for 2, 4, and 6 in CIF format. This material is
available free of charge via the Internet at http://pubs.acs.org.
Cr ysta l Str u ctu r e Solu tion a n d Refin em en t for Com -
p lexes 2, 4, a n d 6. Single crystals of complexes 2, 4, and 6
were mounted in Lindemann capillaries under nitrogen.
Diffraction data were collected on a Siemens CCD area-
detector at 293(2) K with graphite-monochromated Mo KR
OM034045V
(17) Sheldrick, G. M. Acta Crystallogr., Sect. A 1990, 46, 467.
(18) Sheldrick, G. M. SHELXL97, Programs for structure refine-
ment; Universita¨t Go¨ttingen, 1997.