Synthesis and characterisation of alkyl-N,N′-bis(salicylidene)ethylenediamino- and alkyl-N,N′-bis(salicylidene)-1,2-phenylenediaminogallium or indium complexes: Crystal structure of methyl-N,N′-bis(salicylidene)-1,2-phenylenediaminoindium

Article abstract of DOI:10.1016/S0022-328X(99)00466-0

The reaction of trialkylgallium or indium R₃M (M=In, Ga; R=Me, Et) with N,N′-ethylenebis(salicylideneimine) or 1,2-N,N′-phenylenebis(salicylideneimine) yields seven intramolecularly coordinated organogallium or organoindium complexes. Two hydro

Full text of DOI:10.1016/S0022-328X(99)00466-0

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 590 (1999) 242–247
Synthesis and characterisation of alkyl-N,N%-bis(salicylidene)-
ethylenediamino- and alkyl-N,N%-bis(salicylidene)-1,2-phenyl-
enediaminogallium or indium complexes: crystal structure of
methyl-N,N%-bis(salicylidene)-1,2-phenylenediaminoindium
Ying-Zhong Shen a, Yi Pan a,*, Le-Yong Wang a, Gang Dong a, Xiao-Ping Jin a,
Xiao-Ying Huang b, Hongwen Hu a
a State Key Laboratory of Coordination Chemistry, Department of Chemistry, Nanjing Uni6ersity, Nanjing 210093, People’s Republic of China
b State Key Laboratory of Structure Chemistry, Fuzhou 250003, People’s Republic of China
Received 27 April 1999; accepted 30 July 1999
Abstract
The reaction of trialkylgallium or indium R3M (M=In, Ga; R=Me, Et) with N,N%-ethylenebis(salicylideneimine) or
1,2-N,N%-phenylenebis(salicylideneimine) yields seven intramolecularly coordinated organogallium or organoindium complexes.
Two hydroxyl protons in the ligands react with both trialkylindium and trimethylgallium, while one hydroxyl group reacts
1
exclusively with triethylgallium. The complexes obtained have been fully characterised by elemental analysis, H-NMR, IR and
mass spectroscopy. The structure of methyl-N,N%-bis(salicylidene)-1,2-phenylenediaminoindium (1) has been determined by
single-crystal X-ray analysis. The In atom is five coordinate in the structure. Fluorescence spectroscopy has shown that the
maximum emission wavelength of 1 is 499 nm upon radiation by UV light. © 1999 Elsevier Science S.A. All rights reserved.
Keywords: Trialkylgallium; Trialkylindium; Organometallic complex; Schiff base; Luminescent
gallium or indium complexes as OEL materials has
been rarely studied [9]. Application of Group 13
1. Introduction
organometallic compounds in OEL materials will cer-
Organoaluminium, gallium and indium complexes,
tainly create a new variety in this field. The structures
which contain either Group 15 or 16 elements, have
of salicylaldehyde Schiff bases are similar to that of
been under investigation for many years due to their
8-hydroxyquinoline, in that they both have at least
rich structural information and wide applications in
one hydroxyl group, a coordination nitrogen atom,
material science [1–3] and organic reactions [4,5]. Or-
and a delocalised p-system; however, the structures
of salicylaldehyde Schiff bases are certainly more
flexible than that of 8-hydroxyquinoline. Organometal-
lic complexes of salicylaldehyde Schiff base ligands
are expected to show good luminescent properties. As
part of our efforts in searching for new OEL sub-
stances, we wish to report here the synthesis and
characterisation of alkylgallium and indium complex-
es LMR (H2L=N,N%-ethylenebis(salicylideneimine)
or 1,2-N,N%-phenylenebis(salicylideneimine), R=CH3,
M=Ga, In; R=Et, M=In) and (HL)GaEt2. The
ganic electroluminescent (OEL) devices have recently
received much attention because of their potential emis-
sion of all colours (from blue to red) and their possible
applications in large-area light displays [4–6]. Tris(8-
hydroxyquinoline)aluminium (Alq3) [7] is one of the
typical examples of an OEL emitting material. Al-
though there are many reports on OEL devices in
recent years [8], the application of organoaluminium,
* Corresponding author.
E-mail address: mochemnu@public1.ptt.js.cn (Y. Pan)
0022-328X/99/$ - see front matter © 1999 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(99)00466-0

Y.-Z. Shen et al. / Journal of Organometallic Chemistry 590 (1999) 242–247
243
Scheme 1.
crystal structure of methyl-N,N%-bis(salicylidene)-1,2-
phenylenediaminoindium (1) has been determined by
X-ray analysis and the luminescent emission spectrum
of 1 has also been measured.
lium with the ligands, however, formed predominantly
the diethylgallium products (6 and 7), possibly due to
the steric effects around the metal centre. The radius of
gallium is smaller than that of indium and an ethyl
group is also sterically bulkier than a methyl group.
Once one ethyl group is eliminated from the gallium,
the crowded gallium centre may prevent the second
hydroxyl group from approaching. The structure was
2. Results and discussion
1
confirmed by IR and H-NMR spectroscopy. The sig-
The reaction of gallium and indium alkyls R3M
nals of OH protons in the spectra were visible. In their
1H-NMR spectra, the OꢀH signals were observed at
12.76 and 12.83 ppm for 6 and 7, respectively. In the IR
spectra of 6 and 7, the strong OꢀH absorption appeared
at 3454 and 3495 cm−1, respectively. The molecular ion
peaks of complexes 1, 4 and 5 were observed in MS
spectra, suggesting that the complexes are fairly stable,
even in the ionic state. Although there were no M+
peaks for other complexes, fairly intensive fragments
were observed upon elimination of one or two alkyls.
The relative intensity of the peaks for the metal con-
taining species agreed well with the isotopic distribution
of the metals (69Ga (ca. 60%); 71Ga (ca. 40%) and 113In
(ca. 9%); 115In (ca. 91%)).
(M=Ga, In; R=Me, Et) with the Schiff base ligands,
N,N%-ethylenebis(salicylideneimine)
and
1,2-N,N%-
phenylenebis(salicylideneimine), proceeded smoothly at
room temperature in a 1:1 ratio affording the corre-
sponding intramolecularly coordinated complexes as
shown in Scheme 1. The complexes were isolated as
yellow solids in high yields. Although gallium and
indium alkyls are extremely moisture and oxygen sensi-
tive, the complexes obtained are fairly stable on expo-
sure to air. Compounds 1–5 could be left in an ambient
atmosphere for weeks without obvious decomposition.
The complexes are insoluble in cold saturated hydro-
carbons, such as pentane or petroleum, whereas they
are highly soluble in unsaturated hydrocarbons, such as
benzene or toluene. All the products obtained gave
satisfactory elemental analysis results, and were charac-
1
terised by IR, H-NMR and MS spectroscopy.
Two active hydroxyl protons in the ligands of N,N%-
ethylenebis(salicylideneimine) and 1,2-N,N%-phenylene-
bis(salicylideneimine) reacted with trimethylgallium,
trimethylindium and triethylindium to form the
monoalkyl complexes 1–5 with methane or ethane
eliminated as by-products. In both the IR and 1H-
NMR spectra of the complexes, there were no OꢀH
signals. By comparison with the IR spectra of the free
ligands, the CꢀH stretch vibration band of the com-
plexes were relatively stronger. In the 1H-NMR spectra,
the signals due to the metal-bonded methyl or
methylene signals were found to shift downfield from
those of the metallic trialkyls. Reactions of triethylgal-
Fig. 1. Molecular structure of methyl-N,N%-bis(salicylidene)-1,2-
phenylenediaminoindium (1) showing 30% probability displacement
ellipsoids. Hydrogen atoms are omitted for clarity.

244
Y.-Z. Shen et al. / Journal of Organometallic Chemistry 590 (1999) 242–247
Table 1
,
Selected bond lengths (A) and angles (°) for C21H17N2O2In (1)
Bond lengths
InꢀO(1)
InꢀN(1)
InꢀC(21)
O(2)ꢀC(20)
N(1)ꢀC(8)
C(6)ꢀC(7)
C(15)ꢀC(20)
2.092(4)
2.258(4)
2.133(7)
1.301(7)
1.401(6)
1.437(6)
1.416(8)
InꢀO(2)
InꢀN(2)
O(1)ꢀC(1)
N(1)ꢀC(7)
N(2)ꢀC(13)
C(8)ꢀC(13)
C(1)ꢀC(6)
2.093(4)
2.265(4)
1.313(6)
1.283(6)
1.397(6)
1.421(7)
1.417(7)
Bond angles
O(1)ꢀInꢀO(2)
O(1)ꢀInꢀN(1)
O(1)ꢀInꢀN(2)
O(2)ꢀInꢀN(1)
C(21)ꢀInꢀN(1)
N(1)ꢀInꢀN(2)
C(20)ꢀO(2)ꢀIn
C(8)ꢀN(1)ꢀIn
C(13)ꢀN(2)ꢀIn
90.7(2)
83.8(2)
138.3(2)
133.0(2)
112.4(2)
71.6(1)
131.1(4)
112.7(3)
111.8(3)
O(1)ꢀInꢀC(21)
C(1)ꢀC(6)ꢀC(7)
O(2)ꢀInꢀC(21)
O(2)ꢀInꢀN(2)
C(21)ꢀInꢀN(2)
C(1)ꢀO(1)ꢀIn
110.9(2)
125.1(4)
113.0(3)
82.8(2)
109.5(2)
130.0(3)
125.8(3)
127.0(4)
126.7(4)
121.4(4)
125.7(5)
124.4(4)
125.3(5)
C(7)ꢀN(1)ꢀIn
C(14)ꢀN(2)ꢀIn
N(1)ꢀC(7)ꢀC(6)
C(7)ꢀN(1)ꢀC(8)
N(2)ꢀC(14)ꢀC(15)
C(20)ꢀC(15)ꢀC(14)
O(2)ꢀC(20)ꢀC(15)
N(1)ꢀC(8)ꢀC(13) 116.0(4)
N(2)ꢀC(13)ꢀC(8) 115.8(4)
C(14)ꢀN(2)ꢀC(13) 121.2(4)
Fig. 2. Structure unit cell of 1.
O(1)ꢀC(1)ꢀC(6)
124.0(4)
O(2)ꢀC(20)ꢀC(19) 117.6(5)
C(5A)ꢀC(6A) ring of the other [16]. The nearest dis-
,
tance (H(16)ꢀC(5A)) is 3.18 A.
An emission spectrum of complex 1 in chloroform
showed that 1 fluoresces in the blue–green region (see
Fig. 3). The emission maximum was at u=499 nm with
an intensity of 53 cd m−2. The intense emission band
suggests that the incorporation of the organoindium
group to the ligand increases its emission efficiency.
Fluorescence properties of other compounds and their
OEL properties are now under investigation by our
group.
The structure of complex 1 was determined by single-
crystal X-ray analysis. The molecular structure is
shown in Fig. 1 and selected bond lengths and angles
are listed in Table 1. In the structure, the In atom is in
a distorted quadra-pyramidal configuration with the
formation of three new indium rings involved. The In
atom is five-coordinately bonded to two nitrogen atoms
and one oxygen atom. The three phenyl rings bridged
by the two imine linkages are, as expected, almost in
the same plane, indicating that the three phenyl rings
are well conjugated. The InꢀC(21) bond is approxi-
mately perpendicular to the plane. The InꢀO distances
3. Experimental
,
,
(2.092(4) A for InꢀO(1) and 2.093(4) A for InꢀO(2)) are
shorter than those reported for dimethyl[m-(2-pyridine-
carboxaldehydeoximato)]indium (2.241(16) and 2.229
All reactions were performed in a glove box under
purified nitrogen. The solvents were refluxed with
sodium benzophenone and distilled under nitrogen
prior to use. The Schiff-base ligands were prepared by
condensation of salicylaldehyde with ethylenediamine
or 1,2-phenylenediamine. Trimethylgallium, triethylgal-
lium, trimethylindium and triethylindium were pro-
,
(14) A) [10] and dimethyl(salicylaldehyde)indium
,
(2.188(3) A) [11]. This suggests that InꢀO bonding in
compound 1 is very strong. The InꢀN distances in 1
,
(2.258(4) and 2.265(4) A for InꢀN(1) and InꢀN(2),
respectively) are also shorter than those in Me3In-
,
NHMe(CH2)2NHMeInMe3 (2.369(7) and 2.393(7) A)
,
and Me3InNHCMe2(CH2)3CMe2 (2.502(5) A). This
means that the InꢀOꢀOꢀNꢀN pyramidal structure is
rigid in the complex. It is very interesting to note
that every two molecules of the complex are situated
face-to-face in the solid state, as shown in the unit cell
(Fig. 2). The two molecules are just like two gongs
folded closely, suggesting that there are some electronic
interactions between the two molecules, at least in the
solid state. There is also a weak intermolecular CH/p
interaction between the indium-bonded methyl group
of one molecular and the C(1A)ꢀC(2A)ꢀC(3A)ꢀC(4A)ꢀ
Fig. 3. Emission spectrum of 1.

Y.-Z. Shen et al. / Journal of Organometallic Chemistry 590 (1999) 242–247
245
vided by the National 863 Program Advanced Material
MO Precursors R&D Center of China. H-NMR data
3.3. Synthesis of ethyl-N,N%-bis(salicylidene)ethylene-
diaminoindium (3)
1
were collected on Bruker AM-500 and Jeol PMX-60SI
spectrometers with TMS as the internal standard (sol-
vent: C6D6). IR spectra were obtained as KBr pellets on
a 5DX-FT-2 spectrometer. Mass spectra was measured
on a VG-ZAB-HS spectrometer (electron impact ionisa-
tion). Luminescent spectra were measured on a RF-5000
fluorimeter. Elemental analyses were performed on a
Perkin–Elmer 240C elemental analyser. Melting points
were observed in sealed capillaries and were uncorrected.
Compound 3 was prepared in a manner similar to that
described for 1 from N,N%-ethylenebis(salicylideneimine)
(0.536 g, 2 mmol) in 10 ml and 2 ml benzene and tri-
ethylindium (0.41 g, 2.0 mmol) in cyclohexane–benzene
mixture. The yellow crystal of 2 was isolated. Yield: 0.71
g (86.5%); m.p. 227–228°C. IR (cm−1): 3046.6 (w), 3020
(w), 2952 (w), 2935 (w), 2907 (w), 2895.4 (w), 1646.8 (vs),
1628.3 (vs), 1598.9 (m), 1537 (s), 1465.8 (s), 1444.8 (m),
1392.4 (w), 1335.4 (m), 1305 (m), 1198.6 (m), 1149.4 (m),
1
1048.4 (w), 906 (w), 758.1 (vs), 643 (w), 607.4 (w). H-
3.1. Synthesis of methyl-N,N%-bis(salicylidene)-1,2-
phenylenediaminoindium (1)
NMR (ppm, in C6D6): 8.10 (s, 2H, ꢀCH=N), 6.53–7.27
(m, 8H, ArꢀH), 3.76 (m, 4H, ꢀN(CH2)2Nꢀ), 1.05 (t, 3H,
InCH2CH3), 0.77 (q, 2H, InCH2CH3). MS: 383
(9.59%), 381 (1.69%), 269.3 (30.78%), 267.3 (4.27%),
251.1 (7.20%), 177.2 (17.48%), 165.2 (8.61%), 148.2
(23.8%), 134.2 (8.89%), 133.2 (9.19%), 122.1 (10.00%),
121.1 (12.51%), 120.1 (12.66%), 116.3 (100.00%),
107.2 (15.83%), 77.1 (10.22%), 73.1 (18.56%), 59.0
(16.26%), 57.1 (10.27%). Anal. Calc. for C18H19N2O2In:
C, 52.68; H, 4.67; N, 6.83. Found: C, 52.67; H, 4.75; N,
6.90%.
To
a solution of 1,2-N,N%-phenylenebis(salicyli-
deneimine) (0.632 g, 2 mmol) in 10 ml cyclohexane was
added dropwise a solution of triethylindium (0.32 g, 2
mmol) in 10 ml benzene over a period of 10 min with stir-
ring. On addition of trimethylgallium, methane gas was
evolved immediately from the mixture. Then the mixture
was stirred for an additional 5 min at room temperature
(r.t.). The volatiles were removed under vacuum and the
yellow powder residue was recrystallised from a cyclo-
hexane–benzene mixture. Compound 1 was obtained as
yellow crystals. Yield: 82.3%; m.p. 263–264°C. IR
(cm−1): 3072 (w), 3007 (w), 2917 (w), 1609 (vs), 1581
(m), 1525 (m), 1461 (m), 1391 (m), 1328 (m), 1180 (w),
3.4. Synthesis of methyl-N,N%-bis(salicylidene)-1,2-
phenylenediaminogallium (4)
1
1152 (w), 920 (w), 752 (w), 533 (w). H-NMR (ppm, in
A solution of trimethylgallium (0.23 g, 2 mmol) in 10
ml cyclohexane was added dropwise over a period of
10 min with stirring to a solution of 1,2-N,N%-
phenylenebis(salicylideneimine) (0.632 g, 2 mmol) in a
mixture of 10 ml cyclohexane and 2 ml benzene. After
the mixture was stirred for an additional 5 min at r.t., the
solvent was removed under vacuum and the yellow pow-
der residue was recrystallised from a cyclohexane–ben-
zene solution, giving pale yellow crystals of 4. Yield:
0.658 g (82.4%); m.p. 110–111°C. IR (cm−1): 3057.8
(w), 3022 (w), 2924 (w), 2847 (m), 1609 (vs), 1581 (s),
C6D6): 8.45 (s, 2H, ꢀCH=N), 6.5–7.5 (m, 12H, ArꢀH),
−0.03 (s, 3H, InCH3). MS: 445 (2.2%), 444 (9.86%), 429
(92.64%), 327 (2.88%), 115 (100%), 78 (22.58%). Anal.
Calc. for C21H17N2O2In: C, 56.78; H, 3.86; N, 6.31.
Found: C, 56.74; H, 3.81; N, 6.36%.
3.2. Synthesis of ethyl-N,N%-bis(salicylidene)-1,2-
phenylenediaminoindium (2)
Compound 2 was prepared and purified in a manner
1
similar to that described for
1
from 1,2-N,N-
1539 (s). H-NMR (ppm, in C6D6): 8.56 (s, 2H, ꢀCH=
phenylenebis(salicylideneimine) (0.623 g, 2 mmol) and
triethylindium (0.404 g, 2 mmol). The compound was
isolated as yellow crystals. Yield: 0.74 g (81.2%); m.p.
\210°C. IR (cm−1): 3054 (w), 2956.4 (w), 2937 (w),
2906 (w), 2858 (w), 1608 (vs), 1584 (s), 1533 (vs), 1462
(s), 1444 (s), 1387 (s), 1347 (w), 1313 (s), 1252 (w), 1181
(s), 1150 (s), 1125.6 (w), 1032.8 (w), 919.9 (w), 848 (w),
799.8 (w), 754 (s), 686.5 (m), 530.2 (m). 1H-NMR (ppm,
in C6D6): 8.53 (s, 2H, ꢀCH=N), 6.60–8.0 (m, 12H,
ArꢀH), 1.02 (t, 3H, GaCH2CH3), 0.75 (q, 2H,
InCH2CH3). MS: 316.9 (9.30%), 216.9 (30.49%), 214.9
(12.52%), 213.0 (11.65%), 108.9 (33.03%), 91.0
(100.00%), 89.9 (11.21%), 72.9 (27.72%), 61.0 (14.41%),
57.0 (25.93%). Anal. Calc. for C22H19N2O2In: C, 57.66;
H, 4.18; N, 6.12. Found: C, 57.80; H, 4.33; N, 6.24%.
N), 6.6–8.0 (m, 12H, ArꢀH), −0.3 (s, 3H, GaCH3).
MS: 400 (1.71%), 399 (6.85%), 398 (0.64%), 385
(68.26%), 384 (22.6%), 383 (100%), 316 (1.19%), 105
(3.64%), 84 (65.9%), 71 (18.6%), 69 (26.8%). Anal. Calc.
for C21H17N2O2Ga: C, 63.20; H, 4.29; N, 7.02. Found:
C, 63.10; H, 4.16; N, 7.01%.
3.5. Synthesis of methyl-N,N%-bis(salicyli-
dene)ethylenediaminogallium (5)
Compound 5 was prepared in a manner similar to that
described for 4 from trimethylgallium (0.23 g, 2 mmol)
and N,N-ethylenebis(salicylideneimine) (0.536 g,
2
mmol) and was isolated as pale yellow solid. Yield: 0.59
g (85%); m.p. \290°C (dec). IR (cm−1): 3058 (w),

246
Y.-Z. Shen et al. / Journal of Organometallic Chemistry 590 (1999) 242–247
Table 2
3022 (w), 2924 (w), 2917 (w), 2846 (w), 1630 (vs), 1581
(s), 1539 (s), 1461 (s), 1279 (s), 1025 (s), 913 (s), 744
(s). H-NMR (ppm, in C6D6): 8.23 (s, 2H, ꢀCH=N),
Crystal data, collection parameters, and refinements for C21H17
N2O2In (1)
-
1
6.60–7.50 (m, 8H, ArꢀH), 3.92 (m, 4H,
ꢀNꢀCH2CH2ꢀNꢀ), −0.26 (s, 3H, GaCH3). MS: 351.7
(5.72%), 350.7 (32.72%), 336.7 (70.12%), 335.6 (20%),
334.7 (100%), 267.8 (15.89%), 70.8 (7.13%), 68.8
(12.09%). Anal. Calc. for C17H17N2O2Ga: C, 58.16; H,
4.88; N, 7.98. Found: C, 58.03; H, 4.84; N, 7.93%.
Empirical formula
Formula weight
Space group
C21H17N2O2In
444.20
P212121 (no. 19)
Orthorhombic
9.718(2)
10.572(3)
17.604(3)
1808.6(7)
4
Crystal system
,
a (A)
,
b (A)
,
c (A)
3
,
V (A )
Z
3.6. Synthesis of diethyl-N,N%-bis(salicylidene)-1,2-
phenylenediaminogallium (6)
Crystal dimensions (mm)
Crystal colour
0.4×0.35×0.2
Yellow
1.631
13.02
296
1/0.7258
Enraf–Nonius
CAD-4
Graphite
Mo–Ka
Dcalc (g cm−3
)
v(Mo–Ka) (cm−1
Temperature (K)
T(max)/T(min)
Diffractometer
)
Compound 6 was prepared and purified in a manner
similar to that described for
5 from 1,2-N,N%-
phenylenebis(salicylideneimine) (0.632 g, 2 mmol) and
triethylgallium (0.314 g, 2 mmol). Yield: 81.4%; m.p.
105°C. IR (cm−1): 3454.6 (w), 3050 (w), 2933 (w),
2896 (m), 2861 (m), 1613 (vs), 1589 (m), 1570 (s), 1544
(s), 1468 (s), 1448 (s), 1388 (m), 1314 (m), 1276 (m),
1187 (w), 1151 (s), 1105 (w), 975 (w), 877 (w), 795 (w),
Monochromator
Radiation
2qmax (°)
59.9
Index range (°)
05h513,
05k514, 05l524
8.24
Scan speed (° min−1
Reflections collected
)
1
759 (s), 653 (w), 560 (w). H-NMR (ppm, in C6D6):
2994
12.76 (s, 1H, ꢀOH), 8.47 (s, 1H, ꢀCH=NꢀGa), 7.97
(s, 1H, ꢀCH=N), 6.67–7.27 (m, 12H, ArꢀH), 1.10 (t,
6H, GaCH2CH3), 0.50 (q, 4H, GaCH2CH3). MS:
428.9 (5.46%), 385.0 (24.06%), 384.0 (8.61%), 382.9
(35.94%), 297.0 (3.26%), 296.0 (18.99%), 295.0 (4.16%),
294.0 (26.20%), 197.0 (9.96%), 196.0 (8.87%), 114.9
(36.91%), 104.0 (29.11%), 91.0 (14.98%), 78.0 (15.97%),
77.0 (86.82%), 70.9 (72.77%), 68.9 (100.0%). Anal.
Calc. for C24H25N2O2Ga: C, 65.04; H, 5.69; N, 6.32.
Found: C, 65.09; H, 5.79; N, 6.40%.
Independent reflections observed (I)\3.00
2791
(|(I))
No. variables
R(F)
235
0.038
0.051
1.54
1.22
−1.22
0.0007
wR
Goodness-of-fit
−3
,
Dzmax (e A
)
−3
,
Dzmin (e A
)
(D/|)max
3.7. Synthesis of diethyl-N,N%-bis(salicylidene)ethylene-
diaminogallium (7)
(15.29%), 70.9 (34.4%), 68.9 (51.79%). Anal. Calc. for
C20H25N2O2Ga: C, 60.79; H, 6.38; N, 7.09. Found: C,
60.74; H, 6.24; N, 7.08%.
Compound 7 was prepared in a manner similar to
that described for 4 from N,N%-ethylenebis(salicyli-
deneimine) (0.536 g, 2 mmol) and triethylgallium (0.32
g, 2.0 mmol) and was isolated as yellow crystals.
Yield: 0.55 g (84.8%); m.p. 60°C. IR (cm−1): 3495 (w),
3049 (w), 3018 (w), 2943 (m), 2899.5 (m), 2863 (s),
2807.8 (w), 1625.4 (vs), 1578.1 (s), 1541.5 (vs), 1497.8
(s), 1468.8 (s), 1447.3 (s), 1405 (s), 1372 (w), 1341 (m),
1315.6 (s), 1283.5 (m), 1248.1 (m), 1221.2 (m), 1197.4
(m), 1148.4 (s), 1043.2 (s), 1022 (m), 1003 (m), 859.5
(m), 758.4 (vs), 750.2 (vs), 649 (m), 607.8 (m), 562 (m).
1H-NMR (ppm, in C6D6): 12.83 (s, 1H, ꢀOH), 8.36 (s,
1H, ꢀCH=NꢀGa), 8.04 (s, 1H, ꢀCH=N), 6.60–7.34
(m, 8H, ArꢀH), 3.89 (s, 2H, GaꢀNꢀCH3), 3.78 (s, 2H,
ꢀNꢀCH3), 1.14 (t, 6H, Ga(CH2CH3)2), 0.43 (q, 4H,
Ga(CH2CH3)2). MS: 366.9 (15.94%), 364.9 (23.71%),
337.9 (12.37%), 336.9 (67.73%), 335.9 (19.63%), 334.9
(100%), 309.0 (4.42%), 307.9 (7.44%), 127 (2.2%), 107
3.8. Crystal structure determination of 1
A suitable crystal of complex 1 was sealed in a
thin-walled glass capilliary under a nitrogen atmo-
sphere. Data collection was performed with Mo–Ka
,
radiation (u=0.71073 A) on an Enraf–Nonius CAD-4
diffractometer equipped with graphite monochro-
mator. The structure was solved by the direct
methods using MITHRIL [12] and subsequent Fourier
techniques. Hydrogen atoms were added geometrically
(before the final amendment). All calculations were
performed using the TEXSAN [13] program system. OR-
TEPII [14] was used to produce the figures and CAD-4
software [15] was used for data collection and cell
refinement. Crystallographic data are summarised in
Table 2.

Y.-Z. Shen et al. / Journal of Organometallic Chemistry 590 (1999) 242–247
247
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4. Supplementary material
Full information on the crystal structure can be
ordered from the CCDC, 12 Union Road, Cambridge
CB2 1EZ, UK, upon request, quoting the deposition
number CCDC-117964.
[8] Y. Hamada, T. Sano, M. Fujita, T. Fujii, Y. Nishio, K. Shibata,
Jpn. J. Appl. Phys. 32 (1993) L514.
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Acknowledgements
Financial support from the National High Technol-
ogy Program and the National Science Foundation of
China is acknowledged.
[11] N.W. Alcock, I.A. Degnan, S.M. Roe, M.G.H. Wallbridge, J.
Organomet. Chem. 414 (1991) 285.
[12] C.J. Gilmore, MITHRIL, Program for the automatic solution of
crystal structure from X-ray data. Department of Chemistry,
University of Glasgow, UK, 1983.
[13] Molecular Structure Corporation, TEXSAN, Version 5.0 MSC,
Single crystal structure analysis software, 3200 Research Forest
Drive, The Woodlands TX 77381, USA, 1989.
[14] C.K. Johnson, ORTEPII, Report ORNL-5138, Oak Ridge Na-
tional Laboratory, TN, USA, 1976.
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,
[16] Symmetry code A: −x, −0.5+x, 1.5−z; H(16)ꢀC(5A) 3.18 A,
,
C(21)ꢀC(5A) 3.953 A.
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