Diorgano-gallium and -indium complexes with salen ligands: Synthesis, characterization, crystal structure and C-C coupling reactions

Article abstract of DOI:10.1016/j.jorganchem.2009.03.029

The reactions of triorgano-gallium and -indium etherate with salen ligands in benzene afforded complexes of the type [R₂MOC₆H₄CR′{double bond, long}NCH₂-]₂, (R/M/R′ = Me/Ga/H (1), Et/Ga/H (2), Me/In/H (3), Et/Ga/Me (4)) in nearly quantitative yields. These complexes have been characterized by elemental analysis, IR, UV-Vis, NMR (¹H and ¹³C{¹H}) and mass spectral data. The organogallium complexes showed photoluminescence in blue-green region. The complex, [(Me₂Ga)₂(O-(C₆H₄)CH{double bond, long}N-CH₂-)₂] on recrystallization from benzene-hexane and dichloromethane gave orthorhombic and monoclinic forms, respectively. Both the forms are dimeric with gallium atoms acquiring a distorted tetrahedral configuration defined by two methyl groups, phenolate oxygen and azomethene nitrogen. The complexes [(Me₂Ga)₂(O-(C₆H₄)CH{double bond, long}N-CH₂-)₂] and [(Me₂In)₂(O-(C₆H₄)CH{double bond, long}N-CH₂-)₂] have been employed as alkylating agent for C-C coupling reaction of 1-bromonaphthalene in presence of PdCl₂(PPh₃)₂.

Full text of DOI:10.1016/j.jorganchem.2009.03.029

Journal of Organometallic Chemistry 694 (2009) 2375–2379
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Diorgano-gallium and -indium complexes with salen ligands: Synthesis,
characterization, crystal structure and C–C coupling reactions
*
Nisha P. Kushwah, Manoj K. Pal, Amey P. Wadawale, Vimal K. Jain
Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
a r t i c l e i n f o
a b s t r a c t
Article history:
The reactions of triorgano-gallium and -indium etherate with salen ligands in benzene afforded com-
plexes of the type [R2MOC6H4CR0@NCH2–]2, (R/M/R0 = Me/Ga/H (1), Et/Ga/H (2), Me/In/H (3), Et/Ga/Me
(4)) in nearly quantitative yields. These complexes have been characterized by elemental analysis, IR,
UV–Vis, NMR (1H and 13C{1H}) and mass spectral data. The organogallium complexes showed photolumi-
nescence in blue-green region. The complex, [(Me2Ga)2(O–(C6H4)CH@N–CH2–)2] on recrystallization
from benzene–hexane and dichloromethane gave orthorhombic and monoclinic forms, respectively. Both
the forms are dimeric with gallium atoms acquiring a distorted tetrahedral configuration defined by two
methyl groups, phenolate oxygen and azomethene nitrogen. The complexes [(Me2Ga)2(O–(C6H4)CH@N–
CH2–)2] and [(Me2In)2(O–(C6H4)CH@N–CH2–)2] have been employed as alkylating agent for C–C coupling
reaction of 1-bromonaphthalene in presence of PdCl2(PPh3)2.
Received 30 January 2009
Received in revised form 17 March 2009
Accepted 17 March 2009
Available online 26 March 2009
Keywords:
Gallium
Indium
Phenolate
Schiff base
X-ray structures
Ó 2009 Elsevier B.V. All rights reserved.
1. Introduction
2. Results and discussion
The chemistry of organo-gallium/-indium compounds with oxo
ligands has been actively pursued for quite some time [1–3]. Inter-
est in these compounds, particularly with internally functionalized
ligands, appears to be due to their wide structural diversity [1],
potential applications as catalyst [4,5] as well as molecular precur-
sors for the preparation of metal oxide thin films [6–8] and photo-
physical properties [9–12].
The compounds of the type R2ML (R = alkyl, M = Ga or In; LH =
anionic oxo ligand) have been isolated as mono-, bi- and tri-nuclear
derivatives with metal acquiring coordination number between
four and six. The structural preferences in these complexes are
governed by the nature of R, M and L [13–25]. Recently we have de-
scribed the synthesis of diorgano-gallium/-indium complexes con-
taining internally functionalized anionic oxo ligands [9,10,26,27].
Reactions of N,N0-ethylenebis(salicylideneimine) (salenH2) and
N,N0-ethylenebis(2-hydroxy-
-benzyledeneimine) (acenH2) with
trialkylgallium etherate or trimethylindium etherate in 1:2 stoichi-
ometry in benzene readily afforded bimetallic complexes,
[R2MOC6H4CR0@NCH2–]2, in nearly quantitative yield (Eq. (1)).
a
R
O
OH
R
M
+
2 R3M.OEt2
CR`=N(CH2)2N=CR'
CR`=N(CH2)2N=CR'
- 2 RH
M
R
OH
O
ð1Þ
R
M
R
R'
Ga Me
Ga Et
H
1
2
3
4
H
In
Me
H
Ga Et
Me
The electronic spectra displayed a number of bands attributable
to transitions in the benzenoid ring (>300 nm) and in azomethine
linkage (<300 nm). The n ? p* transition of the ligand (ꢀ370 nm)
is red shifted (ꢀ10 nm) in organogallium complexes suggesting
These complexes have a centrosymmetric ‘‘M2(l-O)2” core and
show photoluminescence.
In view to assess photophysical and catalytic properties of
bi- and high-nuclearity organo-gallium and -indium complexes
lacking oxo-bridges, we have chosen salen ligands, although a few
organo-gallium and -indium complexes with these ligands have
been reported earlier [28–32]. In this report we describe the prep-
aration of organo-gallium and -indium complexes with salenH2 and
acenH2, their photophysical and catalytic properties and distortion
isomerism in [Me2GaOC6H4CH@NCH2–]2.
coordination of azomethine nitrogen to the metal atom. The mC@N
absorption in the IR spectra of the complexes appear at lower wave
numbers relative to the free ligand. A strong band in the region 570–
587 cmꢁ1 has been attributed to
mGa–C stretching absorptions [27].
The 1H and 13C{1H} NMR spectra of ligands and complexes
showed expected signals and peak multiplicities. The methyl reso-
nances of gallium complexes appear at higher field than that of the
corresponding indium derivatives. The NCH2 resonances both in
the 1H and 13C{1H} NMR spectra of the complexes are shielded
with respect to the signal for the corresponding ligands. This
* Corresponding author.
E-mail address: jainvk@barc.gov.in (V.K. Jain).
0022-328X/$ - see front matter Ó 2009 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2009.03.029

2376
N.P. Kushwah et al. / Journal of Organometallic Chemistry 694 (2009) 2375–2379
suggests coordination of azomethine nitrogen to the metal atom.
As the consequence of the shift in electron density towards metal
through nitrogen coordination, the CR0@N (R0 = H or Me) resonance
in the 13C{1H} NMR spectra of the organogallium complexes is
deshielded (ꢀ5 ppm) as compared to the free ligand.
3
2
1
0
(a) = excitation
(b) = emission
355
(a)
The mass spectrum of 1 exhibited multiplets at m/e 466 and 451
assignable to molecular ion and the parent ion minus one methyl
group, respectively. These multiplets are consistent with the isoto-
pic patterns for two gallium atoms in a molecule (69Ga (60.4%),
71Ga (39.6%)).
475
(b)
2.1. Photophysical properties
Although 8-hydroxyquinolinate (Ox) and azomethine coordi-
nated complexes (e.g., Al(Ox)3) have been employed as organic
light-emitting diodes (OLEDs) [33–38], organometallic complexes
derived from chelating ligands are emerging as potential molecules
for OLED applications [9–12,39,40].
300
350
400
450
500
550
600
The emission bands for the free ligands and complexes are sum-
marized in Table 1. These bands both for ligand and complexes ap-
peared in blue-green region (Fig. 1). On complexation there is a
slight increase in quantum yield. The observed absorptions and
emissions in diorganogallium complexes can be attributed to tran-
sitions localized on the salen ligands while enhanced quantum
yields in the complexes could be due to the rigidity of the chelating
ligand. The latter minimizes the loss of energy by a non-radiative
Wavelength (nm)
Fig. 1. Excitation spectra (a) and emission spectra (b) of [{Et2GaO–
(C6H4)C(CH3)@N–CH2–}2] recorded in dichloromethane solution.
Table 2
Selected geometric parameters (Å, °) for [(Me2Ga)2(O–(C6H4)CH@N–CH2–)2] recrys-
tallized in benzene–hexane mixture and CH2Cl2 solvents.
pathway and consequently increases p–
p* transition intensity.
Orthorhombic
Literaturea
Monoclinic
This work
2.2. Structure of [Me2GaOC6H4CH@NCH2–]2 (1)
This work
The complex crystallizes in orthorhombic (from benzene–hex-
ane mixture) and monoclinic (from dichloromethane) forms repre-
senting an example of distortion isomerism in organogallium
chemistry. This is the first example, to the best of our knowledge,
of distortion isomerism in organogallium chemistry, although dis-
tortion isomerism for transition metal complexes is not uncommon
[41]. The molecular structures of both the forms are similar except
some variations in geometric parameters which are collected in Ta-
ble 2. In orthorhombic form the molecule is distorted from Ci sym-
metry whereas monoclinic form, which crystallizes with a molecule
of dichloromethane, retains this symmetry as illustrated in Fig. 2.
The geometric parameters for the orthorhombic form are in confor-
mity with the one reported earlier by Trotter and co-workers [28].
The molecule (Fig. 3) essentially comprises of two four-coordi-
nated dimethylgallium fragments containing five membered
chelating ligands and these two fragments are linked through a
–CH2–CH2– spacer. Each gallium atom has a distorted tetrahedral
configuration defined by two methyl groups and phenolic oxygen
and azomethine nitrogen atoms. The Ga–C, Ga–O and Ga–N dis-
tances are well in agreement with the reported values [3,10,28].
Ga1–O1
Ga2–O2
Ga1–N1
Ga2–N2
Ga1–C10
Ga1–C9
Ga2–C19
Ga2–C20
O1–Ga1–C10
O1–Ga1–C9
O2–Ga2–C19
O2–Ga2–C20
O1–Ga1–N1
O2–Ga2–N2
C10–Ga1–C9
C19–Ga2–C20
C10–Ga1–N1
C9–Ga1–N1
C19–Ga2–N2
C20–Ga2–N2
C11–O2–Ga2
C1–O1–Ga1
C7–N1–Ga1
C8–N1–Ga1
C17–N2–Ga2
C18–N2–Ga2
1.869 (2)
1.874 (2)
2.026 (3)
2.035 (3)
1.950 (5)
1.948 (6)
1.959 (5)
1.938 (5)
106.5 (3)
105.7 (3)
112.6 (2)
107.3 (2)
94.0 (1)
1.867 (4)
1.873 (4)
2.022 (5)
2.029 (5)
1.921 (7)
1.942 (7)
1.929 (6)
1.931 (6)
111.5 (3)
105.7 (3)
111.4 (3)
107.0 (3)
94.04 (18)
92.41 (18)
124.6 (4)
125.5 (3)
106.2 (2)
110.5 (3)
103.8 (3)
111.7 (3)
127.2 (4)
128.4 (4)
122.7 (4)
119.3 (4)
121.8 (4)
118.1 (4)
1.895 (3)
–
2.048 (3)
–
1.955 (4)
1.951 (4)
–
–
108.90 (18)
108.51 (19)
–
–
91.99(11)
–
127.6 (2)
–
92.7 (1)
124.6 (4)
123.8 (3)
110.2 (3)
106.3 (2)
104.4 (2)
111.8 (2)
126.6 (2)
128.1 (2)
122.2 (2)
119.6 (3)
121.6 (2)
118.8 (3)
105.65 (18)
108.37 (16)
–
–
–
126.6 (2)
122.0 (2)
119.5 (3)
–
–
3. Cross alkylation reactions
a
Ref. [28].
Organoindium compounds have been employed for cross-cou-
pling of arylhalides in the presence of palladium chloride catalysts
[4,5,42]. In general mononuclear organoindium complexes are bet-
ter alkylating agents than the binuclear complexes containing
Table 1
‘‘In2(l-O)2” core [42]. The bimetallic salen complexes described
Excitation and emission data of salen ligands and their diorganogallium complexes in
dichloromethane.
here are akin to mononuclear compounds, they may be useful in
cross-coupling reactions. Thus in a preliminary experiment, 1-bro-
monaphthalene is readily methylated to 1-methylnaphthalene (1H
NMR (in CDCl3) d: 2.75 (s, Me–)) by 3 in the presence of
PdCl2(PPh3)2 as a catalyst. The reaction of [PdCl2(PPh3)2] with 3
in a separate experiment (Eq. (2)), has shown the formation of
trans-[PdClMe(PPh3)2] (1H NMR (in CDCl3) d: ꢁ0.01 (t, 6.5 Hz, Pd-
Me); 31P{1H} 30.2 ppm). Similarly other palladium complexes,
Compounds
Excitation k
Emission k
Quantum yield (
g)
in nm
in nm
in %
[HO(C6H4)CH@NCH2–]2
365
435
412
335
355
470
473
462
485
475
0.4
3.0
1.2
0.1
1.0
[HO(C6H4)CMe@NCH2–]2
[Me2GaO(C6H4)CH@NCH2–]2
[Et2GaO(C6H4)CH@NCH2–]2
[Et2GaO(C6H4)CMe@NCH2–]2

N.P. Kushwah et al. / Journal of Organometallic Chemistry 694 (2009) 2375–2379
2377
Fig. 2. Line drawing of orthorhombic (a) and monoclinic (b) forms of [Me2GaO(C6H4)CH@NCH2–]2.
e.g. [Pd2Cl2(
l
-Cl)2(PEt3)2] can be methylated to [Pd2Me2(
l
-
zene or dichloromethane on a Chemito Spectroscan UV-double
beam spectrophotometer. Emission spectra were measured in
Cl)2(PEt3)2] (1H NMR (in CDCl3) d: 0.59 (br s, Pd-Me); 31P{1H}NMR
(in CDCl3) d: 32.8 ppm) [43].
deoxygenated solvents on
spectrophotometer.
a
Hitachi F-4010 Fluorescence
trans-½PdCl2ðPPh3Þ2ꢂ þ 3 ! trans-½PdClMeðPPh3Þ2ꢂ
ð2Þ
4.2. Synthesis
4. Experimental
4.2.1. N,N0-ethylenebis(salicylideneimine)
To a benzene solution (50 cm3) of salicyldehyde (13.18 g,
108 mmol), a solution of ethylenediamine (3.24 g, 54 mmol) was
added with stirring and the whole was refluxed on a Dean Stark
apparatus for 5 h. The solvent was evaporated under vacuum and
the yellow residue (yield 95%, 13.92 g) was recrystallised from
4.1. Materials and physical measurements
All experiments involving organo-gallium/-indium compounds
were carried out in anhydrous conditions under a nitrogen atmo-
sphere using Schlenk techniques. Solvents were dried by standard
methods. The R3Ga ꢃ OEt2 (R = Me, Et) were prepared from gallium-
magnesium alloy and alkyl iodide in diethyl ether while
Me3In ꢃ OEt2 was obtained by a reaction between anhydrous InCl3
and MeMgI in ether [44]. Ether contents in each preparation were
evaluated by 1H NMR integration.
Infrared spectra were recorded as KBr plates on a Bomem MB-
102 FT IR spectrometer. The NMR spectra were recorded on a Bru-
ker Avance-II 300 spectrometer in 5 mm tubes as CDCl3 solutions.
Chemical shifts were referenced to internal chloroform peak (d
7.26 and 77.0 ppm for 1H and 13C{1H}, respectively). Mass spectra
were recorded on a Waters Q-TOF micro-mass (YA-105) time of
flight mass spectrometer. Electronic spectra were recorded in ben-
benzene (m.p. 125 °C); IR: m
C@N 1635 cmꢁ1. UV–Vis (in benzene)
kmax (in nm): 233, 258, 290, 318, 377. 1H NMR in CDCl3 d: 3.92
(s, 4H, NCH2–); 6.87 (t, 7 Hz, 2H, CH-4); 6.96 (d, 8 Hz, 2H, CH-3);
7.22–7.33 (m, 4H, CH-5, 6); 8.35 (s, 2H, N@CH–); 13.28 (s, 2H,
OH). 13C{1H} in CDCl3 d: 59.7 (s, NCH2); 116.9, 118.6, 131.5,
132.4, 161.0, 166.5.
4.2.2. Preparation of N,N0-ethylenebis(2-hydroxy-
a-benzylideneimine)
Prepared similarly to the above ligand using ethylenediamine
and 2-hydroxy acetophenone and recrystallised from benzene–
ethanol mixture in 93% yield, m.p. 181 °C. IR: m .
C@N 1610 cmꢁ1
UV–Vis (in benzene) kmax (in nm): 231, 257, 277, 320 and 369.
1H NMR in CDCl3 d: 2.39 (s, 6H, CMe); 3.98 (s, 4H, NCH2–); 6.80
(dt, 1 Hz (d), 7.5 Hz (t, 2H); 6.91 (dd, 1 Hz (d), 8 Hz (d), 2H); 7.29
(td, 1 Hz (d), 8 Hz (t), 2H); 7.54 (dd, 1.5 Hz, 7 Hz, 2H); 13C{1H} in
CDCl3 d: 14.8 (s, CMe); 50.1 (s, NCH2); 117.4, 118.5, 119.4, 128.2,
132.5, 163.2, 172.8.
4.2.3. [Me2GaO(C6H4)CH@NCH2–]2 (1)
To a benzene solution (25 cm3) of trimethylgallium etherate
(2.0 g, containing 1.03 g (9.0 mmol) Me3Ga), was added a solution
of N,N0-ethylenebis(salicylideneimine) (1.2 g, 4.48 mmol) with stir-
ring which continued for 3 h. The solvent was evaporated under a
reduced pressure to give a yellow crystalline solid (2.05 g, 98%)
which was recrystallised from dichloromethane-hexane as a color-
less crystalline solid, m.p. 170 °C. Anal. Calc. C20H26Ga2N2O2: C,
51.5; H, 5.6; N, 6.0; Ga, 29.9. Found: C, 50.1; H, 5.7; N, 5.9; Ga,
29.5% (a slight difference between the calculated and observed val-
ues of analysis may be due to operational difficulty in handling air
and moisture sensitive compounds in the analytical laboratory).
IR: m
C@N, 1623; Ga–C, 585 cmꢁ1. UV–Vis (in CH2Cl2) kmax: 241,
Fig. 3. Crystal structure of [(Me2Ga)2(O–(C6H4)CH@N–CH2–)2]. CH2Cl2 grown in
dichloromethane solvent.
281, 385 nm. 1H NMR in CDCl3 d: ꢁ0.20 (s, 12H, Me2Ga); 3.80 (s,

2378
N.P. Kushwah et al. / Journal of Organometallic Chemistry 694 (2009) 2375–2379
4H, NCH2–); 6.63 (t, 7.8 Hz, 2H); 6.83 (d, 8 Hz, 2H); 6.99 (d, 8 Hz);
7.35 (t, 7.5 Hz, 2H); 7.92 (s, 2H, N@CH–). 13C{1H} in (CDCl3) d:
ꢁ6.6 (s, Me2Ga); 57.3 (s, NCH2); 116.7, 117.6(s), 122.4(s),
135.3 (s), 137.0 (s) 166.7 (s), 171.5 (CH@N). Mass m/e: 466
(M+); 451 (MꢁMe); 351 [MeGaOC6H4CH@NCH2CH2N@CHC6H4O]+;
335 (GaOC6H@CH@NCH2CH2N@CHC6H4O); 269 (L); 247
([Me2GaOC6H4CH@NCH2CH2]+).
(d, 7.8 Hz, 2H); 7.34 (m, 2H); 7.43 (d, 8 Hz, 2H). 13C{1H} (in CDCl3)
3.1 (s, GaCH2–); 9.9 (s, GaCH2Me); 18.5 (s, CMe); 49.1 (s, NCH2);
116.7 (s), 122.2 (s), 123.6 (s), 130.4 (s), 135.0 (s) 166.3 (s), 177.6 (s,
d:
–CMe@N).
5. X-ray crystallography
Intensity data for [Me2GaO(C6H4)CH@NCH2–]2, crystallized
from benzene (orthorhombic) and dichloromethane (monoclinic)
were collected on a Rigaku AFC 7S diffractometer fitted with Mo
4.2.4. [Et2GaO(C6H4)CH@NCH2–]2 (2)
Prepared similar to 1 in 96% yield, m.p. 105 °C. Anal. Calc. for
C24H34Ga2N2O2: C, 55.2; H, 6.6; N, 5.4; Ga, 26.7. Found: C, 54.0;
Ka radiation so that hmax = 27.5°. The structures were solved by di-
H, 6.7; N, 5.6; Ga, 26.9%. IR: m
C@N, 1625; Ga–C, 570 cmꢁ1. UV–
rect methods [45] and refinement was an F2 [45] using data that
had been corrected for absorption effects with an empirical proce-
dure [46] with non hydrogen atoms modeled with anisotropic dis-
placement parameter with hydrogen atoms in their calculated
positions. Molecular structures were drawn using ORTEP [47].
Crystallographic and structural determination data are listed in
Table 3.
Vis (in CH2Cl2) kmax: 244, 275, 392 nm. 1H NMR (in CDCl3) d: 0.52
(m, 8H, GaCH2–); 1.11 (t, 8 Hz, 12H, GaCH2Me); 3.78 (s, 4H,
NCH2–); 6.62 (t, 7.5 Hz, 2H); 6.86 (d, 8 Hz, 2H); 6.99 (d, 8 Hz,
2H); 7.35 (t, 7.5 Hz, 2H); 8.00 (s, 2H, N@CH–). 13C{1H} (in CDCl3)
d: 3.8 (s, GaCH2); 9.7 (s, GaCH2Me); 57.6 (s, NCH2–); 116.7(s),
117.7 (s), 122.3(s), 135.3 (s), 137.1 (s), 167.6(s), 171.8 (s,
–CH@N–).
6. Cross alkylation of 1-bromonaphthalene
4.2.5. [Me2InO(C6H4)CH@NCH2–]2 (3)
Prepared similar manner to 1 in 95% yield, since the complex
was sparingly soluble in organic solvents, it was washed thor-
oughly with benzene and dried in vacuo. m.p. 240 °C (decompose).
Anal. Calc. for C20H26In2N2O2: C, 43.2; H, 4.7; N, 5.0; In, 41.3. Found
In a typical experiment, a benzene solution of 1-bromonaphtha-
lene (1.19 g, 2.82 mmol) containing [Me2InO(C6H4)CH@NCH2–]2
(3) (1.57 g, 2.82 mmol) and [PdCl2(PPh3)2] (45 mg, 0.06 mmol)
was refluxed for 2 h. After cooling the reaction mixture to room
temperature, it was treated with an excess of 10% HCl (25 ml)
which lead to separation of two phases. The organic phase was sep-
arated and aqueous phase was washed with ether (2 ꢄ 10 ml) and
combined with the organic phase which was dried in vacuum to
give a pale yellow liquid which was distilled under vacuum to yield
a colorless liquid (0.44 g, 55%), identified as 1-methylnaphthalene
by 1H NMR spectroscopy.
C, 44.2; H, 4.5; N, 4.7; In, 41.2%. IR: m .
C@N 1600 cmꢁ1 1H NMR (in
dmso-d6) d ppm: ꢁ0.16 (s, 12H, Me2In); 3.85 (s, 4H, NCH2–); 6.62
(t, 7.5 Hz, 2H); 7.01 (d, 7 Hz, 2H); 7.10 (dd, 4H); 8.26 (s, 2H, N@CH).
4.2.6. [Et2GaO(C6H4)CMe@NCH2–]2 (4)
Prepared similar to 1 in 96% yield, m.p. 185 °C. Anal. Calc. for
C26H38Ga2N2O2: C, 56.8; H, 7.0; N, 5.1; Ga, 25.3. Found: C, 56.4;
H, 7.1; N, 5.4; Ga, 25.0%. IR: m
C@N, 1602; Ga–C, 587 cmꢁ1. UV–
Vis (in CH2Cl2) kmax: 233, 262, 275, 325 (sh), 378 nm. 1H NMR (in
CDCl3) d: 0.42 (m, 8H, GaCH2–); 1.05 (t, 8 Hz, 12H, GaCH2Me);
2.58 (s, 6H, CMe); 3.82 (s, 4H, NCH2–); 6.71 (t, 7.0 Hz, 2H); 6.93
Acknowledgements
The authors would like to thank Drs. T. Mukherjee and D. Das
for the encouragement of this work.
Table 3
Appendix A. Supplementary material
Crystallographic and structural refinement data of [Me2GaO–(C6H4)CH@N–CH2–]2.
Recrystallised from
benzene–hexane
Recrystallised from
dichloromethane
CCDC 717099 and 717100 contain the supplementary crystallo-
graphic data for orthorhombic and monoclinic forms. These data
can be obtained free of charge from The Cambridge Crystallo-
graphic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
Supplementary data associated with this article can be found, in
the online version, at doi:10.1016/j.jorganchem.2009.03.029.
Formula
M
T (K)
Colour
Size
C20H26Ga2N2O2
465.87
298
C20H26Ga2N2O2 ꢃ CH2Cl2
550.79
298
Yellow
Yellow
0.1 ꢄ 0.4 ꢄ 0.5
Orthorhombic
P b c a
0.2 ꢄ 0.4 ꢄ 0.5
Monoclinic
C 1 2/c 1
Crystal system
Space group
a (Å)
b (Å)
c (Å)
References
19.700 (5)
22.830 (7)
9.494 (2)
90.00
4270 (2)
8
22.400 (7)
9.117 (2)
13.772 (3)
117.28 (2)
2499.6 (11)
4
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dcalc (g cmꢁ3
l
)
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1.464
(mmꢁ1)/F(000)
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ꢁ14 6 h 6 25
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ꢁ6 6 l 6 12
Psi-scan
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ꢁ11 6 k 6 6
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No. of observed reflections
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r(I)
4927/0/247
0.053/0.169
0.163/0.169
2878/0/166
0.042/0.107
0.084/0.125
x
x

N.P. Kushwah et al. / Journal of Organometallic Chemistry 694 (2009) 2375–2379
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