Synthesis, characterization, and molecular structures of di- and triorganotin(IV) complexes with 9-anthracenecarboxylic acid: The structural diversity in organotin 9-anthracenecarboxylates

Article abstract of DOI:10.1016/j.jorganchem.2007.05.049

The di- and triorganotin(IV) derivatives of anthracenecarboxylic acid, Ph₂MeSnOC(O)C₁₄H₉ (2), Me₃SnOC(O)C₁₄H₉ (3), Me₂Sn[OC(O)C₁₄H₉]₂ · CH₃OH (4) Ph₃SnOC(O)C₁₄H₉ · CH₃OH (5), Ph₂EtSnOC(O)C₁₄H₉ (6), Ph₂Sn[OC(O)(C₁₄H₉)]₂ (7) and PhMe₂SnOC(O)C₁₄H₉ (8) were synthesized by the reaction of Ph₂MeSnI, Me₃SnCl, Me₂SnCl₂, Ph₃SnCl, Ph₂EtSnI, Ph₂SnCl₂, and PhMe₂SnI with 9-anthracenecarboxylic acid, respectively, with the aid of potassium iso-propoxide. All complexes were characterized by elemental analysis, mass spectrometry, IR, ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopes. The molecular structures of complexes 2, 3 and 4 were determined by single crystal X-ray analysis. The X-ray structures reveal that complex 2 and 3 adopt a polymeric trans-C₃SnO₂ trigonal bipyamidal configuration with the oxygen atoms occupying axial positions. Complex 4 adopts a monomeric structure with two carboxylates coordinated to tin in a monodentate form from axial and equatorial positions, and with the coordination number raised to five as the methanol occupies the apical position of the trigonal bipyramid.

Full text of DOI:10.1016/j.jorganchem.2007.05.049

Journal of Organometallic Chemistry 692 (2007) 3922–3930
www.elsevier.com/locate/jorganchem
Synthesis, characterization, and molecular structures of di- and
triorganotin(IV) complexes with 9-anthracenecarboxylic acid:
The structural diversity in organotin 9-anthracenecarboxylates
a,
a
a
b
Mostafa M. Amini *, Amirreza Azadmeher , Hamid Reza Khavasi , S.W. Ng
a
Department of chemistry, Shahid Beheshti University, Tehran 1983963113, Iran
Department of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia
b
Received 24 March 2007; received in revised form 20 May 2007; accepted 24 May 2007
Available online 9 June 2007
Abstract
The di- and triorganotin(IV) derivatives of anthracenecarboxylic acid, Ph2MeSnOC(O)C14H9 (2), Me3SnOC(O)C14H9 (3), Me2Sn-
[OC(O)C14H9]2 Æ CH3OH (4) Ph3SnOC(O)C14H9 Æ CH3OH (5), Ph2EtSnOC(O)C14H9 (6), Ph2Sn[OC(O)(C14H9)]2 (7) and PhMe2SnOC-
(O)C14H9 (8) were synthesized by the reaction of Ph2MeSnI, Me3SnCl, Me2SnCl2, Ph3SnCl, Ph2EtSnI, Ph2SnCl2, and PhMe2SnI with
9-anthracenecarboxylic acid, respectively, with the aid of potassium iso-propoxide. All complexes were characterized by elemental anal-
ysis, mass spectrometry, IR, 1H, 13C and 119Sn NMR spectroscopes. The molecular structures of complexes 2, 3 and 4 were determined
by single crystal X-ray analysis. The X-ray structures reveal that complex 2 and 3 adopt a polymeric trans-C3SnO2 trigonal bipyamidal
configuration with the oxygen atoms occupying axial positions. Complex 4 adopts a monomeric structure with two carboxylates
coordinated to tin in a monodentate form from axial and equatorial positions, and with the coordination number raised to five as
the methanol occupies the apical position of the trigonal bipyramid.
ꢀ 2007 Elsevier B.V. All rights reserved.
Keywords: Anthracenecarboxylic acid; Organotin; Carboxylate; Crystal structure
1. Introduction
boxylate and organic moieties on tin. In this regard, in
recent years, many organotin complexes of fluorinated car-
boxylate acids were synthesized, and their biological activ-
ities reported were [20]. However, it is well known that the
biological activity of organotin compounds decrease with
the increasing length of alkyl-substituted groups on tin
[21]. Interestingly, tri-n-butyltin(IV) benzoate exhibits
higher activity than triphenyltin(IV) benzoate against sev-
eral human tumor cell lines [20]. This clearly demonstrates
the significant role of organic substituent groups on tin.
Although synthesis and characterization of organotin carb-
oxylates have been widely investigated, there are only a
limited number of studies on the preparation of organotin
carboxylates with mixed alkyl and aryl substituent groups
on tin [22–25]. Probably this is because of the difficulties
presented by the syntheses of mixed organic groups on
tin entity. By realizing the important role of organic substi-
tuent groups on tin in vitro antitumor activity as well as the
The interest in organotin compounds in general and
organotin carboxylates in particular continues to grow
because of their biological activity and potential antineo-
plastic and antituberculosis agents [1–3]. Vast studies have
been focused on organotin carboxylates and many of them
have been characterized recently either by single crystal
structure determination or by spectroscopy [4–15]. Organo-
tin carboxylates adopt a wide variety of structure modes
including monomers, dimers, tetramers, oligomeric lad-
ders, and hexameric drums [16–19].
The molecular structures of organotin carboxylates
depend largely on the types of carboxylate groups and
depend less on electro-negativity of substituted group car-
*
Corresponding author. Tel: +98 21 22431661; fax: +96 21 22431663.
E-mail address: m-pouramini@cc.sbu.ac.ir (M.M. Amini).
0022-328X/$ - see front matter ꢀ 2007 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2007.05.049

M.M. Amini et al. / Journal of Organometallic Chemistry 692 (2007) 3922–3930
3923
role of carboxylate group it may be possible to tailor such
activity by introducing a certain number of alkyl and aryl
groups on tin along with a wide variety of carboxylates.
Therefore, synthesis of new organotin carboxylates with
different structural features will be beneficial in the devel-
opment of pharmaceutical organotin and in other proper-
ties and application. In this paper, we report synthesis,
characterization and structural studies of several new
mixed aryl and alkyl triorganotin carboxylates along with
their unmixed di- and triorganotin derivatives.
spectra from 4000 to 400 cmꢀ1 were recorded on a Shima-
1
dzu 470 FT-IR instrument, using KBr pellets. H, 13C and
119Sn NMR spectra were recorded at room temperature in
CDCl3 on a Bruker AVANCE 300-MHz operating at
300.3, 75.4 MHz and 111.9 MHz, respectively. The NMR
spectra are referenced to Me4Si (1H and 13C) or Me4Sn
(
119Sn) as external standards. The mass spectroscopy was
performed on a Varian MAT 44 instrument (electron
impact, 20 eV).
2.2.1. X-ray crystallography
2. Experimental
The X-ray diffraction measurements were made on a
STOE IPDS-II diffractometer with graphite monochro-
mated Mo Ka radiation. For [Ph2MeSnOC(O)C14H9] (2),
a colorless prismatic crystal with a dimension of 0.30 ·
0.25 · 0.10 mm, for [Me3SnOC(O)C14H9] (3), a colorless
needle crystal with a dimension of 0.60 · 0.08 · 0.05 mm
and for {Me2Sn[OC(O)C14H9]2 Æ CH3OH}. CH3OH (4), a
colorless block crystal with a dimension of 0.50 · 0.40
· 0.35 mm were mounted on a glass fiber and used for data
collection. Cell constants and an orientation matrix for the
data collection were obtained by least-squares refinement
of diffraction data from 5487 for (2), 3505 for (3) and
5580 for (4) unique reflections (Table 1). Data were col-
lected at a temperature of 20 ꢁC to a maximum 2h value
of 55.94ꢁ for (2), 55.76ꢁ for (3) and 53.58ꢁ for (4) and in
a series of x scans in 1ꢁ oscillations and integrated using
the Stoe X-AREA software package [26]. The numerical
absorption coefficient, l, for Mo Ka radiation is
1.141 mmꢀ1 for (2), 1.593 mmꢀ1 for (3) and 0.918 mmꢀ1
2.1. Materials
Triphenyltin(IV) chloride, trimethyltin(IV) chloride,
dimethyltin(IV) dichloride, diphenyltin(IV) dichloride,
ethyl iodide, methyl iodide, and silver acetate were pur-
chased from Merck and used without further purification.
All solvents were dried and distilled under nitrogen prior
to use according to a standard procedure. Ethyltriphenyl-
tin(IV) was prepared by using a conventional Grignard
synthesis with triphenyltin(IV) chloride and ethylmagne-
sium bromide and purified by recrystallization from meth-
anol (m.p. 51 ꢁC, yield 70%).
2.2. Physical measurements
Melting points were obtained with Electrothermal 9200
melting point apparatus and were not corrected. Infrared
Table 1
Crystal data for compounds 2, 3 and 4
2
3
4
Formula
C
509.17
Monoclinic
P21
0.30 · 0.25 · 0.10
10.0715(13)
10.5828(16)
10.9810(15)
102.765(10)
1141.5(3)
28H22O2Sn
C18H18O2Sn
385.01
Monoclinic
P21/c
0.60 · 0.08 · 0.05
11.9910(14)
10.1874(9)
13.8854(16)
108.825(9)
1605(3)
C34H32O6Sn
655.29
Monoclinic
P21
Formula weight
Crystal system
Space group
Crystal size (mm3)
0.50 · 0.40 · 0.35
9.010(3)
˚
a (A)
˚
b (A)
12.958(3)
13.045(4)
106.20(2)
1462.5(7)
2
˚
c (A)
b (ꢁ)
3
˚
V (A )
Z
2
4
Dcalc (g cmꢀ1
)
1.481
1.593
1.488
h Ranges for data collection
F(000)
1.90–27.97
512
2.53–27.88
768
1.63–26.79
668
Absorption coefficient
Index ranges
1.141
1.593
0.918
ꢀ13 6 h 6 13, ꢀ13 6 k 6 13,
ꢀ14 6 l 6 14
8559
ꢀ15 6 h 6 14, 0 6 k 6 13,
0 6 l 6 18
3812
ꢀ11 6 h 6 11, ꢀ15 6 k 6 16,
ꢀ16 6 l 6 16
14138
Data collected
Unique data [Rint
Parameters, restrains
Final R1, wRa2 (Observation data)
Final R1, wRa2 (All data)
Absolute structure parameter
Goodness-of-fit on F2 (S)
]
5487 [0.0182]
281, 1
0.0209, 0.0463
0.0227, 0.0470
ꢀ0.050(17)
1.069
3505 [0.0000]
193, 0
0.0290, 0.0773
0.0321, 0.0791
–
5580 [0.0428]
381, 3
0.0215, 0.0589
0.0216, 0.0590
ꢀ.0.007(13)
1.010
1.083
Largest difference in peak and hole
(e A )
0.361, ꢀ0.345
0.611, ꢀ1.205
0.769, ꢀ1.069
3
˚
P
P
P
P
a
2
R1 = iFoj ꢀ jFci/ jFoj, wR2 = [ (w(Fo ꢀ Fc2)2)/ w(Fo2)2]1/2
.

3924
M.M. Amini et al. / Journal of Organometallic Chemistry 692 (2007) 3922–3930
for (4). A numerical absorption correction was applied
using X-RED [27] and X-SHAPE software’s [28]. The data were
corrected for Lorentz and Polarizing effects. The structures
were solved by direct and subsequent difference Fourier
map and then refined on F2 by a full-matrix least-squares
procedure using anisotropic displacement parameters
methods [29]. Subsequent refinement then converged with
R factors and parameters errors significantly better than
for all attempts to model the solvent disorder. Atomic fac-
tors are from International Tables for X-ray Crystallogra-
phy [30]. All refinements were performed using the X-STEP32
crystallographic software package [31].
402 Hz, 1J117Sn–13C, 386 Hz), 128.4 (Cmeta), 129.5 (Cpara),
136.6 (Cortho, 2J119/117Sn–13C, 48 Hz), 139.4 (Cispo), 125.2,
125.6, 126.5, 128.2, 128.5, 128.9, 130.2, 131.1 (C14H9) 175.5
(COO). 119Sn NMR (ppm): ꢀ1.3. Mass spectrum data, tin-
bearing fragment: m/e 294 [Sn(C14H9)]+, 374 [SnPh-
(C14H9)]+, 389 [PhSnMe(C14H9)]+, 451, [Ph2Sn(C14H9)]+,
495 [Ph2SnOCO(C14H9)].
2.3.3. Synthesis of trimethyltin(IV)
(9-anthracenecarboxylato)[Me3SnOCO(C14H9)] (3)
Trimethyltin(IV) chloride (0.77 g, 2 mmol) was treated
with potassium isopropoxide (0.19 g, 2 mmol) in isopropa-
nol (20 ml) to produce trimethyltin(IV) isopropoxide and
potassium chloride. The potassium chloride precipitate
was removed by filtration and then 9-anthracenecarboxylic
acid (0.44 g, 2 mmol) in isopropanol (20 ml) was added to
the filtrate; the solution was refluxed for 2 h. Evaporation
of the solvent gave a yellow solid, which was purified by
recrystallization from a chloroform–methanol (1:1 v/v) mix-
ture at room temperature to furnish yellowish crystals (m.p.
98 ꢁC). Anal. Calc. for C18H18O2Sn: C, 56.14; H, 4.67.
Found: C, 56.82; H, 4.45%. IR (KBr, cmꢀ1): 415m, 458m,
548m,575m, 652m, 731s, 767s, 840w, 884m, 1008w,
1190w, 1271m, 1318s, 1392s, 1437s, 1490sh, 1549s, 1620s,
2.3. Synthesis of complexes
2.3.1. Synthesis of ethyldiphenyltin(IV)iodide (Ph2EtSnI)
(1)
Ethyldiphenyltin(IV) iodide was prepared according to
the similar procedure for the preparation of dimethylphe-
nyltin(IV) iodide [32]. The iodine (5.08 g, 40 mmol) was
extracted by boiling carbon tetrachloride into ethyltriphe-
nyltin(IV) (7.60 g, 20 mmol) in a Soxhlet apparatus. Then,
the iodine was used up after 18 h, the solvent was removed
under reduced pressure, and the crude product was vac-
1
1
uum-distilled (85 ꢁC/0.5 torr). H NMR (ppm): 1.36–1.44
2364sh, 2922w, 3003w. H NMR (CDCl3, ppm): 0.74–0.93
(3H, t, CH3), 1.73–1.81 (2H, q, CH2), 7.39–7.72 (10H, m,
C6H5). 13C NMR (ppm): 9.3 (CH3,2J119Sn–13C, 405 Hz,
2J117Sn–13C, 387 Hz), 11.2 (CH2, 1J119Sn–13C, 672 Hz,
(9H, s, CH3, 2J119Sn–H, 57.0 Hz), 7.27–8.47 (9H, m,
C14H9). 13C NMR (ppm): ꢀ1.9 (CH3, 1J119Sn–13C,
1
393 Hz, J117Sn–13C, 375 Hz), 125.2, 125.5, 126.4, 127.9,
1J117Sn–13C, 653 Hz), 129.1 (Cmeta
,
3J119/117Sn–13C, 58
128.1, 128.5, 130.4, 131.1 (C14H9), 175.4 (CO). 119Sn
NMR (ppm): 163.1.
Hz), 129.6 (Cpara
,
4J119/117Sn–13C, 13 Hz), 136.2 (Cortho
,
2J119/117Sn–13C, 46 Hz), 137.2 (Cipso, J119Sn–13C, 495 Hz,
1J117Sn–13C, 474 Hz). 119Sn NMR (ppm): ꢀ28.5. Mass
spectrum data, tin-bearing fragment: m/e 430 [(C6H5)2
(C2H5)SnI]+, 401 [(C6H5)2SnI]+, 353 [(C6H5)(C2H5)SnI]+,
247 [SnI]+, 197 [(C6H5)Sn]+, 149 [(C2H5)Sn]+, 120 [Sn]+.
1
2.3.4. Synthesis of dimethyltin(IV)
di(9-anthracenecarboxylato){Me2Sn[OC(O)
(C14H9)]2 Æ CH3OH}CH3OH (4)
Dimethyltin(IV) dichloride (0.44 g, 2 mmol) was treated
with potassium isopropoxide (0.39 g, 4 mmol) in isopropa-
nol (20 ml) to produce dimethyltin(IV) diisopropoxide and
potassium chloride. The potassium chloride precipitate was
removed by filtration and then 9-anthracenecarboxylic acid
(0.88 g, 4 mmol) in isopropanol (40 ml) was added to the
filtrate; the solution was refluxed for 2 h. Evaporation of
the solvent gave a yellow solid, which was purified by
recrystallization from a toluene–methanol mixture (1:1
v/v) at room temperature to furnish yellowish crystals
(m.p. 150 ꢁC). Anal. Calc. for C34H32O6Sn: C, 62.31; H,
4.88. Found: C, 63.01; H, 4.53%. IR (KBr, cmꢀ1): 460m,
515 m, 547m, 599w, 635m, 724m, 792w, 847w, 889w,
915w, 1005w, 1174w, 1252m, 1291m, 1344w, 1389m,
1404w, 1448sh, 1625s, 1677s, 2854w, 2924w. 1H NMR
(CDCl3, ppm): 1.52–1.79 (6H, s, CH3, 2J119Sn–H,
81.2 Hz), 3.50 (3H, s, CH3OH) 7.48–8.56 (9H, m, C6H5).
13C NMR (ppm): 5.4 (CH3, 1J119Sn–13C, 642 Hz,
1J117Sn–13C, 625 Hz), 50.3 (CH3OH), 124.8, 124.9, 126.1,
126.7, 128.1, 128.4, 129.6, 130.5 (C14H9), 178.4 (COO).
119Sn NMR (ppm): ꢀ99.5. Mass spectrum data, tin-bearing
fragment: m/e 135 [MeSn]+, 150 [Me2Sn]+, 297
[Sn(C14H9)]+.
1
Mass numbers are based on H, 12C, 119Sn and 127I.
2.3.2. Synthesis of methyldiphenyltin(IV)
(9-anthracenecarboxylato)[Ph2MeSnOC(O)(C14H9)] (2)
Methyldiphenyltin(IV) iodide was prepared by the method
of Davison and Rakita [32]. This reagent (0.83 g, 2 mmol)
was treated with potassium isopropoxide (0.19 g, 2 mmol)
in isopropanol (20 ml) to produce methyldiphenyltin(IV)
isopropoxide and potassium iodide. The potassium iodide
precipitate was removed by filtration and then 9-anthracene-
carboxylic acid (0.44 g, 2 mmol) in isopropanol (20 ml) was
added to the filtrate; the solution was refluxed for 2 h. Evap-
oration of the solvent gave a yellow solid, which was purified
by recrystallization from an isopropanol–methanol (1:1 v/v)
mixture at room temperature which presented yellowish crys-
tals (m.p. 134 ꢁC). Anal. Calc. for C28H22O2Sn: C, 66.04; H,
4.32. Found: C, 66.32; H, 4.50%. IR (KBr, cmꢀ1): 420w,
471m, 501w, 525sh, 569w, 638m, 734m, 771m, 797w, 866w,
894m, 1015m, 1147w, 1258s, 1296s, 1385sh, 1415m, 1443w
1
1485sh, 1579sh, 1646s, 2824w, 2953w. H NMR (CDCl3,
ppm): 1.14–1.34 (3H, s, CH3, 2J119Sn–H, 59.2), 7.40–8.47
(19H, m, C6H5). 13C NMR (ppm): 10.3 (CH3, 1J119Sn–13C,

M.M. Amini et al. / Journal of Organometallic Chemistry 692 (2007) 3922–3930
3925
2.3.5. Synthesis of triphenyltin(IV)
(9-anthracenecarboxylato) [Ph3SnOC(O)(C14H9) Æ
CH3OH] (5)
nol (20 ml) to produce diphenyltin(IV) diisopropoxide and
potassium chloride. The potassium chloride precipitate was
removed by filtration and then 9-anthracenecarboxylic acid
(0.88 g, 4 mmol) in isopropanol (40 ml) was added to the
filtrate; the solution was refluxed for 2 h. Evaporation of
the solvent gave a yellow solid, which was purified by
recrystallization from a toluene–methanol–dichlorometh-
ane mixture (1:1 v/v) at 4 ꢁC to furnish yellowish crystals
(m.p. 142 ꢁC). Anal. Calc. for C42H28O4Sn: C, 70.54; H,
3.91. Found: C, 70.02; H, 4.12%. IR (KBr, cmꢀ1): 449m,
512m, 556w, 596w, 638m, 726sh, 792m, 845w, 888m,
915m, 1020w, 1143w, 1228s, 1253sh, 1292sh, 1342w,
Triphenyltin(IV) chloride (0.77 g, 2 mmol) was treated
with potassium isopropoxide (0.19 g, 2 mmol) in isopropa-
nol (20 ml) to produce triphenyltin iso-propoxide and
potassium chloride. The potassium chloride precipitate
was removed by filtration and then 9-anthracenecarboxylic
acid (0.44 g, 2 mmol) in isopropanol (20 ml) was added to
the filtrate; the solution was refluxed for 2 h. Evaporation
of the solvent gave a yellow solid, which was purified by
recrystallization from a chloroform–methanol (1:1 v/v) mix-
ture at room temperature to furnish yellowish crystals (m.p.
84 ꢁC). Anal. Calc. for C34H28O3Sn: C, 67.71; H, 4.64.
Found: C, 68.05; H, 4.42%. IR (KBr, cmꢀ1): 421w,
447m,495w, 525w, 640m, 695m, 729m, 779m, 866w, 887w,
998w, 1073w, 1295m, 1298m, 1367sh, 1428sh, 1480sh,
1
1424m 1445sh, 1486sh, 1678s, 2824w. H NMR (CDCl3,
ppm): 7.30–8.63 (10H, m, C6H5 and 9H, m, C14H9).
119Sn NMR (ppm): ꢀ49.5. Mass spectrum data, tin-bearing
fragment: m/e 120 [Sn]+, 197 [SnPh]+, 274 [SnPh2]+, 451
[Ph2Sn (C14H9)]+, 495 [Ph2SnOCO(C14H9)].
1
1621s, 2091m. H NMR (CDCl3, ppm): 3.5 (3H, s, CH3O),
7.37–8.48 (24H, m, C6H5). 13C NMR (ppm): 50.8 (CH3OH),
2.3.8. Synthesis of dimethylphenyltin(IV)
128.4 (Cmeta), 129.5 (Cpara), 137.1 (Cortho
,
J
2 119/117Sn–C,
(9-anthracenecarboxylato)[PhMe2SnOC(O)(C14H9)] (8)
Dimethylphenyltin(IV) iodide was prepared according to
published procedure [32]. This reagent (0.7 g, 2 mmol) was
treated with potassium isopropoxide (0.19 g, 2 mmol) in
isopropanol (20 ml) to produce methyldiphenyltin(IV) iso-
propoxide and potassium iodide. The potassium iodide
precipitate was removed by filtration and then 9-anthracen-
ecarboxylic acid (0.44 g, 2 mmol) in isopropanol (20 ml)
was added to the filtrate; the solution was refluxed for 2 h.
Evaporation of the solvent gave a yellow solid, which was
purified by recrystallization from a dichloromethane–meth-
anol mixture (1:1 v/v) at 4 ꢁC to furnish yellowish crystals
(m.p. 109 ꢁC). Anal. Calc. for C23H20O2Sn: C, 61.81; H,
4.47. Found: C, 61.22; H, 4.35 %. IR (KBr, cmꢀ1): 415w,
449w, 524w, 555w, 589w, 697m, 729s, 767m, 845w, 865w,
895w, 960w, 1015w, 1077w, 1278m, 1318sh, 1389s, 1429s,
49 Hz), 138.1 (Cipso), 125.2, 125.6, 126.6, 128.6, 128.8,
129.0, 130.4, 131.0 (C14H9), 175.0 (COO). 119Sn NMR
(ppm): ꢀ85.6. Mass spectrum data, tin- bearing fragment:
m/e 197 [SnPh]+, 351 [SnPh3]+, 451 [Ph2Sn(C14H9)]+, 495
[Ph2SnOOC(C14H9)]+, 572 [Ph3SnOOC(C14H9)]+.
2.3.6. Synthesis of ethyldiphenyltin(IV)
(9-anthracenecarboxylato)[Ph2EtSnOC(O)(C14H9)] (6)
Ethyldiphenyltin(IV) iodide (0.86 g, 2 mmol) was trea-
ted with potassium isopropoxide (0.19 g, 2 mmol) in
isopropanol (20 ml) to produce ethyldiphenyltin(IV) iso-
propoxide and potassium iodide. The potassium iodide
precipitate was removed by filtration and then 9-anthracen-
ecarboxylic acid (0.44 g, 2 mmol) in isopropanol (20 ml)
was added to the filtrate; the solution was refluxed for
2 h. Evaporation of the solvent gave a yellow solid, which
was purified by recrystallization from a chloroform–meth-
anol (1:1 v/v) mixture at room temperature to furnish
yellowish crystals (m.p. 123 ꢁC). Anal. Calc. for
C29H24O2Sn: C, 66.59; H, 4.58. Found: C, 66.02; H,
4.66%. IR (KBr, cmꢀ1): 465m, 510w, 536sh, 575w, 618s,
663m,731m, 764w, 792w, 843m, 888m, 949m, 1011m,
1175sh, 1275m, 1321s, 1378s, 1436sh, 1479sh, 1520s,
1568s, 1640s, 2869w, 2917w, 3049w. 1H NMR (CDCl3,
ppm): 1.63–1.68 (3H, t, CH3), 7.37–8.48 (19H, m, C6H5).
13C NMR (ppm): 10.0 (CH3), 10.2 (CH2), 128.3 (Cmeta),
1
1485sh, 1546s, 1621sh, 2854w, 2924w. H NMR (CDCl3,
ppm): 0.93–1.15 (6H, s, CH3, 2J119Sn–H, 64.2 Hz),
7.18–8.46 (5H, m, C6H5 and 9H, m, C14H9).
13C NMR (ppm): ꢀ4.3 (CH3, 1J119Sn–13C, 428 Hz,
1J117Sn–13C, 415 Hz), 128.3 (Cmeta), 129.5 (Cpara), 136.1
2
(Cortho, J119/117Sn–13C, 48 Hz), 139.2 (Cispo), 124.9, 125.3,
126.4, 128.1, 128.4, 128.7, 130.8, 131.2 (C14H9), 176.1
(COO). 119Sn NMR (ppm): 79.8. Mass spectrum data, tin-
bearing fragment: m/e 120 [Sn]+, 135 [SnMe]+, 150
[SnMe2]+, 197 [SnPh]+, 227 [PhSnMe2]+, 294 [Sn(C14H9)]+,
389 [PhSnMe(C14H9)]+, 433 [PhMeSn OCO(C14H9)].
2
129.2 (Cpara), 136.8 (Cortho, J119/117Sn–13C, 45 Hz), 139.2
(Cispo), 125.2, 125.6, 126.5, 128.2, 128.4, 128.9, 130.1,
131.1 (C14H9), 175.6 (COO). 119Sn NMR (ppm): ꢀ17.0.
Mass spectrum data, tin-bearing fragment: m/e 149
[EtSn]+, 197 [PhSn]+, 374 [PhSn(C14H9)]+, 403 [PhEtSn-
(C14H9)]+, 451 [Ph2Sn(C14H9)]+.
3. Results and discussion
3.1. Synthesis
A new methodology has been used to synthesize organo-
tin carboxylates. Organotin carboxylates are usually
prepared by reacting organotin hydroxide or di-alkyltin
oxide to corresponding carboxylic acid. However, organo-
tin hydroxides or oxides are limited and other routes are
needed for the preparation of organotin carboxylate,
2.3.7. Synthesis of diphenyltin(IV) di-
(9-anthracenecarboxylato){Ph2Sn[OC(O)(C14H9)]2} (7)
Diphenyltin(IV) dichloride (0.69 g, 2 mmol) was treated
with potassium isopropoxide (0.39 g, 4 mmol) in isopropa-

3926
M.M. Amini et al. / Journal of Organometallic Chemistry 692 (2007) 3922–3930
specifically organotin carboxylates with mixed alkyl and
aryl groups on tin. Several authors have used various
approaches for synthesis of organotin carboxylates, includ-
ing reacting organotin chloride to carboxylic acid in the
presence of sodium hydroxide or sodium salt of carboxylic
acids. Alternatively, they were prepared by reacting organo-
tin iodide to silver acetates [24]. However, in the latter
approach, cleavage of aryl groups present some difficulties,
consequently a milder synthetic approach has been used. In
the present study, we have replaced halogens of di- or tri-
organotin with isopropoxide group by reacting them to
potassium isopropoxide. The triorganotin isopropoxide
was isolated and reacted to anthracenecarboxylic acid. This
procedure provides a clean reaction for the preparation of
organotin carboxylates without any side product.
O
O
C
H3C
H
O
Sn
Scheme 2. Proposed structure for complex 5.
3.2. General characterization
O
O
O
O
C
Sn
C
3.2.1. Infrared spectroscopy
The infrared data of di- and triorganotin carboxylates are
usually used to predict their solid-state structures. In the
simplest triorganotin carboxylates, trimethyltin acetate,
the oxygen atom of the acetate, and the carbonyl oxygen
of the acetate occupy the apical positions in the C3SnO3
polyhedron, which is a common feature in triorganotin
compounds [33], to form a polymer with zigzag configura-
tion. The bridging carboxylate in organotin compounds is
simply followed by infrared spectroscopy with shift of
t(CO2) bands, as compared to the parent carboxylic acid.
In the infrared spectra of Ph2MeSnOCO(C14H9) (2), Me3-
SnOCO(C14H9) (3), Me2Sn[OCO(C14H9)]2 (4), Ph3SnO-
CO(C14H9) (5), Ph2EtSnOCO(C14H9) (6), Ph2Sn[OCO
(C14H9)]2 (7), and PhMe2SnOCO(C14H9) (8), the tsym(CO2)
and tasym(CO2) modes appear at 1385, 1579; 1392, 1549;
1389, 1677; 1367, 1621; 1378, 1568; 1486, 1678; 1389,
1546 cmꢀ1, respectively. The shift of those bands to red
for 2–8 with respect to free acid confirms formation of
organotin carboxylates. The magnitude of tasym ꢀ tsym
(Dt) separation has been used to explain the type of carbox-
ylate structure present [34]. The magnitude of tasym ꢀ tsym
(Dt) for 2, 3, 6, and 8 are in the expected range (below
Scheme 3. Proposed structure for complex 7.
above-mentioned triorganotin carboxylates rules out an
exactly planar arrangement of the three Sn–C bonds and
therefore a precisely symmetrical trans-trigonal bipyramidal
geometry around the tin. Infrared assignments are con-
firmed by single crystal structure determination of 2, 3,
and 4.
In contrast, for the complexes 4 and 5, the values of Dt
exceed 230 cmꢀ1; this clearly shows that these complexes
adopt the monodentate carboxylate structure. A five-coordi-
nated tin is expected for the triphenyltin derivative 5, by con-
sidering that the carboxylate group is monodentate and the
coordinated methanol is present in the complex (Scheme 2).
Interestingly, triphenyltin arylcarboxylates are generally
monomeric molecules with tetrahedral tin [35,36], the aryl
group prefers to be conjugated to the carboxylate group so
that those two planes can remain coplanar, but this orienta-
tion prevents the carbonyl oxygen from approaching the tin
[37]. Apparently, similar behavior is intact for the complex 5,
however, orientation of aryl groups should be different to
some extent in order to allow methanol to coordinate to
tin. The infrared spectrum of complex 7 exhibited single
200 cmꢀ1
) for the bridged triorgnotin carboxylates
(Scheme 1). Furthermore, the observation of two Sn–C
absorption bands in the 524–575 cmꢀ1 region for the
R1
t
sym(CO2) and tasym(CO2) peaks which indicate that both
carboxylate groups have similar bonding mode. The magni-
tude of Dt, 192 cmꢀ1, is on the broader-line of monodentate
and bidentate carboxylates; therefore, one can conclude a
four- or six-coordinated tin for this complex (Scheme 3).
However, a Dt value of 200 10 cmꢀ1, is attributed to the
chelated carboxyl groups [38].
Sn
R3
O
O
C
R2
n
3.2.2. NMR spectroscopy
For the determination of structural features of organo-
tin carboxylates in solution, their 1H, 13C, and 119Sn
Scheme 1. R1 = CH3, R2 = R3 = C6H5 (2); R1 = R2 = R3 = CH3 (3);
R1 = C2H5, R2 = R3 = C6H5 (6); R1 = R1 = CH3, R3 = C6H5 (8).

M.M. Amini et al. / Journal of Organometallic Chemistry 692 (2007) 3922–3930
3927
NMR have been recorded in CDCl3. The 1H NMR spectra
of all complexes show the expected aliphatic and aromatic
peaks with right integration and multiplicities. For those
ꢀ17.0 and 79.8 ppm), and those of complexes 4 and 5 in
noncoordinating solvents (ꢀ99.5 and ꢀ85.6 ppm) falling
within the range of four- and five-coordinated organotin
compounds, respectively [43,44]. Although by considering
that the 119Sn chemical shift in addition to the tin coordi-
nation number is influenced by the type of aromatic and
aliphatic groups or donor atoms bound to the tin [45],
the 119Sn chemical of complex 7, ꢀ49.5 ppm, is far from
the range noted for the six-coordinated tin. Therefore, it
is reasonable to assume that the complex 7, similar to poly-
meric triorganotin carboxylates, do not retain solid-state
structure in solution.
2
that resolved the J(119Sn–C–1H), namely, 2 (59.2 Hz), 3
(57.0 Hz), 4 (81.0 Hz) and 8 (64.2 Hz), their values indicate
tetrahedral geometries for complexes 2, 3 and 8, and octa-
hedral for 4. The magnitude of the two-band coupling,
2J(119Sn–C–1H), for compounds 2, 3, 4 and 8 are 59.2,
57.0, 81.2 and 64.2 Hz, respectively. The estimated value
of C–Sn–C angle in 2, 3, 4 and 8 is 112ꢁ, 110ꢁ, 132ꢁ and
115ꢁ, respectively [39]. The estimated value for compound
4 is in good agreement with the C–Sn–C angle found in
the solid state. Apparently, polymeric organotin carboxy-
lates, 2, 3, 6 and 8 do not retain a solid-state structure in
3.3. Crystal structures
2
solution in contrast to complex 4 with J(119Sn–C–1H) of
1
81.0 Hz. When H NMR spectra of 2, 3, 6, and 8 was
3.3.1. Crystal structure of [Ph2MeSnOC(O)(C14H9)] (2)
Selected bond angles and distances for complex 2 are
given in Table 2 and the molecular structure is shown in
Fig. 1. This complex is a one-dimensional polymer
2
recorded in CD3OD, the J(119Sn–C–1H) values increased
2
to around 70–72 Hz. The increase in the J(119Sn–C–1H)
coupling constant from 57–64 Hz in CDCl3 to about
70–72 Hz in CD3OD reveals a five-coordinated tin atom
in a coordinating solvent for the latter-mentioned com-
plexes. Similar to other polymeric triorganotin carboxy-
lates [40], their solid-state structures in solution
depolymerize to monomers and four-coordinated species,
and then the solvent coordinate to the tin and return them
to the five-coordinated status. The increase of coupling
constants, 2J119Sn–C–1H, is in agreement with the decrease
of the s-character of the CH3–Sn bonds from four- to five-
coordinated tin [4].
Table 2
˚
Selected bond lengths (A) and angels (ꢁ) for [Ph2MeSnOC(O)(C14H9)] (2)
Bond lengths
Sn(1)–C(1)
C(14)–O(1)
Sn(1)–C(2)
Sn(1)–C(8)
2.116(3)
1.268(3)
2.124(2)
2.143(2)
C(14)–O(2)
C(14)–C(15)
Sn(1)–O(1)
Sn(1)–O(2)#1
1.247(3)
1.501(3)
2.2231(18)
2.3800(18)
Bond angles
C(1)–Sn(1)–C(2)
C(1)–Sn(1)–C(8)
C(2)–Sn(1)–C(8)
C(2)–Sn(1)–O(1)
C(1)–Sn(1)–O(2)#1
C(8)–Sn(1)–O(2)#1
C(7)–C(2)–Sn(1)
O(2)–C(14)–C(15)
C(3)–C(2)–Sn(1)
119.36(11)
131.74(11)
108.61(9)
99.64(8)
82.82(9)
87.26(8)
119.84(18)
120.3(2)
122.11(19)
C(13)–C(8)–Sn(1)
O(1)–C(14)–C(15)
C(1)–Sn(1)–O(1)
C(8)–Sn(1)–O(1)
C(2)–Sn(1)–O(2)#1
O(1)–Sn(1)–O(2)#1
O(2)–C(14)–O(1)
C(9)–C(8)–Sn(1)
118.8(2)
116.1(2)
88.88(10)
88.19(8)
96.27(8)
164.08(7)
123.6(2)
123.02(19)
The COO resonance in the 13C NMR spectra of com-
plexes 2, 3, 4, 5, 6 and 8 were observed at 175.5, 175.4,
178.4, 175.0, 175.6 and 176.1 ppm, respectively. By consid-
ering that the polymeric organotin carboxylates, 2, 3, 6 and
8 do not retain solid-state structure and the carboxylate
groups become monodentate in solution; similar 13C chem-
ical shifts are expected for the COO groups in all complexes.
The insufficient solubility of complex 7 in chloroform did
not allow us to record the 13C NMR spectrum and reach
a similar conclusion. Furthermore, Cipso resonances were
observed for the complexes 2 (139.4 ppm), 3 (138.1 ppm),
6 (139.2 ppm) and 8 (139.2 ppm) these values are consistent
with the four-coordinated organotin structures [41,42]. The
C–Sn–C angles for compounds 2 (112ꢁ), 3 (111ꢁ), 4 (133ꢁ)
and 8 (114ꢁ) is also estimated from their magnitude of
1J119Sn–13C [39]. The estimated value for compound 4 is
in good agreement with the C–Sn–C angle found in the solid
state and also with the value estimated from magnitude of
2J(119Sn–C–1H). The 13C NMR spectra of all organotin
carboxylates did not show a shift to anthracene ring carbon
atoms in comparison with the free anthracenecarboxylic
acid, however, as expected, their COO resonances slightly
shifted downfield.
All 119Sn NMR spectra were recorded in noncoordinat-
ing solvents in order to preclude possible changes in the
coordination number of tin. The solution 119Sn NMR spec-
tra of all complexes consists of only one resonance, the
chemical shifts of complexes 2, 3, 6 and 8 (ꢀ1.3, 163.1,
Fig. 1. Molecular structure of methyldiphenyltin (9-anthracenecarboxy-
late)[Ph2MeSnOC(O)C14H9] (2).

3928
M.M. Amini et al. / Journal of Organometallic Chemistry 692 (2007) 3922–3930
Table 3
(R1 = CH3, R2 = R3 = C6H5 in Scheme 1) with five-coordi-
nated tin with electronegative oxygen atoms occupying the
apical position of the trigonal bipyramid, a feature common
in five-coordinated triorganotin compounds [34,46]. The
˚
Selected bond lengths (A) and angels (ꢁ) for [Me3SnOC(O)C14H9] (3)
Bond lengths
Sn(1)–C(3)
Sn(1)–C(1)
Sn(1)–C(2)
Sn(1)–O(2)#1
C(4)–C(5)
2.123(2)
2.126(3)
2.126(3)
2.2214(16)
1.507(3)
C(4)–O(1)
Sn(1)–O(1)
Sn(1)–O(2)
C(4)–O(2)
C(5)–C(6)
1.247(3)
2.4010(17)
4.5933(17)
1.271(3)
˚
tin–oxygen bond lengths of 2.2231(2) and 2.3800(2) A is
attributed to the unevenness in bonding; the latter value is
in the range of Sn–O bond lengths, which have been
reported for intramolecular bonds in triorganotin carboxy-
lates [47]. The intramolecular tin–oxygen bond length
1.403(3)
Bond angles
C(3)–Sn(1)–C(1)
C(3)–Sn(1)–C(2)
C(1)–Sn(1)–C(2)
C(3)–Sn(1)–O(2)#1
C(1)–Sn(1)–O(2)#1
C(2)–Sn(1)–O(2)#1
C(3)–Sn(1)–O(1)
O(2)–C(4)–C(5)
121.46(11)
118.60(12)
119.33(12)
93.20(8)
95.97(9)
88.42(9)
C(1)–Sn(1)–O(1)
C(2)–Sn(1)–O(1)
C(3)–Sn(1)–O(2)
C(1)–Sn(1)–O(2)
C(2)–Sn(1)–O(2)
O(1)–C(4)–O(2)
O(1)–C(4)–C(5)
C(4)–O(1)–Sn(1)
92.00(9)
83.78(8)
81.57(7)
91.81(8)
88.92(8)
123.5(2)
119.87(19)
141.48(14)
˚
[Sn(1)–O(2), 2.3800 A] is similar to those of trimethyltin(IV)
and dimethylphenyltin(IV) acetates [24,48] but is slightly
longer than that of triphenyltin acetate(IV) [49]. Although
the oxygen–tin–oxygen skeleton is bent, 164.08(7)ꢁ, the
sum of the carbon–tin–carbon angles (359.71ꢁ) is consistent
with the ideal value of 360ꢁ. One of the phenylmethyltin
angle, C(1)–Sn(1)–C(8), is significantly larger than the
other, C(1)–Sn(1)–C(8), and both are larger than the diphe-
nyltin angle [108.61(9)ꢁ]. It seems that the carbonyl oxygen
is opens up the carbon–tin–carbon angle nearest to it. Fur-
thermore, the smaller diphenyltin angle in complex 2 in
comparison with those of ethyldiphenyltin(IV) chloroace-
tate [115.2(1)ꢁ] [50] and ethyldiphenyltin(IV) dichloroace-
tate [115.6(1)ꢁ] [35] is probably imposed by anthracene
group to minimize steric interactions. Furthermore, torsion
angles of C(1)–Sn(1)–C(2)–C(7) and C(8)–Sn(1)–C(2)–C(7)
with values of 174.9(2)ꢁ and ꢀ0.4(2)ꢁ show that phenyl rings
are twisted and become almost perpendicular to the equato-
rial plane to decrease steric interaction further. In complex
2, which carries two phenyl groups, the phenyl groups that
occupy the equatorial position are farthest from the
intramolecular carbonyl oxygen. The bond length of
C(14)–O(1) is almost equivalent to the bond length of
C(14)–O(2), which is associated with the oxygen bridging
the two tin atoms; the bond length of C(14)–O(1) suggests
delocalization of p-electron density in it.
86.41(8)
116.63(19)
3.3.2. Crystal structure of [Me3SnOC(O)(C14H9)] (3)
Selected bond angles and distances for complex 3 are
listed in Table 3 and the molecular structure is shown
in Fig. 2. This complex, which is similar to complex 2
adapt a carboxylate bridged motif in which the tin center
shows trans-C3SnO2 trigonal–bipyramidal coordination
(R1 = R2 = R3 = CH3 in Scheme 1), with one axial
tin–oxygen bond much longer than the other axial
Fig. 2. Molecular structure of trimethyltin(IV) (9-anthracenecarboxy-
lato)[Me3SnOCO(C14H9)] (3).
3.3.3. Crystal structure of
{Me2Sn[OC(O)(C14H9)]2 Æ CH3OH}CH3OH (4)
Selected bond lengths and angles for complex 4 are given
in Table 4. Complex 4, as shown in Fig. 3, with trigonal
bipyramid geometry possessing a monomeric structure.
Two carboxylates are coordinated to tin in monodentate
form from axial and equatorial positions and the coordina-
tion number is raised to five as the methanol occupies the
apical position of the trigonal bipyramid. Apparently,
because of the anthracene steric demand, coordination of
the preparation solvent, CH3OH, is preferred to bridge car-
boxylate. Such a steric control over the molecular structure
for diorganotin carboxylates has been noticed previously
[51]. Although, several monomeric diorganotin carboxy-
lates with general formula of R2Sn(O2CR0)2 exist in which
the carboxylate ligands are chelated to tin as a bidentate
˚
tin–oxygen bond [2.4010(17) and 2.2214(16) A]. The oxy-
gen–tin–oxygen skeleton in comparison with complex 2 is
less bent [170.87(6)ꢁ] and is very similar to that of trim-
ethyltin(IV) acetate [48]. The carbon–tin–carbon angles
and tin–carbon bond lengths of complex 3 are almost
identical with those of trimethyltin acetate. Comparison
of carbon–tin–carbon angles with such angles in complex
2 clearly shows that distortion of triorganotin carboxy-
lates from ideal geometry is influenced by type of organic
group on tin to a great extent and by steric interactions of
bulkier ones with anthracene group to a less extent. As
expected, other structural features of complex 2 and 3
are similar.

M.M. Amini et al. / Journal of Organometallic Chemistry 692 (2007) 3922–3930
3929
Table 4
˚
Selected bond lengths (A) and angels (ꢁ) for Me2Sn[OC(O)C14H9]2 Æ
CH3OH (4)
Sn1–O3
Sn1–C1
Sn1–C2
Sn1–O1
Sn1–O5
O1–C3
O2–C3
C3–C4
O3–C18
O4–C18
O5–C33
O6–C34
2.0637(15)
2.108(2)
2.120(2)
2.1562(16)
2.3056(17)
1.290(3)
1.245(3)
1.511(3)
1.309(3)
1.219(3)
1.443(3)
1.424(3)
O3–Sn1–C1
O3–Sn1–C2
C1–Sn1–C2
O3–Sn1–O1
C1–Sn1–O1
C2–Sn1–O1
O3–Sn1–O5
C1–Sn1–O5
C2–Sn1–O5
O1–Sn1–O5
C3–O1–Sn1
O1–Sn1–O5 1
121.07(9)
100.94(9)
137.12(10)
81.61(7)
97.15(9)
97.11(8)
82.34(7)
88.00(9)
89.52(8)
163.54(7)
112.33(14)
63.54(7)
Fig. 4. The molecular packing of complex 4 showing intermolecular
hydrogen bonding though solvated CH3OH.
As shown in Fig. 3, a solvent molecule, methanol, is
associated with the coordinated methanol and both metha-
nol molecules, as illustrated in Fig. 4, are engaged in hydro-
gen bonding. The O(5) atom of coordinated methanol acts
as a hydrogen-bond donor by H(5) to the O(6) atom of sol-
˚
˚
vated methanol (O5–H5, 0.849 A; O5–Hꢁ ꢁ ꢁO6, 1.729 A;
˚
O5ꢁ ꢁ ꢁO6, 2.575 A; and an angle at H 173.97ꢁ) and O(6) acts
´
as a hydrogen-bond donor by H(6) to O(2), a coordinated
´
carboxylate oxygen. The O6–H6, O6–Hꢁ ꢁ ꢁO(2), and
˚
˚
˚
O6ꢁ ꢁ ꢁO2 distances are 0.783 A, 1.941 A and 2.718 A,
respectively, at angle of 171.8ꢁ.
4. Conclusion
This contribution has shown that the combination of di-
and triorganotin(IV) moiety with anthracenecarboxylic
acid result in the formation of polymeric or discrete com-
plexes. The steric demand of anthracene group influences
the coordination geometry of tin. Low coordinated tin is
dominant in the majority of di- and trioganotin(IV) deriv-
atives of 9-anthracenecarboxylic acid. For the entire mixed
aryl and alkyl groups of triorganotin complexes, carboxyl-
ate-bridged motifs were observed, in contrast to discrete
triphenyltin derivative which is highly steric demanding.
Fig. 3. Molecular structure of dimethyltin(IV) (9-anthracenecarboxy-
late)[Me2Sn(OCOC14H9)2 Æ CH3OH] (4).
ligand [17], to the best of our knowledge the structure of
complex 4 is the first example of a five-coordinated mono-
meric diorganotin carboxylate among rich and diverse
organotin carboxylate structures [17]. It seems that the
extensive crowding imposed by anthracene prevents car-
boxylate groups to coordinate to tin by inter- or intramolec-
ular interaction. The equatorial tin–oxygen bond length,
Acknowledgements
˚
2.0637(15) A, somewhat is quite shorter than the axial
˚
tin–oxygen bond length, 2.1562(16) A, which associates
The authors thank the Vice-President’s Office for
Research Affairs of Shahid Beheshti University for sup-
porting this work.
with the oxygen atom of carboxylates, and both bond
length are shorter than tin–oxygen bond that arises from
the coordination of methanol. The later mentioned tin–oxy-
˚
gen bond length, 2.1562(16) A, is much shorter than the
Appendix A. Supplementary material
similar tin–oxygen bond length in organotin car-
boxylates with a general formula of R2Sn(O2CR0)2. The
oxygen–tin–oxygen angle, which associated with the car-
boxylate and methanol oxygen, bends 163.54(7)ꢁ, and the
distortion from idealized geometry is also seen in the sum
of the equatorial plane angles (359.13ꢁ).
CCDC 639904, 639906, and 639905 contain the supple-
mentary crystallographic data for 2, 3 and 4. These data
can be obtained free of charge via http://www.ccdc.cam.ac.
uk/conts/retrieving.html, or from the Cambridge Crystal-
lographic Data Centre, 12 Union Road, Cambridge CB2

3930
M.M. Amini et al. / Journal of Organometallic Chemistry 692 (2007) 3922–3930
[25] M.M. Amini, V. Alijani, A. Azadmeher, S.W. Ng, Acta Crystallogr.,
Sect. E 62 (2006) m2427.
1EZ, UK; fax: (+44) 1223-336-033; or e-mail: deposit@
ccdc.cam.ac.uk. Supplementary data associated with this
article can be found, in the online version, at doi:10.1016/
j.jorganchem.2007.05.049.
[26] Stoe and Cie, X-AREA, Version 1.30: Program for the Acquisition and
Analysis of Data, GmbH, Darmstadt, Germany, 2005.
[27] Stoe and Cie, X-RED, Version 1.28b: Program for Data Reduction and
Absorption Correction, GmbH, Darmstadt, Germany, 2005.
[28] Stoe and Cie, X-SHAPE, Version 2.05: Program for Crystal Optimiza-
tion for Numerical Absorption Correction, GmbH, Darmstadt,
Germany, 2004.
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