New hexacyclic binuclear tin complexes derived from bis-(3,5-di-tert-butyl-2-phenol)oxamide

Article abstract of DOI:10.1016/S0022-328X(00)00689-6

The syntheses of bis-(3,5-di-tert-butyl-2-phenol)oxamide (2a) and four new hexacyclic bimetallic tin compounds derivatives are reported: bis-(3,5-di-tert-butyl-2-oxo-phenyl)-oxamido-bis(dibutyltin) (3), bis-(3,5-di-tert-butyl-2-oxo-phenyl)-oxamido-bis-(di

Full text of DOI:10.1016/S0022-328X(00)00689-6

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Journal of Organometallic Chemistry 614–615 (2000) 283–293
New hexacyclic binuclear tin complexes derived from
bis-(3,5-di-tert-butyl-2-phenol)oxamide
Victor M. J´ımenez-Pe´rez a, Carlos Camacho-Camacho b, Marisol Gu¨izado-Rodr´ıguez a,
Heinrich No¨th c, Rosalinda Contreras a,*
a Departamento de Qu´ımica, Centro de In6estigacio´n y de Estudios A6anzados del IPN, AP 14-740, CP 07000, Mexico, DF Mexico
b Departamento de Sistemas Biolo´gicos, Uni6ersidad A. Metropolitana, Xochimilco, Calzada del Hueso 1100, Colonia Villa Quietud, CP 04960,
Mexico, DF Mexico
c Department Chemie, Ludwig-Maximilians Uni6ersita¨t, Butenandt-Strasse 5-13 (Haus D), D-81377 Munich, Germany
Received 30 May 2000
Dedicated to Professor Sheldon Shore on the occasion of his 70th birthday.
Abstract
The syntheses of bis-(3,5-di-tert-butyl-2-phenol)oxamide (2a) and four new hexacyclic bimetallic tin compounds derivatives are
reported: bis-(3,5-di-tert-butyl-2-oxo-phenyl)-oxamido-bis(dibutyltin) (3), bis-(3,5-di-tert-butyl-2-oxo-phenyl)-oxamido-bis-
(diphenyltin) (4), bis(triethylammonium) bis-(3,5-di-tert-butyl-2-oxo-phenyl)-oxamido-bis-(dichlorobutyl-stannate) (5), and bis-
[(OꢀSn) ethanol]-bis-(3,5-di-tert-butyl-2-oxo-phenyl)-oxamido-bis-(chlorophenyltin) (6). All tin compounds show a planar ligand
skeleton in which each tin atom is linked to the phenoxy group, to the anilinic nitrogen atom and to the oxygen of the oxamide
group. Compounds 3 and 4 have two pentacoordinated diorganyl tin atoms with a distorted bpt geometry, whereas 5 contains a
dianionic structure with two hexacoordinated tin atoms bonded to a n-butyl group and to two chlorine atoms and two triethyl
ammonium as counterions. Compound 6 has two hexacoordinated tin atoms, each atom is bonded, in addition to the ligand, to
one phenyl and one chlorine and coordinated to an ethanol molecule. Characterization of the compounds was made through usual
analytical and spectroscopic methods. Structures of 4,6-di-tert-butyl-1-phenol-2-amine 1, the oxamide 2a and the four tin
compounds 3–6 were established by the X-ray diffraction analyses. © 2000 Elsevier Science B.V. All rights reserved.
Keywords: Hexacyclic binuclear tin complexes ; Bis-(3,5-di-tert-butyl-2-phenol)oxamide
1. Introduction
and to study its reactions with organometallic tin com-
pounds. Interest in this investigation is based on several
different structures that could be expected due to the
polyfunctional nature of the ligand. In addition to the
different possible coordination numbers for the tin
atom and that the ligand could be found in different
oxidation states in the reaction products depending on
the tin substitution [7,8,20]. Another point of interest in
the preparation of the tin compounds derived from
phenolamines is based on the biocidic properties of the
diphenolamine 2b [21] and the potential activity of tin
compounds as anticancer agents [22–25].
We are interested in the preparation of main group
derivatives of phenolamines [1–8]. These molecules are
particularly relevant due to their rich oxidation–reduc-
tion chemistry which allows the preparation of different
types of coordination compounds [9–20]. As a conse-
quence of their easiness to coordinate Lewis acids, they
give very rigid and stable heterocyclic molecules which
are suitable models for structural and spectroscopic
investigation (Fig. 1). In particular phenolamines give
stable derivatives with tin compounds [7,18–20], some
examples are shown in Fig. 2.
In continuing with our research, we decided to pre-
pare the bis-(3,5-di-tert-butyl-2-phenol)-oxamide (2a)
2. Results and discussion
Herein, we report the synthesis of the 4,6-di-tert-bu-
tyl-1-phenol-2-amine 1 the bis-(3,5-di-tert-butyl-2-phe-
* Corresponding author. Fax: +525-7-477113.
E-mail address: rcontrer@mail.cinvestav.mx (R. Contreras).
0022-328X/00/$ - see front matter © 2000 Elsevier Science B.V. All rights reserved.
PII: S0022-328X(00)00689-6

284
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Fig. 1. Heterocycles derived from bis-(2-phenol)amine [3,6,8].
by spectroscopic methods and by an X-ray diffraction
study (Fig. 4 and Tables 1, 3, 5–7). The molecular
structure of 4,6-di-tert-butyl-1-phenol-2-amine 1 has
normal parameters for a phenolamine, an intramolecu-
lar hydrogen bond has been found between the OH
,
proton and the nitrogen (2.352 A), but not intermolecu-
lar interactions (Fig. 4, Tables 5 and 7). The synthesis
of compound 1 is not in agreement with a literature
report [27] which establishes that the reaction of the
3,5-di-tert-butyl-benzoquinone with ethylenediamine
gives the bis-(2-phenolamine)-1,2-ethylene.
Fig. 2. Tin compounds derived from bis-(3,5-di-tert-butyl-2-phenol)-
amine, R=t-Bu [7].
Compound 1 was reacted with diethyloxalate to give
compound 2a. It was characterized by the common
spectroscopic methods, the assignment of its NMR data
(Tables 1 and 3), was based on HETCOR C/H and
nol)-oxamide 2a and the preparation of its binuclear
hexacyclic compounds bearing penta- or hexacoordi-
nated tin atoms: bis-(3,5-di-tert-butyl-2-oxo-phenyl)-
oxamido-bis-(dibutyltin) (3), bis-(3,5-di-tert-butyl-2-
oxo-phenyl)-oxamido-bis-(diphenyltin) (4), bis-(triethyl-
ammonium) bis-(3,5-di-tert-butyl-2-oxo-phenyl)-oxam-
ido-bis-(dichlorobutyl-stannate) (5), and bis-[(OꢀSn)-
ethanol]-bis-(3,5-di-tert-butyl-2-oxo-phenyl)-oxamido-
bis-(chlorophenyltin) (6), as well as the X-ray diffrac-
tion analyses of compounds 1, 2a, and 3–6.
In order to prepare the oxamide 2a we had first to
synthesize the 4,6-di-tert-butyl-1-phenol-2-amine 1. The
synthesis of 1 from the reduction reaction of the 4,6-di-
tert-butyl-benzo-2-iminoquinone and its NMR charac-
terization are known [26]. We have prepared compound
1 by a different method: using the deamination reaction
of ethylenediamine by the 3,5-di-tert-butyl-benzo-
quinone, (Fig. 3). The structure of 1 was characterized
1
N/H and COSY experiments. H-NMR variable tem-
perature experiments were used to estimate the nature
of the hydrogen bond having in mind that the NꢀH
hydrogen bonds are a model of metallic coordination,
the method is based on the shift calculations of the
labile hydrogen atom resonance at different tempera-
ture [28]). Calculations for 2a shows Dl/DT for NꢀH
−4.65×10−3 ppm K−1 and for OꢀH −3.9×10−3
ppm K−1 which means weak intramolecular coordina-
tion of these protons, and a fast exchange with the
solvent. The contrast with bis-(2-phenol)-oxamide 2b is
interesting [28,29] because 2b presents a strongly
bonded tricoordinated hydrogen atom in a planar
molecular array, with carbonyl groups in trans position.
1H-NMR experiments evidenced Dl/DT= −0.5×
10−3 ppm K−1 for NꢀH and −6.5×10−3 ppm K−1
Fig. 3. Synthesis of bis-(3,5-di-tert-butyl-2-phenol)-oxamide 2a and bis-(2-phenol)-oxamide 2b [28,29].

V.M. J´ımenez-Pe´rez et al. / Journal of Organometallic Chemistry 614–615 (2000) 283–293
285
compounds 3–6, respectively, which were microcrys-
talline solids, Figs. 6–7. The characterization was per-
formed by the usual spectroscopic and X-ray
diffraction analyses, Figs. 8–13. It was found that the
ligand gave in all cases dinuclear derivatives, with the
skeleton of the ligand in a planar array. The ligand
2a was also reacted with dichlorodimethyltin and the
binuclear compound of analogous structure to com-
pounds 3 and 4 was submitted to an extensive NMR
study [32].
All compounds gave good NMR spectra, Tables
1–4. The 119Sn-NMR data is indicative of the coordi-
nation number of the tin atoms in solution [30,31],
Table 1, for a similar compound bis-(3,5-di-tert-butyl-
2-oxo-phenyl)-oxamido-bis-(dibutyltin) [32], it was
found that the 119Sn chemical shift was the same in
the solid state (−83.6 ppm) than in solution (−85.5
ppm), indicating that in both the tin atom is pentaco-
ordinated. By comparison with this chemical shifts, it
is deduced that compounds 3 and 4, derived from
diorganyltin reagents, have pentacoordinated tin
atoms (l= −120.5 for 3 and −257.5 for 4) whereas
in compounds 5–6 they are hexacoordinated (l=
−390.0 for 5 and −257.0 for 6). It should be noted
that 4 and 6 have the same chemical shift but differ-
Fig. 4. Molecular structure of compound 1.
for OꢀH, the same situation was found in the solid
state by the X-ray diffraction study [29] ((NꢀH···OꢀH
,
2.172(2), NꢀH···OꢁC 2.138(2) A). The solid state
structure of 2a (Fig. 5, Tables 5–7) is consistent with
the structure in solution, it has a trans conformation
for the oxamide group, the C1ꢀO1 bond length is
,
short (1.236(1) A) whereas the N1ꢀC1 bond is longer
1
ent substitutents at tin atom. Assignment of H- and
,
(1.323(3) A). The proton is bonded to the nitrogen
13C- data of compounds 3–6 was based on the values
of the coupling constants nJ(117/119Snꢀ13C) [30–32]
and by comparison with other phenolamine deriva-
tives and by HETCOR and COSY experiments (Ta-
bles 1–4). 1H- and 13C-NMR data of the ionic
compound 5 shows that two triethyl ammonium ions
are present, whereas compound 6 contains a coordi-
nated ethanol molecule. One interesting feature of the
1H-NMR spectra of compounds 3–6 is the shifting to
atom, the distance of NꢀH proton to the cis carbonyl
oxygen atom O1 is 1.72 A indicating a strong hydro-
,
gen bond. The oxygen atom of the phenolic group is
not on the same side of the NꢀH group [29] and the
phenol ring is not coplanar with the oxamide unit as
is in the case of ligand 2b.
The reactions of 2a with dichloro-di-n-butyltin,
dichloro-diphenyltin, trichloro-n-butyltin and tri-
chloro-phenyltin in ethanol gave only one product,
Table 1
119Sn-, 15N- and 1H-NMR data (CDCl3)
Compound
119Sn
15N
1H
H3
H5
2-t-bu
4-t-bu
OH
NH
1
2
3
4
5
6
6.93
7.31
8.44
8.65
8.26
8.39
6.83
7.14
7.18
7.31
7.09
7.19
1.30
1.31
1.36
1.44
1.31
1.35
1.43
1.47
1.45
1.62
1.43
1.50
3.28
7.56
3.28
9.56
−255
−120.5
−257.5
−390.0
−257.0
8.33
9.93

286
V.M. J´ımenez-Pe´rez et al. / Journal of Organometallic Chemistry 614–615 (2000) 283–293
Fig. 5. Molecular structure of compound 2a.
Fig. 6. Syntheses of compounds 3 and 4.
higher frequency for the aromatic H3 atoms due to
their interaction with the lone pairs of the carbonyl
groups, Table 1. The same interaction was observed at
the molecular structures in the solid state.
X-ray diffraction studies of 3–6 show that all
molecules contain two tin atoms and a planar hexo-
cyclic skeleton. Molecular structures of 3–5 feature a
symmetric arrangement of the substitutents with respect
to the plane of the molecule and have a symmetry C2
axis whereas 6 does not has a plane but a S2 improper
axis. Tin atoms are always linked to oxygen atoms from
the phenol and carbonyl groups, as well as to the
anilinic nitrogen atom. The CꢀC bond lengths of the
benzenic ring very near to those of an aromatic ring
and O3ꢀC3 and N1ꢀC2 (sp2–sp2) single bond character
Fig. 7. Syntheses of complexes 5 and 6, compound 5 is a dianion and
is accompanied of two triethylammonium cations, 6 is coordinated to
one ethanol molecule.

V.M. J´ımenez-Pe´rez et al. / Journal of Organometallic Chemistry 614–615 (2000) 283–293
287
Fig. 8. ORTEP diagram of the molecular structure of compound 3.
,
1.336–1.376 and 1.408–1.432 A, respectively (Table 5)
triethyl ammonium cations. The two SnꢀCl distances in
5 are not equivalent (SnꢀCl2 2.429(1) and SnꢀCl1
exclude a quinone structure of an oxidated ligand. The
oxamide group represents a delocalyzed system with
O1ꢀC1A and C1ꢀN1 having short bond lengths (in the
,
2.593(1) A), one of the chloride atoms has a longer
bond length due to a short NꢀH···Cl interaction (2.22
,
range 1.271–1.280, and 1.282–1.323 A, respectively)
and with C1ꢀC1A forming a single bond (1.52–1.526
,
A). The bond lengths OꢀSn show that tin atoms are
covalently bonded to the phenol oxygen atoms (SnꢀO3
,
2.02–2.07 A) and coordinated to the carbonyl groups
,
(SnꢀO1 2.13–2.23 A). The bond angles show that tin
atoms in compounds 3–4 are present in a distorted bpt
geometry [4]. In all compounds the angle OꢀSnꢀO is
found in the range between 150.3(8) and 153.5(4) prob-
ably due to the ligand tension. In compounds 3–4 the
organyl groups in equatorial position have a wide angle
(CꢀSnꢀC 128.9(1)–129.7(4)). Compound 3 does not
present intermolecular interactions but short contacts
between some protons of the aromatic ring and of the
methyl groups and oxygen lone pairs (H7AꢀO1 2.334;
,
H10CꢀO3 2.351; H11CꢀO3 2.332 A and their symmet-
rical counterparts). For compound 4 the cell has two
molecules of the compound with four of CHCl3, there
are no intermolecular interactions, but only intramolec-
ular hydrogen bonds between the protons of the aro-
matic ring, of the methyl and phenyl groups and the
oxygen lone pairs (H7AꢀO1 2.384; H9CꢀO3 2.410;
H10BꢀO3 2.355; H23AꢀO1 2.672; H27AꢀO3 2.607,
Fig. 9. Molecular structure of compound 4.
Table 2
1H-NMR data of Sn substituents
Compound
a-CH2
b-CH2
g-CH2
CH3
3
5
1.73
2.09
o-
7.9
8.1
1.55
1.57
m,-p
7.40
7.46
1.43
1.42
0.93
1.0
a
,
H17AꢀO1 2.609 A). Tin atoms in 5–6 display a dis-
torted octahedral geometry, Figs. 10–13. In both com-
pounds the organyl group lies in the molecular plane,
the two chlorides or the chloride and the ethanol
groups are in trans position. Compound 5 is ionic, the
metallic complex being a dianion and bearing two
4
6 b
a NHEt+3 : CH2 2.76, CH3 0.98.
b OEt CH2 3.0, CH3 1.20.

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V.M. J´ımenez-Pe´rez et al. / Journal of Organometallic Chemistry 614–615 (2000) 283–293
Table 3
13C-NMR data (CDCl3) (nJ(13C–119/117Sn))
Compound
C1
C2
C3
C4
C5
C6
CO
t-bu quater.
t-bu CH3
1
2
3
4
5
6
143.0
143.3
154.5 (25)
153.6 (22)
152.4 (35)
153.7
132.9
124.0
128.6 (42)
127.9 (50)
126.5 (77)
128 (52)
116.0
117.7
115.8 (23)
115.8 (28)
116.1 (50)
115.9 (33)
144.4
145.8
137.5
138.4
137.3
138.5
117.4
123.2
122.2
122.6
122.0
123.3
136.4
139.8
136.9
137.3 (16)
137.1
34.7, 35.1
34.4, 35.4
34.8, 35.6
34.5, 35.4
35.6, 36.2
34.7, 35.8
30.2, 32.0
29.9, 31.5
29.0, 32.1
29.7, 31.7
29.8, 32.2
30.1, 32.1
157.3
159.2 (42)
158.0 (55)
155.2 (94)
158.3
137.6 (13)
,
,
A) and a weaker CꢀH···Cl (2.74 A) of two Et3NH
cations as is shown in Fig. 11. Hydrogen contacts
with oxygen atoms were also found (H7AꢀO1 2.323;
mass spectrometry (FAB+ mass) was performed on
a Jeol SX102A instrument of inverted geometry, in a
matrix of 3-nitrobenzyl alcohol and in the 0–2200
m/z range. Elemental Analyses were performed by
Oneida Research Services, Whitesboro, New York.
NMR spectra were obtained on a Jeol GSX-270 15N
(27.25 MHz), 119Sn (100.73); Jeol Eclipse 400 MHz
15N (40.51 MHz), 119Sn (149.05), Bruker Advance 300
MHz 15N (30.42 MHz), 119Sn (111.92). The X-ray dif-
fraction studies of compounds 1, 5 and 6 were per-
formed with an Enraf–Nonius CAD4 diffractometer
,
H9AꢀO3 2.320; H11AꢀO3 2.386 A). Compound 6
crystallized with two ethanol molecules and presents
intermolecular hydrogen bonds, the OH proton of the
coordinated ethanol is bonded to the oxygen of one
,
free ethanol (H2AꢀO4 1.831 A) and the OH of one
free ethanol is bonded to the chlorine atom (H4AꢀCl
,
2.653 A). There are contacts between the chlorine
,
atoms (ClꢀCl 3.511 A), Figs. 12 and 13. There are
also intramolecular hydrogen bonds similar to those
found in the previously discussed molecules (H7AꢀO1
2.385 A). The tin geometries in compounds 3 and 5
are similar to those of diphenolamine derivatives, Fig.
2 [7].
In conclusion, we report that the reactions of bis-
(3,5-di-tert-butyl-2-phenol)-oxamide 2a with dior-
ganyldichlorotin and organyltrichlorotin reagents gave
selectively in all the reactions only one compound
with two tin atoms penta- or hexa-coordinated. Tin
compounds were moisture stable. The skeleton of the
ligand was found linked to two tin atoms in an hexa-
cyclic symmetric planar array. The ligand presents in
all compounds a phenolic instead of a paramagnetic
quinone structure and the NMR data could be ob-
tained, the solid state structures of the tin compounds
were retained in solution as was deduced by the spec-
troscopic data.
,
(u(Mo–Ka)=0.71073 A). The X-ray diffraction study
of compounds 2–4 was performed with a Siemens P4
instrument equipped with a CCD area detector and a
low temperature device LTP2. Relevant crystallo-
graphic data are summarized in Tables 5 and 6.
Structure solution and refinement were performed
with the program SHELXL-97. Absorption correction
,
(SADABS for 2–4 and SEMIEMPIRICAL for 5 and 6).
3.1. 4,6-Di-tert-butyl-1-phenol-2-amine (1)
A solution of 8.0 g (36.3 mmol) of 3,5-di-tert-bu-
tyl-1,2-benzoquinone in 2-propanol (70 ml) was added
to 9 ml of 1,2-ethylenediamine (70% in water) and
Table 4
13C-NMR data, Sn-substituents (nJ(13C–119/117Sn))
Compound a-CH2
b-CH2
g-CH2
CH3
14.1
14.3
3. Experimental
3
21.3
27.6 (27)
27.5(63)
27.1 (84)
(576/550)
36.5
Tin reagents and 3,5-di-tert-butyl-1,2-benzoquinone
were commercially available. All reactions were per-
formed with freshly distilled solvents. Melting points
were obtained on a Mel-Temp II apparatus and are
uncorrected. IR spectra were recorded on an FT-IR
1600 Perkin Elmer spectrophotometer using KBr pel-
lets in the 4000–400 cm−1 range. Mass spectra in the
EI mode were recorded at 20 eV on a Hewlett–Pack-
ard HP 5989 spectrometer. Fast atom bombardment
5 a
25.8
(173.3/165.3)
(1130/1082)
i-
o-
m-
129.2 (86)
p-
4
138.2
(955/913)
138.2
136.5 (46)
131.0 (17)
6 b
136.5 (54)
129.5 (84)
131.1 (16)
a NHEt+3 46.1, 8.6.
b OEt 59.9, 17.5.

V.M. J´ımenez-Pe´rez et al. / Journal of Organometallic Chemistry 614–615 (2000) 283–293
289
Table 5
Selected bond lengths (A) of compounds 1–6
,
1
2
3
4
5
6
SnꢀO1
SnꢀO3
SnꢀO2
SnꢀN
SnꢀC
SnꢀC
C3ꢀO3
C1AꢀO1
C2ꢀN1
N1ꢀC1
C1ꢀC1A
C2ꢀC3
C3ꢀC4
C4ꢀC5
C5ꢀC6
C6ꢀC7
C7ꢀC2
2.230(2)
2.071(2)
2.22(1)
2.07(1)
2.172(3)
2.049(3)
2.132(3)
2.020(4)
2.287(4)
2.142(4)
2.112(5)
2.145(2)
2.15(1)
2.139(3)
2.120(5)
2.122(4) (C20)
2.119(3) (C16)
1.351(4)
1.271(4)
1.419(4)
1.303(4)
1.526(6)
1.403(5)
1.416(5)
1.399(5)
1.385(4)
1.386(4)
1.388(4)
2.12(1) (C22)
2.14(1) (C16)
1.34(1)
1.28(1)
1.41(1)
1.31(1)
1.52(2)
1.41(1)
1.43(1)
1.39(1)
1.40(1)
1.38(1)
1.39(1)
1.355(5)
1.400(7)
1.376(1)
1.236(1)
1.432(2)
1.323(3)
1.532(3)
1.395(2)
1.400(2)
1.394(2)
1.401(2)
1.375(2)
1.393(2)
1.336(5)
1.280(4)
1.408(5)
1.282(5)
1.523(7)
1.402(5)
1.412(5)
1.376(5)
1.391(6)
1.388(5)
1.387(5)
1.340(6)
1.278(6)
1.409(6)
1.283(6)
1.524(9)
1.405(7)
1.409(7)
1.383(7)
1.393(7)
1.376(7)
1.381(7)
1.394(7)
1.413(7)
1.390(7)
1.406(7)
1.382(7)
1.381(6)
the mixture was refluxed for 2 h. The solvent was
removed at reduced pressure. Then the solid was sus-
pended in n-hexane and filtered to give 6.0 g (75%)
of a colorless crystalline powder. It was recrystallized
from toluene–ethanol (8:2). M.p. 165–167°C. MS;
(EI, 20 eV) m/z [M+] 221. IR (KBr) w(cm−1) 3367,
3290, 2714, 2598, 1594, 1491, 1420, 1359, 1314, 1235,
951. Anal. Found: C, 75.81; H, 10.32; N, 6.39. Calc.
for C14H23NO: C, 75.98; H, 10.46; N, 6.32%.
crystalline powder was obtained (0.95 g, 98%). Single
crystals were obtained from ethanol–CH2Cl2 (3:2).
M.p. 168–170°C. MS; (FAB+) m/z [M+] 961. IR
(KBr) w(cm−1): 1600, 1480, 1410, 1380, 1300, 1280.
Anal. Found: C, 56.79; H, 7.70; N, 3.20. Calc. for
C46H76N2O4Sn21/8CH2Cl2: C, 57.16; H, 7.93; N,
2.90%.
3.3.2. Bis-(3,5-di-tert-butyl-2-oxo-phenyl)-
oxamido-bis(-diphenyltin) (4)
An orange microcrystalline powder was obtained
3.2. Bis-(3,5-di-tert-butyl-2-phenol)-oxamide (2a)
(98%) by a procedure analogous to 3. It was recrys-
A mixture of 0.5 g (2.3 mmol) of 3,5-di-tert-butyl-
1,2-phenolamine and 1.2 ml of diethyloxalate (9
mmol) was heated at 80°C for 1.5 h. The solid was
suspended in n-hexane and filtered to give 0.88 g
(80%) of a yellow crystalline powder. It was recrystal-
lized from ethanol–CH2Cl2 (8:2). M.p. 198–200°C.
MS; (EI, 20 eV) m/z [M+] 496, IR (KBr) w(cm−1):
1662, 1514, 1477, 1235, 1359, 1314, 1235, 951. Anal.
Found: C, 72.49; H, 9.08; N, 5.59. Calc. for
C30H44N2O4: C, 72.54; H, 8.92; N, 5.63%.
3.3. General procedure for 3–6
3.3.1. Bis-(3,5-di-tert-butyl-2-oxo-phenyl)-
oxamido-bis-(dibutyltin) (3)
A solution of 0.5 g (1 mmol) of 2a in ethanol (10
ml) and triethylamine (0.25 ml, 2 mmol) was mixed
with a solution of dichoro-di-n-butyltin(IV) (0.63 g 2
mmol) in ethanol (5 ml). After 15 min the solid was
filtered and washed with n-hexane. An orange micro-
Fig. 10. Molecular structure of the dianion of compound 5.

290
V.M. J´ımenez-Pe´rez et al. / Journal of Organometallic Chemistry 614–615 (2000) 283–293
Found: C, 50.04; H, 7.29; N, 4.82. Calc. for
C50H90N4O4Cl4Sn2: C, 50.44; H, 7.61; N, 4.70%.
3.3.4. Bis[(OꢀSn)-ethanol]-bis(3,5-di-tert-butyl-2-
oxo-phenyl)-oxamido-bis-(chlorophenyltin) (6)
An orange crystalline powder was obtained (72%).
It was recrystallyzed from ethanol–ethylacetate. M.p.
368–370°C. MS; (FAB+) m/z [M+] 1038. IR (KBr)
w(cm−1): 3478 (OꢀH), 1623, 1473, 1402, 1346. Anal.
Found: C, 51.76; H, 6.18; N, 2.63. Calc. for
C46H62N2O6Cl2Sn2·H2O: C, 51.80; H, 6.05; N, 2.63%.
4. Supplementary material
Crystallographic data (excluding structure factors)
for the structures reported in this paper have been
deposited with the Cambridge Crystallographic Data
Centre: Compound 1, CCDC no. 147409; Compound
2a, CCDC no. 148140; Compound 3, CCDC no.
148141; Compound 4, CCDC no. 148139; Compound
5, CCDC no. 147407; and Compound 6, CCDC no.
147408. Copies of the information may be obtained
free of charge from The Director, CCDC, 12 Union
Road, Cambridge CB2 1EZ, UK (Fax: +44-1223-
336033; e-mail: deposit@ccdc.cam.ac.uk or www:
http://www.ccdc.cam.ac.uk).
Fig. 11. View of the molecular structure of compound 5, showing the
intermolecular interactions between the chlorine atom and protons of
the triethylammonium.
tallized from CHCl3, orange crystals. M.p. 366–
368°C. MS; (FAB+) m/z [M+] 1038. IR (KBr)
w(cm−1): 1600, 1470, 1434, 1410, 1364, 1290. Anal.
Found: C, 61.03; H, 5.43; N, 2.75. Calc. for
C54H60N2O4Sn2·1/4CHCl3: C, 60.99; H, 5.68; N,
2.62%.
3.3.3. Bis-(triethylammonium)-bis-(3,5-di-tert-
butyl-2-oxo-phenyl)-oxamido-bis-(dichlorobutyl-
stannate) (5)
An orange crystalline powder was obtained (82%).
It was recrystallyzed from ethylacetate. M.p.
270–272°C. MS; (EI) m/z 793. IR (KBr) w(cm−1):
3450 (NꢀH), 1618, 1474, 1398, 1362, 1268. Anal.
Acknowledgements
Financial support from Conacyt-Mexico and Cin-
vestav is acknowledged as well as Conacyt-Mexico
scholarships for M.G.-R. and V.M.J.-P. We thank
M.A. Leiva-Ram´ırez for performing the X-ray diffrac-
tion studies of compound 1.
Fig. 12. Molecular structure of compound 6.

V.M. J´ımenez-Pe´rez et al. / Journal of Organometallic Chemistry 614–615 (2000) 283–293
291
Fig. 13. Compound 6, view of the intermolecular contacts between the chlorine atoms and the OH protons of ethanol of the lattice and between
the OH proton of the coordinated ethanol and the oxygen of the ethanol of the lattice.
Table 6
Selected bond angles (°) of compounds 2–6
2
3
4
5
6
O1ꢀSnꢀO3
O1ꢀSnꢀN
O1ꢀSnꢀX
O1ꢀSnꢀCl2
O1ꢀSnꢀC
O1ꢀSnꢀC
O1ꢀC1ꢀC1A
O3ꢀSnꢀN
O3ꢀSnꢀX
O3ꢀSnꢀCl2
O3ꢀSnꢀC
O3ꢀSnꢀC
CꢀSnꢀC
150.3(8)
74,4(1)
151.4(3)
75.2(3)
153.5(1)
75.8(1)
85.0(1) (Cl1)
88.2(1)
153.4(1)
76.3(1)
81.6(1) (O2)
92.0(1)
93.9(1) (C16)
91.0(1) (C20)
118.2(4)
94.4(4) (C16)
89.4(4) (C22)
119.3(1)
99.5(1)
101.4(2)
120.6(1)
118.1(4)
77.8(1)
91.2(1) (Cl1)
93.1(1)
118.5(5)
78.4(1)
87.0(2) (O2)
96.3(1)
77.2(1)
77.4(3)
102.8(1) (C16)
97.0(1) (C20)
128.9(1)
127.3(3)
107.2(1)(C16)
123.0(1)(C20)
102.4(4) (C16)
97.2(4) (C22)
129.7(4)
128.6(9)
110.2(4) (C16)
119.1(4) (C22)
106.6(1)
102.2(2)
C1ꢀNꢀC2
NꢀSnꢀC
NꢀSnꢀC
128.7(1)
112.8(1)
129.0(3)
172.0(2)
130.3(4)
170.5(2)
NꢀSnꢀX
84.3(1) (Cl1)
90.3(1) (Cl2)
114.0(4)
88.9(2) (Cl1)
96.0(2) (Cl2)
172.3(1) (Cl)
82.0(2) (O2)
90.6(1) (Cl1)
113.3(5)
88.5(2) (O2
98.7(Cl1)
NꢀSnꢀCl
NꢀC1AꢀC1
CꢀSnꢀX
CꢀSnꢀCl
XꢀSnꢀCl
113.5(4)
112.9(1)
171.2(1) (O2)

292
V.M. J´ımenez-Pe´rez et al. / Journal of Organometallic Chemistry 614–615 (2000) 283–293
Table 7
Crystal and data collection parameters
Compound
1
2
3
4
5
6
Empirical formula
Formula weight
Crystal size (mm)
C28H46N2O2
442.67
0.09×0.10
×0.12
Monoclinic
C2/c
19.4635(10)
6.2665(10)
21.6534(10)
90.00
91.78
90.00
2639.8(5)
4
1.114
C
496.67
0.2×0.24
×0.44
Triclinic
30H44N2O4
C46H76N2O4Sn2 C56H62Cl6N2O4Sn2 C50H90Cl4N4O4Sn2 C50H74Cl2N2O8Sn2
958.47
0.1×0.1×0.5
1277.16
0.25×0.28
×0.42
Monoclinic
P21/n
1190.45
0.14×0.28
×0.50
Monoclinic
P21/n
1146.8
0.31×0.62×0.64
Crystal system
Space group
Monoclinic
P21/n
Triclinic
(
(
P1
P1
,
a (A)
8.0534(8)
9.4565(10)
10.2581(11)
87.060(2)
79.687(2)
69.868(2)
721.60(13)
1
7.8851(7)
18.1611(19)
17.4155(19)
90.00
102.334(2)
90.00
9.2465(8)
29.939(2)
10.7897(10)
90.00
101.7692(1
90.00
9.628(2)
19.745(4)
16.110(3)
90.00
97.55(3)
90.00
9.775(2)
11.182(2)
14.814(3)
99.22(3)
107.95(3)
110.49(3)
1376.1(5)
1
,
b (A)
,
c (A)
h (°)
i (°)
k (°)
3
,
V (A )
Z
2436.4(4)
2
2924.1(4)
2
3036.0(10)
2
zcalc (mg m−3
)
1.143
0.075
270
1.307
1.451
1.302
1.375
v (mm−1
F(000)
)
0.069
976
1.064
1.172
1.039
1.053
996
1292
1236
586
Index range
−225h522
−75k50
−255l50
49.26
−65h510
−125k512
−135l513
58.42
−55h55
−225k522
−215l521
55.10
−115h511
−385k533
−135l513
46.52
−115h511
05k524
05l519
51.94
−115h512
−135k50
−185l518
51.94
.
2q (°)
Temperature (K)
Reflections collected
Reflections unique
Reflections Observed
(4|)
293(2)
2292
2225
845
193(2)
4231
2256
1717
193(2)
13181
3493
2543
193(2)
12820
3998
3524
293(2)
5129
5129
3522
293(2)
5666
5376
4132
Rint
0.1241
145
0.0197
165
0.0724/0
1.068
0.0387
0.1079
0.170
0.0592
272
0.0275/0.0354
1.001
0.0243
0.0522
0.456
0.0379
315
0.0951/39.7388
1.198
0.0767
0.1753
3.318
0.0000
299
0.0571/0
0.979
0.0366
0.0953
0.507
0.0337
299
0.0784/1.7227
1.086
0.0417
0.1118
1.330
Variables
Weighting scheme a x/y 0.1330/0
Goodness-of-fit
Final R indicies (4|)
Final wR2
Largest res. peak
(e A
0.958
0.0780
0.1939
0.243
−3
,
)
a w−1=|2F2o+(xP)2+yP; P=(Fo2+2F2c)/3.
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