Synthesis, characterization and behaviour in solution of organotin complexes based on azole ligands. Single crystal X-ray study of dichlorodimethylbis(1,2,3-benzotriazole)tin(IV)

Article abstract of DOI:10.1016/j.inoche.2010.10.004

Nine new organotin complexes, namely [SnR₂XY(BtzH)₂] (1: R = Me, X = Y = Cl, 2: R = Me, X = Y = Br, 3: R = ⁿBu, X = Cl, Y = OH; 4: R = Ph, X = Y = Cl; 5a: R = Me, X = Y = NO₃; 5b: R = Me, X = Y = ClO₄) and [SnR₂X₂(5-NO₂indH) ₂] (6: R = Me, X = Cl; 7: R = ⁿBu, X = Cl; 8: R = Me, X = 5-NO₂ind) were obtained by reaction of SnR₂X₂ with BtzH (1,2,3-benzotriazole) and 5-NO₂indH (5-nitroindazole). These compounds were characterized by IR, NMR and ESI MS, and 1 is shown by a single crystal X-ray study to comprise mononuclear centrosymmetric molecules, all pairs of ligands being mutually opposed in a quasi-octahedral coordination sphere. Sn-Cl, C, N are 2.5700(5), 2.108(2), 2.357(2)?. A new triclinic (P1?) polymorph of the binuclear [{^tBu₂ClSn(μ-OH)} ₂], 9 is also described (cf. the earlier monoclinic (P2 ₁/c)). The unit cell contents comprise a pair of centrosymmetric dimers: Sn-O are 2.042(4)-2.215(4), Sn-Cl 2.489(2), 2.491(2), Sn-C 2.166(6)-2.203(7) ?, O-Sn-O 68.4(2) (x2), and Sn-O-Sn 111.6(2)° (x2).

Full text of DOI:10.1016/j.inoche.2010.10.004

Inorganic Chemistry Communications 14 (2011) 133–136
Contents lists available at ScienceDirect
Inorganic Chemistry Communications
journal homepage: www.elsevier.com/locate/inoche
Synthesis, characterization and behaviour in solution of organotin complexes
based on azole ligands. Single crystal X-ray study of
dichlorodimethylbis(1,2,3-benzotriazole)tin(IV)
c
c
Corrado Di Nicola a, Fabio Marchetti b, Claudio Pettinari a, , Brian W. Skelton , Allan H. White
⁎
a
School of Pharmacy, Università degli Studi di Camerino, via S Agostino 1, 62032 Camerino MC, Italy
School of Science and Technology, Università degli Studi di Camerino, via S Agostino 1, 62032 Camerino MC, Italy
b
c
Chemistry M313, School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Crawley, WA 6009, Australia
a r t i c l e i n f o
a b s t r a c t
Article history:
Nine new organotin complexes, namely [SnR2XY(BtzH)2] (1: R=Me, X=Y=Cl, 2: R=Me, X=Y=Br,
3: R=nBu, X=Cl, Y=OH; 4: R=Ph, X=Y=Cl; 5a: R=Me, X=Y=NO3; 5b: R=Me, X=Y=ClO4) and
[SnR2X2(5-NO2indH)2] (6: R=Me, X=Cl; 7: R=nBu, X=Cl; 8: R=Me, X=5-NO2ind) were obtained by
reaction of SnR2X2 with BtzH (1,2,3-benzotriazole) and 5-NO2indH (5-nitroindazole). These compounds were
characterized by IR, NMR and ESI MS, and 1 is shown by a single crystal X-ray study to comprise mononuclear
centrosymmetric molecules, all pairs of ligands being mutually opposed in a quasi-octahedral coordination
Received 21 July 2010
Accepted 7 October 2010
Available online 15 October 2010
Keywords:
Benzotriazole
Indazole
Organotin(IV)
Crystal structure
ESI MS
¯
sphere. Sn–Cl, C, N are 2.5700(5), 2.108(2), 2.357(2)Å. A new triclinic (P 1) polymorph of the binuclear
[{tBu2ClSn(μ-OH)}2], 9 is also described (cf. the earlier monoclinic (P21/c)). The unit cell contents comprise a pair
of centrosymmetric dimers: Sn–O are 2.042(4)–2.215(4), Sn–Cl 2.489(2), 2.491(2), Sn–C 2.166(6)–2.203(7) Å,
O–Sn–O 68.4(2) (x2), and Sn–O–Sn 111.6(2)° (x2).
© 2010 Elsevier B.V. All rights reserved.
The chemistry of SnRnX4 − n derivatives of azoles is well known
[1], but to date there has been no structural report concerning tin and
organotin(IV) complexes of benzotriazoles and, also, 5-nitroindazole,
both of which occupy important positions amongst heterocyclic rings
for their relevance to the chemistry, for example, of natural products
[2]. Here we report the syntheses, structural and spectroscopic
characterization for several new complexes obtained from the
reaction of SnR2X2 (R=Me, nBu; Ph, X=Cl, or Br) acceptors and
1,2,3-benzotriazole or 5-nitroindazole.
Preparation of the organotin complexes is usually attempted by
using a variety of azole ligand to organotin(IV) ratios [3,4], in order to
determine if more than one kind of derivative is afforded between
L (L=BtzH or 5-NO2IndH) and a specific organotin(IV) acceptor.
Interaction between excess azole ligand L and SnR2X2in organic
solvent (diethyl ether, dichloromethane, acetonitrile, ethanol) gave
the 2:1 adducts 1–4, 6 and 7 [3,4] according to Eq. (1):
reactants was exposed to moisture for a long time, the adduct
[SnnBu2Cl(OH)(BtzH)2] (3) formed, where one chloride had been
replaced by a hydroxide group. Reaction of 1 with AgNO3 in acetone
gave immediately the derivative [SnMe2(NO3)2(BtzH)2] 5a, upon
substitution of both Cl groups from the tin coordination sphere [5]. An
analogous species [SnMe2(ClO4)2(BtzH)2], 5b, was obtained when 1
was reacted with AgClO4. The complexes 1–7 are poorly soluble in
chlorinated solvents and acetone and moderately soluble in DMSO.
Several attempts to obtain crystals of adducts 1–7 in suitable form for
X-ray studies failed with the exception of 1, amorphous powders or
well-known hydrolysis products being isolated. It is noteworthy that
the reaction of 5-NO2IndH with SnMe2Br2 gives compound 8, where
both Br− ions have been replaced by a deprotonated 5-NO2Ind [4]. The
occurrence of a hydrolysis reaction yielding the hydroxo species 3 is
confirmed by the acquisition of compound 9, [{tBu2ClSn(μ-OH)}2] [6],
formed when the reaction between BtzH and Sn(tBu)2Cl2 was carried
out in ethanol for 12 h. The IR spectra of the ligands and their
complexes have also been recorded. In the 3100–2800 cm−1 region
the ligands exhibit broad bands typical of N–H stretching, but always
shifted, suggesting an important consequence of coordination to tin.
The positions and the broadening of the N–H stretching bands are also
consistent with the presence of hydrogen bonds between the N–H
moieties and the halide groups [7]. The appearance of only a single
Sn–C stretching vibration in the spectra of the dimethyltin(IV)
complexes 1, 2, and 6, is in accordance with a trans-octahedral
disposition of the two alkyl groups [8]. The 1H NMR spectra of the
2L þ SnR2X2→½SnR2X2ðL2Þꢀ
ð1Þ
No adduct has been isolated from the reaction of L with R3SnX. The
reaction between SnnBu2Cl2 and BtzH seemed not to produce any
identifiable product. However when a solution containing both
⁎
Corresponding author. Tel.: +39 0737 402234; fax: +39 0737 637345.
E-mail address: claudio.pettinari@unicam.it (C. Pettinari).
1387-7003/$ – see front matter © 2010 Elsevier B.V. All rights reserved.
doi:10.1016/j.inoche.2010.10.004

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C. Di Nicola et al. / Inorganic Chemistry Communications 14 (2011) 133–136
5a,b the Δ is greater suggesting greater stability of these species in
solution. The measured δ(119Sn) and tin-proton coupling constant
values for selected compounds do not fit clearly into the reported
ranges of values of six-coordinate organotin(IV) compounds, but are
in accordance with the dissociation proposed on the basis of 1H NMR
data [9,10].
ESI MS spectra carried out in MeCN for complexes 1, 2 and 4
exhibit some weak intensity signals due to the formation of species
such as [SnR2Cl(BtzH)2]+ upon chloride abstraction. The ESI MS
spectra of 5a shows a different pattern likely due to the presence of
readily ionizable NO3 groups. In fact in the positive spectrum we have
found signals due not only to mononuclear species [SnMe2(NO3)
(BtzH)+] derived from NO3 dissociation, but also signals due to
Fig. 1. Projection of a single centrosymmetric molecule of trans-[Me2Cl2Sn(C6H5N3)2] (1).
Sn–C(0), N(1), and Cl are 2.108(2), 2.357(2), and 2.5700(5) Å; C(0)-Sn-N(1), Cl, and N(1)–
Sn–Cl are 88.80(7), 88.84(7), and 90.42(4)°. H(6)…Cl′ is 3.2 Å (est.). With Sn at (0.5, 0.5,
0.5), the aromatic ligand stack interleaves up crystallographic a (7.0156(6) Å). Non-
hydrogen atoms are shown with 50% probability amplitude displacement envelopes,
hydrogen atoms having arbitrary 0.1 Å radii.
complexes, recorded in MeOD or DMSO, due to the poor solubility of
1–8 in CDCl3, suggest almost complete dissociation into the starting
reagents, the Δ values (difference in chemical shift for the same type
of proton in the free base and its organotin complex) being in the
range 0.1–0.15 ppm. The spectrum of 1 in acetone is also unusual, two
different sets of signals due to the benzotriazole protons being
detected. We hypothesize, also on the basis of the conductivity data
which suggest partial ionic dissociation, that acetone could be able to
displace one chloride from the tin coordination sphere, yielding a
species such as [SnMe2Cl(acetone)(BtzH)2]+ where the two BtzH
groups experience two different environments, although we cannot
exclude that this could be due to differing coordination modes of the
two BtzH in solution. In the case of the nitrate and perchlorate species
Table 1
Benzotriazole ligand non-hydrogen atom geometries; the two values in each entry are
for the present tin(IV) complex, (1), and the means of those for the free ligand, reported
in Ref. [15].
Atoms
Parameter
Atoms
Parameter
Distances (Å)
C(1)–N(1)
N(1)–N(2)
N(2)–N(3)
C(2)–N(3)
C(1)–C(2)
1.376(3), 1.369(3)
1.308(2), 1.308(3)
1.322(2), 1.343(5)
1.358(2), 1.352(5)
1.397(3), 1.382(3)
C(2)–C(3)
C(3)–C(4)
C(4)–C5))
C(5)–C(6)
C(1)–C(6)
1.392(3), 1.386(4)
1.378(3), 1.352(7)
1.412(4), 1.391(4)
1.378(3), 1.358(4)
1.396(3), 1.398(4)
Angles (°)
C(1)–N(1)–N(2)
N(1)–N(2)–N(3)
N(2)–N(3)–C(2)
N(3)–C(2)–C(1)
C(2)–C(1)–N(1)
N(1)–C(1)–C(6)
N(3)–C(2)–C(3)
Sn–N(1)–N(2)
109.1(2), 108.1(6)
108.4(2), 108.5(7)
111.3(2), 110.6(5)
104.3(2), 104.3(2)
106.9(2), 108.5(4)
132.1(2), 130.9(7)
132.8(2), 133.4(6)
114.5(1)
C(2)–C(1)–C(6)
C(1)–C(2)–C(3)
C(2)–C(3)–C(4)
C(3)-C(4)-C(5)
C(4)–C(5)–C(6)
C(1)–C(6)–C(5)
121.0(2), 120.4(2)
122.9(2), 122.3(5)
115.7(2), 116.4(2)
121.9(2), 122.2(3)
122.2(2), 121.9(5)
116.3(2), 116.8(5)
Fig. 2. (a) A projection of binuclear, centrosymmetric molecule 1 of [{tBu2ClSn(μ-OH)}2] (9)
(molecule 2 is similar); non-hydrogen atoms are shown with 50% probability amplitude
displacement envelopes, hydrogen atoms having arbitrary radii of 0.1 Å. (b) Unit cell
contents, projected down a, showing the H…Cl interactions. The molecules are linked into
two separate columns along a, each one associated with one of the independent components
of the asymmetric unit.
Sn–N(1)–C(1)
136.4(1)
The tin atom lies out of the C6N3 plane (χ2 103) by 0.057(3) Å.

C. Di Nicola et al. / Inorganic Chemistry Communications 14 (2011) 133–136
135
Table 2
Selected molecular geometry (9); the two values in each entry are for molecules n=1,2. Primed atoms are inversion related. Italicized values pertain to the monoclinic polymorph of
Ref. [17].
Atoms
Parameter
Atoms
Parameter
Distances (Å)
Sn(n)–O(n)
Sn(n)–Cl(n)
Sn(n)–C(n1)
Sn(n)…Sn(n′)
2.045(4), 2.042(4); 2.036(6), 2.036(6)
2.491(2), 2.489(2); 2.506(3), 2.506(3)
2.203(7), 2.172(7); 2.181(9), 2.182(9)
3.520(2); 3.522(2); 3.545(1)
Sn(n)–O(n′)
2.210(4), 2.215(4), 2.237(9), 2.224(9)
Sn(n)–C(n2)
O(n)…O(n′)
2.166(6), 2.181(6); 2.184(9), 2.127(9)
2.396(4), 2.396)4); 2.38(1)
Angles (°)
O(n)–Sn(n)–O(n′)
O(n)–Sn(n)–Cl(n)
68.4(2), 68.4(2); 67.6(3), 67.9(3)
86.2(1), 86.2(1); 86.6(3), 86.5(2)
Sn(n)–O(n)–Sn(n′)
O(n′)–Sn(n)–Cl(n)
111.6(2), 111.6(2); 112.5(3), 112.0(3)
154.6(1), 154.6(1); 154.2(2), 154.3(2)
dinuclear [Sn2Me4(NO3)(OH)(Btz)(BtzH)+], [Sn2Me4(NO3)2(Btz)
(BtzH)+], [Sn2Me4(NO3)(Btz)2(BtzH)+] and trinuclear [Sn3Me6
(NO3)(Btz)4(BtzH)+2 ] aggregates.
atoms (Table 2). The complex has been previously described in a
different monoclinic P21/c polymorph [17], in which the dimer is of
similar aspect, and the dimensions of the core similar (Table 2). The
molecules interact via OH…Cl hydrogen bonds in the lattice, forming
two independent columns each derived from one component of the
asymmetric unit, and similar to the array of the other polymorph
(Fig. 2(b)). An interesting feature of all molecules in all phases is a
systematic and similar difference in the Sn–O distances, presumably
consequent on the asymmetry of the environments of the OH
hydrogen atoms, vis-a-vis the chlorine atom disposition in particular,
the overall molecular symmetry being 2/m.
The results of the single crystal X-ray study [11] of (1) are consistent
with the expected mononuclear molecular formula [SnMe2Cl2
(C6H5N3)2] [13], the molecule lying with a crystallographic inversion
centre coincident with the tin atom, and the pairs of ligands mutually
trans (Fig. 1). Although there are numerous structural characterizations
of species of the form trans-[SnR2X2(unidentate N-donor)2], the present
appears tobe the first in which theN-donor is a triazole. The geometry of
the quasi-octahedral coordination sphere is similar to those of the
numerous other [SnMe2Cl2N2] arrays and unremarkable. The triazole is
bound at the 1-position. The parent ligand has thus far been defined in
two rather remarkable polymorphs [14,15], in forms which contrast
with the simplicity of the present structure. In the monoclinic P21 form,
four molecules comprises the asymmetric unit of the structure, in the
Note added in Proof
A single crystal X-ray structure determination of 5a (Fig. 3) has just
come to hand, confirming that, like 1, it is a trans-complex. However,
of the two nitrate groups, supplanting the chloride atoms, one is
monodentate (Sn-O 2.2647(12)A) and the other bidentate (Sn-O
2.4361(12), 2.4790(12)A). Sn-N are 2.3640(12), 2.4695(12), and Sn-C
2.1024(15), 2.1054(15)A. CCDC 797934.
¯
triclinic P 1 form five, all molecules being devoid of crystallographic
symmetry. The mean geometries of the more recently determined
triclinic form [15] are compared with those of the present ligand in
Table 1, showing remarkably little change consequent on coordination
to the tin atom. In all structures, packing of the planar ligands is a
determinant of the form, but in the free ligand, hydrogen-bonding leads
to the formation of strings or macrocycles, primarily through N–H…N
interactions. In the present array, however, N–H…Cl (1−x, 1−y, 2−z)
hydrogen bonds are found (N,H…Cl 3.183(2). 2.3 Å (est.)); N–H…Cl
163.8°). There is a considerable asymmetry in the coordination of the tin
atom at N(1) (Sn–N(1)–C(1),N(2) 136.4(1), cf. 114.5(1)°), presumably
to be ascribed to interaction between H(6) and the neighbouring
chlorine and methyl ligands.
Acknowledgement
Financial support from University of Camerino is gratefully
acknowledged.
References
[1] C. Pettinari, Recent Res. Devel. Organomet. Chem. 4 (2001) 71.
[2] N. Eweiss, A. Bahajaj, E. Elsherbini, Heterocycl. Chem. 23 (1986) 1451.
[3] Synthesis and characterization of the benzotriazole complexes 1–4. [SnMe2Cl2
(BtzH)2] (1): To a stirred diethyl ether solution (20 mL) of Me2SnCl2 (0.219 g,
1.0 mmol) was added benzotriazole (BtzH) (0.240 g, 2.0 mmol). The solution was
stirred for 48 h under N2 at room temperature. The colorless precipitate formed
was isolated by filtration and dried in vacuum. The residue obtained was washed
with 5 mL of diethyl ether and shown to be compound 1 (0.417 g, 0.92 mmol,
yield 92 %). The same compound formed when 1:1 ligand to metal ratio was
employed. Mp. 130° subl. 190–192 °C dec. anal. calc. For C14H16Cl2N6Sn, C, 36.72;
H, 3.52; N, 18.35. Found: C, 34.89; H, 3.44; N, 17.30. IR (nujol, cm−1): 1620w,
1590w ν(C…C, C…N), 632m, 537m, 428vs, 397m, 384w, 375w, 352, 302sh, 292s,
279s, 266w, 246w; 582m, ν(Sn–C), 229s ν(Sn–Cl). 1H NMR (DMSO-d6, 293 K): δ,
The results of the X-ray study of (9) [16] confirm the formulation
of the complex as binuclear [{tBu2ClSn(μ-OH)}2]. One formula unit
comprises the asymmetric unit of the structure, made up of two
halves of two independent centrosymmetric dimers, one of which is
shown in Fig. 2(a). The geometries of the two arrays are very similar,
with consistent t-butyl dispositions, torsion angles |O(n)–Sn(n)–C
(n1)–C(n11)| closely ranged between 143.6(4)–147.5(4), O–Sn–C
95.6(2)–96.5(2) and 115.1(2)–117.6(2), Cl–Sn–C 94.7(2)–95.6(2)°
and C–Sn–C 126.6(2), 128.2(2)°, about the five-coordinate metal
1.02 (s, 6H, CH3Sn
,
1J(119Sn–1H): 114 Hz; 1J(117Sn–1H): 109 Hz), 7.4, 7.5, 7.8 (s br,
1J
8H, CHBtzH), 8.0 (s br, 2H, NHBtzH). 1H NMR (CDCl3, 293 K): δ, 1.20 (s, 6 H, CH3Sn
,
(
119Sn–1H): 74 Hz; 1J(117Sn–1H): 60 Hz), 7.47, 7.0 (m, 8H, CHBtzH), 3.0–4.0 (s br,
2H, NHBtzH). 1H NMR (acetone-d6, 293 K): δ, 1.20 (s, 6H, CH3Sn
,
1J(119Sn–1H):
86 Hz; 1J(117Sn–1H): 82 Hz), 7.40, 7.46, 7.79, 8.05 (m, 8H, CHBtzH), 14.3 (s br, 2H,
NHBtzH). Λm (CH3OH, 293 °C): 9.0 μS (0.8×10−3 M). Λm (acetone, 293 °C): 42.8 μS
(1.1×10−3 M). ESI MS (+), 120 [90] [BtzH+H+], 142 [100] [BtzH+Na+], 304
[20] [SnMe2Cl(BtzH)2]+ 119Sn (CDCl3, 293 K): δ: +113.6, −176.0 ppm. [SnMe2-
.
Br2(BtzH)2] (2): Compound 2 has been obtained as for 1 in 85% yield (0.464 g,
0.85 mmol). Mp. 194–196 °C dec. anal. calc. For C14H16Br2N6Sn, C, 30.75; H, 2.95;
N, 15.37. Found: C, 30.76; H, 2.95; N, 15.32. IR (nujol, cm−1): 1610w, 1591w
ν(C…C, C…N), 631w, 577w ν(Sn–C), 535m, 426vs, 291s, 250m ν(Sn–Br). 1H NMR
(acetone-d6, 293 K): δ, 0.85 (s, 6H, CH3Sn,
1J(119Sn–1H): 107 Hz; 1J(117Sn–1H):
102.6 Hz), 7.3, 7.6 (m br, 10H, NHBtzH +CHBtzH). Λm (acetone, 293 °C): 1.2 μS
(0.9×10−3 M). ESI MS (+), 120 [90] [BtzH+H+], 142 [100] [BtzH+Na+], 348
[20] [SnMe2Br(BtzH)2]+. [SnnBu2Cl(OH)(BtzH)2] (3): To a stirred diethyl ether
solution (20 mL) of nBu2SnCl2 (0.304 g, 1.0 mmol) was added BtzH (0.120 g,
1.0 mmol). The solution was stirred for 48 h at room temperature and then
Fig. 3. Projection of a single molecule of 5a.

136
C. Di Nicola et al. / Inorganic Chemistry Communications 14 (2011) 133–136
maintained to air until a colorless precipitate formed which was isolated by
temperature. Silver chloride immediately formed which was filtered off. The
solution was then evaporated and the residue was washed with 5 mL of diethyl
ether/ethanol 1:1 and shown to be compound 5a (0.255 g, 0.5 mmol, yield 99 %).
Anal. calc. for C14H16N8O6Sn, C, 32.90; H, 3.16; N, 21.93. Found: C, 32.69; H, 3.24;
N, 21.80. IR (cm−1): 3200br, 1623w, 1596w, 1473s, 1458s, 1283s, 1219km,
1198m, 1149m, 1133m, 1112m, 1018s, 886m, 843m, 777s, 741s. 1H NMR
filtration and dried in vacuum. The residue obtained was washed with 10 mL of
diethyl ether and shown to be compound 3 (0.360 g, 0.89 mmol, yield 89 %). Mp.
62–64 °C dec. anal. calc. For C14H24ClN3OSn, C, 41.57; H, 5.98; N, 10.39. Found: C,
41.89; H, 5.67; N, 10.86. IR (nujol, cm−1): 3260 ν(O–H), 1620w, 1598w ν(C…C,
C…N), 648w, 627w, 538w, 517w, 472w, 457w, 427sh, 417s, 397m, 384w, 375w,
351m, 328s, 302sh, 279s, 253w, 247w, 597w, ν(Sn–C), 224m ν(Sn–Br). 1H NMR
(acetone-d6, 293 K): δ, 1.09 (s, 6H, CH3Sn,
1J(Sn–1H): 103 Hz), 7.31, 7.8 (s br, 8H,
(CDCl3, 293 K): δ, 0.94t, 1.45m, 1.80m, (18H, C4H9Sn), 7.5, 8.0 (m br, 5H, NHBtzH
+
CHBtzH), 8.3 (s br, 2H, NHBtzH). ESI MS (+) 331 [60] [SnMe2(NO3)(BtzH)+], 613
[100] [Sn2Me4(NO3)(OH)(Btz)(BtzH)+], 659 [Sn2Me4(NO3)2(Btz)(BtzH)+], 715
[Sn2Me4(NO3)(Btz)2(BtzH)+], 1217 [Sn3Me6(NO3)(Btz)4(BtzH)2+]. (b) Addition
of AgClO4 to a acetone-d6 solution of 1, gave a colorless precipitate identified as
AgCl. The 1H NMR spectrum of the solution confirms the formation of [SnMe2
CHBtzH). Λm (CH2Cl2, 293 °C): 1.2 μS (0.9×10−4 M). [SnPh2Cl2(BtzH)2] (4): To a
stirred diethyl ether solution (20 mL) of SnPh2Cl2 (0.344 g, 1.0 mmol) was added
benzotriazole (BtzH) (0.240 g, 2.0 mmol). The solution was stirred for 12 h at
room temperature. The colorless precipitate formed was isolated by filtration
and dried in vacuum. The residue obtained was washed with 5 mL of diethyl ether
and shown to be compound 4 (0.465 g, 0.80 mmol, yield 80 %). Mp. 130° subl.
190–192 °C dec. anal. calc. For C24H20Cl2N6Sn, C, 49.52; H, 3.46; N, 14.44. Found: C,
49.23; H, 3.38; N, 14.88. IR (nujol, cm−1): 3180 (NH), 3120w, 3057w (CH),
1620w, 1593w, 1575w ν(C…C, C…N), 1481m, 1453m, 1432m, 1386m, 1264m,
1219m, 1161w, 1150w, 1103m, 1068w, 1027m, 996m, 908w, 763m, 746s, 727s,
(ClO4)2(BtzH)2] (5b). 5b: 1H NMR (acetone-d6, 293 K): δ, 1.28 (s, 6H, CH3Sn 1J
,
(Sn–1H): 103 Hz), 7.73, 8.15 (m br, 8H, CHBtzH), 10.0 (s br, 2H, NHBtzH). IR (cm−1):
3200br, 1617m, 1599m, 1462s, 1411m, 1387m, 1301w, 1270m, 1252m, 1050 sbr,
1024s, 1000s, 803s, 777s, 765s, 749s.
[6] [{(tBu2)2Sn(μ-OH)}2] (9) was recovered when the reaction between Sn(tBu)2Cl2
and BtzH was carried out in refluxing ethanol for 12 h, and identified
crystallographically as a new polymorph.
690s. 1H NMR (CDCl3, 293 K): δ, 7.5 (t, 4H, C6H5Sn) 7.7 (d, 4H, C6H5Sn 1J(119Sn–
,
1H): 90 Hz; 1J(117Sn–1H): 80 Hz), 7.5 (d br, 8H, CHBtzH), 7.9 (t, 2H, C6H5Sn), 9.0 (s
br, 2H, NHBtzH). 119Sn (CDCl3, 293 K): δ: −64.6, −175.0 ppm. ESI MS (+): 428
[7] G. Valle, R. Ettorre, V. Perruzzo, G. Plazzogna, J. Organomet. Chem. 326 (1987) 169.
[8] W.F. Edgell, C.H. Ward, J. Mol. Spectrosc. 8 (1962) 343.
[9] B. Wrackmeyer, Ann. Rep. NMR Spectroscop. 16 (1985) 73.
[25] [SnPh2Cl(BtzH)2]+; 428 [25] 959 [Sn3Ph6Cl3(OH)2]+
.
[4] Synthesis and characterization of the 5-nitroindazole complexes 6–8. [SnMe2Cl2
(5-NO2IndH)2] (6): To a stirred diethyl ether solution (20 mL) of SnMe2Cl2
(0.219 g, 1.0 mmol) was added 5-nitroindazole (5-NO2IndH), (0.320 g,
2.0 mmol). The solution was stirred for 48 h under N2 at room temperature.
The colorless precipitate formed was isolated by filtration and dried in vacuum.
The residue obtained was washed with 5 mL of diethyl ether and shown to be
compound 5 (0.436 g, 0.80 mmol, yield 80 %). Mp. N200 °C dec. anal. calc. For
C16H16Cl2N6O4Sn, C, 35.20; H, 2.95; N, 15.39. Found: C, 35.11; H, 2.98; N, 15.41. IR
(nujol, cm−1): 1738w, 1622w, 1589w, 1524w ν(C…C, C…N), 582w ν(Sn–C),
[10] P.G. Harrison, Investigating tin using spectroscopy, in: P.G. Harrison (Ed.),
Chemistry of Tin, Ch. 3, Chapman and Hall, London, 1989, pp. 61–115.
[11] Full spheres of CCD/area detector diffractometer data (Bruker AXS instrument,
monochromatic Mo Kα radiation (λ=0.71073 Å), ω-scans) were measured at ca.
153 K yielding Nt(otal) reflections, these merging to N unique (Rint cited) after
‘empirical’/multiscan absorption correction (proprietary software) and used in
the full matrix least squares refinement on F2, refining anisotropic displacement
parameter forms for the non-hydrogen atoms, hydrogen atom treatment
following
a
riding model (reflection weights: (σ2(Fo2)+ (aP)2)– 1(P=(F2o
533w, 427m, 327w, 278w. 1H NMR (DMSO-d6, 293 K): δ, 1.02 (s, 6H, CH3Sn
,
1J
+2F2c)/3)); No with IN2σ(I) were considered ‘observed’. Neutral atom complex
scattering factors were employed within the SHELXL 97 program [12]. Pertinent
results are given below and in the table and figures, the latter showing non-
hydrogen atoms with 50% probability amplitude displacement envelopes,
hydrogen atoms having arbitrary radii of 0.1 Å. Full.cif depositions reside with
the Cambridge Crystallographic Data Centre, CCDC 779498, 780529.
(
119Sn–1H): 114 Hz; 1J(117Sn–1H): 109 Hz), 7.4, 7.5, 7.8 (s br, 8H, CHBtzH), 8.0 (s br,
2H, NHBtzH). Λm (acetone, 293 °C): 1.0 μS (1.1×10−3 M). [SnnBu2Cl2(5-NO2-
IndH)2] (7): 7 has been prepared following the same procedure employed for 6
(0.580 g, 0.92 mmol, yield 92 %). Mp. N200 °C dec. anal. calc. For C22H28Cl2N6O4Sn,
C, 41.93; H, 4.48; N, 13.34. Found: C, 42.31; H, 4.50; N, 13.80. IR (nujol, cm−1):
1623w, 1597w, 1540w, ν(C…C, C…N), 604m, 583w, 554w, 533m, 457w, 428m,
419w, 397m, 384w, 375w, 351vs, 326w, 314, 302w, 279vs, 266w, 253sh, 246m,
224s ν(Sn–C), 229s ν(Sn–Cl). 1H NMR (acetone-d6, 293 K): δ, 7.72 (d, 2H, CHind),
8.18 (dd, 2H, CHind), 8.40 (d, 2H, CHind), 8.84 (d, 2H, CHind), 0.91t, 1.43m, 1.82m
(18H, C4H9Sn). Λm (acetone, 293 °C): 0.5 μS (1.1×10−3 M). [SnMe2(5-NO2Ind)2
(5-NO2IndH)2] (8): This compound has been obtained in 80% yield by following
the same procedure employed for 6 by using SnMe2Br2 and L in 1 to 4 ratio. (Mp.
N200 °C dec. anal. calc. For C30H24N12O8Sn, C, 45.08; H, 3.03; N, 21.03. Found: C,
44.88; H, 3.02; N, 21.43. IR (nujol, cm−1): 1623w, 1590w, 1534w ν(C…C, C…N),
582m ν(Sn–C), 533m, 428s, 355w, 244w. 1H NMR (CD3OD, 293 K): δ, 1.08 (s, 6H,
CH3Sn) 7.66d, 8.24dd, 8.32s, 8.81d (16H, CHind). Λm (acetone, 293 °C): 0.4 μS
(1.0×10−3 M).
[12] G.M. Sheldrick, Acta Crystallogr. Sect. A 64 (2008) 112.
[13] C14H16Cl2N6Sn (1), M=457.9. Triclinic, space group P1
b=7.9418(7), c=8.3231(7) Å, α=107.074(2), β=92.755(2), γ=109.917(2)°,
V=411.08(6) Å3. Dc (Z=1)=1.850 g cm− 3 Mo =1.89 mm−1
specimen:
̄
(C1i , No. 2), a=7.0156(6),
.
μ
;
0.38× 0.25× 0.17 mm; ‘T’min/max = 0.47. 2θmax = 75°; Nt = 8133, N =3966
(Rint =0.051), No =3848. R1=0.048, wR2=0.12 (a=0.063), S=1.05.
[14] A. Escande, J.L. Galigné, J. LaPasset, Acta Crystallogr. Sect. B 30 (1974) 1490.
[15] S. Krawczyk, M. Gdaniec, Acta Crystallogr. Sect. E 61 (2005) o2967.
[16] C16H38Cl2O2Sn (9), M=570.7. Triclinic, space group P1̄ a, =9.298(6), b=11.040
(7), c=13.124(8) Å, α=67.73(2), β=71.29(2), γ=88.93(2)°, V=1173(1) Å3.
Dc (Z=2 dimers)=1.616 g cm−3. µMo =2.4 mm−1; specimen: 0.12×0.08×0.06;
‘T’min/max =0.80. 2θmax =65°; Nt =13.712, N=6027 (Rint =0.056), No =4132.
R1=0.050, wR2=0.14 (a=0.082), S=0.97.
[5] (a) Synthesis and characterization of [SnMe2(NO3)2(BtzH)2] (5a): To a stirred
acetone solution (20 mL) of 1 (0.228 g, 0.5 mmol) was added AgNO3 (BtzH)
(0.168 g, 1.0 mmol). The solution was stirred for 12 h under N2 at room
[17] H. Puff, H. Hevendehl, K. Höfer, H. Reuter, W. Schuh, J. Organomet. Chem. 287
(1985) 163.