Organotin(IV) derivatives of novel β-diketones: Part V. Synthesis and characterization of di- and triorganotin(IV) derivatives of 4-acyl-5-pyrazolones modified in position 3 of the pyrazole. Crystal structure of (1,3-diphenyl-4-benzoyl-pyrazolon-5-ato)tri

Article abstract of DOI:10.1016/S0022-328X(01)01333-X

The interaction between R₃SnCl, (R₃Sn)₂O, R₂SnO or R₂SnCl₂ acceptors (R = Me, ⁿBu or Ph) and the two novel β-diketone proligands (LH = 1,3-diphenyl-4-R⁴(C=O)-pyrazol-5

Full text of DOI:10.1016/S0022-328X(01)01333-X

Journal of Organometallic Chemistry 645 (2002) 134–145
www.elsevier.com/locate/jorganchem
Organotin(IV) derivatives of novel b-diketonesꢀ
Part V. Synthesis and characterization of di- and triorganotin(IV)
derivatives of 4-acyl-5-pyrazolones modified in position 3 of the
pyrazole. Crystal structure of
(1,3-diphenyl-4-benzoyl-pyrazolon-5-ato)triphenyltin(IV)
Fabio Marchetti a,*, Claudio Pettinari a,*, Augusto Cingolani a, Riccardo Pettinari a,
Miriam Rossi b, Francesco Caruso c
a Dipartimento di Scienze Chimiche, Uni6ersita´ degli Studi di Camerino, 6ia S. Agostino 1, 62032 Camerino, Macerata, Italy
b Department of Chemistry, Vassar College, Poughkeepsie, NY 12604-0484, USA
c Istituto di Strutturistica Chimica ‘G. Giacomello’, CNR, CP 10, 00016, Monterotondo Stazione, Rome, Italy
Received 2 August 2001; accepted 28 September 2001
Abstract
n
The interaction between R3SnCl, (R3Sn)2O, R2SnO or R2SnCl2 acceptors (R=Me, Bu or Ph) and the two novel b-diketone
proligands (LH=1,3-diphenyl-4-R4(CꢀO)-pyrazol-5-one: L1H, R4=Ph; L2H, R4=Me) yields complexes [SnR3(L)(H2O)] (R=
n
Me or Bu, L=L1 or L2), [SnPh3(L)] and [SnR2(L)2] (L=L1 or L2). The phenyl substituent on position 3 induces instability of
the triorganotin derivatives in solution with the formation of SnR2(L)2 and SnR4 compounds. Moreover, diorganotin derivatives
partially dissociate in solution yielding [SnR2(L)(solvent)]2+ species. When compared with the related 3-methyl species, the crystal
structure of (1,3-diphenyl-4-benzoyl-pyrazolon-5-ato)triphenyltin(IV) is not modified by the 3-phenyl substitution. The chemical
instability generated by the Ph in position 3 is greater than in positions 1 and 4. In addition, the Ph in position 3 of the pyrazole
influences the solution behavior of the free neutral 4-acyl-5-pyrazolones stabilizing a novel amino-diketo tautomeric form. © 2002
Elsevier Science B.V. All rights reserved.
Keywords: Triorganotin complexes; 4-Acyl-5-pyrazolones; Crystal structures; NMR; IR
1. Introduction
foams [3], their promising antineoplastic activity and,
more recently, their use as molecular precursors in
LAD (laser ablation and subsequent deposition) tech-
nology [4]. Triphenyltin compounds are widely used as
biocides in agriculture whereas tributyltin species are
the best additives for paints applied on the hull of
vessels to avoid corrosion from marine microorganisms.
Recently some triorganotin benzoates have also shown
good antitumor activity [5]. There is much literature
about triorganotin carboxylates [6] whereas analogous
triorganotin b-diketonates has received less attention
[7], probably due to their low stability, both in solution
and in the solid state. In 1992, we initiated an investiga-
tion of the interaction between diorganotin acceptors
and 4-acyl-5-pyrazolone proligands (LH) [8] which are
asymmetric b-diketones (Fig. 1), synthesized first by
The understanding of the chemistry of di- and tri-
organotin derivatives is important because of their anti-
tumoral [1] and biocide properties which make some of
these species suitable for pharmaceutical, industrial and
agricultural applications [2]. Several studies have ap-
peared in the literature regarding structural and spec-
troscopic features of tin b-diketonates, including their
catalytic properties in the formation of polyurethane in
ꢀ Part IV is Ref. [15b].
* Corresponding authors. Tel.: +39-0737-402217; fax: +39-0737-
637345.
E-mail addresses: marfab@camserv.unicam.it (F. Marchetti),
pettinar@camserv.unicam.it (C. Pettinari).
0022-328X/02/$ - see front matter © 2002 Elsevier Science B.V. All rights reserved.
PII: S0022-328X(01)01333-X

F. Marchetti et al. / Journal of Organometallic Chemistry 645 (2002) 134–145
135
binding is also observed in the diorganotin derivatives
[13g].
Here we extend our investigation to include the syn-
thesis of organotin(IV) compounds containing some
novel acylpyrazolonates (L1, R1=R3=R4=Ph; L2,
R1=R3=Ph, R4=Me) with a phenyl in position 3 of
the pyrazole. Since thus far only a methyl group in such
position had been known we demonstrate that all sub-
stitutions on the pyrazole (positions 1, 3 and 4) are
chemically feasible.
Fig. 1. 4-Acyl-pyrazol-5-one proligands LH.
This research is performed using X-ray diffraction
methods, solution multinuclear NMR and analytical
techniques, and includes a systematic comparison of
these derivatives with those synthesized earlier. It is our
goal to tune the properties of these species through the
appropriate choice of R1, R3 and R4 substituents.
Jensen [9], and then widely employed as dyes [10] and
as metal extractants [11]. Recently some X-ray struc-
tures of their metal derivatives appeared in the litera-
ture showing that 4-acyl-5-pyrazolonates can display
several modes of bonding [12].
We have synthesized several di- [8,13,14] and tri-
organotin(IV) acylpyrazolonates [15] earlier using lig-
ands with different substituents near the carbonyl
groups (positions 1 and 4 of the pyrazole), and studied
their electronic and steric influence on their physico-
chemical and structural features, both in solution and
in the solid state. The dialkyltin(IV)bis(acylpyrazolo-
nato) derivatives generally possess either strongly de-
formed octahedral structures with both (L)− ligands
pointing their equivalent arms in a syn configuration
[8,13], or perfect octahedral tin coordination environ-
ments with centrosymmetrical (anti ) configuration [14].
The trialkyltin(IV) derivatives are five-coordinate
trigonal bipyramidal (TBP) aquo species with the
acylpyrazolonato donor acting in the monodentate
form through the O(pyrazolonato) (the oxygen closest
to the pyrazole ring), while the O(acyl) participates in a
network of H bonds. Instead, triphenyltin compounds
adopt cis-trigonal bipyramidal geometry with the
acylpyrazolonato coordinating the metal in a strongly
asymmetric bidentate form. The p-CF3ꢁPh group in
position 1 of the pyrazole enhances the instability of
these compounds in solution [15b]. This asymmetric
2. Results and discussion
2.1. Synthesis of triorganotin(IV) deri6ati6es 1–6
The triorganotin(IV) derivatives [SnR3(L)(H2O)x] 1–
6 (x=0 or 1, L=L1 or L2) have been obtained from
the metathesis reaction of the sodium salt of the
n
acylpyrazolonate (NaL) with R3SnCl (R=Me, Bu or
Ph) in 1:1 molar ratio in toluene (Scheme 1). The
[SnnBu3(L)(H2O)] and [SnPh3(L)] compounds can also
be obtained in higher yields by reacting the correspond-
ing (R3Sn)2O with the neutral ligands LH in refluxing
toluene (Scheme 1).
As observed earlier for similar species containing
pyrazolonate ligands having a methyl in position 3, the
tri-n-butyl- and trimethyl-tin(IV) derivatives rapidly ab-
sorb water on exposure to air, whereas the triphenyl–
tin(IV) complexes are air and moisture stable. These
species are generally low melting solids, with the excep-
tion of compound 5 that is a dense liquid at room
Scheme 1.

136
F. Marchetti et al. / Journal of Organometallic Chemistry 645 (2002) 134–145
Scheme 2.
Scheme 3.
−2H O
2
temperature. Derivatives 1–6 are highly soluble in
acetone, acetonitrile, DMSO, alcohols and chlorohy-
drocarbons, sparingly soluble in diethyl ether and in-
soluble in hydrocarbons and water.
2SnR3(L)(H2O) “ 2SnR3(L)“SnR2(L)2+SnR4
CHCl
3
(1)
This process is accelerated at the experimental temper-
ature of 40 °C. Only a negligible dissociation is shown
by the triphenyltin(IV) derivative 3 whose ratio, r, is 0.91.
Conductivity values in dichloromethane indicate the
existence of neutral species in solution. All these com-
pounds undergo a partial dissociation in DMSO, a
behavior also observed for diorganotin(IV) derivatives
of 1-phenyl-3-methyl-4-trichloroacetyl-pyrazolon-5-ato
ligand [13c,f] and triorganotin(IV) derivatives of 1-
(4-trifluoromethyl)-phenyl-3-methyl-4-R4(CꢀO)-pyra-
zolon-5-ato ligands (R4=Me, CF3 or Ph) [15a].
The molecular weight determinations carried out in
chloroform solution on selected triorganotin(IV) com-
pounds indicate a partial dissociation in solution, es-
pecially in the case of aquo-triorganotin(IV)
derivatives: the experimental molecular weight values
are generally less than expected and the ratio r (r=
MW/FW) is of the order of 0.7–0.9, generally in-
creasing with concentration. This seems to indicate
the partial dissociation of the anionic L− donor and/
or of H2O. However, a decomposition process (1)
that takes place in solution very slowly at room tem-
perature (see Sections 2.4, 2.5 and 2.6), cannot be
excluded:
2.2. Synthesis of diorganotin(IV) deri6ati6es 7–12
The diorganotin(IV) derivatives [SnR2(L)2] (7–12)
were obtained from the reaction of 2 mmol of
acylpyrazolones LH with 1 mmol of R2SnCl2 (R=
Me, Bu or Ph) and 2 mmol of potassium hydroxide
in methanol (Scheme 2).
All complexes are air and moisture stable. They are
highly soluble in acetone, acetonitrile, DMSO, and
chlorohydrocarbon solvents, insoluble in diethyl ether,
alcohols, hydrocarbons and water.
Compounds 7–12 undergo a partial dissociation in
DMSO, as evidenced from the conductivity values in
this solvent. In dichloromethane, however, values typ-
ical of non-electrolyte species have been found al-
ways. Molecular weight determinations, carried out in
chloroform solution, also indicate a partial dissocia-
tion. Therefore, the formation of ionic pairs and the
n

F. Marchetti et al. / Journal of Organometallic Chemistry 645 (2002) 134–145
137
occurrence of an equilibrium as that proposed in
Scheme 3 is likely.
The dissociation is a function of the concentration of
the solutions, the ratio r between the experimental and
calculated molecular weight ranging from 0.71 to 0.96
at concentrations between 0.7 and 1.9×10−2 m.
systems [9,12]. Therefore, electron-withdrawing groups
such as Ph, in position 3 of the pyrazole ring, influence
the solution behavior of the free neutral acyl-
pyrazolones.
1
In the H spectrum of derivatives 1–3 and 7–9 the
acylpyrazolonato aromatic signals undergo a more
complex pattern upon chelation, whereas the
CH3(CꢀO) group shows only a negligible shift in 4–6
and three signals or one very broad high-field shifted in
10–12.
2.3. IR data
In the solid state, the donors L1H and L2H exist in
the keto-enolic tautomeric form and show a broad
absorption at 2600 cm−1 due to intramolecular
(OꢁH···O) bond. Upon coordination, these absorptions
disappear and, for derivatives 2, 3 and 6–12 the w(CꢀO)
at ca. 1620 cm−1 shifts to lower frequencies (ca. 1600
cm−1), in accordance with the loss of the acidic proton
and binding of both carbonyls to the metal. For deriva-
tives 1, 4 and 5 this band remains essentially un-
changed, most likely indicating weak interactions with
a neighboring H atom of tin-coordinated water, as
observed earlier [15]. In the aquo derivatives the band
at 3100–3200 cm−1 is attributed to the intermolecu-
larly H-bonded water. The absorption bands of the
azomethine and phenyl groups are found between 1500
and 1600 cm−1. Bands due to w(SnꢁO) have been
assigned in the 400–500 cm−1 range, based on previous
reports [16]. Some bands of methyl- (1, 4, 7, 10) and
butyl-tin(IV) (2, 5, 8, 11) derivatives, in the 500–620
cm−1 range, are likely due to was(SnꢁC) and ws(SnꢁC)
[17] whereas the corresponding absorptions for phenyl-
tin(IV) complexes (3, 6, 9, 12) have been observed in
the 200–300 cm−1 region [18]. By comparing these
bands with those observed in the known organotin(IV)
acylpyrazolonates no correlation is found between the
SnꢁO bond strength and the instability of these com-
pounds in solution.
The trimethyl- and tri-n-butyl-tin(IV) derivatives
show at least two different sets of signals for the alkyl
groups bonded to tin, with the coupling constant
2J(119Snꢁ1H) falling in the 55–58 Hz range, typical
values of four- to five-coordinate species [19]. On the
basis of conductivity and osmometric molecular weight
values reported above, we conclude that these com-
pounds lose the molecule of coordinated water in solu-
tion, forming isomeric tetrahedral non-fluxional forms
as those shown in Fig. 2, or five-coordinate tin(IV)
species containing a bidentate acylpyrazolonato.
This suggests equivalence, at least in solution, of the
donating ability of the two carbonyls, similarly to tri-
organotin(IV) derivatives containing an electron-with-
drawing p-CF3ꢁPh group in position 1 of the pyrazole
ring [15b]. This differs from the triorganotin(IV) deriva-
tives of 1-phenyl-3-methyl-4-acylpyrazolonates reported
earlier [15a].
For triphenyltin(IV) complexes it is not possible to
distinguish between signals due to aromatic ligand pro-
tons and those linked to tin, but integration takes their
presence into account.
The dimethyl-tin(IV) (7, 10) and di-n-butyl-tin(IV)
(8, 11) derivatives show at least two different sets of
signals for the alkyl groups bonded to tin, with the
coupling constant 2J(119Snꢁ1H) of the more intense
signal falling in the 96–102 Hz range, typical values for
six-coordinate species having skewed trapezoidal
bipyramidal geometry [19]. The less intense signal is
likely due to the five-coordinate organotin(IV) species
originating from the partial dissociation of the complex
in chloroform solution (see Section 2.6). The proton
spectra of the diphenyltin(IV) complexes 9 and 12 show
broad signals suggesting fluxionality in solution be-
tween different geometrical isomers and/or dissociation
equilibria as (1) also in accordance with 13C and 119Sn
data (see below).
1
2.4. H-NMR data
Since the acidic proton signal is found between 2.50
and 4.50 ppm, a chemical shift typical for NꢁH groups,
L1H and L2H exist in chloroform in the amino-diketo
tautomeric form. Instead, the earlier 4-acylpyrazolones
showed a resonance up to 10.0 ppm due to (OꢁH···O)
2.5. 13C-NMR data
In the 13C-NMR spectra of the proligands L1H and
L2H the pyrazole C3 resonance, bonded to Ph (R3
group), falls at ca. 151 ppm, deshielded by about 5 ppm
with respect to that of the same C atom in all previous
acylpyrazolones containing a Me group in position 3.
This signal is slightly shifted upon coordination, be-
Fig. 2. Two tetrahedral possible isomers for trimethyl- and tributyl-
tin(IV) species.

138
F. Marchetti et al. / Journal of Organometallic Chemistry 645 (2002) 134–145
trum of 3 a small absorption at −47 ppm has been
observed, likely due to a tetrahedral [SnPh3(L)] species
in which the donor is probably monodentate. This
shows that the SnꢁO binding is weaker than in the
previous triphenyltin(IV) derivatives containing
a
methyl group in position 3 of the pyrazole [15], and
indicates the possibility of tuning the donor ability of
this class of b-diketones also by using this peripheral
position.
Derivatives 1–6 slowly decompose in chloro-hydro-
carbon solvents giving SnR4 and SnR2(L)2 species
within 2 days. It is worth noting that 3-methyl related
species showed such a reaction for trialkyltin but not
for triphenyltin derivatives [15]. From 119Sn-NMR spec-
troscopy we find that [SnPh3(L)] are always more stable
than the [SnMe3(L)(H2O)] and [SnnBu3(L)(H2O)]
derivatives, however, they are less stable than all the
previously reported triphenyltin(IV) acylpyrazolonates
[15].
Fig. 3. X-ray molecular structure of (1,3-diphenyl-4-benzoyl-pyra-
zolon-5-ato)triphenyltin(IV) with H atoms omitted.
cause of reduced shielding due to electron density flow
toward tin.
The dialkyltin(IV)pyrazolonato derivatives 7, 8, 10
and 11 show two different signals, one in the range
typical of a four- to five-coordinate tin center, the other
typical of SnO4C2 cores [19], in accordance with the
molecular weight measurements and 1H-NMR data
from which a partial dissociation of these complexes in
solution has been hypothesized.
In the case of the diphenyltin(IV) derivative 9 one
signal for a five-coordinate tin center and two different
signals for the six-coordinate species have been found,
the latter due to different isomers that are non-fluxional
at room temperature, as previously reported [8,13]. The
two signals collapse at 328 K in a single resonance at
−486 ppm.
The tributyltin derivatives 2 and 5 show at least two
sets of resonances and those of triphenyltin 3 and 6
broad signals, due to the presence of the forms hypoth-
esized in Fig. 2. It was not possible to obtain 13C-NMR
spectra of the trimethyltin derivatives 1 and 4 which
disproportionate in solution yielding the corresponding
diorganotin derivatives 7 and 10 and Me4Sn during the
time necessary to acquire a sufficient number of
transients.
The 13C-NMR spectra of the species resemble those
of the previously reported ones [8,13,14]. The values of
1J(13Cꢁ119Sn) for dimethyltin derivatives 7 and 10 and
dibutyltin 8 and 11 are in the 870–950 Hz range, thus
indicating six-coordinated tin atoms. On the basis of
the empirical relation derived by Lockhart [19a] the
CꢁSnꢁC angles for derivatives 7, 8, 10 and 11 were
found in the 153–160° range typical of skewed trans-
octahedral species. In the case of 8, 9 and 12 more than
one set of resonance or broad signals has been observed
for each magnetically equivalent carbon atom, in accor-
2.7. X-ray crystal structure of [SnPh3(L1)] (3)
The crystal structure of the title compound shows
little intermolecular interaction. The molecular struc-
ture is depicted in Fig. 3 and selected geometrical
parameters are shown in Table 1.
The metal is five-coordinate in a TBP arrangement,
made up of three C from the phenyls and two O from
the chelating ligand. The apical positions are occupied
by one oxygen and one carbon, O2 and C25, respec-
tively. The intrinsically asymmetric ligand 4-acyl-pyra-
1
dance with the H- and 119Sn-NMR spectra likely due
to different geometrical isomers or to the presence of
species arising from dissociation of one acylpyrazolone
donor, as hypothesized in Scheme 1.
zolonato generally displays
(pyrazolonato) bond and a weaker, longer, SnꢁO2
(acyl) bond: these values are 2.053(5) and 2.409(5) A,
a
covalent SnꢁO1
2.6. 119Sn-NMR data
,
The trialkyltin(IV) acylpyrazolonates show two sig-
nals in the +80 to +155 ppm range typical of tetrahe-
dral species SnOR3 [20], corresponding to SnꢁOH2
bond cleavage and formation of isomers as of those in
Fig. 2.
Instead, the triphenyltin(IV) derivatives give a unique
resonance between −132 and −181 ppm due to a
five-coordinate TBP geometry [21]. In the 119Sn spec-
respectively, in this structure. In the TBP geometry, the
axial lengths are longer than those equatorial and O2
occupies the expected position. For ‘O2SnC3’ TBP
cores, the literature shows the two apical positions
occupied by either two oxygens or one oxygen and one
carbon. The former type is electronically preferred by
the metal (because of the greater electronegativity of O)
and is generally found in polymeric structures. Instead,

F. Marchetti et al. / Journal of Organometallic Chemistry 645 (2002) 134–145
139
the chelating nature of our ligand induces the latter
form, although the bite generates distortion from a
regular TBP geometry. Thus, the ideal trans axial angle
of 180° differs from the found C25ꢁSnꢁO2 bond angle
triphenyltin species the electron density is shifted from
the metal to the phenyls. It is likely that a weakly
coordinated molecule of water, such as in the alkyl
structure, could not provide enough electron donation
to balance the Ph electronic request (the water molecule
is also involved in a supramolecular H bonding ar-
rangement). Thus, the unstable TBP axial system
···H···O(aquo)···SnꢁO(pyrazolonato)CꢀO(acyl)···H···
cannot form while a contribution from the acyl car-
bonyl to the coordination sphere results in the forma-
tion of a stable chelate. Support for this explanation is
observed experimentally as the aquo derivatives react
more easily than the chelate triphenyltin derivatives. In
addition, if the 4-acyl-5-pyrazolonato ligand itself con-
tains electron-withdrawing groups, then the additional
competition may develop instability. As shown in 119Sn-
NMR spectra, the triphenyltin derivative 3 is more
unstable than the previous 3-methyl-4-acyl-5-pyra-
zolonato-triphenyltin species. We conclude that the
electron-withdrawing effect of Ph in position 3 is more
destabilizing than in positions 1 and 4 as the Ph in these
positions is not able to induce reaction (1).
Instead, reaction (1) was increased when p-CF3ꢁPh
was the substituent in position 1 [15b]. It is a more
potent electron-withdrawing group than Ph and its
behavior concurs with the competitive effect mentioned
above. Further, when position 4 is occupied by the
electron-withdrawing group CCl3, the haloformic reac-
tion takes place in alcohol (R%OH) changing the CCl3
substituent to a COR% group [13c,f]. This reaction,
although different than reaction (1), is nevertheless an
expression of instability.
,
of 163.6(3)°. The metal is 0.33 A out of the equatorial
plane (defined by O1, C31 and C37) towards C25 and
the sum of the equatorial angles (O1ꢁSnꢁC31,
O1ꢁSnꢁC37, C31ꢁSnꢁC37) is 352.6° which differs from
360°. The torsion angle C8ꢁC7ꢁN1ꢁC5 of 32.0(9)° is
greater than that of [1-(4-trifluoromethylphenyl)-3-
methyl-4-acetylpyrazolon-5-ato]triphenyltin(IV) (22°)
and indicates no extended conjugation between the
C7ꢁC12 phenyl and the pyrazole rings. In contrast,
such co-planarity is seen in bis(4-acyl-5-pyrazo-
lonato)diorganotin compounds [13e]. Fig. 3 shows that
the Ph ring C36···C41 is affected by disorder.
This structure is similar to the related species [1-(4-
trifluoromethylphenyl)-3-methyl-4-acetylpyrazolon-5-
ato]triphenyltin [15b]. On the other hand, it is interest-
ing to compare the title compound with the aquo
related species [LSnR3(H2O)], L=1-phenyl-3-methyl-4-
benzoyl-pyrazolon-5-ato, R=nBu [22], L=1-phenyl-3-
methyl-4-p-methoxybenzoyl-pyrazolon-5-ato, R=Me
[15a], where the O-acyl is out of the coordination
sphere and involved in intermolecular H bonding, and
the molecule of water is weakly coordinated to the
,
,
metal (SnꢁO 2.34 A [22] or 2.41A [15a]). The different
structural behavior may be explained using an elec-
tronic basis. Phenyls are electron-withdrawing groups
and alkyls are electron releasing, therefore in
Table 1
Such a feature may be important in explaining the
antitumor activity of some triphenyltin-benzoates [5]
since benzoates containing F (an electron-withdrawing
atom) show increased antitumor activity. It is likely
that these triorganotins evolve or metabolize to
diorganotins in a reaction like (1), for instance, since
not only tri- [5] but also diorganotins are a systematic
class of antitumor species [5e,23]. Therefore, the F
containing benzoate may augment destabilizing its tri-
organotin derivatives as the Ph, in position 3 of pyra-
zole, does for reaction (1) in this study.
,
Selected bond lengths (A) and bond angles (°)
Bond lengths
SnꢁO1
SnꢁO2
SnꢁC25
SnꢁC31
SnꢁC37
O1ꢁC5
2.053(5)
2.409(5)
2.139(7)
2.12(1)
2.12(1)
1.304(9)
1.251(9)
O2ꢁC6
Bond angles
C31ꢁSnꢁO1
O2ꢁSnꢁO1
O2ꢁSnꢁC31
C37ꢁSnꢁO1
C37ꢁSnꢁC31
C37ꢁSnꢁO2
C25ꢁSnꢁO1
C25ꢁSnꢁC31
C25ꢁSnꢁO2
C25ꢁSnꢁC37
SnꢁO1ꢁC5
SnꢁO2ꢁC6
C6ꢁC4ꢁC5
O1ꢁC5ꢁC4
O2ꢁC6ꢁC4
115.5(3)
77.0(2)
80.7(3)
114.3(3)
122.8(3)
84.7(3)
3. Conclusions
87.0(2)
Since 1959, 4-acyl-5-pyrazolones have had exclusively
a methyl group in position 3 of the pyrazole and this
work reports the synthesis and characterization of
novel 3-phenyl substituted compounds. The uncoordi-
nated ligand is in the keto-enolic tautomeric form in
solution, which was not found for other 4-acyl-5-pyra-
zolonates. A disproportion reaction not observed ear-
lier in solution for related 3-methyl-triphenyltins is
103.3(3)
163.6(2)
105.6(3)
129.1(5)
130.8(5)
121.5(6)
131.5(6)
121.3(6)

140
F. Marchetti et al. / Journal of Organometallic Chemistry 645 (2002) 134–145
found for 3-phenyl-triphenyltin derivatives. However,
the metal coordination of 3-methyl- and 3-phenyl-
triphenyltin compounds is similar in the solid state. It is
also found that the Ph in position 3 acts as a stronger
destabilizer than in positions 1 and 4. To generate
chemical instability from positions 1 and 4 more power-
ful electron-withdrawing groups are needed: these are
p-CF3ꢁPh [15] and CCl3 [13c,f], respectively.
Thus far, only substitution on position 4 of the
1-R1-3-R3-4-CꢀOꢁR4-5-pyrazolone was widely applied,
mainly for dyes and extraction purposes, and until
recently R1 and R3 were exclusively Ph and Me, respec-
tively. Recently, we obtained 1-methyl [13e] and 1-(p-
CF3ꢁPh) [14,15b] derivatives. The present study shows
that a Ph substituent in position 3 induces novel fea-
tures making this area worth exploring further.
tor and the crude product washed with Et2O (50 ml)
and light petroleum (50 ml). After filtration, the brown
powder was dried in vacuo and shown to be 1,3-
diphenylpyrazol-5-one. Yield: 78%. M.p. 138–139 °C.
MS; m/z: 236 [M+]. Anal. Found: C, 76.46; H, 5.18; N,
11.65. Calc. for C15H12N2O: C, 76.25; H, 5.12; N,
11.86%; IR (cm−1): w 1699s br, 1655sh, 1632m, 1592s,
1561m, 1495s, 651s, 616m, 600s, 595sh, 526m. 1H-
NMR (CDCl3): l 3.85s (2H, 4CH2), 7.25t, 7.45m,
7.70m, 8.02dd (10H, N(1)ꢁC6H5, C(3)ꢁC6H5).
The donors L1H and L2H were then synthesized
following the procedure reported by Jensen [9].
4.1.2. 1,3-Diphenyl-4-benzoylpyrazol-5-one (L1H)
Yield: 84%. M.p. 114–116 °C. MS; m/z: 340 [M+].
Anal. Found: C, 77.48; H, 4.80; N, 8.05. Calc. for
C22H16N2O2: C, 77.63; H, 4.74; N, 8.23%. IR (Nujol,
cm−1): w(OH···O) 2700br; 1620vs (br). 1H-NMR
(CDCl3): l 2.50s (br, 1H, NH···O), 7.05m, 7.25m,
7.75m, 7.88d (15H, C6H5). 13C-NMR (CDCl3): l 121.4,
121.8, 126.0, 126.3, 126.5, 126.8, 127.9, 128.0, 128.4,
128.8, 129.2, 129.7, 131.7 (s, Carom of C6H5), 103.8 (s,
C3), 150.8 (s, C4), 161.0 (s, C5), 193.4 (s, CO).
4. Experimental
The reactions were carried out under N2 stream using
Schlenk techniques. Solvents were dried by standard
techniques. The samples were dried in vacuo to con-
stant weight (20 °C, ca. 0.1 Torr). Elemental analyses
(C, H, N) were performed in-house with a Carlo–Erba
Strumentazione 1106 instrument. Melting points (m.p.)
were measured with an IA 8100 Electrothermal instru-
ment. The electrical resistances of solutions were mea-
sured with a Crison CDTM 522 Conductimeter at
room temperature (r.t.). Molecular weight determina-
tions were performed with a Knauer A0280 Vapour
Pressure Osmometer. Mass Spectra were obtained in a
HP 5971A Mass Spectrometer. IR spectra from 4000 to
100 cm−1 were recorded with a Perkin–Elmer 2000
4.1.3. 1,3-Diphenyl-4-acetylpyrazol-5-one (L2H)
Yield: 72%. M.p. 145–147 °C. MS; m/z: 278 [M+].
Anal. Found: C, 73.16; H, 5.16; N, 10.12. Calc. for
C17H14N2O2: C, 73.37; H, 5.07; N, 10.07%. IR (Nujol,
cm−1): w(OH···O) 2800br; 1622vs (br). 1H-NMR
(CDCl3): l 2.18s (3H, CH3(CꢀO)), 3.20s (br, 1H,
NH···O), 7.25m, 7.33d, 7.60m, 7.92d (10H, C6H5). 13C-
NMR (CDCl3): l 26.8 (s, CH3(CꢀO)), 120.9, 126.8,
128.5, 128.7, 129.1, 129.3, 129.4, 132.9, 137.3 (s, Carom
of C6H5), 104.0 (s, C3), 151.3 (s, C4), 160.5 (s, C5), 195.3
(s, CO).
1
FT-IR instrument. H-, 13C- and 119Sn-NMR spectra
were recorded in a VXR-300 Varian spectrometer oper-
1
ating at r.t. (300 MHz for H, 75 MHz for 13C and
4.2. Syntheses of the complexes
111.9 MHz for 119Sn). H and C chemical shifts are
reported in ppm versus SiMe4 whereas Sn chemical
shifts are reported in ppm versus SnMe4. Relative in-
tensity of signals is given in square brackets. The C
spectra were run in samples with high concentrations
(\4×10−2 m), to avoid complications due to disso-
ciative and/or degradative processes in dilute solutions.
The Sn spectra were run with a spectral width of 1000
ppm. Each tin spectrum was acquired in ca. 1/2 h (ca.
300 transients). All the chemicals were analytical
reagent grade from Aldrich.
4.2.1. [SnMe3(L1)(H2O)] (1)
A toluene solution (30 ml) of the proligand L1H (1.0
mmol, 340 mg) was added to a methanolic solution (10
ml) of CH3Ona (1.0 mmol, 54 mg) and refluxed for 1 h.
A toluene solution (20 ml) of Me3SnCl (1.0 mmol, 200
mg) was then added to the above solution drop-wise
and the reaction mixture was stirred at r.t. for about 3
h. Sodium chloride was filtered and the solvent re-
moved under reduced pressure on a rotary evaporator
until a thick oil was obtained. This was treated with
Et2O and light petroleum, and a brown solid afforded.
This was recrystallized from toluene–petroleum ether
mixture and shown to be compound 1. Yield: 56%,
m.p. 212–214 °C. Anal. Found: C, 57.35; H, 5.23; N,
5.28. Calc. for C25H26N2O3Sn: C, 57.61; H, 5.03; N,
5.37%. FW 521. Molecular weight (CHCl3, 40 °C, c
(mol kg−1 solvent)=1.2×10−2 M), MW 385 (r=
MW/FW=0.74). Conductivity (CH2Cl2, c (mol l−1)=
4.1. Syntheses of proligands
4.1.1. 1,3-Diphenylpyrazol-5-one
Ethyl benzoylacetate (0.052 mol, 10.0 g) was added
dropwise to a solution (30 ml) of phenylhydrazine
(0.052 mol, 5.63 g). The mixture was stirred to refluxing
1 h, then the solvent was removed in a rotary evapora-

F. Marchetti et al. / Journal of Organometallic Chemistry 645 (2002) 134–145
141
0.610−2 M), \M (V−1 cm2 mol−1)=0.3; (DMSO, c=
4.2.4. [SnMe3(L2)(H2O)] (4)
0.8×10−3 M), \M=10.0. IR (Nujol, cm−1): w(H2O)
3250br; w(H2O) 1655m; w(CꢀO) 1620vs (br); w(SnꢁO)
448m, 416s, 410m; w(SnꢁC) 552s, 548sh. 1H-
Yield: 42%, m.p. 107–110 °C. Anal. Found: C,
52.56; H, 5.22; N, 6.23. Calc. for C20H24N2O3Sn: C,
52.32; H, 5.27; N, 6.10%. FW 459. Molecular weight
(CHCl3, 40 °C, c (mol kg−1 solvent)=1.1×10−2 M),
NMR (CDCl3):
l
0.62s (2J(119Snꢁ1H)=57.6 Hz,
2J(117Snꢁ1H)=55.4 Hz), 0.67s (2J(119/117Snꢁ1H)=56.3)
(9H, SnꢁCH3), 2.50s (br) (2H, H2O), 7.15m, 7.45m,
7.85m, 7.98d, 8.15d (15H, C6H5(L1)). 1H-NMR
(DMSO-d6): l 0.25s (br), 0.45s (br), 1.00s (2J(117/
119Snꢁ1H)=100.8 Hz) (9H, SnꢁCH3), 2.35s (br) (2H,
H2O), 7.20m, 7.35m, 7.55m, 7.98m (15H, C6H5 (L1)).
13C-NMR (CDCl3): After acquiring 1000 cycles, the
spectrum exhibits the same signals found in the spec-
trum of 7. 119Sn-NMR (CDCl3): l +146.6, +151.7.
Compounds 2–6 were obtained similarly.
MW=326
(r=MW/FW=0.71).
Conductivity
(CH2Cl2, c (mol l−1)=0.9×10−3 M), \M (V−1 cm2
mol−1)=0.4; (DMSO, c=1.3×10−3 M), \M=8.7.
IR (Nujol, cm−1): w(H2O) 3320br; w(H2O) 1650m;
w(CꢀO) 1619vs (br); w(SnꢁO) 444sh, 431s, 424sh;
w(SnꢁC) 553m. 1H-NMR (CDCl3): l 0.62s (2J(117/
119Snꢁ1H)=57.5 Hz), 0.67s (2J(119/117Snꢁ1H)=56.6)
(9H, SnꢁCH3), 2.02s, 2.10s (3H, CH3(CꢀO)(L2)), 2.20s
(br) (2H, H2O), 7.12m, 7.48m, 7.95m (10H, C6H5 (L2)).
13C-NMR (CDCl3) after acquiring 1000 cycles the spec-
trum exhibits some signals found in the spectrum of
10+small signals due to 4: l 8.9 (1J(119Snꢁ13C)=947
4.2.2. [SnnBu3(L1)(H2O)] (2)
1
Yield: 97%, m.p. 69–70 °C. Anal. Found: C, 62.85;
H, 7.02; N, 4.36. Calc. for C34H44N2O3Sn: C, 63.08; H,
6.85; N, 4.33%. FW 647. Molecular weight (CHCl3,
40 °C, c (mol kg−1 solvent)=0.9×10−2 M), MW=
500 (r=MW/FW=0.77); (CHCl3, 40 °C, c=2.4×
10−2 M), MW=531 (r=0.82). Conductivity (CH2Cl2,
c (mol l−1)=1.0×10−3 M), \M (V−1 cm2 mol−1)=
0.2; (DMSO, c=0.6×10−3 M), \M=14.5. IR (Nujol,
cm−1): w(H2O) 3240br; w(H2O) 1648m; w(CꢀO) 1598vs
(br); w(SnꢁO) 460m, 412m, 390vs; w(SnꢁC) 627m,
Hz, J(117Snꢁ13C)=906 Hz) (s, SnꢁCH3), 28.1 [6], 26.8
[1] (s, CH3(CꢀO)(L2)), 104.6 (s, C4), 121.3, 125.8, 126.8,
128.4, 128.9, 129.4, 134.5, 138.3 (s, Carom of C6H5 (L2)),
153.0 (s, C3), 161.6 (s, C5), 194.0 (s, CO). 119Sn-NMR
(CDCl3): l +131.2, +135.4.
4.2.5. 3.2.5. [SnnBu3(L2)(H2O)] (5)
Yield: 55%, oil at r.t. Anal. Found: C, 59.64; H, 7.36;
N, 4.43. Calc. for C29H42N2O3Sn: C, 59.51; H, 7.23; N,
4.79%. FW 585. Molecular weight (CHCl3, 40 °C, c
(mol kg−1 solvent)=0.8×10−2 M), MW=480 (r=
MW/FW=0.82). Conductivity (CH2Cl2, c (mol l−1)=
1.1×10−3 M), \M (V−1 cm2 mol−1)=0.3; (DMSO,
c=1.9×10−3 M), \M=11.9. IR (Nujol, cm−1):
w(H2O) 3260br; w(H2O) 1648m; w(CꢀO) 1620vs (br);
1
509vs. H-NMR (CDCl3): l 0.90t, 0.95t, 1.35m, 1.65m
(27H, Sn-nꢁC4H9), 2.25s (br) (2H, H2O), 7.10m, 7.20d,
7.35d, 7.45m, 7.95d (15H, C6H5 (L1)). 13C-NMR
(CDCl3): l 13.7, 19.5br (1J(Snꢁ13C)=256 Hz, SnꢁnBu),
26.1 (J(Snꢁ13C)=86 Hz, s, SnꢁnBu), 27.1 (J(Snꢁ13C)=
45 Hz, s, SnꢁnBu), 27.3, 27.8 (2J(Snꢁ13C)=12.9 Hz, s,
SnꢁnBu), 29.3 (1J(Snꢁ13C)=555 Hz, s, SnꢁnBu), 103.3
(s, C4), 121.2, 122.4, 125.7, 126.2, 127.4, 127.5, 127.6,
128.0, 128.6, 128.9, 129.0, 129.3, 130.1, 130.9, 131.3,
133.6, 133.8, 138.1, 138.4, 138.6, 139.3 (s, Carom of C6H5
(L1)), 151.9, 152.9 (s, C3), 161.2, 163.5 (s, C5), 191.5 (s,
CO). 119Sn-NMR (CDCl3): l +124.7.
1
w(SnꢁO) 455s, 407s; w(SnꢁC) 615m. H-NMR (CDCl3):
l 0.92t, 0.98t, 1.32m, 1.62m (27H, Sn-nꢁC4H9), 1.95s,
2.00s (3H, CH3(CꢀO)(L2)), 2.22s (br) (2H, H2O), 7.25t,
7.44m, 7.88d (10H, C6H5 (L2)). 13C-NMR (CDCl3): l
13.6, 26.2, 27.5, 27.7, 28.0, 29.1 (s, SnꢁnBu), 27.2, 28.4
(s, CH3(CꢀO)(L2)), 103.4 (s, C4), 121.5, 122.8, 126.2,
126.5, 127.2, 127.4, 127.8, 128.1, 128.5, 128.9, 129.1,
129.3, 130.4, 130.7, 131.2, 133.3, 133.6, 138.4, 138.5,
138.8, 139.5 (s, Carom of C6H5 (L2)), 152.4, 153.4 (s, C3),
162.6, 163.8 (s, C5), 192.3 (s, CO). 119Sn-NMR
(CDCl3): l +103.8.
4.2.3. [SnPh3(L1)] (3)
Yield: 73%, m.p. 90–92 °C. Anal. Found: C, 69.40;
H, 4.50; N, 3.86. Calc. for C40H30N2O2Sn: C, 69.69; H,
4.39; N, 4.06%. FW 689. Molecular weight (CHCl3,
40 °C, c (mol kg−1 solvent)=1.6×10−2 M), MW=
627 (r=MW/FW=0.91). Conductivity (CH2Cl2, c
(mol l−1)=0.6×10−3 M), \M (V−1 cm−2 mol−1)=
0.2; (DMSO, c=0.7×10−3 M), \M=4.9. IR (Nujol,
cm−1): w(CꢀO) 1595vs (br); w(SnꢁO) 449vs, 422sh,
4.2.6. [SnPh3(L2)] (6)
Yield: 58%, m.p. 170–173 °C. Anal. Found: C,
67.25; H, 4.64; N, 4.46. Calc. for C35H28N2O2Sn: C,
67.01; H, 4.50; N, 4.47%. FW 627. Molecular weight
(CHCl3, 40 °C, c (mol kg−1 solvent)=0.9×10−2 M),
MW=459 (r=MW/FW=0.73) (CHCl3, 40 °C, c=
2.3×10−2 M), MW=519 (r=0.83). Conductivity
1
407w; w(SnꢁC) 263s, 233s. H-NMR (CDCl3): l 6.95m,
7.10m, 7.35m, 7.70m, 8.08d (15H, SnꢁC6H5, 15H, C6H5
(L%)). 13C-NMR (CDCl3): l 103.7 (s, C4), 120.9br,
126.3, 127.4, 127.6, 127.8, 128.2, 128.8, 129.5, 131.6,
133.1, 135.4, 136.5, 137.2, 138.0, 148.1 (s, Carom of
SnꢁPh and C6H5 (L1)), 153.0 (s, C3), C5 not observed,
191.5 (s, CO). 119Sn-NMR (CDCl3): l −132.0, −47.7.
(CH2Cl2,
c
(mol l−1)=0.9×10−3
M),
\
M
(V−1 cm2 mol−1)=0.42; (DMSO, c=0.6×10−3 M),
\M=16.9. IR (Nujol, cm−1): w(CꢀO) 1606vs (br);
w(SnꢁO) 466m, 451vs; w(SnꢁC) 256s, 237s. 1H-NMR
(CDCl3): l 2.20s (3H, CH3(CꢀO)(L2)), 7.22d, 7.38m,

142
F. Marchetti et al. / Journal of Organometallic Chemistry 645 (2002) 134–145
7.55m, 7.68m, 7.85d (15H, SnꢁC6H5, 10H, C6H5 (L2)).
13C-NMR (CDCl3): l 27.6, 28.3 (s, CH3(CꢀO)(L2)),
104.4 (s, C4), 122.7, 126.2, 126.6, 128.4, 128.5, 128.7,
128.9, 129.3, 129.4, 129.5, 134.1, 137.0 (s, Carom of
SnꢁPh and C6H5 (L2)), 152.1, 153.0 (s, C3), 160.4, 161.2
(s, C5), 195.3 (s, CO). 119Sn-NMR (CDCl3): l −180.7.
In the case of derivatives 2, 3, 5 and 6 the following
alternative synthesis can be used (the example applies
to compound 3):
6.95–7.20m, 7.30–7.50m, 7.60m, 7.90dbr, 8.10dbr
(30H, C6H5 (L1)). 13C-NMR (CDCl3): l 13.7, 26.2, 27.3
(2J(Snꢁ13C)=24 Hz, SnꢁnBu), 29.2 (1J(Snꢁ13C)=650
Hz, SnꢁnBu), 103.1 (s, C4), 121.2, 126.0, 127.5, 127.7,
127.9, 129.0, 129.4, 131.5 (s, Carom of C6H5 (L1)), 152.7,
153.1 (s, C3), 163.1 (s, C5), 187.9br, 189.6br, 191.8 (s,
CO). 119Sn-NMR (CDCl3): l −133.9, −355.8.
4.2.9. [SnPh2(L1)2] (9)
A toluene solution (30 ml) of (Ph3Sn)2O (1.0 mmol,
716 mg) was added to a toluene solution (30 ml) of the
proligand L1H (2.0 mmol, 680 mg), and the reaction
mixture was refluxed for about 2 h. After removing the
solvent under reduced pressure in a rotary evaporator,
thick oil was obtained. This was treated with Et2O and
petroleum ether, and a pale yellow solid was formed.
This was recrystallized from a toluene/petroleum ether
mixture and shown to be compound 3.
Yield: 78%, m.p. 152–155 °C. Anal. Found: C,
70.55; H, 4.38; N, 5.53. Calc. for C56H40N4O4Sn: C,
70.68; H, 4.24; N, 5.89%. FW 952. Molecular weight
(CHCl3, 40 °C, c (mol kg−1 solvent)=0.8×10−2 m),
MW=738 (r=MW/FW=0.77) (CHCl3, 40 °C, c=
2.0×10−2 m), MW=794 (r=0.83). Conductivity
(CH2Cl2,
c
(mol l−1)=0.7×10−3
M),
\
M
(V−1 cm2 mol−1)=0.1; (DMSO, c=0.4×10−3 M),
\M=5.6. IR (Nujol, cm−1): w(CꢀO) 1595vs (br);
w(SnꢁO) 448sbr; w(SnꢁC) 267m, 246m. 1H-NMR
4.2.7. [SnMe2(L1)2] (7)
(CDCl3):
l 6.80–6.90m, 6.95–7.20m, 7.30–7.50m,
To a MeOH solution (30 ml) of L1H (2 mmol) KOH
(2 mmol) and Me2SnCl2 (1 mmol) was added and a
precipitate was formed immediately. The mixture was
stirred overnight and the precipitate was then filtered,
washed with MeOH (ca. 10 ml) and dried under re-
duced pressure at r.t. This was recrystallized from
chloroform–MeOH. Yield: 81%, m.p. 215–218 °C.
Anal. Found: C, 66.45; H, 4.51; N, 6.83. Calc. for
C46H36N4O4Sn: C, 66.77; H, 4.39; N, 6.77%. FW 827.
Conductivity (CH2Cl2, c (mol l−1)=0.6×10−3 M),
7.70mbr, 8.00mbr (40H, SnꢁC6H5 and C6H5 (L1)). 13C-
NMR (CDCl3): l 103.9 (s br, C4), 120.4, 121.3, 121.9,
126.5, 127.2, 127.6, 127.6, 128.0, 128.2, 128.4, 128.6,
128.9, 129.1, 129.7, 129.9, 130.1, 130.2, 131.8, 132.6,
132.7, 132.9, 135.7, 136.2, 136.5, 137.3, 137.7, 138.2,
148.3 (s, Carom of SnꢁPh and C6H5 (L2)), 153.2 (s, C3),
164.8 (s, C5), 191.8 (s, CO). 119Sn-NMR (CDCl3, 295
K): l −276.5, −482.5, −490.0. 119Sn-NMR (CDCl3,
328 K): l −276.5, −486br.
\
(V−1 cm2 mol−1)=0.2; (DMSO, c=0.9×10−3
M
4.2.10. [SnMe2(L2)2] (10)
M), \M=7.7. IR (Nujol, cm−1): w(CꢀO) 1600vs (br);
Yield: 67%, m.p. 244–247 °C. Anal. Found: C,
61.23; H, 4.73; N, 8.07. Calc. for C36H32N4O4Sn: C,
61.48; H, 4.59; N, 7.97%. FW 703. Molecular weight
(CHCl3, 40 °C, c (mol kg−1 solvent)=0.7×10−2 m),
MW=537 (r=MW/FW=0.76) (CHCl3, 40 °C, c=
1.3×10−2 m), MW=556 (r=0.79) (CHCl3, 40 °C,
c=1.6×10−2 m), MW=571 (r=0.81) (CHCl3,
40 °C, c=1.7×10−2 m), MW=600 (r=0.85)
(CHCl3, 40 °C, c=1.9×10−2 m), MW=685 (r=
0.97). Conductivity (CH2Cl2, c (mol l−1)=0.7×10−3
M), \M (V−1 cm2 mol−1)=0.1; (DMSO, c=0.6×
10−3 M), \M=12.5. IR (Nujol, cm−1): w(CꢀO) 1613vs
(br); w(SnꢁO) 444w, 413m; w(SnꢁC) 587s. UV–vis: u
(nm) (m, mol l−1 cm−1) (CHCl3): 242 (55 900). 1H-
NMR (CDCl3): l 0.95s [6] (2J(119Snꢁ1H)=102.7 Hz,
2J(119Snꢁ1H)=98.2 Hz), 1.15s [1] (6H, SnꢁCH3), 1.98s
[6], 2.05s [1], 2.22s [1] (6H, CH3(CꢀO)(L2)), 7.15–
7.30m, 7.40–7.52m, 7.95d (20H, C6H5 (L2)). 13C-
1
w(SnꢁO) 455s, 409sbr; w(SnꢁC) 590m, 544s. H-NMR
(CDCl3):
l
1.12s [5] (2J(119Snꢁ1H)=101.5 Hz,
2J(119Snꢁ1H)=98.5 Hz), 1.24s [1] (6H, SnꢁCH3), 6.95–
7.20m, 7.30–7.40m, 8.05d (30H, C6H5 (L1)). 13C-
NMR (CDCl3):
l
9.1 (1J(119Snꢁ13C)=928 Hz,
1J(117Snꢁ13C)=885 Hz) (s, SnꢁMe), 103.0 (s, C4),
121.4, 125.9, 126.2, 127.5, 127.6, 127.7, 129.0, 129.4,
131.4, 133.5, 138.0, 138.4 (s, Carom of SnꢁC6H5 and
C6H5 (L1)), 153.0 (s, C3), 163.2 (s, C5), 191.2 (s, CO).
119Sn-NMR (CDCl3): l −99.5, −319.7.
Compounds 8–12 were obtained similarly.
4.2.8. [SnnBu2(L1)2] (8)
Yield: 75%, m.p. 65–66 °C. Anal. Found: C, 68.73;
H, 5.57; N, 6.21. Calc. for C52H48N4O4Sn: C, 68.51; H,
5.31; N, 6.15%. FW 912. Molecular weight (CHCl3,
40 °C, c (mol kg−1 solvent)=0.9×10−2 m), MW=
784 (r=MW/FW=0.86) (CHCl3, 40 °C, c=1.5×
10−2 m), MW=839 (r=0.92). Conductivity (CH2Cl2,
c (mol l−1)=0.8×10−3 M), \M (V−1 cm2 mol−1)=
0.3; (DMSO, c=0.6×10−3 M), \M=5.3. IR (Nujol,
cm−1): w(CꢀO) 1594vs (br); w(SnꢁO) 450m, 420sh, 408s;
w(SnꢁC) 617m, 516s. 1H-NMR (CDCl3): l 0.75m,
0.90m, 1.25–1.50m, 1.65–1.90m (18H, Sn-n-C4H9),
NMR (CDCl3):
l
9.0 (1J(119Snꢁ13C)=948 Hz,
1J(117Snꢁ13C)=906 Hz) (s, SnꢁMe), 28.3 (s, C3ꢁMe),
104.8 (s, C4), 121.5, 125.9, 128.6, 129.1, 129.6, 134.7,
138.5 (s, Carom of C6H5 (L2)), 153.2 (s, C3), 161.8 (s, C5),
194.2 (s, CO). 119Sn-NMR (CDCl3):
−321.0.
l −100.7,

F. Marchetti et al. / Journal of Organometallic Chemistry 645 (2002) 134–145
143
Table 2
66.77; H, 4.39; N, 6.77%. FW 827. Conductivity
(CH2Cl2, c (mol l−1)=1.0.10−3 M), \M (V−1 cm2
mol−1)=0.1; (DMSO, c=0.7×10−3 M), \M=5.4.
IR (Nujol, cm−1): w(CꢀO) 1614vs (br); w(SnꢁO) 455m,
Crystal data and structure refinement parameters for (1,3-diiphenyl-4-
benzoyl-pyrazolon-5-ato)triphenyltin(IV)
Empirical formula
Formula weight
Temperature (K)
Wavelength (A) (graph monochr)
Crystal habit
Crystal size (mm)
Crystal system
Space group
Crystal color
Unit cell dimensions
C40H30N2O2Sn
689.38
298
Mo–Ka
447s, 426s; w(SnꢁC) 243s. UV–vis:
mol l−1cm−1) (CHCl3): 232 (36 200), 250 (29 650), 282
(20 100). 1H-NMR (CDCl3):
1.95sbr (6H,
u (nm) (m,
,
l
Bloc
CH3(CꢀO)(L2)), 7.15–7.55mbr, 7.75mbr, 7.90–8.10mbr
(30H, SnꢁC6H5 and C6H5 (L2)). 13C-NMR (CDCl3): l
27.6 (s, CH3(CꢀO) (L2)), 105.6 (s, C4), 120.7, 121.2br,
126.2, 127.6, 128.4, 128.8, 128.9, 129.1, 129.3, 133.9,
135.4, 138,0, 147.9 (s, Carom of SnꢁC6H5 and C6H5
(L2)), 153.0 (s, C3), 162.9 (s, C5), 195.3 (s, CO). 119Sn-
NMR (CDCl3): l −280.1, −484.3.
0.35×0.20×0.20
Monoclinic
P21/c
Pale-yellow
,
a (A)
10.674(5)
29.452(14)
11.054(5)
109.31(1)
3279(3)
4
1.397
56
0.82
,
b (A)
,
c (A)
i (°)
3
,
V (A )
Z
4.3. Crystallographic study of [SnPh3(L1)] (3)
Dcalc (g cm−3
2qmax (°)
v (mm−) 1
)
A preliminary study was performed with a Weis-
senberg Camera to determine the cell parameters and
the monoclinic space group. A P21 Syntex diffractome-
ter was used for measuring the cell constants and for
data collection; a set of 25 reflections (with high theta
angle) was used to obtain refined cell parameters. A
summary of crystal data together with details of data
collection and structure solution is given in Table 2.
No decay was observed after monitoring the three
reflections (taken every 100 reflections). Slight absorp-
tion effect was found after a psi-scan and so data were
corrected for absorption as well as for Lorentz and
polarization effects [24]. The molecular structure was
solved using the Patterson–Fourier method using the
CAOS program [25].
Scan speed (° min−1
)
2.3
0.90/1.00
1.0
Transmission factors
Scan range (°)
Scan mode
ꢀ
Reflections collected
Unique reflections
Refined reflections [F\5|(F))]
Refined parameters
R, a Rw
7147
5725
3559
361
0.050, 0.056
0.90
b
S
a R(F)=ꢀꢁ(Fo−Fc)ꢁ/ꢀFo.
b S=[ꢀ{w(Fo2−Fc2)2}/(n−p)]0.5, n=no. of data and p=no. of
refined parameters.
4.2.11. [SnnBu2(L2)2] (11)
Subsequent calculations were performed as follows:
refinement based on the minimization of the function
ꢀw(ꢁFoꢁ−ꢁFcꢁ)2 with the weighting scheme w=1/(a+
Fo+cF2o), where a and c are of the order of 2Fo(min)
and 2/Fo(max), respectively [26]. After refinement con-
vergence, H atoms were introduced at fixed positions
Yield: 70%, m.p. 168–171 °C. Anal. Found: C,
63.84; H, 5.72; N, 7.10. Calc. for C42H44N4O4Sn: C,
64.06; H, 5.63; N, 7.11%. FW 787. Conductivity
(CH2Cl2, c (mol l−1)=0.9×10−3 M), \M (V−1 cm2
mol−1)=0.3; (DMSO, c=0.6×10−3 M), \M=9.2.
IR (Nujol, cm−1): w(CꢀO) 1610vs (br); w(SnꢁO) 459m,
446sh, 428s; w(SnꢁC) 593m. UV–vis: u (nm) (m,
,
with a CꢁH distance of 0.96 A and H isotropic dis-
placement parameters were kept fixed until the final
refinement convergence was reached. Atomic scattering
factors and anomalous dispersion terms were taken
from the literature [27].
mol l−1 cm−1
)
(CHCl3): 236 (57 000). 1H-NMR
(CDCl3): l 0.82t [6], 0.95t [1], 1.35mbr, 1.60m [6],
1.78m [1] (18H, Sn-nꢁC4H9), 1.98s [6], 2.05s [1], 2.22s
[1] (6H, CH3(CꢀO)(L2)), 7.15–7.30m, 7.40–7.55m,
7.96dd (30H, C6H5 (L2)). 13C-NMR (CDCl3): l 28.3 (s,
CH3(CꢀO)(L2)), 13.9, 26.3 (2J(119/117Snꢁ13C)=44 Hz),
27.2 (3J(119Snꢁ13C)=127 Hz, J(117Snꢁ13C)=121 Hz),
3
5. Supplementary material
28.9 (1J(119Snꢁ13C)=870 Hz, J(117Snꢁ13C)=830 Hz)
1
(s, SnꢁnBu), 105.0 (s, C4), 121.3, 125.8, 128.6, 129.1,
129.6, 134.9, 138.7 (s, Carom), 153.1 (s, C3), 162.0 (s, C5),
Crystallographic data for structural analysis have
been deposited with the Cambridge Crystallographic
Data Centre, CCDC no. 169093 for compound 3.
Copies of this 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).
191.5 (s, CO). 119Sn-NMR (CDCl3):
−355.9.
l −132.1,
4.2.12. [SnPh2(L2)2] (12)
Yield: 65%, m.p. 180–183 °C. Anal. Found: C,
66.40; H, 4.53; N, 6.85. Calc. for C42H36N4O4Sn: C,

144
F. Marchetti et al. / Journal of Organometallic Chemistry 645 (2002) 134–145
(c) R.C. Mehrotra, V.D. Gupta, J. Organomet. Chem. 4 (1965)
Atomic coordinates; anisotropic displacement
parameters; full list of bond distances and angles; and
Fo/Fc listing is available from F. Caruso on request.
287;
(d) R.R. Jain, J.C. Maire, Y. Maire-Limouzin, A. Baldy, B.P.
Bachlas, Indian J. Chem. Sect. A 19A (1980) 482;
(e) B.D. James, S. Gioskos, S. Chandra, R.J. Magee, J.D.
Cashion, J. Organomet. Chem. 436 (1992) 155.
[8] C. Pettinari, G. Rafaiani, G. Gioia Lobbia, A. Lorenzotti, F.
Bonati, B. Bovio, J. Organomet. Chem. 405 (1991) 75.
[9] B.S. Jensen, Acta Chem. Scand. 13 (1959) 1347, 1668 and 1890.
[10] K. Venkataraman, In The Chemistry of Synthetic Dyes, vol. 1,
Academic Press, New York, 1952.
Acknowledgements
Financial support by Universita` di Camerino, Con-
siglio Nazionale delle Ricerche C.N.R.-Rome, Vassar
College Research Committee (M.R.) and Camille and
Henry Dreyfus Foundation (M.R.).
[11] (a) E.C. Okafor, Z. Naturforsh. B 36 (1981) 213;
(b) E.C. Okafor, Spectrochim. Acta A 37 (1987) 939, 945 and
951;
(c) S. Umetani, H. Freiser, Inorg. Chem. 26 (1987) 3179;
(d) E.C. Okafor, B.A. Uzoukwu, Radiochim. Acta 51 (1990)
167.
References
[12] (a) D. Zhou, Q. Li, C. Huang, G. Yao, S. Umetani, M. Matsui,
L. Ying, A. Yu, X. Zhao, Polyhedron 16 (1997) 1381;
(b) B.A. Uzoukwu, S.S. Al-Juaid, P.B. Hitchcock, J.D. Smith,
Polyhedron 12 (1993) 2719;
[1] (a) H.J. Keller, B. Keppler, U. Kru¨ger, R. Linder, Eur. Pat. No.
49486, 1982;
(b) D. Searle, P.J. Smith, N.A. Bell, L.A. March, I.W. Nowell,
J.D. Donaldson, Inorg. Chim. Acta 162 (1989) 143.
[2] (a) A.G. Davies, P.J. Smith, in: G. Wilkinson, F.G.A. Stone,
E.W. Abel (Eds.), Comprehensive Organometallic Chemistry,
vol. 2, Pergamon Press, Oxford, 1982;
(c) R.R. Ryan, G.D. Jarvinen, Acta Crystallogr. C 43 (1986)
1295;
(d) E.T. Karaseva, V.E. Karasev, A.A. Udovenko, A.I. Sigula,
Koord. Khim. 9 (1983) 692;
(e) C. Pettinari, F. Marchetti, A. Cingolani, C. Marciante, R.
Spagna, M. Colapietro, Polyhedron 13 (1994) 939;
(f) A. Jain, S. Saxena, R. Bohra, A.K. Rai, Main Group Met.
Chem. 18 (1995) 139 (and references therein);
(g) F. Marchetti, C. Pettinari, A. Cingolani, D. Leonesi, M.
Camalli, A. Pifferi, Polyhedron 15 (1996) 3835;
(h) M.F. Mahon, K.C. Molloy, B.A. Omotowa, M.A. Mesubi, J.
Organomet. Chem. 525 (1996) 239;
(b) S.J. Blumen, A.H. Chapman, in: P.J. Craig (Ed.),
Organometallic Compounds in the Environment, Longman,
Harlow, London, 1986;
(c) M.A. Champ, P.F. Seligman, in: M.A. Champ, P.F. Seligman
(Eds.), Organotin: Environmental Fate and Effects, Chapman
and Hall, London, 1996 (chap. 1).
[3] R. Merten, G. Loew, US No. 3055845, 1962.
[4] M. Vrnata, V. Myslik, F. Vyslouzil, M. Jelinek, J. Electrical Eng.
49 (1998) 200.
[5] (a) M. Gielen, Coord. Chem. Rev. 151 (1996) 41;
(b) R. Willem, A. Bouhdid, M. Biesemans, J.C. Martins, D. de
Vos, E.R.T. Tiekink, M. Gielen, J. Organomet. Chem. 514
(1996) 203;
(i) B.A. Uzoukwu, P.U. Adiukwu, S.A. Al-Juaid, P.B. Hitch-
cock, J.D. Smith, Inorg. Chim. Acta 250 (1996) 173.
[13] (a) C. Pettinari, F. Marchetti, D. Leonesi, M. Rossi, F. Caruso,
J. Organomet. Chem. 483 (1994) 123;
(b) F. Caruso, D. Leonesi, F. Marchetti, E. Rivarola, M. Rossi,
V. Tomov, C. Pettinari, J. Organomet. Chem. 519 (1996) 29;
(c) C. Pettinari, F. Marchetti, A. Gregori, A. Cingolani, J.
Tanski, M. Rossi, F. Caruso, Inorg. Chim. Acta 257 (1997) 37;
(d) C. Pettinari, F. Marchetti, A. Cingolani, A. Lorenzotti, E.
Mundorff, M. Rossi, F. Caruso, Inorg. Chim. Acta 262 (1997)
33;
(c) R. Willem, A. Bouhdid, B. Mahieu, L. Ghys, M. Biesemans,
E.R.T. Tiekink, D. de Vos, M. Gielen, J. Organomet. Chem. 531
(1997) 151;
(d) M. Kemmer, H. Dalil, M. Biesemans, J.C. Martins, B.
Mahieu, E. Horn, D. de Vos, E.R.T. Tiekink, R. Willem, M.
Gielen, J. Organomet. Chem. 608 (2000) 63;
(e) C. Pettinari, F. Marchetti, A. Cingolani, D. Leonesi, E.
Mundorff, M. Rossi, F. Caruso, J. Organomet. Chem. 557
(1998) 187;
(f) F. Marchetti, C. Pettinari, M. Rossi, F. Caruso, Main Group
Met. Chem. 21 (1998) 255;
(e) M. Gielen, M. Biesemans, D. de Vos, R. Willem, J. Inorg.
Biochem. 79 (2000) 139.
[6] (a) R. Willem, I. Verbruggen, M. Gielen, M. Biesemans, B.
Mahieu, T.S. Basu Baul, E.R.T. Tiekink, Organometallics 17
(1998) 5758 (and references therein);
(g) C. Pettinari, F. Marchetti, A. Cingolani, A. Gindulyte, L.
Massa, M. Rossi, F. Caruso, Eur. J. Inorg. Chem. (2001) 2171.
[14] F. Caruso, M. Rossi, F. Marchetti, C. Pettinari, Organometallics
18 (1999) 2398.
[15] (a) F. Marchetti, C. Pettinari, A. Cingolani, G. Gioia Lobbia, A.
Cassetta, L. Barba, J. Organomet. Chem. 517 (1996) 141;
(b) F. Marchetti, C. Pettinari, A. Cingolani, L. Brocanelli, M.
Rossi, F. Caruso, J. Organomet. Chem. 580 (1999) 344.
[16] (a) R.C. Mehrotra, R. Bohra, D.P. Gaur, Metal b-Diketonates
and Allied Derivatives, Academic Press, London, 1978 (chap. 2,
and references therein);
(b) M. Kemmer, L. Ghys, M. Gielen, M. Biesemans, J.E.R.T.
Tiekink, R. Willem, J. Organomet. Chem. 582 (2000) 195 (and
references therein);
(c) E.R.T. Tiekink, Trends Organomet. Chem. 1 (1994) 71 (and
references therein);
(d) M. Gielen, A. El Khloufi, M. Biesemans, F. Kayser, R.
Willem, B. Mahieu, D. Maes, J.N. Lisgarten, L. Wyns, A.
Moreira, T.K. Chattopadhay, R.A. Palmer, Organometallics 13
(1994) 2849 (and references therein);
(e) K.C. Molloy, K. Quill, I.W. Nowell, J. Chem. Soc. Dalton
Trans. (1987) 101;
(b) K. Nakamoto, C. Udovich, J. Takemoto, J. Am. Chem. Soc.
92 (1970) 3973 (and references therein).
[17] (a) B.Y.K. Ho, J.J. Zuckermann, Inorg. Chem. 12 (1973) 1552;
(b) R. Okawara, D.E. Webster, E.G. Rochow, J. Am. Chem.
Soc. 82 (1960) 3287;
(f) M. Gielen, H. Dalil, L. Ghys, B. Boduszek, E.R.T. Tiekink,
J.C. Martins, M. Biesemans, R. Willem, Organometallics 17
(1998) 4259 (and references therein).
[7] (a) G.M. Bancroft, B.W. Davies, N.C. Payne, T.K. Sham, J.
Chem. Soc. Dalton Trans. (1975) 973;
(b) C. Cauletti, C. Furlani, M.N. Piancastelli, J. Organomet.
Chem. 149 (1978) 289;
(c) G.K. Sandhu, G. Kaur, J. Holecek, A. Lycka, J. Organomet.
Chem. 345 (1988) 51.

F. Marchetti et al. / Journal of Organometallic Chemistry 645 (2002) 134–145
145
[18] (a) J.R. May, W.R. McWhinnie, R.C. Poller, Spectrochim. Acta
A 27 (1971) 969;
[22] M.F. Mahon, K.C. Molloy, B.A. Omotowa, M.A. Mesubi, J.
Organomet. Chem. 511 (1996) 227.
(b) A.L. Smith, Spectrochim. Acta A 24 (1967) 695;
(c) M.S. Dance, W.R. McWhinnie, R.C. Poller, J. Chem. Soc.
Dalton Trans. (1976) 2349;
[23] (a) A.J. Crowe, Drugs Future 12 (1987) 255;
(b) M. Gielen, Tin-Based Antitumor Drugs, Springer, Berlin,
1990, p. 47 and 209, and references therein;
(d) D.H. Whiffen, J. Chem. Soc. (1956) 1350.
[19] (a) T.P. Lockhart, W.F. Manders, Inorg. Chem 25 (1986) 892;
(b) B. Wrackmeyer, Ann. Rep. NMR Spectrosc. 16 (1985) 73;
(c) W.F. Howard Jr., R.W. Crecely, W.H. Nelson, Inorg. Chem.
24 (1985) 2204.
[20] (a) M. Nadvornik, J. Holecek, K. Handlir, A. Lycka, J.
Organomet. Chem. 275 (1984) 43;
(b) P.J. Smith, R.F.M. White, L. Smith, J. Organomet. Chem. 40
(1972) 341.
[21] J. Holecek, M. Nadvornik, K. Handlir, A. Lycka, J. Organomet.
Chem. 241 (1983) 177.
(c) M. Gielen, Tin as a vital nutrient: implications in cancer
prophylaxis and other physiological processes, in: N.F. Car-
darelli (Ed.), Antitumor Active Organotin Compounds, CRC
Press, Boca Raton, 1986 (chap. 13 and references therein).
[24] M.P. Byrn, C.E. Strouse, J. Am. Chem. Soc. 113 (1991)
2501.
[25] M. Camalli, R. Spagna, J. Appl. Crystallogr. 27 (1994) 861.
[26] D.J. Cruickshank, in: J. Rollet (Ed.), Computing Methods in
Crystallography, Pergamon, Oxford, 1965, pp. 114.
[27] International Tables for X-ray Crystallography, Kynoch, Birm-
ingham, 1974.