Novel cyclometallated complexes derived from a halogenated thiosemicarbazone. Crystal and molecular structures of 2-FC6H 4C(Me)=NN(H)C(=S)NHPh and [(Pd{2-FC6H3C(Me)=NN= C(S)NHPh})2(μ-PPh2(CH2)2PPh 2)]

Article abstract of DOI:10.1002/zaac.200570044

Treatment of the thiosemicarbazone 2-FC₆H₄C(Me)= NN(H)C(=S)NHPh, a, with palladium(II) acetate in acetic acid, or with lithium tetrachloropalladate(II) in methanol, gave the tetranuclear cyclometallated complex [Pd{2-FC₆H₃C(Me)=NN= C(S)NHPh}]₄ (1a). Reaction of 1a with the diphosphines Ph₂P(CH₂) ₂PPh₂ (dppe), Ph₂PCH=CHPPh₂ (trans-dpe) Ph₂P(CH₂)₃Ph₂ (dppp) or Ph₂P(CH₂)₄Ph₂ (dppb) in a 1:2 molar ratio gave the dinuclear cyclometallated complexes [(Pd{2-FC₆H ₃C(Me)=NN=C(S)NHPh})₂(μ-Ph₂P(CH ₂)_nPPh₂)], (n = 2, 2a; 3, 4a; 4, 5a) and [(Pd{2-FC₆H₃C(Me)=NN=C(S)NHPh})₂(μ-Ph ₂PCH=CHPPh₂)], (3a). The X-ray crystal structure of ligand a and of complex 2a are described. The structure of complex 2a shows the palladium atom is bonded to four different donor atoms: C, N, S and P.

Full text of DOI:10.1002/zaac.200570044

Novel Cyclometallated Complexes Derived From a Halogenated
Thiosemicarbazone. Crystal and Molecular Structures of
2-FC6H4C(Me)؍NN(H)C(؍S)NHPh and
[(Pd{2-FC6H3C(Me)؍NN؍C(S)NHPh})2(μ-PPh2(CH2)2PPh2)]
a
a
a
b
a
´
´
´
´
Luis A. Adrio , Adriana Amoedo , Jose M. Antelo , Jesus J. Fernandez , Javier Martınez ,
a
a
a,
´
Juan M. Ortigueira , M. Teresa Pereira , and Jose M. Vila *
a
´
´
Santiago de Compostela/Spain, Departamento de Quımica Inorganica, Universidad de Santiago de Compostela
b
´
A Corun˜a/Spain, Departamento de Quımica Fundamental, Universidad de A Corun˜a
Received December 3rd, 2004; accepted February 16th, 2005.
Abstract. Treatment of the thiosemicarbazone 2-FC6H4C(Me)ϭ
NN(H)C(ϭS)NHPh, a, with palladium(II) acetate in acetic acid,
or with lithium tetrachloropalladate(II) in methanol, gave the tetra-
nuclear cyclometallated complex [Pd{2-FC6H3C(Me)ϭNNϭ
C(S)NHPh}]4 (1a). Reaction of 1a with the diphosphines
2a; 3, 4a; 4, 5a) and [(Pd{2-FC6H3C(Me)ϭNNϭC(S)NHPh})2(μ-
Ph2PCHϭCHPPh2)], (3a). The X-ray crystal structure of ligand a
and of complex 2a are described. The structure of complex 2a
shows the palladium atom is bonded to four different donor atoms:
C, N, S and P.
Ph2P(CH2)2PPh2
(dppe),
Ph2PCHϭCHPPh2
(trans-dpe)
Ph2P(CH2)3Ph2 (dppp) or Ph2P(CH2)4Ph2 (dppb) in a 1:2 molar
ratio gave the dinuclear cyclometallated complexes [(Pd{2-
FC6H3C(Me)ϭNNϭC(S)NHPh})2(μ-Ph2P(CH2)nPPh2)], (n ϭ 2,
Keywords: Cyclometallation; C-H activation; Palladium; Thiosem-
icarbazones
1 Introduction
allated complexes have reported earlier [22], in those cases,
the terdentate ligand, [C, N, N] [23] or [C, N, O] [24] showed
no sulfur donor atoms, and only mononuclear complexes
were isolated.
In the present work we report the novel cyclometallated
compounds derived from a halogenated thiosemicarbazone,
2-FC6H4C(Me)ϭNN(H)C(ϭS)NHPh, which are tetranu-
clear species, and the reactivity of the latter with tertiary
phosphines where the strength of the Pd-Schelating bond al-
lows only cleavage of the Pd-Sbridging bond.
The last two decades have seen a growing interest in cyclo-
metallated palladium(II) complexes [1] in view of their no-
vel and outstanding applications, for instance their use as
intermediates in organic and organometallic synthesis [2],
the design of liquid crystals [3], or their pharmacological
properties [4] which include antiparasital [5], antibacterial
[6], and antitumoral activities [7Ϫ10]. Some thiosemicarba-
zones increase their antitumoral activity upon chelate for-
mation with specific metal ions [11]. These ligands are pro-
duced by the condensation of a thiosemicarbazide and an
aldehyde or ketone, and although they usually coordinate
to the metal through the imine nitrogen and the sulphur
atoms [12, 13], additional coordination sites, pertaining to
the aldehyde and/or ketone, may also be present, enhancing
their coordination capability [14], which is, as well, depen-
dent on the thiol-thione tautomeric equilibrium [15, 16], al-
though the most common coordinate mode is in the anionic
thiolate form [12Ϫ17]. Consequently, a tremendous amount
of transition metal chemistry has been published involving
these ligands, which in some cases show terdentate coordi-
nation [18Ϫ20]. We have studied the tetranuclear ortho-met-
allated complexes with thiosemicarbazones as terdentate [C,
N, S] donors [21], and although other terdentate ortho-met-
2 Experimental Section
General procedures
Solvents were purified by standard methods [25]. Chemicals were
reagent grade. Lithium tetrachloropalladate was prepared in situ by
treatment of palladium(II) chloride with lithium chloride in meth-
anol. Palladium(II) acetate and palladium(II) chloride were pur-
chased from Alfa Products. The phosphines Ph2P(CH2)2PPh2
(dppe), and trans- Ph2PCHϭCHPPh2 (t-dpe), Ph2P(CH2)3PPh2
(dppp) and Ph2P(CH2)4PPh2 (dppb) were purchased from Aldrich-
´
Chemie. Microanalyses were carried out at the Servicio de Analisis
Elemental at the Universidad of Santiago de Compostela using a
Carlo Erba Elemental Analyzer Model EA1108. IR spectra were
recorded as Nujol mulls or KBr discs with a Perkin-Elmer 1330,
with a IR-FT Mattson Model Cygnus-100 and with a Bruker
Model IFS-66V spectrophotometers. NMR spectra were obtained
as CDCl3 solutions and referenced to SiMe4 (1H) or H3PO4 (31P-
{1H}) and were recorded with Bruker AMX 300, AMX 500 and
WM250 spectrometers. All chemical shifts are reported downfield
from standards. The FAB mass spectra were recorded with a Fisons
Quatro mass spectrometer with a Cs ion gun; 3-nitrobenzyl alcohol
was used as the matrix.
´
* Jose M. Vila
´
´
Departamento de Quımica Inorganica
Universidad
E-15782 Santiago de Compostela/Spain
Fax: ϩ34/981-595012
E-mail: qideport@usc.es
2204
© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim
DOI: 10.1002/zaac.200570044
Z. Anorg. Allg. Chem. 2005, 631, 2204Ϫ2209

Cyclometallated Complexes Derived From a Halogenated Thiosemicarbazone
8.3 Hz, 4JH4F ϭ 5.5 Hz), 6.19 (m, 1 H, H5), 2.65 (d, 3 H, CH3CϭN, 5JHF
ϭ
Syntheses
4.2 Hz). 31P-{1H} NMR (CDCl3): δ ϭ 32.3 (s).
Preparation of 2-FC6H4C(Me)؍NN(H)C(؍S)NHPh (a): 2Ј-
Fluoroacetophenone (82.6 mg, 5.98 mmol) and hydrochloric acid
(35 %, 0.65 mL) were added to a suspension of 4-phenyl-3-thiosem-
icarbazide (100 mg, 5.98 mmol) in water (25 mL) to give a clear
solution, which was stirred at room temperature for 4 h. The white
solid that precipitated was filtered off, washed with cold water, and
dried in air. Yield: 158 mg, 92 %. Anal. found: C 62.5; H 4.9; N
14.7; S 11.4; C15H14N3SF (287.4 g/mol) requires C 62.7; H 4.9; N
14.6; S 11.2 %.
[(Pd{2-FC6H3C(Me)؍NN؍C(S)NHPh})2(μ-Ph2P(CH2)3PPh2)]
(4a). Yield: 48.6 mg, 64 %. Anal. found: C 57.4; H 4.4; N 6.7; S
5.3; C57H50N6S2P2Pd2F2 (1196.0 g/mol) requires C 57.2; H 4.2; N
7.0; S 5.4 %.
IR (cmϪ1): ν(N-H) 3420s; ν(CϭN) 1584m. 1H NMR (CDCl3): δ ϭ 7.42 (d,
3
2 H, H2Ј, H6Ј, JHH ϭ 7.9 Hz), H3Ј, H5Ј (signals hidden by the phosphane
3
resonances), 6.90 (t, 1 H, H4Ј, JHH ϭ 7.4 Hz), 6.68 (s, 1 H, NHPh), 6.46
(m, 2 H, H3, H4), 6.08 (m, 1 H, H5), 2.55 (d, 3 H, CH3CϭN, 5JHF ϭ 4.2 Hz),
2.42 (br, 2 H, PCH2CH2CH2P), 2.01 (br, 1 H, PCH2CH2CH2P). 31P-{1H}
NMR (CDCl3): δ ϭ 26.9 (s).
IR (cmϪ1): ν(N-H) 3301m, 3232w; ν(CϭN) 1616w; ν(CϭS) 833w. 1H NMR
(CDCl3): δ ϭ 9.38 (s, 1 H, NH), 8.80 (s, 1 H, NHPh), 7.67 (d, 2 H, H2Ј,
[(Pd{2-FC6H3C(Me)؍NN؍C(S)NHPh})2(μ-Ph2P(CH2)4PPh2)]
(5a). Yield: 50.0 mg, 65 %. Anal. found: C 57.3; H 4.5; N 6.6; S
5.2; C58H52N6S2P2Pd2F2 (1210.0 g/mol) requires C 57.6; H 4.3; N
6.9; S 5.3 %.
3
3
4
H6Ј, JHH ϭ 7.9 Hz), 7.56 (td, 1 H, H6, JH6H5 ϭ 7.9 Hz, JH6F ϭ 7.9,
4JH6H4 ϭ 1.9 Hz), 7.39 (m, 3 H, H3Ј, H5Ј, H4), 7.23 (t, 1 H, H4Ј, JHH
7.4 Hz), 7.20 (td, 1 H, H5, JH5H4 ϭ 7.9 Hz, JH5H6 ϭ 7.9 Hz, JH5H3
ϭ
ϭ
ϭ
3
3
3
4
3
3
4
0.9 Hz), 7.14 (ddd, 1 H, H3, JH53F ϭ 11.1 Hz, JH3H4 ϭ 8.3 Hz, JH3H5
IR (cmϪ1): ν(N-H) 3402m; ν(CϭN) 1584m. 1H NMR (CDCl3): δ ϭ 7.48 (d,
0.9 Hz), 2.36 (d, 3 H, CH3CϭN, JHF ϭ 2.8 Hz). FAB-MS: m/z 288 [MH]ϩ.
3
2 H, H2Ј, H6Ј, 3JHH ϭ 7.4 Hz), 7.27 (t, 2 H, H3Ј, H5Ј, JHH ϭ 7.4 Hz), 6.97
3
(t, 1 H, H4Ј, JHH ϭ 7.4 Hz), 6.71 (s, 1 H, NHPh), 6.54 (m, 2 H, H3, H4),
Preparation of [Pd{2-FC6H3C(Me)؍NN؍C(S)NHPh}]4 (1a).
Method 1: Ligand a (269 mg, 0.94 mmol, 5 % excess) and pal-
ladium(II) acetate (200 mg, 0.89 mmol) were added to glacial acetic
acid (45 mL) to give a clear solution, which was heated to 60 °C
under nitrogen for 24 h. After this had cooled to room temperature,
the yellow precipitate was filtered off, washed with ethanol, and
dried. Yield: 231 mg, 66 %. Anal. found: C 45.9; H 3.1; N 10.8; S
8.3; C60H48N12S4Pd4F4 (1567.0 g/mol) requires C 46.0; H 3.1; N
10.7; S 8.2 %.
5
6.18 (m, 1 H, H5), 2.65 (d, 3 H, CH3CϭN, JHF ϭ 4.2 Hz), 2.34 (br, 2 H,
PCH2CH2CH2CH2P), 1.82 (br, 2 H, PCH2CH2CH2CH2P). 31P-{1H} NMR
(CDCl3): δ ϭ 28.7 (s).
Crystal structures
Crystals of ligand a and complex 2a·2CHCl3 were mounted on a
glass fiber and transferred to the diffractometer.
IR (cmϪ1): ν(N-H) 3407m, ν(CϭN) 1586s. 1H NMR (CDCl3): δ ϭ 7.50 (d,
For a room temperature X-ray data was collected on a MACH3
Enraf Nonius diffractometer using graphite monochromated Cu-
Kα radiation by the omega/2-theta method.
3
2 H, H2Ј, H6Ј, JHH ϭ 7.9 Hz), 7.33 (t, 2 H, H3Ј, H5Ј, 3JHH ϭ 7.9 Hz), 7.18
3
3
(d, 1 H, H5, JH5H4 ϭ 6.9 Hz), 7.06 (t, 1 H, H4Ј, JHH ϭ 7.4 Hz), 6.89 (s,
1 H, NHPh), 6.84 (td, 1 H, H4, 3JH4H3 ϭ 8.3 Hz, 4JH4F ϭ 5.1 Hz), 6.71 (ddd,
1 H, H3, JH3F ϭ 12.0 Hz, 3JH3H4 ϭ 8.3 Hz, 4JH3H5 ϭ 0.9 Hz), 2.09 (d, 3 H,
3
Three dimensional, room temperature X-ray data was collected
with Siemens (2a) by the omega scan method, using monochrom-
ated Mo-Kα radiation.
CH3CϭN, JHF ϭ 3.7 Hz). FAB-MS: m/z 1567 [M]ϩ.
5
Method 2: Ligand a (340 mg, 1.18 mmol, 5 % excess) and sodium
acetate (185 mg, 2.26 mmol) were added to a stirred solution of
palladium(II) chloride (200 mg, 1.13 mmol) and lithium chloride
(96 mg, 2.26 mmol) in methanol (40 mL). The mixture was stirred
for 48 h at room temperature under nitrogen. The yellow precipitate
was filtered off, washed with methanol, and dried. Yield: 402 mg,
91 %.
All the measured reflections were corrected for Lorentz and polar-
ization effects and for absorption by semiempirical methods based
on symmetry-equivalent and repeated reflections [Tmax/Tmin
ϭ
0.8112/0.5898 (a), and 1.0000/0.7925 (2a)]. The structures were
solved by direct methods and refined by full matrix least squares
on F2. Hydrogen atoms were included in calculated positions and
refined in riding mode. Refinement converged at a final R ϭ 0.0524
(a) and 0.0411 (2a) (observed data, F), and wR2 ϭ 0.1585 (a) and
0.1200 (2a) (all unique data, F2), with allowance for thermal aniso-
tropy of all non-hidrogen atoms. Minimum and maximum final
electron densities: Ϫ0.414 and 0.384 (a), Ϫ0.987 and 0.926 (2a).
The structure solutions and refinements were carried out with the
SHELX-97 [26] program package.
Preparation
of
[(Pd{2-FC6H3C(Me)؍NN؍C(S)NHPh})2(μ-
Ph2P(CH2)2PPh2)] (2a). The diphosphine Ph2P(CH2)2PPh2 (26 mg,
0.065 mmol) was added to a suspension of complex 1a (50 mg,
0.032 mmol) in acetone (15 mL). The mixture was stirred for 4 h
and the resulting yellow solid was filtered off and dried. Yield:
30.4 mg, 40 %. Anal. found: C 56.9; H 4.2; N 6.8; S 5.2;
C56H48N6S2P2Pd2F2 (1181.9 g/mol) requires C 56.9; H 4.1; N 7.1;
S 5.4 %.
Crystallographic data (excluding structure factors) for the struc-
tures reported in this paper have been deposited with the Cam-
bridge Crystallographic Data Centre as supplementary publication
no. 257436 (a) and no. 257437 (2a). Copies of the data can be
obtained free of charge on application to The Director, CCDC, 12
Union Road, Cambridge CB2 1EZ, UK.
IR (cmϪ1): ν(N-H) 3423m; ν(CϭN) 1585m. 1H NMR (CDCl3): δ ϭ 7.50 (d,
2 H, H2Ј, H6Ј, 3JHH ϭ 7.9 Hz), 7.41 (t, 2 H, H3Ј, H5Ј, 3JHH ϭ 7.4 Hz), 6.99
3
(t, 1 H, H4Ј, JHH ϭ 7.4 Hz), 6.66 (s, 1 H, NHPh), 6.55 (m, 2 H, H3, H4),
6.13 (m, 1 H, H5), 2.87 (br, 2 H, P(CH2)2P), 2.67 (d, 3 H, CH3CϭN, 5
4.6 Hz). 31P-{1H} NMR (CDCl3): δ ϭ 31.6 (s).
JHF ϭ
Compounds 3a-5a were obtained following a similar procedure and
obtained as yellow solids.
3 Results and Discussion
[(Pd{2-FC6H3C(Me)؍NN؍C(S)NHPh})2(μ-Ph2PCH؍CHPPh2)]
(3a). Yield: 44.7 mg, 59 %. Anal. found: C 56.8; H 3.8; N 6.9; S
5.2; C56H46N6S2P2Pd2F2 (1179.9 g/mol) requires C 57.0; H 3.9; N
7.1; S 5.4 %.
IR (cmϪ1): ν(N-H) 3412m; ν(CϭN) 1583m. 1H NMR (CDCl3): δ ϭ H2Ј,
H6Ј (signals hidden by the phosphane resonances), 7.26 (t, 2 H, H3Ј, H5Ј,
3JHH ϭ 7.4 Hz), 6.97 (t, 1 H, H4Ј, 3JHH ϭ 7.4 Hz), 6.62 (s, 1 H, NHPh), 6.51
(dd, 1 H, H3, 3JH3F ϭ 12.0 Hz, 3JH3H4 ϭ 8.3 Hz), 6.40 (td, 1 H, H4, 3JH4H3 ϭ
Ligand a was prepared by reaction of 4-phenythiosemicar-
bazide with 2Ј-fluoroacetophenone (see Experimental sec-
tion). The bands at 3301 and 3232 cmϪ1 were due to ν(N-
H) of the NH2 and NH groups, respectively, the latter dis-
appears in the spectra of the complexes [27]. The NH2 pro-
tons gave rise to two characteristic broad resonances in the
Z. Anorg. Allg. Chem. 2005, 631, 2204Ϫ2209
zaac.wiley-vch.de
© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim
2205

´
´
L. A. Adrio, A. Amoedo, J. M. Antelo, J. J. Fernandez, J. Martınez, J. M. Ortigueira, M. T. Pereira, J. M. Vila
Scheme 1 (i) Pd(AcO)2 / AcOH or LiCl ϩ PdCl2 / MeOH; (ii) Ph2P(CH2)2PPh2 / acetone (1:2); (iii) Ph2PCHϭCHPPh2 / acetone (1:2); (iv)
Ph2P(CH2)3PPh2 / acetone (1:2); (v) Ph2P(CH2)4PPh2 / acetone (1:2).
1H NMR spectra which were attributed to the restricted
rotation of the NH2 group about the C(ϭS)NH2 bond axis.
The NH proton showed a broad signal at δ8.80. The new
cyclometallated complexes obtained from a are shown in
Scheme 1.
bond in the structures of 2a (vide infra).The absence of the
signal for the NH group in the H NMR spectra reveals
deprotonation as observed in coordination compounds of
these ligands [31, 32].
1
Preparative details, characterizing microanalytical, mass
Reactivity of the complexes
1
spectra, IR and H and 31P-{1H} data are in the Exper-
imental section. Treatment of a with palladium(II) acetate
in glacial acetic acid a gave clear solution from which
[Pd{2-FC6H3C(Me)ϭNNϭC(S)NHPh}]4 (1a), was iso-
lated as a yellow air-stable solid, with the ligand in the E,Z
configuration. Alternatively, compound 1a could be ob-
tained by reaction of ligand a with lithium tetrachloropall-
ate in methanol. The product was characterized by elemen-
tal analysis (C, H, N and S) and the mass spectrum (FAB)
showed a peak at m/z 1567 for the molecular ion whose
isotopic composition suggests a tetranuclear complex of
formula C60H48N12S4Pd4F4. The position of the NH2 bands
in the spectra of the complexes shows this group is un-coor-
dinated to the palladium atom. The ν(CϭN) band was
shifted to lower wavenumbers upon complex formation [28],
a trend that is opposed to the one observed in other thiose-
micarbazone complexes where the shift is towards higher
wavenumbers [27]. We suggest this should be attributed to
the CϭN moiety being part of a five-membered metalacy-
cle, as has been found by us and others [29, 30]. The ν(Cϭ
S) band disappears in the complexes, in accordance with
loss of the double bond character upon deprotonation of
the NH group; this is shown in the lengthening of the C-S
The reaction of the complexes 1a with nucleophiles such as
amines, thallium(I) acetylacetonate, thallium(I) cyclopen-
tadienyl or tertiary phosphines is difficult when compared
to the analogous palladium(II) semicarbazone compounds;
this is due to thepresence of the stronger Pd-S bond as com-
pared to the Pd-O bond in terms of Pearson’s concept [33],
and to the tetranuclear nature of the Pd4 cluster. Only in
the case of tertiary phosphines was the reaction successful
as we report here. Thus, treatment of 1a with tertiary di-
phosphines gave dinuclear species, where only the bond at
palladium to the Sbridging atom was cleaved. The Pd-Schelating
bond of the tridentate thiosemicarbazone ligands remains,
even when a large excess of diphosphine was used; further-
more, the chelate effect of the bidentate phosphine did not
promote Pd-Schelating bond cleavage. This behavior is in
contrast with that shown by semicarbazone ligands, in re-
lated cyclometalated palladium(II) complexes, where the
Pd-O bond was easily cleaved by the phosphine [34]. Some
examples are given here with Ph2P(CH2)nPPh2 (n ϭ 2,
dppe; n ϭ 3, dppp; n ϭ 4dppb) and Ph2PCHϭCHPPh2
(trans-dppe). Thus, when 1a and 1b were treated with the
corresponding phosphine in 1:2 molar ratio, the com-
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Z. Anorg. Allg. Chem. 2005, 631, 2204Ϫ2209

Cyclometallated Complexes Derived From a Halogenated Thiosemicarbazone
Figure 1 Molecular structure of ligand a with labelling scheme.
C(1)-C(7) 1.485(3), C(7)-N(1) 1.278(3), N(1)-N(2) 1.382(3), N(2)-C(8)
1.355(3), C(8)-S(1) 1.674(2), C(8)-N(3) 1.345(3), N(3)-C(9) 1.421(3), C(1)-
C(7)-N(1) 113.9(2), C(7)-N(1)-N(2) 119.0(2), N(2)-C(8)-N(3) 114.4(2), C(8)-
N(3)-C(9) 127.6(2).
pounds
Ph2P(CH2)2PPh2)]
C(S)NHPh})2(μ-Ph2PCHϭCHPPh2)]
FC6H3C(Me)ϭNNϭC(S)-NHPh})2(μ-Ph2P(CH2)3PPh2)]
(4a), [(Pd{2-FC6H3C(Me)ϭNNϭC(S)NHPh})2(μ-
[(Pd{2-FC6H3C(Me)ϭNNϭC(S)NHPh})2(μ-
(2a), [(Pd{2-FC6H3C(Me)ϭNNϭ
(3a), [(Pd{2-
Figure 2 Hydrogen bonding in ligand a.
Ph2P(CH2)3PPh2)] (5b), were obtained as pure air-stable
solids, which were fully characterised (see Experimental).
The 1H NMR spectra showed the H5 resonance was shifted
to lower frequency by ca. 1 ppm, appearing as a multiplet
due to additional coupling to the 31P nucleus. The 31P res-
onance was a singlet signal in accordance with centrosym-
metric compounds [35]; the chemical shift values are in
agreement with a phosphorus trans to nitrogen [36Ϫ39].
Crystal Structure of
2-FC6H4C(Me)؍NN(H)C(؍S)NHPh
¯
Ligand a crystallizes in the monoclinic P1 space group as
the E-isomer with respect to the N(1)-C(7) bond and Z with
respect to the N(8)-C(3) bond, Figure 1.
Figure 3 Molecular structure of complex 2a with labelling scheme.
Ellipsoids drawn at 30 %. Hydrogen atoms and solvent have been
omitted for clarity.
This arrangement is often found in thiosemicarbazones
with at least one hydrogen attached to N(3) [40, 41] due
to weak N(3)-H(3)...N(1) hydrogen bonding. The C(8)-S(1)
˚
bond distance, 1.674(2) A,the N(1)-C(7) distance,
˚
1.278(3) A, are consistent with a formal double bond
˚
˚
˚
2.91 A, C(15)#1-H(15C)#1···S(1) 118.7°, S(1)···N(2)#1 3.684(2) A,
character. Furthermore, the C(8)-N(3) distance, 1.345(3) A,
˚
H(2)#1···S(1) 2.83 A, N(2)#1-H(2)#1···S(1) 169.8°, C(15)···S(1)#
3.470(3) A, H(15C)···S(1)#1 2.91 A, C(15)-H(15)···S(1)#1 118.7°,
with the symmetry operation #1[Ϫxϩ2, Ϫy, Ϫzϩ2].
is also consistent with partial double bond character. The
C(1)-C(7)-N(1) 113.9(2)° and C(7)-N(1)-N(2) 119.0(2)°, are
in agreement with sp2 hybridization of the carbon and ni-
trogen atoms of the CϭN moiety. The thioamide chain
C(7)-N(1)-N(2)-C(8)-S(1)-N(3) is planar (rms ϭ 0.0384)
and at an angle of 37.06° with the fluorinated phenyl ring
(rms ϭ 0.0016). The parameters for the hydrogen bonding
interaction in ligand a, which may be seen in Figure 2, are
as follows:
˚
˚
Crystal Structure of [(Pd{2-FC6H3C(Me)؍NN؍
C(S)NHPh})2(μ-Ph2P(CH2)2P-Ph2)]
Suitable crystals were grown by slowly evaporating a
chloroform/n-hexane solution of the complex. The labeling
scheme for the compound is shown in Figure 3.
The crystals consist of discrete molecules, separated by
normal van der Waals distances. Crystallographic data and
˚
˚
N(3)···N(1) 2.564(3) A, H(3)···N(1) 2.13 A, N(3)-H(3)···N(1)
˚
˚
˚
110.8 A, N(2)···S(1)#1 3.684 A, H(2)···S(1)# 2.83 A, N(2)-
H(2)···S(1)#1 169.8°; S(1)···C(15)#1 3.470(3) A, H(15)#1···S(1)
˚
Z. Anorg. Allg. Chem. 2005, 631, 2204Ϫ2209
zaac.wiley-vch.de
© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim
2207

´
´
L. A. Adrio, A. Amoedo, J. M. Antelo, J. J. Fernandez, J. Martınez, J. M. Ortigueira, M. T. Pereira, J. M. Vila
Table 1 Crystallographic data for complexes a and 2a.
ence of the phosphorus donor ligand, which is reflected in
˚
the Pd(1)-N(1) distance of 2.024(3) A (cf. sum of the coval-
a
2a
˚
ent radii for palladium and nitrogen, 2.01 A [40]). The
˚
Pd(1)-C(6) bond length [2.0324 A] is shorter than the ex-
Empirical formula
Formula mass
T /K
C15 H14 F N3
287.35
S
C58 H50 Cl6 F2 N6 P2 Pd2 S2
˚
1420.60
293(2)
pected value of 2.081 A [40]; partial multiple-bond charac-
293(2)
ter has been invoked as reasoning [41,42]. The S(1)-C(8)
˚
˚
˚
λ /A
1.54184 A
1.54184 A
˚
bond length, 1.7704(11) A, and the N(2)-C(8) length,
Crystal system
Space group
triclinic
P1
triclinic
P1
¯
¯
˚
1.294(3) A, are consistent with increased single and double
˚
a /A
6.1685(12)
10.8190(11)
11.2038(8)
99.954(9)
91.746(11)
98.229(7)
727.70(17)
2
9.8353(2)
12.7847(3)
12.9406(3)
111.1160(10)
97.8950(10)
96.2960(10)
1481.05(6)
1
bond character, respectively, in the deprotonated form. The
palladium coordination plane [Pd(1), N(1), S(1), C(6),
P(1)), plane 1] is coplanar with the metalacycle [Pd(1), C(1),
C(6), C(7), N(1), plane 2], and with the coordination ring
[Pd(1), N(1), N(2), C(8), S(1), plane 3] (angles between
planes: 1/2 ϭ 1.35, 1/3ϭ 3.64°). Furthermore, the metalacy-
cle [Pd(1), C(1), C(6), C(7), N(1), plane 2], is also co-planar
with the coordination ring [Pd(1), N(1), N(2), C(8), S(1),
plane 3] and with the metallated phenyl ring [C(1), C(2),
C(3), C(4), C(5), C(6), plane 4] (angles between planes: 2/
3 ϭ 2.34, 2/4 ϭ 3.65°).
˚
b /A
˚
c /A
Ͱ /°
β /°
γ /°
3
˚
V /A
Z
μ /mmϪ1
2.019
1.053
max., min. transmissions 0.8112, 0.5898
0.9492, 0.7788
1.593
ρcalc. /gcmϪ3
1.311
θ range /°
reflections collected
independent reflections
4.01 to 74.79
3124
2959
1.57 to 23.34
10158
7014
[R(int) ϭ 0.0267] [R(int) ϭ 0.1169]
R1 [I>2σ(I)]
R1 [all data]
wR2
0.0524
0.0958
0.1379
0.1585
0.0411
0.1095
0.0532
0.1186
Acknowledgments. We thank the DGESIC (Ministerio de Ciencia y
´
Tecnologıa) Proyecto BQU2002-04533-C02-01 and the Xunta de
wR2 [all data]
Galicia, incentive PGIDIT03PXIC20912PN, for financial support.
J. Martinez acknowledges a fellowship from the Ministerio de Cien-
o
´
cia y Tecnologıa (Grant n PB98-0638-C02-01/02).
˚
Table 2 Selected bond lengths/A and angles/° for complex 2a.
References
Pd(1)-N(1)
Pd(1)-S(1)
Pd(1)-P(1)
Pd(1)-C(6)
N(1)-C(7)
C(7)-C(1)
C(1)-C(6)
N(1)-N(2)
N(2)-C(8)
C(8)-S(1)
N(1)-Pd(1)-S(1)
N(1)-Pd(1)-C(6)
2.024(3)
2.3333(9)
2.2663(8)
2.0324
1.293(3)
1.4650
N(1)-Pd(1)-S(1)
N(1)-Pd(1)-C(6)
S(1)-Pd(1)-P(1)
P(1)-Pd(1)-C(6)
N(1)-Pd(1)-P(1)
S(1)-Pd(1)-C(6)
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C(1)-C(6)-Pd(1)
82.88(8)
80.55(8)
99.24(3)
97.34(3)
176.18(8)
163.42(3)
111.74(4)
118.46(17)
113.34(12)
116.6
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2209