Synthesis and characterization of chalcogenolato-bridged allyl palladium complexes: Versatile precursors for palladium chalcogenides

Article abstract of DOI:10.1021/om8000795

The complexes [Pd(μ-ER)(η³-allyl)]₂ (ER = EMes; E = S, Se; allyl = C₃H₅, C₄H₇) have been isolated by the reaction of [Pb(ER)₂]_n with [Pd₂(μ-Cl)₂(η³-allyl)₂]. Similar reactions with [Pb(SeCH₂CH₂NMe₂) ₂]_n resulted in the formation of a trinuclear complex [Pd₃Cl₂(κ²-Se,N-SeCH₂CH ₂NMe₂)(η³-allyl)₃]. Treatment of [Pd(μ-SR)(η³-C₄H₇)]₂ with [Pd(SMes)₂]_n in 1:1 ratio yielded [Pd₃(μ- SMes)₄(η³-C₄H₇)2]. These complexes were characterized by elemental analyses and mass, UV-vis, and NMR spectroscopy. The structures of [Pd₂(μ-EMes)₂(η ³-C₄H₇)₂] (E = S, Se) were established by single-crystal X-ray diffraction analysis, which revealed a syn configuration. Two new structural motifs for [Pd₃Cl ₂(κ²-Se,N-SeCH₂CH₂NMe ₂)(η³-C₃H₅)₃] and [Pd₃(μ-SMes)₄(η³-C₄H ₇)₂] have also been identified. Pyrolysis of [Pd(μ-ER)(η³-C₄H₇)]₂ yielded palladium chalcogenides, which were characterized by powder XRD and EDAX.

Full text of DOI:10.1021/om8000795

Organometallics 2008, 27, 3297–3302
3297
Synthesis and Characterization of Chalcogenolato-Bridged Allyl
Palladium Complexes: Versatile Precursors for Palladium
Chalcogenides
Ninad Ghavale, Sandip Dey,* Amey Wadawale, and Vimal K. Jain*
Chemistry DiVision, Bhabha Atomic Research Centre, Mumbai-400085, India
ReceiVed January 29, 2008
The complexes [Pd(µ-ER)(η3-allyl)]2 (ER ) EMes; E ) S, Se; allyl ) C3H5, C4H7) have been isolated
by the reaction of [Pb(ER)2]n with [Pd2(µ-Cl)2(η3-allyl)2]. Similar reactions with [Pb(SeCH2CH2NMe2)2]n
resulted in the formation of a trinuclear complex [Pd3Cl2(κ2-Se,N-SeCH2CH2NMe2)(η3-allyl)3]. Treatment
of [Pd(µ-SR)(η3-C4H7)]2 with [Pd(SMes)2]n in 1:1 ratio yielded [Pd3(µ-SMes)4(η3-C4H7)2]. These complexes
were characterized by elemental analyses and mass, UV-vis, and NMR spectroscopy. The structures of
[Pd2(µ-EMes)2(η3-C4H7)2] (E ) S, Se) were established by single-crystal X-ray diffraction analysis, which
revealed a syn configuration. Two new structural motifs for [Pd3Cl2(κ2-Se,N-SeCH2CH2NMe2)(η3-C3H5)3]
and [Pd3(µ-SMes)4(η3-C4H7)2] have also been identified. Pyrolysis of [Pd(µ-ER)(η3-C4H7)]2 yielded
palladium chalcogenides, which were characterized by powder XRD and EDAX.
semiconducting materials (e.g., PdS: Eg ) ∼2.0 eV).12 The
utility of palladium sulfides has been demonstrated in a wide
range of catalytic reactions13–15 such as dehydrosulfurization
of thiophenes13 and dehydrogenation.14 Besides the reactions
of palladium salts with H2S or Na2S for the preparation of
PdS,16,17 classical complexes [Pd(S2COPri)2]18 and [Pd(S2CN-
MeHex)2]19 have been used for the deposition of thin films of
PdS. The allylpalladium complexes [Pd2(µ-SR)2(η3-C4H7)2]4 and
[Pd(η3-C3H5)(S2CNMeHex)],11 in contrast, yield palladium-rich
sulfides, Pd4S and Pd2.8S, respectively. The allyl thiolate
complexes are formed by the reactions of [Pd2(µ-Cl)2(η3-allyl)2]
with the alkali metal thiolate salts. Thus, the reactions of [Pd2(µ-
Cl)2(η3-allyl)2] with 1,1-dithiolates give [Pd(η3-allyl)(SkS]
complexes,1 while with simple thiols binuclear derivatives are
formed.4 Studies of heavier chalcogenolate complexes are rather
scanty.4 In the above perspective the present investigation on
allylpalladium complexes containing both bulkier and internally
functionalized chalcogenolate ligands has been undertaken.
Introduction
The chemistry of η3-allylpalladium complexes has been a
subject area of extensive research for the past several decades.1
There are several obvious reasons for this sustained interest.
These include their diverse reactivity and utility in palladium-
catalyzed organic transformations2,3 and more recently in
materials science.4 The allylpalladium complexes are usually
isolated as mono- and binuclear derivatives with a few examples
of tri-5 and high-nuclearity complexes.6
The lability of the allyl group has made these complexes,
such as [Pd(η3-allyl)2] (allyl ) C3H5 or C4H7),7 [Pd(Cp)(η3-
C3H5)2],7 [Pd(η3-allyl)(ꢀ-diketonate)],8 and [Pd(η3-allyl)(ꢀ-
ketoiminato)],9 attractive precursors for deposition of high-
quality palladium films under mild conditions. Similarly the
binuclear complex [Pd2(µ-Cl)2(η3-C3H5)2] has been used for the
preparation of palladium nanoparticles.10 The lability of the allyl
group has also led to the development of single-source precur-
sors for palladium sulfides.4,11
Palladium forms a range of palladium chalcogenides differing
in stoichiometry and structures, and several of them are
Results and Discussion
Synthesis and Spectroscopy. Reactions of chloro-bridged
allylpalladium complexes with lead salts of organochalcogeno-
late ligands gave bi- and trinuclear chalcogenolato-bridged
allylpalladium complexes (Scheme 1). With mesityl chalco-
genolate, binuclear complexes [Pd2(µ-EMes)2(η3-allyl)2] (1-4)
are formed as yellow-orange crystalline solids, whereas with
internally functionalized chalcogenolate ligand, Me2NCH2CH2-
Se-, trinuclear complexes [Pd3Cl2(κ2-Se,N-SeCH2CH2NMe2)(η3-
allyl)3] (6, 7) are isolated, in which selenolate selenium atom
* Corresponding authors. E-mail: dsandip@barc.gov.in.
(1) Jain, V. K.; Jain, L. Coord. Chem. ReV. 2005, 249, 3075.
(2) Trost, B. M.; Van Vranken, D. L. Chem. ReV. 1996, 96, 395.
(3) Tsuji, J. Palladium Reagents and Catalysts, New PerspectiVe for
the 21st Century; Wiley: Chichester, 2004.
(4) Singhal, A.; Jain, V. K.; Mishra, R.; Varghese, B. J. Mater. Chem.
2000, 10, 1121.
(5) (a) Bailey, P. M.; Kelley, E. A.; Maitlis, P. M. J. Organomet. Chem.
1977, 144, C 52. (b) Ukhin, L. Y.; Dolgopolova, N. A.; Kuzmina, L. G.;
Struchkov, Y. T. J. Organomet. Chem. 1981, 210, 263.
(6) Fenske, D.; Hollnagel, A.; Merzweiler, K. Z. Naturforsch. 1988, B
43, 634.
(12) Dey, S.; Jain, V. K. Platinum Met. ReV. 2004, 48, 16.
(13) Mashkina, A. V.; Sakhaltueva, L. G. Kinet. Catal. 2002, 43, 107.
(14) Shalimova, L. V.; Berents, A. D.; Popov, S. V.; Chebaeva, O. V.
Kinet. Catal. 1991, 32, 45.
(7) Zinn, A. A.; Braudt, L.; Kaesz, H. D.; Hicks, R. F. The Chemistry
of Metal CVD; Kodas, T. T., Smith, H. M. J., Eds.; VCH: Weinheim,
Germany, 1994.
(8) Zhang, Y.; Yuan, Z.; Puddephatt, R. J. Chem. Mater. 1998, 10, 2293.
(9) Tung, Y. L.; Tseng, W. C.; Lee, C. Y.; Hsu, P. F.; Chi, Y.; Peng,
S. M.; Lee, G. H. Organometallics 1999, 18, 864.
(15) Misono, M.; Nojiri, N. Appl. Catal. 1990, 64, 1.
(16) Yamamoto, T.; Taniguchi, A.; Dev, S.; Kubota, E.; Osakada, K.;
Kubota, K. Colloid Polym. Sci. 1991, 269, 969.
(10) Ramirez, E.; Jansat, S.; Philipot, K.; Lecante, P.; Gomez, M.;
Masdeu-Bulto´, A. M.; Chaudret, B. J. Organomet. Chem. 2004, 689, 4601.
(11) Birri, A.; Harvey, B.; Hogarth, G.; Subasi, E.; Ug˘ur, F. J.
Organomet. Chem. 2007, 692, 2448.
(17) Schultz, M.; Matijevic´, E. Colloids Surf. A 1998, 131, 173.
(18) Cheon, J.; Talaga, D. S.; Zink, J. I. Chem. Mater. 1997, 9, 1208.
(19) Malik, M. A.; O’Brien, P.; Revaprasadu, N. J. Mater. Chem. 2002,
12, 92.
10.1021/om8000795 CCC: $40.75
2008 American Chemical Society
Publication on Web 06/10/2008

3298 Organometallics, Vol. 27, No. 13, 2008
GhaVale et al.
Scheme 1
Scheme 2
ppm) for the central carbon proton, and two doublets (δ 2.68,
2.84, each 11 Hz) for anti protons of the allyl group at room
temperature.
The 1H NMR spectrum of [Pd3Cl2(κ2-Se,N-SeCH2CH2NMe2)-
(η3-C3H5)3] (6) displayed broad resonances at room temperature,
indicating fluxional behavior of the molecule. The spectrum at
-40 ꢁC however showed separate resonances for the allyl
groups and selenolate ligand. Due to the complexity of the
ꢁ
spectrum, a 2D COSY experiment at -40 C was performed
(Supporting Information S3), and various assignments [2.78,
2.82 (each s, NMe2); 2.90 (m, SeCH2); 3.35 (m, NCH2)
(selenolate ligand); 2.45 (m, anti); 3.45 (br, syn); 5.22 (br, central
CH) (chelated Pd1 allyl); 4.12 (syn); 3.00 (anti) (Pd2 allyl);
4.42 (syn); 3.05 (anti) (Pd3 allyl); 5.35 (central CH) (nonchelated
Pd2 and Pd3 allyls)] were made by establishing correlations.
X-ray Structures. Solid-state structures of [Pd2(µ-EMes)2(η3-
C4H7)2] (E ) S (3); Se (4)), [Pd3(µ-SMes)4(η3-C4H7)2] (5), and
[Pd3Cl2(κ2-Se,N-SeCH2CH2NMe2)2(η3-C3H5)3] (6) were estab-
lished by single-crystal X-ray diffraction analyses. Complexes
4 and 5 crystallized out with a benzene and three water
molecules, respectively. In the latter O1 and O1′ have half-
occupancy in the molecule. The ORTEP plots with atomic
numbering schemes are shown in Figures 1–4, and selected bond
lengths and angles are given in Tables 1–3.22
The molecular structures of 3 and 4 are isomorphous. The
dimeric molecules have two distorted square-planar palladium
atoms bridged together by two EMes groups, forming a
nonplanar four-membered Pd2E2 ring. The sterically crowded
mesityl and 2-methylallyl groups are all mutually syn, and the
former are oriented in an endo-cyclic configuration. The point
group of the molecule is C2V; the C2 axis passes through the
mid point of the nonplanar Pd2E2 ring. Both of the phenyl rings
of the mesityl group lie on one σv plane. The Se(1) · · · Se(2)
(3.252 Å) and Pd(1) · · · Pd(2) (3.356 Å) distances are slightly
shorter than the reported binuclear complex having a similar
Pd2Se2 core, as in [{Pd(η3-C3H5)[Ph2P(O)NP(Se)Ph2-Se]}2]
(Se · · · Se 3.46 Å, Pd · · · Pd 3.54 Å).23 The Pd-S and Pd · · · Pd
distances in sulfur complex 3 closely resemble those in another
allyl palladium complex, [Pd2(µ-SBut)2(η3-C4H7)2].4 The bond
is triply bridging. When a dichloromethane solution of 3 is left
in open air for several days for recrystallization, growth of some
red crystals, identified as the trimeric complex 5, in addition to
yellow-orange crystals of 3 was observed. The formation of 5
from 3 in open air seems to take place via a reaction between
3 and [Pd(SMes)2]n. The formation of 5 from 3 and [Pd(SMes)2]n
has been ascertained by carrying out a reaction between them
in refluxing dichloromethane. The [Pd(SMes)2]n appears to be
formed by the nucleophilic attack of thiolate ligand on an allyl
group. Cleavage of the allyl group in allylpalladium complexes
by thiolate ligands has been reported earlier.11,20,21
The chalcogenolato-bridged allylpalladium complexes have
been characterized by mass, NMR, and single-crystal X-ray
diffraction analyses. The mass spectra of 3 and 6 exhibited
molecular ion peaks, while for 5 a molecular ion peak was not
observed. The highest ion peak (m/z ) 661) in the mass
spectrum of 5 has been attributed to the [Pd2(SMes)3]+ fragment.
In the case of 6, a peak attributable to a high molecular weight
species, [PdCl(SeCH2CH2NMe2)]3-Cl, was also observed.
The 1H NMR spectra displayed expected peaks and integra-
tion. The complexes 1-4 exist into syn and anti forms
depending on mutual disposition of the allyl groups (Scheme
2). Thus, the 1H NMR spectrum of [Pd2(µ-SeMes)2(η3-C3H5)2]
(2) at 500 MHz displayed two doublets (δ 3.43, 3.56 each d 5
Hz) for syn protons, two closely spaced multiplets (5.09, 5.12
(22) Johnson, C. K. ORTEP II-A FORTRAN thermal ellipsoid plot
program for crystal structure illustrations, ORNL-5138, 1976.
(23) Bhattacharyya, P.; Slawin, A. M. Z.; Smith, M. B. J. Chem. Soc.,
Dalton Trans. 1998, 2467.
(20) Singhal, A.; Jain, V. K. J. Organomet. Chem. 1995, 494, 75.
(21) Maitlis, P. M. ComprehensiVe Organomet. Chem. 1982, 6, 38–7.

Chalcogenolato-Bridged Allyl Palladium Complexes
Organometallics, Vol. 27, No. 13, 2008 3299
are within the range reported for several thiolato-bridged bi-
([Pd2Cl2(µ-SR)2(PR3)2])1,26 and trinuclear ([Pd3Cl2(µ-Sc-
Hx)4(PMe3)2]26) complexes. The three allyl carbons are equi-
distant from the palladium atom. The C-C distances of the allyl
group are intermediate between single and double bond distances.
The molecular structure of [Pd3Cl2(κ2-Se,N-SeCH2CH2NMe2)-
(η3-C3H5)3] (6) is unique and represents the first example of a
triply bridging selenolato ligand, and is also an example where
three square planes of palladium are sharing a corner. The
coordination around Pd(1) is defined by a η3-bonded allyl group
and a chelating N,N-dimethylaminoethylselenolate ligand, while
the Pd(2) and Pd(3) are each coordinated to a η3-bonded allyl
group, a chloride ligand, and a Se atom. The Pd-Se distance
with Pd(1), having a chelated selenolate ligand, is slightly shorter
than the Pd-Se distances with Pd(2) and Pd(3), although three
distances are within the range reported for several palladium-
selenolate complexes.27,28 The Pd-Cl and Pd-C distances are
all normal. The five-membered chelate ring is puckered, as
reported for a number of mononuclear complexes of the type
[MCl(PR3)(SeCH2CH2NMe2)] (M ) Pd or Pt).29,30 The coor-
dination planes of Pd(2) and Pd(3) lie with the square plane of
Pd(1) at 50.61° and 75.71ꢁ, respectively.
Figure 1. Molecular structure of [Pd2(µ-SMes)2(η3-C4H7)2] (3).
Recently we have demonstrated the use of [MCl(PR3)-
(ECH2CH2NMe2)] (E ) S, Se, Te) as a metallo-ligand in
constructing bi- and trinuclear complexes28,31 in which a
chelating chalcogenolate ligand is singly bonded to another
metal atom, leaving one lone pair of electrons on the chalcogen
atom uncoordinated. In the present case all the lone pairs of
electrons on selenium are utilized in coordination to the metal
atom.
Thermal Studies. Palladium-rich chalcogenides are semi-
conducting materials and are used in the electronic industry.12
To assess the suitability of these complexes as molecular
precursors for palladium chalcogenides, thermal studies were
carried out (Supporting Information S6-S9). Thermolysis of 3
in HDA at 175 °C gave Pd4S, as revealed by the XRD pattern.
Similarly, when 4 was pyrolyzed in a furnace at 160 °C, Pd4Se
was formed. The pyrolysis of 3 in the temperature range
300-350 °C in a furnace, however, resulted in the formation
of a mixture of palladium sulfides, Pd16S7 and Pd2.8S.
Figure 2. Molecular structure of [Pd2(µ-SeMes)2(η3-C4H7)2] (4).
angles and average C-C (1.42 Å), Pd-C (2.14 Å), and Pd-S
(2.36 Å) distances compare well with those found in other allyl
palladium complexes.4,24
Although the overall quality of diffraction data for 5 was
rather low due to poor quality of crystals, the overall chemical
structure could be determined unambiguously. The trimeric
complex [Pd3(µ-SMes)4(η3-C4H7)2] (5) comprises palladium
atoms arranged in a linear chain fashion and are held together
by four bridging thiolate groups. The three palladium coordina-
tion spheres are almost planar. The central palladium atom is
coordinated by an S4 core, while the coordination environment
around peripheral palladium atoms is defined by a η3-C4H7
group and two bridging thiolate groups. The molecule 5, with
C2h symmetry, has a horizontal plane σh that passes through
the three Pd atoms and the Pd-C bond connecting to the central
carbon atom of the allyl ligand. The central Pd(1) atom is the
inversion center. The two mesitylthiolato ligands and the allyl
group attached to the terminal palladium atoms are all mutually
syn; however, these groups of Pd(2) and Pd(2′) adopt an anti
configuration (see inset in Figure 3). Both of the terminal
palladium square planes are parallel to each other and tilted
from the central palladium square plane by 46.9ꢁ, giving a
zigzag shape to the molecule.
Conclusion
Bi- and trinuclear allylpalladium complexes stabilized by
bridging chalcogenolate ligands have been isolated. A new
trinuclear palladium complex (6) was formed, in which a corner
from each square plane of three palladium atoms is connected
by a triply bridging selenolate ligand. The binuclear complexes
have been shown to be versatile precursors for the preparation
of palladium-rich chalcogenides.
Experimental Section
General Procedures. Solvents were dried by standard methods
with subsequent distillation under nitrogen. All reactions were
All the Pd-S distances are essentially similar (av 2.39 Å)
and are within the expected range reported for palladium thiolate
complexes.4,25 Various S-Pd-S angles around palladium atoms
(26) Padilla, E. M.; Jensen, C. M. Polyhedron 1991, 10, 89.
(27) Dey, S.; Jain, V. K.; Klein, A.; Kaim, W. Inorg. Chem. Commun.
2004, 7, 601.
(28) Kumbhare, L. B.; Jain, V. K.; Phadnis, P. P.; Nethaji, M. J.
Organomet. Chem. 2007, 692, 1546.
(24) (a) Mason, R.; Wheeler, A. G. J. Chem. Soc. A 1968, 2543. (b)
Mason, R.; Wheeler, A. G. J. Chem. Soc. A 1968, 2549. (c) Dahl, L. F.;
Oberhansli, W. E. Inorg. Chem. 1965, 4, 629.
(29) Dey, S.; Jain, V. K.; Chaudhary, S.; Knoedler, A.; Lisner, F.; Kaim,
W. J. Chem. Soc., Dalton Trans. 2001, 723.
(30) (a) Dey, S.; Jain, V. K.; Knoedler, A.; Kaim, W.; Zalis, S. Eur.
J. Inorg. Chem. 2001, 2965. (b) Dey, S.; Jain, V. K.; Knoedler, A.; Klein,
A.; Kaim, W.; Zalis, S. Inorg. Chem. 2002, 41, 2864.
(31) Dey, S.; Jain, V. K.; Butcher, R. J. Inorg. Chem. Commun. 2007,
10, 1385.
(25) (a) Canovese, L.; Visentin, F.; Uguagliati, P.; Lucchini, V.; Bandoli,
G. Inorg. Chim. Acta 1998, 277, 247. (b) Ferna´ndez-Gala´n, R.; Manzano,
B. R.; Otero, A.; Poujaud, N.; Kubicki, M. J. Organomet. Chem. 1999,
579, 321.

3300 Organometallics, Vol. 27, No. 13, 2008
GhaVale et al.
Figure 3. Molecular structure of [Pd3(µ-SMes)4(η3-C4H7)2] · 3H2O (5).
literature methods. Synthesis and analytical data for lead
chalcogenolates used in this study are given in the Supporting
Information. Elemental analyses were carried out on a Carlo-
Erba EA-1110 CHN-O instrument. Melting points were deter-
1
mined in capillary tubes and are uncorrected. H NMR spectra
were recorded on a Bruker DPX-200 NMR spectrometer
operating at 200 MHz. Chemical shifts are relative to an internal
1
chloroform peak at δ 7.26. Variable-temperature H NMR and
2D COSY experiments at -40 °C were performed on a Bruker
Avance 500 MHz NMR instrument. Mass spectra were recorded
on a Waters Q-TOF micro (YA-105) time-of-flight mass
spectrometer. UV-vis absorption spectra were recorded on a
Chemito Spectrascan UV 2600 spectrophotometer. TG curves
were obtained at a heating rate of 10 °C min-1 under flowing
argon on a Setaram 92-16-18 instrument. EDAX measurements
were carried out with a Tescan Vega 2300T/40 instrument.
Powder XRD patterns were recorded on a Philips PW1820 using
Cu KR radiation.
[Pd2(µ-SMes)2(η3-C3H5)2] (1). To a benzene solution (20 mL)
of [Pd2(µ-Cl)2(η3-C3H5)2] (170 mg, 0.46 mmol) was added solid
Pb(SMes)2 (240 mg, 0.47 mmol). The yellow solution was stirred
for 3 h at room temperature, whereupon PbCl2 precipitated out.
The solvent was evaporated in Vacuo, and the yellow residue was
extracted with dichloromethane (3 × 10 mL). The volume of extract
was reduced to 5 mL, and a few drops of hexane were added to
yield yellow crystals (193 mg, 64%), mp 160 °C (dec). UV-vis
Figure4.Molecularstructureof[Pd3Cl2(κ2-Se,N-SeCH2CH2NMe2)(η3-
C3H5)3] (6).
carried out in a Schlenk flask under a nitrogen atmosphere. PdCl2,
MesSH, Me2NCH2CH2SH · HCl, and other reagents were obtained
from commercial sources and were used without further purification.
The compounds [Pd2(µ-Cl)2(η3-C3H5)2], [Pd2(µ-Cl)2(η3-C4H7)2],32
(MesSe)2,33 and (Me2NCH2CH2Se)229 were prepared according to
1
(CH2Cl2) λmax in nm: 304 (14 023). H NMR (200 MHz, CDCl3,
25 °C): δ 2.24 (s, 4-Me); 2.62 (d, 12.6 Hz, anti CH); 2.71, 2.74 (s,
(34) Higashi, T. ABSCOR, empirical absorption correction based on
Fourier series approximation; Rigaku Corporation: Akishima: Japan, 1995.
(35) Sheldrick, G. M. SHELXL-97: A computer program for crystal
structure solution and refinement; Universita¨t Go¨ttingen: Go¨ttingen, Ger-
many, 1997.
(32) Palenik, R. C.; Palenik, G. J. Synth. React. Inorg. Met-Org. Chem.
1992, 22, 1395.
(33) Ghavale, N.; Dey, S.; Jain, V. K.; Nethaji, M. Inorg. Chim. Acta.
2008, 361, 2462.
(36) Farrugia, L. J. J. Appl. Crystallogr. 1999, 32, 837.

Chalcogenolato-Bridged Allyl Palladium Complexes
Organometallics, Vol. 27, No. 13, 2008 3301
Table 1. Selected Bond Lengths (Å) and Angles (deg) for [Pd2(µ-EMes)2(η3-C4H7)2] (E ) S (3), Se (4))
S (3)
Se (4)
S (3)
Se (4)
C(19)-C(20)
C(20)-C(21)
Pd(1)-C(19)
Pd(1)-C(20)
Pd(1)-C(21)
E(1)-Pd(1)
E(2)-Pd(1)
C(1)-E(1)
1.383(8)
1.404(8)
2.127(6)
2.157(5)
2.129(6)
2.3654(15)
2.3725(15)
1.786(5)
3.265
1.44(2)
1.40(2)
C(23)-C(24)
C(24)-C(25)
Pd(2)-C(23)
Pd(2)-C(24)
Pd(2)-C(25)
E(1)-Pd(2)
E(2)-Pd(2)
C(10)-E(2)
E(1) · · · E(2)
1.385(8)
1.410(8)
2.126(6)
2.153(6)
2.140(5)
2.3582(15)
2.3750(14)
1.791(5)
3.072
1.361(15)
1.391(15)
2.142(15)
2.135(15)
2.113(14)
2.468(2)
2.4730(18)
1.938(11)
3.252
2.139(14)
2.180(14)
2.123(14)
2.4694(17)
2.4732(18)
1.946(11)
3.356
Pd(1) · · · Pd(2)
C(19)-Pd(1)-C(20)
C(19)-Pd(1)-C(21)
C(20)-Pd(1)-C(21)
Pd(1)-C(19)-C(20)
Pd(1)-C(20)-C(19)
Pd(1)-C(20)-C(21)
Pd(1)-C(21)-C(20)
Pd(1)-C(20)-C(22)
C(19)-C(20)-C(21)
E(1)-Pd(1)-E(2)
37.7(2)
67.4(2)
38.2(2)
72.4(3)
70.0(3)
69.8(3)
71.9(3)
121.1(4)
115.9(5)
80.88(5)
80.98(5)
87.45(5)
86.92(5)
38.9(6)
67.9(6)
38.0(6)
72.1(8)
69.1(8)
68.8(8)
73.1(9)
120.3 (12)
113.9(6)
82.29(6)
82.33(6)
85.63(6)
85.44(6)
C(23)-Pd(2)-C(24)
C(23)-Pd(2)-C(25)
C(24)-Pd(2)-C(25)
Pd(2)-C(23)-C(24)
Pd(2)-C(24)-C(23)
Pd(2)-C(24)-C(25)
Pd(2)-C(25)-C(24)
Pd(2)-C(24)-C(26)
C(23)-C(24)-C(25)
Pd(1)-E(1)-C(1)
37.8(2)
67.3(2)
38.3(2)
72.2(3)
70.1(3)
70.4(3)
71.3(3)
121.2(5)
115.6(6)
115.12(17)
116.15(17)
116.08(18)
116.25(18)
37.1(4)
67.2(6)
38.2(4)
71.2(9)
71.7(9)
70.0(9)
71.7(9)
121.3(11)
117.6(16)
114.1(3)
107.4(4)
110.5(3)
116.7(3)
E(1)-Pd(2)-E(2)
Pd(2)-E(1)-C(1)
Pd(1)-E(1)-Pd(2)
Pd(1)-E(2)-Pd(2)
Pd(1)-E(2)-C(10)
Pd(2)-E(2)-C(10)
Table 2. Selected Bond Lengths (Å) and Angles (deg) for
Table 3. Selected Bond Lengths (Å) and Angles (deg) for
[Pd3(µ-SMes)4(η3-C4H7)2] · 3H2O (5)
[Pd3Cl2(K2-Se,N-SeCH2CH2NMe2)(η3-C3H5)3] (6)
Pd(2i)-C(19i)
Pd(2i)-C(20i)
Pd(2i)-C(21i)
C(19i)-C(20i)
C(20i)-C(21i)
C(20i)-C(22i)
2.159(14)
2.155(11)
2.174(14)
1.422(18)
1.421(17)
1.517(14)
Pd(1i)-S(1i)
Pd(1i)-S(2i)
Pd(2i)-S(1i)
Pd(2i)-S(2i)
C(1i)-S(1i)
C(10i)-S(2i)
2.344(3)
2.35(3)
2.345(4)
2.355(3)
1.795(12)
1.782(12)
Pd(1)-C(1)
Pd(1)-C(2)
Pd(1)-C(3)
Pd(1)-N(1)
Pd(1)-Se(1)
Se(1)-C(10)
Pd(2)-Cl(1)
Pd(2)-Se(1)
2.144(11)
2.105(13)
2.180(12)
2.178(7)
2.4255(11) Pd(3)-C(8)
2.007(8)
2.380(3)
Pd(2)-C(4)
Pd(2)-C(5)
Pd(2)-C(6)
Pd(3)-C(7)
2.131(12)
2.123(14)
2.154(12)
2.158(12)
2.107(14)
2.135(10)
2.399(3)
Pd(3)-C(9)
Pd(3)-Cl(2)
S(1i)-Pd(1i)-S(1ii)
S(1i)-Pd(1i)-S(2ii)
S(1i)-Pd(1i)-S(2i)
S(1ii)-Pd(1i)-S(2i)
S(2i)-Pd(1i)-S(2ii)
S(1ii)-Pd(1i)-S(2ii)
100.03(18) Pd(1i)-S(1i)-Pd(2i)
179.43(14) Pd(1i)-S(2i)-Pd(2i)
79.44 (10) Pd(1i)-S(1i)-C(1i)
179.43(15) Pd(1i)-S(2i)-C(10i)
101.09(17) Pd(2i)-S(1i)-C(1i)
89.97(11)
89.57(11)
117.4(5)
116.4(4)
113.2(5)
113.3(4)
2.4968(11) Pd(3)-Se(1)
2.4846(11)
Pd(1)-C(1)-C(2)
Pd(1)-C(2)-C(3)
C(1)-Pd(1)-C(2)
C(1)-Pd(1)-C(3)
N(1)-Pd(1)-C(1)
N(1)-Pd(1)-C(2)
N(1)-Pd(1)-Se(1)
Pd(1)-Se(1)-Pd(2) 119.90(4)
Pd(1)-Se(1)-Pd(3) 101.71(4)
Pd(1)-Se(1)-C(10) 94.5(2)
Pd(1)-N(1)-C(11)
Se(1)-Pd(1)-C(1)
Pd(2)-C(4)-C(5)
Pd(2)-C(5)-C(6)
C(4)-Pd(2)-C(6)
70.5(8)
75.6(9)
35.8(3)
70.8(5)
170.5(4)
135.2(5)
87.28(19)
C(5)-Pd(2)-C(6)
35.0(6)
C(4)-Pd(2)-Se(1)
C(5)-Pd(2)-Se(1)
C(4)-Pd(2)-Cl(1)
C(5)-Pd(2)-Cl(1)
C(6)-Pd(2)-Cl(1)
167.1(5)
131.7(6)
96.3(5)
131.1(6)
163.3(4)
79.44(10)
Pd(2i)-S(2i)-C(10i)
Pd(2i)-C(19i)-C(20i) 70.6(7)
Pd(2i)-C(20i)-C(19i) 70.9(7)
Pd(2i)-C(20i)-C(21i) 71.6(7)
Pd(2i)-C(20i)-C(22i) 120.4(8)
Pd(2i)-C(21i)-C(20i) 70.1(7)
C(19i)-Pd(2i)-C(20i) 38.5(5)
C(19i)-Pd(2i)-C(21i) 67.8(5)
C(20i)-Pd(2i)-C(21i) 38.3(5)
C(19i)-C(20i)-C(21i) 116.5(10)
C(19i)-Pd(2i)-S(1i)
C(20i)-Pd(2i)-S(1i)
C(21i)-Pd(2i)-S(1i)
C(19i)-Pd(2i)-S(2i)
C(20i)-Pd(2i)-S(2i)
C(21i)-Pd(2i)-S(2i)
S(1i)-Pd(2i)-S(2i)
105.6(4)
137.8(4)
172.3(4)
171.7(4)
139.7(4)
106.8(4)
79.33(10)
Cl(1)-Pd(2)-Se(1) 96.47(7)
Pd(2)-Se(1)-Pd(3) 121.71(4)
Pd(3)-C(7)-C(8)
Pd(3)-C(9)-C(8)
C(7)-Pd(3)-C(8)
C(7)-Pd(3)-Se(1)
C(8)-Pd(3)-Se(1)
C(7)-Pd(3)-Cl(2)
74.3(8)
70.9(8)
35.6(3)
96.1(4)
130.5(4)
164.1(4)
111.7(6)
101.8(4)
71.7(8)
73.8(8)
67.9(6)
Cl(2)-Pd(3)-Se(1) 99.76(8)
2, 6-Me); 3.19 (d, 6.8 Hz), 3.28 (d, 6.6 Hz) (syn CH); 5.21 (m,
CH); 6.83 (s, Mes) ppm. Anal. Calcd for C24H32S2Pd2 (%): C, 48.2;
H, 5.3; S, 10.7. Found: C, 48.4; H, 5.5; S, 10.6.
[Pd(SMes)(η3-C4H7)]+ (12%), 463 [Pd(SMes)2(η3-C4H7)]+ (35%),
559 [Pd(SMes)3]+ (8%), 661 [Pd2(SMes)3]+ (100%). Anal. Calcd
for C44H58S4Pd3 (%): C, 51.0; H, 5.7; S, 12.4. Found: C, 51.0; H,
5.5; S, 12.8.
The complexes [Pd2(µ-SeMes)2(η3-C3H5)2] (2) and [Pd2(µ-
SMes)2(η3-C4H7)2] (E ) S (3); Se (4)) were prepared analogously
and are reported in the Supporting Information (S12).
[Pd3Cl2(K2-Se,N-SeCH2CH2NMe2)(η3-C3H5)3] (6). To a ben-
zene (20 mL) solution of [Pd2(µ-Cl)2(η3-C3H5)2] (206 mg, 0.56
mmol) was added solid Pb(SeCH2CH2NMe2)2 (287 mg, 0.56 mmol),
and the mixture was stirred for 2 h, whereupon a white precipitate
of PbCl2 was separated out. The solvent was evaporated under
vacuum, and the residue was washed with hexane and extracted
with acetone (3 × 8 mL). The extract was concentrated to 5 mL,
and a few drops of benzene were added to yield yellow crystals
(187 mg, 50%), mp 155 ꢁC (dec). MS: 847 [PdCl(SeCH2-
CH2NMe2)]3 - Cl (10%), 665 [M]+ (70%), 557 [M - (2Cl +
C3H5]+ (100%), 507 [M - (3C3H5) + Cl)]+ (15%). Anal. Calcd
for C13H25NCl2SePd3 (%): C, 23.5; H, 3.8; N, 2.1. Found: C, 24.0;
H, 4.0; N, 2.4.
[Pd3(µ-SMes)4(η3-C4H7)2] (5). After separating the yellow
crystals of 3, the supernatant when left in air for 2 days gave red
crystals in low yield (∼5%), which were characterized as 5. This
has been conveniently prepared by the following reaction. To a
dichloromethane solution (25 mL) of [Pd2(µ-SMes)2(η3-C4H7)2] (96
mg, 0.15 mmol) was added solid [Pd(SMes)2] (62 mg, 0.15 mmol),
and the reaction mixture was refluxed for 2 h and then stirred for
72 h. The solution was filtered through G-3 sintered bed, and the
maroon residue on the bed was extracted with hot dichloromethane
(3 × 8 mL). The filtrate and extract were combined and concen-
trated to 8 mL, and a few milliliters of acetone was added to yield
a red solid at -5 °C (74 mg, 47%), mp 148 °C (dec). UV-vis
(CH2Cl2) λmax in nm: 326 (28 666); 370 (26 733); 419 (15 800).
ꢁ
1H NMR (200 MHz, CDCl3, 25 C): 1.73, 1.78; 2.19; 2.24; 2.30;
[Pd3Cl2(K2-Se,N-SeCH2CH2NMe2)(η3-C4H7)3] (7) was prepared
2.39; 2.45; 2.61; 2.66; 2.73; 2.77; 6.48, 6.72, 6.82. MS: 312
analogously and is reported in the Supporting Information (S13).

3302 Organometallics, Vol. 27, No. 13, 2008
GhaVale et al.
and EDAX), and synthesis of lead chalcogenolates and complexes
2, 3, 4, and 7, and crystallographic experimental data and refinement
of complexes 3, 4, 5, and 6; crystallographic data are also available
as CIF files. This material is available free of charge via the Internet
at http://pubs.acs.org.
Acknowledgment. We thank Drs. T. Mukherjee and D.
Das for encouragement of this work. We are thankful to the
Chemistry Department, IIT Bombay, Mumbai, for providing
microanalysis and mass spectra of the complexes. We are
grateful to Dr. M. Nethaji, IISc, Bangalore, for helpful
discussions.
Supporting Information Available: Mass spectra, COSY NMR
spectra of 6, details of thermal studies (TG curves, XRD pattern,
OM8000795