Structural variety and multiple isomerism in 1-(dimethylamino)propyl-2- chalcogenolate and 2-(dimethylamino)propyl-1-chalcogenolate complexes of palladium(II) and platinum(II): Synthesis, spectroscopy and structures

Article abstract of DOI:10.1002/ejic.200400524

Isomeric dichalcogenides [Me₂NCH(Me)CH₂E]₂ [(N∩E**)₂] and [Me₂NCH ₂CH(Me)E]₂ [(N∩E*)₂] (E = S, Se, Te) have been obtained by the reactions of NaSH or M′₂E₂ (M′ = Na or K) with Me₂NCH₂CHMeCl. The former reaction affords mainly (N∩E**)₂ (E = S) while from the latter mixtures of (N∩E**)₂ and (N∩E**)₂ [referred to as (N∩E)₂, E = S, Se, Te] were isolated, the ratios in the mixtures depending on the chalcogen. Reactions of (N∩E)Na with [M₂Cl₂(μ-Cl) ₂(PR₃)₂] gave complexes (MCl(N∩E)(PR ₃)] (M = Pd or Pt). These chiral, mixed-ligand complexes have been characterised by elemental analysis, IR, UV/Vis and NMR (¹H, ¹³C, ³¹P, ⁷⁷Se, ¹²⁵Te, ¹⁹⁵Pt) spectroscopy, and, in part, by X-ray structure analysis. The complexes display a typical pattern of mutually trans-oriented neutral (P and N) and anionic (Cl and E) donor atoms in an approximately square-planar environment. In contrast to the platinum(II) analogues, the X-ray structures of the complexes [PdCl(N∩E) (PMePh₂)] (E = S or Se) revealed both a conformational isomerism of the five-membered chelate ring and, for Se, the co-crystallisation of complexes with both the N∩E* and N∩E** isomeric ligands. The thermal behaviour of some complexes has been investigated. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.

Full text of DOI:10.1002/ejic.200400524

FULL PAPER
Structural Variety and Multiple Isomerism in 1-(Dimethylamino)propyl-2-
chalcogenolate and 2-(Dimethylamino)propyl-1-chalcogenolate Complexes of
Palladium(II) and Platinum(II): Synthesis, Spectroscopy and Structures
Sandip Dey,[a] Liladhar B. Kumbhare,[a] Vimal K. Jain,*[a] Thilo Schurr,[b] Wolfgang Kaim,*[b]
Axel Klein,*[b] and Ferdinand Belaj[c]
Keywords: Chalcogens / Isomers / N ligands / Palladium / Platinum
Isomeric dichalcogenides [Me2NCH(Me)CH2E]2 [(NʝE**)2]
and [Me2NCH2CH(Me)E]2 [(NʝE*)2] (E = S, Se, Te) have
been obtained by the reactions of NaSH or MЈ2E2 (MЈ = Na
or K) with Me2NCH2CHMeCl. The former reaction affords
mainly (NʝE**)2 (E = S) while from the latter mixtures of
(NʝE**)2 and (NʝE*)2 [referred to as (NʝE)2, E = S, Se, Te]
were isolated, the ratios in the mixtures depending on the
chalcogen. Reactions of (NʝE)Na with [M2Cl2(µ-Cl)2(PR3)2]
gave complexes [MCl(NʝE)(PR3)] (M = Pd or Pt). These
chiral, mixed-ligand complexes have been characterised by
elemental analysis, IR, UV/Vis and NMR (1H, 13C, 31P, 77Se,
analysis. The complexes display a typical pattern of mutually
trans-oriented neutral (P and N) and anionic (Cl and E) donor
atoms in an approximately square-planar environment. In
contrast to the platinum(II) analogues, the X-ray structures of
the complexes [PdCl(NʝE)(PMePh2)] (E = S or Se) revealed
both a conformational isomerism of the five-membered che-
late ring and, for Se, the co-crystallisation of complexes with
both the NʝE* and NʝE** isomeric ligands. The thermal be-
haviour of some complexes has been investigated.
( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
125Te, 195Pt) spectroscopy, and, in part, by X-ray structure Germany, 2004)
Introduction
have led to the isolation of complexes with quite varied
structural patterns. Some of these complexes also provided
an opportunity to study metal-mediated donorϪacceptor
interactions between coordinated ligands.[14,15]
The chemistry of metal chalcogenolates continues to be
an active area of research. Their emerging application as
single-source precursors for low-decomposition-tempera-
ture synthesis of solid-state chalcogenide materials has pro-
vided a further momentum to this activity.[1Ϫ4] The chemis-
try of the heavier metal chalcogenolates is dominated by
thiolate complexes, which are often isolated as non-volatile,
insoluble (or sparingly soluble) polymers.[5] One of the stra-
tegies to suppress polymerisation has been to use internally
functionalised ligands.[3] Among such ligands are (amino-
alkyl)chalcogenolate ions R2N(CR2Ј)nEϪ. While the chem-
istry of mercaptoalkylamines is now fairly well
documented,[6Ϫ12] the heavier analogues containing Se and
Te have been more recently developed and investigated by
us.[13Ϫ17] Subtle variations in either the carbon chain length
of the ligand or in the auxiliary ligands at the metal centre
A new series of (aminoalkyl)chalcogenolate ligands with
asymmetrically substituted carbon atoms in the alkyl
chain was conceived for the following reasons: (i) chiral thi-
olate complexes such as the recently reported
[PdCl{SCH2CH(COOEt)NH2}(PPh3)] are useful asymmet-
ric homogeneous catalysts;[12,18Ϫ20] (ii) the cleavage of sec-
ondary chalcogenolates often proceeds more cleanly than
that of primary or tertiary analogues;[21] (iii) the influence
of electron-releasing methyl groups on donorϪacceptor in-
teractions in metal complexes can be studied.[14,15]
In this perspective, 2-[(dimethylamino)propyl]-1-chalcog-
enolate (NʝE**) (A) and 1-[(dimethylamino)propyl]-2-chal-
cogenolate (NʝE*) (B) ligands have been synthesised, and
their chemistry with palladium() and platinum() has been
explored. The results of this work are described in this
paper.
[a]
Novel Materials & Structural Chemistry Division, Bhabha
Atomic Research Centre (BARC)
Mumbai 400085, India
E-mail: jainvk@apsara.barc.ernet.in
[b]
Institut für Anorganische Chemie, Universität Stuttgart,
Pfaffenwaldring 55, 70569, Stuttgart, Germany
E-mail: aklein@uni-stuttgart.de
kaim@iac.uni-stuttgart.de
[c]
Institut für Chemie, Karl-Franzens-Universität Graz,
Schubertstrasse 1, 8010 Graz, Austria
Supporting information for this article is available on the
WWW under http://www.eurjic.org or from the author.
4510
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
DOI: 10.1002/ejic.200400524
Eur. J. Inorg. Chem. 2004, 4510Ϫ4520

Chalcogenolate Complexes of Palladium(II) and Platinum(II)
FULL PAPER
1
Results and Discussion
The H and 13C NMR spectra of the disulfide obtained
from reaction according to Equation (1) display only one
set of resonances attributable to [Me2NCH(Me)CH2S]2
(NʝS**)2. However, the spectra of the dichalcogenides pre-
pared from the reaction according to Equation (2) exhibit
two sets of resonances which can be assigned to mixtures
[referred to as (NʝE)2].
Synthesis of Dichalcogenides
Two general reactions [Equations (1) and (2)] have been
employed for the synthesis of the dichalcogenides. The dis-
ulfide formed by the reaction according to Equation (1) was
isolated mainly as a single rearranged product [Me2NCH-
(Me)CH2S]2 (NʝE**)2, whereas the raction according to
Equation (2) gave a mixture of [Me2NCH(Me)CH2E]2
(NʝE**)2 (E ϭ S, Se, Te) and (Me2NCH2CH(Me)E]2
(NʝE*)2 (E ϭ S, Se, Te). The relative amounts of (NʝE**
)2 and (NʝE*)2 are chalcogen-dependent: the ratios were
1:2 for E ϭ S, approx. 1:1 for E ϭ Se, and 5:1 for E ϭ Te
The corresponding 77Se (Figure 1) and 125Te NMR spec-
tra show eight and four lines, respectively. The molecules
R2E2 (E ϭ O, S, Se, Te) have a ‘‘skew’’ structure and can
show restricted rotation about the EϪE bond. For the mol-
ecules (NʝE**)2 and (NʝE*)2 three stereoisomers — (R,R),
(S,S) and a meso form — are expected. Thus, each molecule
is expected to display two resonances [(R,R)/(S,S) and meso]
for the chalcogen atom in the 77Se or 125Te NMR spectrum.
The resonances at δ ϭ Ϫ791 and Ϫ559 ppm and δ ϭ Ϫ870
and Ϫ659 ppm in the 125Te NMR spectra may be assigned
to molecules (NʝTe*)2 and (NʝTe**)2. Similarly, reson-
ances at δ ഠ 226 and 357 ppm and δ ഠ 286 and 415 ppm
in the 77Se NMR spectra can be attributed to (NʝSe*)2 and
(NʝSe**)2. However, each signal in the 77Se NMR spec-
trum appears as two closely spaced lines (ca. 1 ppm separ-
ation). The presence of intramolecular interactions between
nitrogen and selenium atoms may lead to the magnetic non-
equivalence of the two selenium atoms in each molecule,
resulting in two separate but closely spaced resonances. Re-
cently, intramolecular Se···N interactions have been re-
ported in several diselenides.[23Ϫ25] The Se···N distances of
1
(from H NMR integration).
Several factors have been identified which influence the
product formation in nucleophilic substitution reactions of
alkyl halides. In the present case, the participation of a nu-
cleophilic neighbouring group (NMe2) is believed to play
an essential role to produce the C-methylaziridinium species
C as a possible intermediate. In C, the less substituted car-
bon atom (i.e. the CH2 group) seems to be the preferred
site of attack by a nucleophile such as HSϪ in the reaction
according to Equation (1) as it is sterically less encumbered
and electronically more positive. Accordingly, an iso-
merized product [Me2NCH(Me)CH2S]2 (type A) could be
isolated from the reaction according to Equation (1). The
reaction according to Equation (2) is carried out using
˚
about 2.8 A in these compounds are longer than the sum
of the covalent radii, but significantly shorter than the sum
[23Ϫ25]
˚
of the corresponding van der Waals radii (ca. 3.5 A).
For instance, the atomic distances Se(1)ϪN(1) and
˚
Se(2)ϪN(2) in D are 2.819(5) and 2.705(5) A, respec-
tively.[24] For the same reasons one would anticipate an
analogous pattern for the 125Te NMR spectrum. However,
relatively large line widths [ca. 100 Hz (1 ppm)] for the 125Te
resonances appear to preclude a visible separation of closely
spaced signals.
2Ϫ
Ϫ
M2E2 in DMF. The nucleophiles E2 and RE2 as inter-
mediates in a solvent such as DMF may attack either of the
carbon centres (CH2 or CHMe) leading to the formation of
different products. Their formation in different ratios re-
flects the differing nucleophilic character of anionic S, Se,
or Te. Cyclic intermediates similar to C with various het-
eroatoms (e.g, N, O, S) are commonly invoked in organic
reactions. The cleavage of the NϪC bond in C-substituted
aziridines or aziridinium ions frequently leads to iso-
merized products.[22]
Figure 1. 77Se{1H} NMR spectrum of (NʝSe)2 [mixture of
(NʝSe**)2 and (NʝSe*)2] in CDCl3
Eur. J. Inorg. Chem. 2004, 4510Ϫ4520
www.eurjic.org
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
4511

S. Dey, L. B. Kumbhare, V. K. Jain, T. Schurr, W. Kaim, A. Klein, F. Belaj
FULL PAPER
(3)
NMR Spectroscopy of Complexes [MCl(NʝE)(PR3)]
Synthesis of Palladium(II) and Platinum(II) Complexes
1
Treatment of [M2Cl2(µ-Cl)2(PR3)2] with NʝENa in meth-
The H NMR spectra (Table 1) of the thiolate complexes
anol/dichloromethane readily gave coloured complexes of [MCl(SCH2CHMeNMe2)(PR3)] as prepared from the
the general formula [MCl(NʝE)(PR3)] [Equation (3)].
NʝS** (A) ligand display only one set of signals. The NMe2
1
Table 1. H and 31P NMR spectroscopic data of palladium and platinum complexes [MCl(NʝE)(PR3)][a]
1H
31P{1H}[b]
23.8
[PdCl(NʝS**)(PnPr3)]
1.06 (t, J ϭ 7.1 Hz, PCH2CH2Me), 1.16 (d, J ϭ 6 Hz, CHMe),
1.60Ϫ1.67 (m, PCH2CH2), 1.78Ϫ1.83 (m, PCH2), 2.51 (br., s),
2.76 (br., s) NMe2, 2.56Ϫ2.70 (m, SCH2), 2.86Ϫ2.96 (m,
NCH)
[PdCl(NʝS**)(PEt3)]
1.15Ϫ1.29 (m, PCH2Me, NCHMe), 1.83Ϫ2.00 (m, PCH2),
2.53 (d, J ϭ 2.5 Hz), 2.78 (d, J ϭ 2.8 Hz) NMe2, 2.57Ϫ2.73
(m, SCH2), 2.92 (m, NCH)
1.15 (d, J ϭ 6.5 Hz NCHMe), 1.79 (d, J ϭ 11.6 Hz), 1.83 (d,
J ϭ 11.7 Hz, PMe2), 2.52 (d, J ϭ 3.0 Hz), 2.80 (d, J ϭ 3.3 Hz)
NMe2, 2.46Ϫ2.66 (m, SCH2), 2.98 (m, NCH), 7.41Ϫ7.44 (m),
7.70Ϫ7.75 (m) PPh
1.15 (d, J ϭ 6.5 Hz NCHMe), 2.16 (d, J ϭ 11.4 Hz, PMe),
2.37Ϫ2.64 (m, SCH2), 2.59 (d, J ϭ 3.0 Hz), 2.86 (d, J ϭ
3.3 Hz) NMe2, 3.04 (m, NCH), 7.34Ϫ7.44 (m), 7.55Ϫ7.62 (m),
7.70Ϫ7.77 (m) PPh
34.5
7.0
[PdCl(NʝS**)(PMe2Ph)]
[PdCl(NʝS**)(PMePh2)]
21.0
[PdCl(NʝS*)(PMePh2)]
[PdCl(NʝS**)(PPh3)]
[PtCl(NʝS**)(PnBu3)]
1.21 (d, J ϭ 6.5 Hz, SCHMe), 2.11 (d, J ϭ 11 Hz, PMe) 2.70,
2.78 (d, J ϭ 2.5 Hz, NMe2), 2.62 (br., SCH2), 2.74 (m, NCH2),
3.38 (m, CHS), 7.39Ϫ7.81 (m, PPh).
1.20 (d, J ϭ 6.4 Hz SCHMe), 2.66 (d, J ϭ 3.0 Hz), 2.93 (d,
J ϭ 3.2 Hz) NMe2, 2.45Ϫ2.85 (m, SCH2), 3.15 (m, NCH),
7.38Ϫ7.49, 7.71Ϫ7.78 (m, PPh)
0.94 (t, J ϭ 7.3 Hz, PCH2CH2CH2Me), 1.22 (d, J ϭ 6.5 Hz,
NCHMe), 1.39Ϫ1.59 (m, PCH2CH2CH2), 1.80Ϫ1.89 (m,
PCH2), 2.39Ϫ2.53 (m, SCH2), 2.58, 2.88 (each d, J ϭ 2.7 Hz,
NMe2 with Pt satellites), 2.83 (br., NCH)
1.04 (t, J ϭ 7.3 Hz, PCH2CH2Me), 1.21 (d, J ϭ 6.5 Hz,
NCHMe), 1.57Ϫ1.66 (m, PCH2CH2), 1.78Ϫ1.87 (m, PCH2),
2.58, 2.88 (each d, J ϭ 2.7 Hz, NMe2 with Pt satellites,
2.48Ϫ2.54 (m, SCH2), 2.82 (br., NCH)
1.15 (dt, J ϭ 7.6, 16.7 Hz, PCH2Me), 1.22 (d, J ϭ 6.7 Hz,
NCH), 1.83Ϫ1.94 (m, PCH2), 2.59, 2.89 (each d, J ϭ 2.2 Hz;
JPt,H ϭ 17 Hz, NMe2), 2.82 (br., NCH), 2.43Ϫ2.54 (m, SCH2)
1.22 (d, J ϭ 6.5 Hz, NCHMe), 1.83, 1.87 (each d, J ϭ 11 Hz,
PMe2), 2.38Ϫ2.58 (m, SCH2), 2.62, 2.93 (each d, J ϭ 2.9 Hz,
NMe2 with Pt satellites), 2.86 (br., NCH), 7.42, 7.74Ϫ7.81
(m, PPh)
1.20 (d, J ϭ 6.5 Hz, NCHMe), 2.19 (d, J ϭ 11 Hz, PMe),
2.64, 2.97 (each d, J ϭ 3 Hz, NMe2), 2.52 (m, CH2S), NCH
merged in NMe2, 7.40Ϫ7.70 (m, PPh)
19.6
34.2
Ϫ1.7 [3468]
[PtCl(NʝS**)(PnPr3)]
Ϫ2.4 [3472]
[PtCl(NʝS**)(PEt3)]
6.2 [3468]
[PtCl(NʝS**)(PMe2Ph)]
Ϫ18.7 [3548]
[PtCl(NʝS**)(PMePh2)]
[PdCl(NʝSe)(PEt3)]
Ϫ4.3 [3616]
1.08Ϫ1.14 (m, PCH2CH3), 1.18 (d,
J
ϭ
6.4 Hz, CHMe,
31.3 (s), 31.2 (s)
NʝE**), 1.36 (d, J ϭ 6.7 Hz, CHMe, NʝE*), 1.75Ϫ1.89 (m,
PCH2), 2.48, 2.51, 2.66, 2.70 (each, d, J ϭ 2.5 Hz JP,H, NMe2,
NʝE* ϩ NʝE**), 2.55 (NCH2, NʝE*, merged in NMe2),
2.92Ϫ2.97 (m, CH2Se, NʝE**), 3.42Ϫ3.50 (m, CHSe, NʝE*)
1.19 (d, J ϭ 6.4 Hz, CHMe, NʝE**), 1.35 (d, J ϭ 6.6 Hz,
CHMe, NʝE*), 1.79 (d, J ϭ 13 Hz, PMe2), 1.87 (d, J ϭ
11.5 Hz, PMe2), 2.53 (d, J ϭ 3.0 Hz), 2.58 (d, J ϭ 2.6 Hz, 2.72
(d, J ϭ 3.5 Hz), 2.78 (d, J ϭ 3 Hz) NMe2, NʝE*ϩ NʝE**)
NCH, NCH2, merged in NMe2, 3.01Ϫ3.08 (m, CH2Se, NʝE**,
3.44Ϫ3.52 (m, CHSe, NʝE*), 7.40Ϫ7.43 (m), 7.66Ϫ7.73
(m) PPh
[PdCl(NʝSe)(PMe2Ph)]
2.5 (s)[c]
4512
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
Eur. J. Inorg. Chem. 2004, 4510Ϫ4520

Chalcogenolate Complexes of Palladium(II) and Platinum(II)
FULL PAPER
Table 1 (continued)
1H
31P{1H}[b]
[PdCl(NʝSe)(PMePh2)]
1.21 (d, J ϭ 6.4 Hz, CHMe, NʝE**), 1.29 (d, J ϭ 6.6 Hz,
16.7 (s)
CHMe, NʝE*), 2.18 (d, J ϭ 11.3 Hz minor), 2.21 (d, J ϭ
11.4 Hz, major, PMe), 2.53 (AB pattern, NCH2), NCH merged
with NMe2, 2.60 (d, J ϭ 3.1 Hz), 2.66 (d, J ϭ 2.5 Hz), 2.77 (d,
J ϭ 3.4 Hz), 2.85 (d, J ϭ 3.0 Hz) (NMe2, NʝE*ϩ NʝE**),
3.07Ϫ3.16 (m, CH2Se, NʝE*), 3.46 (m CHSe, NʝE*),
7.33Ϫ7.44 (m), 7.49Ϫ7.80 (m) PPh[b]
[PdCl(NʝSe)(PPh3)]
1.27 (d, J ϭ 6.4 Hz), 1.30 (d, J ϭ 6.5 Hz, NMe2), 2.66, 2.92,
2.72, 2.84 (each d, J ϭ 3 Hz) NMe2, 2.52Ϫ2.61 (m, NCH),
2.95Ϫ3.30 (m, CH2Se, NCH2), 3.50 (m, CHSe) 7.19Ϫ7.80 (m,
PPh)
0.80 (t, J ϭ 7.1 Hz, PCHCH2CH2Me), 1.13 (d, J ϭ 6.3 Hz,
CHMe, NʝE*), 1.25Ϫ1.45 (m, PCH2CH2CH2 ϩ doublet due to
CHMe, NʝE*), 1.59Ϫ1.78 (m, PCH2), 2.15, 2.40 (AB pattern,
NCH2), 2.49 (d, J ϭ 2.4 Hz), 2.70 (d, J ϭ 2.5 Hz), 2.74 (d,
J ϭ 2.6 Hz) (JP,H, NMe2, NʝE* ϩ NʝE** merged with CH2Se
NʝE**), 3.08Ϫ3.20 (m, SeCH, NʝE*)
29.6, 29.8
[PtCl(NʝSe)(PnBu3)]
Ϫ4.0 [3431], Ϫ4.3 [3416]
[PtCl(NʝSe)(PEt3)]
1.06Ϫ1.20 (m, PCH2CH3), 1.24 (d, J ϭ 6.3 Hz, CHMe, NʝE**
), 1.48 (d, J ϭ 6.6 Hz, CHMe, NʝE*), (3:2 ratio), 1.78Ϫ1.92
(m, PCH2), 2.25 (quadruplet, NCH, NʝE**), 2.49 (AB pattern,
NCH2, NʝE*), 2.61 (d, JP,H ϭ 2.6, JPt,H ϭ 14.5 Hz), 2.81 (d,
JP,H ϭ 2.5 Hz), 2.86 (d, JP,H ϭ 2.8 Hz) NMe2, NʝE*ϩ
NʝE**, (br., CH2Se, NʝE**), 3.26 (m, CHSe, NʝE*)
1.24 (d, J ϭ 6.4 Hz, CHMe, NʝE**), 1.45 (d, J ϭ 6.7 Hz,
CHMe, NʝE*), 1.89 (d), 1.86, 1.83 (each d, J ϭ 11 Hz, PMe2),
2.27 (AB, NCH2), 2.43 (AB, NCH and NCH2), 2.64, 2.66 (each
d, J ϭ 2.5 Hz), 2.88, 2.90 (each d, J ϭ 3 Hz) (NMe2, NʝE*
ϩ NʝE**), 3.26 (m, SeCH, NʝE*), 7.38Ϫ7.48 (m), 7.70Ϫ7.77
(m) PPh
4.3[d] [3435], 4.6[e] [3450]
[PtCl(NʝSe)(PMe2Ph)]
Ϫ22.2[d] [3476], Ϫ21.9[e] [3489]
[PdCl(NʝTe)(PnPr3)][f]
1.02 (t, J ϭ 7 Hz, PCH2CH2Me), 1.25 (d, J ϭ 6.1 Hz, CHMe,
Ϫ6.9 [3373], Ϫ7.2 [3350]
NʝE**), 1.52Ϫ1.63 (m, PCH2CH2
ϩ
CHMe, NʝE*),
1.77Ϫ1.84 (m, PCH2), 2.15Ϫ2.21 (m, NCH2), 2.68 (d, J ϭ
2.7 Hz), 2.73 (d, J ϭ 2.0 Hz) NMe2, 2.55, 2.86 (m, NCH2),
1.33 (d, J ϭ 6.0 Hz, CHMe), 2.63 (d, J ϭ 3.0 Hz), 2.90 (d, J ϭ
1.8 Hz) NMe2, 3.10 (br., NCH), 3.48 (br., TeCH2), 7.36Ϫ7.86
(m, PPh)
1.41 (d, J ϭ 6.8 Hz CHMe), 2.81 (d, J ϭ 3.2 Hz), 2.98 (br)
NMe2, 2.70 (br., NCH2), 3.80 (m, TeCH), 7.36Ϫ7.86 (m, PPh)
1.12 (d, J ϭ 6.4 Hz, CHMe), 2.57, 3.27 (each br, NMe2), 3.10
(m, NCH), 3.21 (br., TeCH2), 7.32Ϫ7.87 (m, PPh).
[PdCl(NʝTe**)(PPh3)][g]
21.6 (s)
[PdCl(NʝTe*)(PPh3)][g]
[PtCl(NʝTe**)(PPh3)]
[PtCl(NʝTe*)(PPh3)]
22.4 (s)
8.7 [3742]
0.4 [3538]
1.27 (br., CHMe), 2.80 (d, J ϭ 2.9 Hz), 2.94 (d, J ϭ 2.2 Hz)
NMe2, 2.63 (br., NCH2), 3.90 (br., TeCH), 7.32Ϫ7.87 (m, PPh)
[a]
[c]
[d]
[e]
[f]
Measured in CDCl3. [b] 1J(195Pt,31P) in Hz in parentheses. Separate signals not resolved.
Minor product. Major product.
The 31P NMR spectrum shows an additional small resonance at δ ϭ Ϫ1.3 ppm (1JPt,P ϭ 3103 Hz). The 31P NMR spectrum shows an
[g]
impurity of [PdCl2(PPh3)2] at δ ϭ 23.8 ppm (ca. 10%).
proton resonances appear as two doublets of equal intensity
The 31P{1H} (Figure 2), 77Se{1H} (Figure 3) and
due to JP,H coupling. However, the spectra of those com- 195Pt{1H} NMR spectra (Figure 4) of compounds
plexes synthesised with ligands obtained from the reaction [MCl(NʝE)(PR3)] (E ϭ Se or Te; Tables 1 and 2) and
according to Equation (2) show two sets of resonances for the thiolate complex [PdCl(NʝS)(PMePh2)], display two
the organochalcogenolate fragments and for the phosphane sets of resonances. For the (R) and (S) forms (EϪH) of
methyl protons (if present). Each set of resonances can be each stereoisomer one set of resonances is observed. The
assigned to NʝE** (A) and NʝE* (B) ligand protons. The 1JPt,P coupling constants for the two resonances (from
NMe2 proton signals for both isomers appear as two separ- 31P and 195Pt NMR spectra) are of the same magni-
ate doublets with 4JP,H ഠ 3 Hz. The appearance of two dou- tude and are thus indicative of a similar configuration.
4
1
blets for the NMe2 protons suggests that the methyl groups The magnitude of JPt,P for the platinum complexes
are diastereotopic in both the isomers, possibly due to the suggests that the phosphane ligand is trans to the nitro-
1
asymmetric carbon centre in the chalcogenolate moiety. In gen atom. The values of JPt,P can be compared with
contrast, the complexes [MCl(ECH2CH2NMe2)(PR3)] show those observed for analogous complexes derived from
only one doublet for the NMe2 protons.[13Ϫ15]
achiral ligands.[13Ϫ15] The two sets of resonances in the
Eur. J. Inorg. Chem. 2004, 4510Ϫ4520
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 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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S. Dey, L. B. Kumbhare, V. K. Jain, T. Schurr, W. Kaim, A. Klein, F. Belaj
Table 2. 77Se and 195Pt NMR spectroscopic data of selected [MCl(NʝE)(PR3)] complexes[a]
FULL PAPER
31
77Se{1H}
195Pt{1H} [1J195
in Hz]
P
Pt,
[PdCl(NʝSe)(PEt3)]
[PdCl(NʝSe)(PMePh2)]
[PtCl(NʝSe)(PEt3)]
[PtCl(NʝSe)(PnBu3)]
[PtCl(NʝSe)(PMe2Ph)]
[PtCl(NʝTe)(PnPr3)]
201 (s), 351 (s)
282 (s), 425 (s)
Ϫ
88 (s), 244 (s)
113 (s), 263 (s)
Ϫ
Ϫ
Ϫ
Ϫ4211 (d) [3445] (40%), Ϫ4315 (d) [3432] (60%)
Ϫ4286 (d) [3426], Ϫ4182 (d) [3419]
Ϫ4165 (d) [3452] (minor), Ϫ4267 (d) [3478] (major)
Ϫ4425 (d) [3362], Ϫ4569 (d) [3371]
[a]
Measured in CDCl3.
31P, 77Se, and 195Pt NMR spectra are assigned to com- Electronic Spectra
plexes containing the NʝE* and NʝE** ligand moieties.
Like the analogous achiral derivatives,[14,15,27] the absorp-
tion spectra (Table 3) of the complexes [MCl(NʝE)(PR3)]
display very weak long-wavelength bands. These absorp-
tions are slightly red-shifted when compared with the corre-
sponding achiral complexes. While the absorptions of the
platinum complexes are blue-shifted in comparison to the
palladium analogues, the selenium- and especially the tel-
lurium-containing compounds absorb at lower energies
than the corresponding sulfur analogues. Replacement of
a methyl substituent by a phenyl group in PR3 leads to a
bathochromic shift.
Table 3. UV/Vis absorption data for [MCl(NʝE)(PR3)] complexes
in CH2Cl2
Figure 2. 31P{1H} NMR spectrum of [PtCl(NʝSe)(PMe2Ph)] in
CDCl3
Complex
λmax (ε)[a]
[PdCl(NʝS**)(PnPr3)]
[PdCl(NʝS**)(PMe2Ph)]
[PdCl(NʝS**)(PMePh2)]
[PdCl(NʝS)(PMePh2)][b]
[PdCl(NʝS**)(PPh3)]
[PtCl(NʝS**)(PEt3)]
[PtCl(NʝS**)(PMe2Ph)]
[PtCl(NʝS**)(PMePh2)]
[PdCl(NʝSe)(PEt3)]
277 (2730), 325 (1780), 407 (br., 440)
329 (2150), 462 (90)
331 (1980), 474 (70)
327 (2000), 459 (90)
337 (3340)
282 (3000), 325 (780)
281 (2600), 396 (80)
289 (2130), 404 (70)
338 (1830), 476 (80)
339 (2780), 483 (90)
255 (2860), 345 (2580), 495 (90)
284 (3980), 406 (110)
285 (6380), 412 (180)
392 (4280), 616 (110)
[PdCl(NʝSe)(PMe2Ph)]
[PdCl(NʝSe)(PMePh2)]
[PtCl(NʝSe)(PEt3)]
Figure 3. 77Se{1H} NMR spectrum of [PdCl(NʝSe)(PEt3)] in
CDCl3
[PtCl(NʝSe)(PMe2Ph)]
[PdCl(NʝTe)(PPh3)]
[a]
Wavelengths, λmax, at the absorption maxima in nm; molar ex-
tinction coefficients, ε, in Ϫ1·cmϪ1 (in parentheses). [b] Ligand pre-
pared by the Na2S2 route.
Such weak long-wavelength absorptions have been attri-
buted for similar complexes to ligand (E) to ligand (PR3)
charge-transfer (LЈLCT) transitions, based on DFT calcu-
lations.[14,15] The results presented here are fully in line with
this assignment.[14,15,26]
Figure 4. 195Pt{1H} NMR spectrum of [PtCl(NʝSe)(PMe2Ph)] in
CDCl3
4514
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Eur. J. Inorg. Chem. 2004, 4510Ϫ4520

Chalcogenolate Complexes of Palladium(II) and Platinum(II)
FULL PAPER
Crystal Structure Analysis
(PMePh2)] (Figures 5 and 6) contain two crystallograph-
ically independent molecules, both of which show a dis-
order according to the conformations I and J. The structure
was best refined using 45% and 55% occupancy for the two
conformers, respectively (see Figure 6). For the platinum
The molecular structures of [PdCl(NʝS**)(PMePh2)],
[PtCl(NʝS**)(PMe2Ph)],
the
isostructural
complex
[PtCl(NʝSe**)(PMe2Ph)] and two molecules from a crystal
of [PdCl(NʝSe)(PMePh2)] were unambiguously established
by single-crystal X-ray diffraction analyses.
The compounds were found to crystallise in the space
group P21 with the exception of [PdCl(NʝS**)(PMePh2)]
¯
(P1). The quality of the obtained data was excellent
for [PdCl(NʝS**)(PMePh2)], [PtCl(NʝS**)(PMe2Ph)]
and
[PtCl(NʝSe**)(PMe2Ph)]
and
moderate
for
[PdCl(NʝSe)(PMePh2)] (see Exp. Sect.). No significant in-
termolecular contacts were found in any of the crystal
structures. Selected bond lengths and angles for the mol-
ecules are given in Table 4, crystallographic and refinement
data are given in Table 5.
The coordination environments around the central metal
atom in each molecule are approximately square-planar, de-
fined by the P, Cl, N and E atoms. The strong donor atoms
E and P are oriented cis to each other to avoid an unfavour-
able trans interaction. Such a configuration with trans-ori-
ented neutral (P and N) and anionic (Cl and E) donor
atoms has also been reported for several related achiral
complexes.[13Ϫ15,26]
Figure 5. Molecular structure of [PdCl(NʝS**)(PMePh2)]; one of
two independent molecules in one possible orientation is shown
(for disorder I/J, see text) with 30% thermal ellipsoids; H atoms
have been omitted for clarity
The five-membered chelate rings exhibit a twist confor-
mation which, combined with the presence of the methyl
substituent, gives rise to two conformations, I and J, with
different configurations at the asymmetric carbon [(R) for
I and (S) for J]. For three compounds — both platinum
complexes and [PdCl(NʝS**)(PMePh2)] — the crystals
analysed contained exclusively Me2NCH(Me)CH2E (E ϭ S
or Se) ligands (NʝE**), whereas complexes with both iso-
meric ligands NʝSe* and NʝSe** had co-crystallised in
Figure 6. View of [PdCl(NʝS**)(PMePh2)] showing one of two in-
dependent molecules with conformation disorder I/J (30% thermal
[PdCl(NʝSe)(PMePh2)]. The crystals of [PdCl(NʝS**)- ellipsoids; H atoms have been omitted for clarity)
ʝ
[a]
˚
Table 4. Selected bond lengths [A] and bond angles [°] of complexes [MCl(N E)(PR3)]
[PdCl(NʝS**)(PMePh2)]
[PtCl(NʝS**)(PMe2Ph)]
[PdCl(NʝSe)(PMePh2)]
[PtCl(NʝSe**)(PMe2Ph)]
Pd1
Pd2
Pd1(NʝE**)
Pd2(NʝE*)
MϪE
MϪCl
MϪP
MϪN
NϪMϪP
NϪMϪCl
NϪMϪE
PϪMϪCl
ClϪMϪE
PϪMϪE
2.2560(10)
2.3676(10)
2.2399(10)
2.172(2)
2.2521(11)
2.3639(10)
2.2409(9)
2.169(2)
2.235(2)
2.403(3)
2.247(2)
2.130(9)
176.2(3)
91.1(2)
2.323(3)
2.332(6)
2.195(6)
2.149(18)
174.2(6)
97.0(5)
84.0(5)
87.1(2)
176.8(2)
91.78(14)
2.322(4)
2.360(8)
2.184(6)
2.127(17)
177.7(6)
93.5(6)
87.6(6)
86.8(2)
176.6(2)
92.22(18)
2.3860(11)
2.348(3)
2.193(2)
2.220(8)
177.4(3)
89.43(10)
86.6(2)
91.6(2)
177.81(9)
92.42(7)
177.58(7)
177.32(7)
93.40(7)
87.33(7)
88.60(3)
177.83(3)
90.72(3)
93.95(7)
87.10(7)
88.71(3)
176.33(4)
90.27(3)
88.6(2)
86.95(10)
179.40(13)
93.29(9)
[a]
Numbering scheme employed in figures and text is shown below the table.
www.eurjic.org
Eur. J. Inorg. Chem. 2004, 4510Ϫ4520
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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S. Dey, L. B. Kumbhare, V. K. Jain, T. Schurr, W. Kaim, A. Klein, F. Belaj
FULL PAPER
homologue [PtCl(NʝS**)(PMe2Ph)] only one kind of mol- as one conformer (similar to J). Attempts to introduce dis-
ecule with conformation J (see Figure 7) was found in the order models to this molecule were unsuccessful.
crystal. The C(1) atom in this molecule shows some distor-
tion according to a possible disorder. However, attempts to
introduce the same disorder as observed for the palladium
analogue or refining the structure in triclinic space groups
failed. The C(2) atom does not show any sign of disorder;
the extended thermal ellipsoid of C(1) can thus be attri-
buted to a molecular vibration.
Figure 9. Molecular structure of molecule 2 in [PdCl(NʝSe)(P-
MePh2)] (NʝSe* isomer)
The coordination planes around the metal atoms in these
complexes exhibit only small tilt angles (NϪMϪE/
Figure 7. Molecular structure of [PtCl(NʝSe**)(PMe2Ph)] with
ClϪMϪP), ranging between 2.5 and 4.9°. The NϪMϪP
and ClϪMϪE angles are only slightly below 180° (Table 4).
The metalϪligand distances are all longer for the palladium
complexes than for the platinum homologues. This has also
been found in related studies[14,27Ϫ29] and is attributed to
the lanthanide contraction and relativistic effects.[29] The
MϪN and MϪCl distances are slightly longer than those
reported in [M2Cl2(µ-Me2pz)2(PR3)2][30,31] owing to the
strong trans influence of PR3 and E (E ϭ S or Se) donors.
The MϪE, MϪP, MϪN and MϪCl distances and various
angles around the metal centre are similar to those reported
for [MCl(ECH2CH2NMe2)(PR3)] complexes.[13Ϫ15,26]
In summary, it is remarkable that the two crystallised
platinum complexes both contain exclusively the same con-
former J [(S) enantiomer]; the two palladium derivatives
are nonselective in this respect, showing disorder in the che-
late ring according to both conformers in the crystal. For
the selenium derivative [PtCl(NʝSe**)(PMe2Ph)] multiple
selectivity is observed for the molecules in the crystal: (i)
regioselectivity of the ligands Se, Cl, P and N around the
metal atom; (ii) the crystal contains only one regioisomer
(NʝSe**) although the compound was prepared using re-
gioisomeric mixed ligands; (iii) from the two possible con-
formers arising from the twist of the chelate ring only one
conformer (enantiomer) is found in the crystal.
30% thermal ellipsoids; H atoms have been omitted for clarity; the
sulfur analogue [PtCl(NʝS**)(PMe2Ph)] looks essentially the same
The crystals of [PtCl(NʝSe**)(PMe2Ph)] also contain
only one molecule, which clearly shows conformation J
(Figure 7). In contrast, the palladium derivative
[PdCl(NʝSe)(PMePh2)] was found to contain both isomeric
ligands NʝSe* and NʝSe**. One of the two independent
molecules found in the unit cell contains the ligand
Me2NCH(Me)CH2SeϪ (NʝSe**) and exhibits the disorder
described by conformations I and J (Figure 8). This has
also been observed for the sulfur analogue. The other com-
plex molecule, which contains the isomeric ligand
Me2NCH2CH(Me)SeϪ (NʝSe*; Figure 9), exists exclusively
Thermal Studies
The thermal behaviour of some of the complexes has
been evaluated to assess their suitability as molecular pre-
cursors for the synthesis of metal chalcogenides. The TG
curve of [PdCl(NʝS**)(PMePh2)] (Figure 10) shows a
three-step decomposition, finally leading to Pd4S at 374 °C.
The first two stages are overlapping steps which account for
70% of the weight loss. This weight loss can be attributed to
elimination of phosphane, organic residue and the chloride
ligand with the formation of PdS. There is further loss of
Figure 8. Molecular structure of the disordered (I/J) molecule 1 in
[PdCl(NʝSe)(PMePh2)] (NʝSe** isomer)
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Eur. J. Inorg. Chem. 2004, 4510Ϫ4520

Chalcogenolate Complexes of Palladium(II) and Platinum(II)
FULL PAPER
sulfur at 374 °C, resulting in the formation of Pd4S which ligand. Despite these various possibilities of constitutional,
remains stable up to 500 °C. To prepare bulk quantities, a positional and conformational isomerism the isolated com-
sufficient amount of [PdCl(NʝS**)(PMePh2)] (128 mg) was pounds were found to be sufficiently stable to be used as
heated at 400 °C in a furnace and the residue (35 mg, 30 mg molecular precursors for metal chalcogenide phases.
calcd. for Pd4S) was annealed for 2 h. The X-ray powder
pattern of this residue corresponds to that of Pd4S[32]
Experimental Section
(JC,PDS-10-335; analysis: found C 4.7, H ca. 0.2, N ca.
0.2%). Decomposition of [PdCl(NʝSe)(PMePh2)] (107 mg)
at 350 °C in a furnace gave a bulk residue (35 mg, 37 mg
calcd. for Pd17Se15), identified as Pd17Se15 from the XRD
pattern (JC,PDS-29-1427; analysis: found C 2.6, H ca. 0.2,
N ca. 0.2%). The TG curve of [PtCl(NʝS**)(PMe2Ph)]
shows a two-step decomposition, the first step occurring at
265 °C being attributed to the loss of the phosphane ligand
by the weight loss (obsd. 26%, calcd. 28%). The second step
leads to the formation of PtS at 374 °C.
General: The complexes [M2Cl2(µ-Cl)2(PR3)2] (M ϭ Pd or Pt;
PR3 ϭ PnBu3, PnPr3, PEt3, PMe2Ph, PMePh2, PPh3) were prepared
according to literature methods.[33] The phosphanes (Strem Chemi-
cals) and Me2NCH2CH(Me)Cl·HCl (Fluka Chemika, Cat. No.
24367) were obtained from commercial sources. All reactions were
carried out under nitrogen in dry and distilled analytical grade sol-
vents. Microanalyses were carried out in the Analytical Chemistry
Division of BARC. 1H, 13C{1H}, 31P{1H}, 77Se{1H}, 125Te{1H}
and 195Pt{1H} NMR spectra were recorded with a Bruker DPX-
300 NMR spectrometer operating at 300, 75.47, 121.49, 57.24,
94.86 and 64.52 MHz, respectively. Chemical shifts are relative to
the internal chloroform peak at δ ϭ 7.26 ppm for 1H and δ ϭ
77.0 ppm for 13C, external 85% H3PO4 for 31P, Me2Se for 77Se,
[Te(dtc)2] (dtc
ϭ
N,N-diethyldithiocarbamate) for 125Te, and
Na2[PtCl6] in D2O for 195Pt. A 90° pulse was used in every case.
The IR spectra were recorded as Nujol mulls between CsI plates
with a Bomem MB-102 FT-IR spectrometer. UV/Vis absorption
spectra were recorded with a JASCO V-530 spectrometer. Thermo-
gravimetric analysis (TGA) was carried out with a NETZSCH STA
449C instrument calibrated with CaC2O4.H2O. The TG curves were
recorded at a heating rate of 10 °C·minϪ1 under a flow of argon.
X-ray powder diffraction patterns were measured using Cu-Kα radi-
ation.
Preparation of [Me2NCH(Me)CH2S]2 [(NʝS**)2]: Sodium hydro-
gensulfide was prepared by bubbling an excess of hydrogen sulfide
into an ethanolic solution (150 mL) of sodium ethoxide (from
14.02 g Na metal) for 4 h until a pale yellow solid began to separ-
ate. Freshly distilled Me2NCH2CH(Me)Cl (59.34 g, 488 mmol) [ob-
tained
by
neutralising
an
aqueous
solution
of
Me2NCH2CH(Me)Cl·HCl with 10% sodium hydroxide, extracting
with diethyl ether, drying with anhydrous CaCl2 and distilling at
120Ϫ122 °C as a colourless liquid; 1H NMR (CDCl3): δ ϭ 1.49 (d,
J ϭ 6.6 Hz, CHMe), 2.26 (s, NMe2), 2.48 (doublet of AB pattern,
NCH2), 4.02 (m, 6.5 Hz, CHCl) ppm; 13C{1H} NMR (CDCl3): δ ϭ
23.2 (s, CHMe), 45.8 (s, NMe2), 55.1 (s, NCH2), 68.0 (s, CHCl)
ppm] was added dropwise to this solution, whereupon a white pre-
Figure 10. TG curve of [PdCl(NʝS**)(PMePh2)]
Conclusion
This report illustrates how, by NMR spectroscopy and cipitate formed. The reaction mixture was heated to reflux under
nitrogen for 2 h, and, after cooling, the mixture was filtered. The
filtrate was concentrated in vacuo, leaving behind a pale-yellow
solid [Me2NCH(Me)CH2SH] which was found to be contaminated
by disulfide. Oxygen was bubbled through an ethanol solution
(50 mL) of the residue until a yellow liquid was obtained. The sol-
vent was stripped off and the residue was distilled in vacuo at
120Ϫ125 °C/1 Torr to give a yellow oil (30.2 g, 53%). 1H NMR
(CDCl3): δ ϭ 1.00 (d, J ϭ 6.5 Hz, CHMe), 2.19 (s, NMe2), 2.52
(m, CH2S), 2.77Ϫ2.92 (m, NCH) ppm. 13C{1H} (CDCl3): δ ϭ 12.7
(s, CHMe), 40.0 (s, NMe2), 42.4 (s, NCH), 58.2 (CH2S) ppm. The
partial crystal structure analysis, the attempts to obtain am-
inochalcogenolate chelate ligands with an asymmetrically
substituted carbon atom lead to regioisomeric dichalcogen-
ide precursor molecules. In the chiral metal complexes
[MCl(NʝE)(PR3)] (M ϭ Pt, Pd) the neutral (P and N) and
charged donor atoms (Cl and E) were invariably found trans
to each other. Further conformational isomerism in these
complexes results from the twisted chelate rings. Whereas
the two crystallised platinum complexes [PtCl(NʝS**)-
(PMe2Ph)] and [PtCl(NʝSe**)(PMe2Ph)] exhibit exclusively NMR spectra showed resonances attributable to traces (less than
1%) of [Me2NCH2CH(Me)S]2.
one conformer (enantiomer), the palladium derivatives were
nonselective, showing disorder in the chelate ring according
to both conformers in the crystal. The regio- and enantio-
selectivity in the case of the selenium derivative
[PtCl(NʝSe**)(PMe2Ph)] is highly remarkable since the
Preparation of (NʝS)2. [Me2NCH(Me)CH2S]2 [(NʝS**)2] and
[Me2NCH2CH(Me)S]2 [(NʝS*)2]: Finely powdered yellow sulfur
(3.20 g, 100 mmol) and sodium metal (2.37 g, 103 mmol) were al-
lowed to react in liquid ammonia (100 mL) at Ϫ78 °C. The re-
compound was prepared using a regioisomerically mixed sulting yellow solution was stirred for 90 min and the ammonia
Eur. J. Inorg. Chem. 2004, 4510Ϫ4520
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S. Dey, L. B. Kumbhare, V. K. Jain, T. Schurr, W. Kaim, A. Klein, F. Belaj
FULL PAPER
was evaporated by leaving the flask to stand at room temperature.
The yellow residue (Na2S2) was dried under vacuum and dissolved
in DMF (200 mL) with stirring. Freshly distilled Me2NCH2CH(-
methane solution (40 mL) of [Pd2Cl2(µ-Cl)2(PMe2Ph)2] (156 mg,
0.25 mmol) was added to a freshly prepared methanol solution of
NaSCH2CH(Me)NMe2, prepared by treating (NʝS**)2 (58 mg,
Me)Cl (10.5 g, 86 mmol) in DMF (100 mL) was added dropwise. 0.25 mmol) with NaBH4 (19 mg, 0.51 mmol). The reaction mixture
The mixture was stirred at room temperature for 18 h whereupon was stirred at room temperature for 4 h. After solvent evaporation
the green colour of the solution changed to yellow. The reaction
was quenched with water (300 mL) and the product was extracted
with diethyl ether (3 ϫ 60 mL). The ether extracts were dried with
CaCl2. The solvent was stripped off and the residue was distilled
in vacuo, the brown residue was extracted with dichloromethane
(20 mL). The solution was passed through a Florisil column and
the solvent was removed in vacuo. The residue was recrystallised
from a acetone/hexane mixture to give reddish crystals. Other thiol-
in vacuo (100Ϫ105 °C/0.5 Torr) to give a mixture of (NʝS**)2 and ate complexes with M ϭ Pd and PnPr3, PEt3, PMe2Ph, PMePh2 or
(NʝS*)2 as a yellow liquid (7.9 g, 77%). Attempts to separate the
two isomers by vacuum distillation were unsuccessful. 1H NMR
(CDCl3): δ ϭ 1.01 [d, J ϭ 6.5 Hz, (NʝS**)2], 1.26 [d, J ϭ 6.5 Hz,
(NʝS*)2] (CHMe) (ratio 1:2), 2.18 [s, NMe2, (NʝS*)2], 1.20 [s,
NMe2, (NʝS**)2], 2.26Ϫ2.95 (m, NCH, CH2S, NCH2, CHS) ppm.
13C{1H} NMR (CDCl3): (NʝS*)2: δ ϭ 18.6 (s, NMe2), 43.9 (s,
NCH2), 45.3 (s, NMe2), 64.8 (s, CHS) ppm; (NʝS**)2: δ ϭ 12.7 (s,
CHMe), 40.1 (s, NMe2), 42.4 (s, NCH), 58.2 (s, CH2S) ppm [(NʝS*
PPh3 and M ϭ Pt and PnBu3, PnPr3, PEt3, PMe2Ph or PMePh2
were prepared similarly.
Selenolate Complexes: As an example for the selenolate complexes
the synthesis of [PdCl(NʝSe)(PMe2Ph)] is described. An acetone
suspension (20 mL) of [Pd2Cl2(µ-Cl)2(PMe2Ph)2] (180 mg,
0.29 mmol) was added to a freshly prepared methanol solution
(5 mL) of NʝSeNa, prepared from (NʝSe)2 (96 mg, 0.29 mmol)
and NaBH4 (23 mg, 0.61 mmol). The reaction mixture was stirred
for 4 h. The solvents were evaporated in vacuo, the residue was
washed with hexane and extracted with toluene (3 ϫ 8 mL). The
extracts were passed through a Florisil column. The solvent was
reduced to 2 mL and a few drops of hexane were added which, on
cooling to Ϫ5 °C, gave pink crystals (156 mg, 62%). Analogously,
complexes of the type [MCl(NʝSe)(PR3)] (M ϭ Pd with PEt3,
PMe2Ph, PMePh2 or PPh3 and M ϭ Pt with PnBu3, PEt3, PMe2Ph)
were prepared.
1
)2 and (NʝS**)2 in 2:1 ratio from H NMR integration].
Preparation of (NʝSe)2. [Me2NCH(Me)CH2Se]2 [(NʝSe**)2] and
[Me2NCH(Me)CH2Se]2 [(NʝSe*)2]: A mixture of (NʝSe)2 was pre-
pared (in 54% yield) in an analogous manner to the sulfur analogue
as described above, from Me2NCH2CH(Me)Cl and Na2Se2. The
orange liquid was fractionally distilled at 130Ϫ138 °C/2 Torr. 1H
NMR (CDCl3): δ ϭ 1.08 [dd, J ϭ 6.3, 2 Hz, (NʝSe**)2], 1.47 [d,
J ϭ 6.2 Hz, (NʝSe*)2 (CHMe)], 2.22 [br., NCH, (NʝSe**)2], 2.24
(NʝSe**)2, 2.25 (NʝSe*)2 (each s, NMe2), 2.48 [AB pattern with
doublet NCH2, (NʝSe*)2], 2.89 (m, CH2Se), 3.25 [m, CHSe,
(NʝSe*)2] ppm. 13C{1H} NMR (CDCl3): δ ϭ [(NʝSe*)2] 20.8 (s,
CHMe), 36.8 (NCH2), 45.6 (NMe2), 67.0 (SeCH) ppm; [(NʝSe**
)2]: δ ϭ 13.7 (s, CHMe), 35.8 (NCH2), 40.5 (NMe2), 60.3 (SeCH)
ppm. 77Se{1H} NMR (CDCl3): δ ϭ 225.4, 226.6, 286.0, 286.8,
356.5, 357.9, 415.1, 416.2 ppm.
Tellurolate Complexes: As an example for the tellurolate complexes
the synthesis of [PdCl(NʝTe)(PPh3)] is described. To a freshly pre-
pared solution of NʝTeNa, prepared from (NʝTe)2 (127 mg,
0.30 mmol) and NaBH4 (24 mg, 0.63 mmol) in methanol (10 mL),
an acetone suspension (25 mL) of [Pd2Cl2(µ-Cl)2(PPh3)2] (261 mg,
0.30 mmol) was added with vigorous stirring which continued for
3 h. The solvents were removed under vacuum and the residue was
washed with hexane and extracted with acetone (3 ϫ 6 cm3). The
volume of the acetone was reduced to 8 mL which on cooling gave
a brown powder (142 mg, 39% yield). [PtCl(NʝTe)(PnPr3)] and
[PtCl(NʝTe)(PPh3)] were prepared similarly.
Preparation of (NʝTe)2. [Me2NCH(Me)CH2Te]2 [(NʝTe**)2] and
[Me2NCH2CH(Me)Te]2 [(NʝTe*)2]: (NʝTe)2 was synthesised in a
similar manner to the corresponding selenium analogue from
Me2NCH2CH(Me)Cl and K2Te2 (prepared from potassium and
tellurium powder in liquid ammonia). The brown-red liquid was
dissolved in hexane, passed through a Florisil column and dried
under vacuum (yield 68%). The compound was contaminated by
(Me2NCH2CHMe)2Te; attempted vacuum distillation resulted in
X-ray Crystallography: Single crystals of [PdCl(NʝS**)(PMePh2)]
and [PtCl(NʝS**)(PMe2Ph)] were obtained at Ϫ10 °C from
CH2Cl2/hexane and at room temperature from acetone/hexane mix-
tures, while single crystals of [PdCl(NʝSe)(PMePh2)] and
[PtCl(NʝSe**)(PMe2Ph)] were obtained from toluene/hexane mix-
tures at room temperature and Ϫ10 °C, respectively. The X-ray data
of these complexes were collected at 173(2) K or 178(2) K with
Siemens (P4 or P3) or Stoe diffractometers, using graphite-mon-
1
excessive decomposition. H NMR ([D6]acetone): δ ϭ 1.01 [d, J ϭ
6.5 Hz, (NʝTe**)2], 1.66 [d, J ϭ 6.5 Hz, (NʝTe*)2] (CHMe), 2.23
[s, NMe2, (NʝTe**)2], 2.25 [s, NMe2 minor, (NʝTe*)2], 2.75 (m,
CH), 3.12Ϫ3.49 (m, CH2) ppm. 13C NMR ([D6]acetone): [(NʝTe*
)2]: δ ϭ 14.9 (s, CHMe), 35.0 (s, NCH2), 45.5 (s, NMe2), 68.7 (s,
TeCH) ppm; (NʝTe**)2: δ ϭ 13.7 (each s, CHMe), 31.6 (s, NCH),
40.4 (s, NMe2), 61.4 (s, TeCH) ppm. 125Te{1H} NMR ([D6]ace-
tone): δ ϭ Ϫ870 (very small), Ϫ791, Ϫ639 (very small), Ϫ559 ppm;
peaks at δ ϭ Ϫ455, Ϫ461 and Ϫ504 (integrating to about 7%) are
due to partial decomposition of the ligand.
˚
ochromated Mo-Kα radiation (λ ϭ 0.71073 A) and employing
Wyckoff scans. Further details are given in Table 5. All structures
were solved by the Patterson method using the SHELXTL package
while refinement was carried out with SHELXL-97 employing full-
2
2
matrix least-squares methods on F2 with Fo ϭ Ϫ2σ(Fo ).[34] All
non-hydrogen atoms were refined anisotropically, except for the dis-
ordered C and N atoms in the chelate ligand of [PdCl(NʝSe**)-
(PMePh2)]. The same atoms had to be refined using DFIX re-
straints. Hydrogen atoms were introduced using appropriate riding
models. Empirical absorption correction was performed using
XABS2.[35] CCDC-235479 for [PdCl(NʝS**)(PMePh2)], -235480
for [PtCl(NʝS**)(PMe2Ph)], -235481 for [PdCl(NʝSe)(PMePh2)]
and -235482 for [PtCl(NʝSe**)(PMe2Ph)] contain the supplemen-
tary crystallographic data for this paper. These data can be ob-
tained free of charge at www.ccdc.cam.ac.uk/conts/retrieving.html
[or from the Cambridge Crystallographic Data Centre, 12 Union
Synthesis of Palladium(II) and Platinum(II) Complexes: All prep-
arations
involving
thiolate
were
carried
out
using
Me2NCH(Me)CH2SϪ (NʝS**) unless otherwise stated. For the
preparation of selenolate and tellurolate complexes, (EʝN)2 was
employed.
NMR
spectroscopic
data
for
complexes
[MCl(EʝN)(PR3)] are collected in Tables 1 and 2. Yields, recrystal-
lisation solvents and analytical data for all complexes are provided
in the Supporting Information.
Thiolate Complexes: As an example for the thiolate complexes the
synthesis of [PdCl(NʝS**)(PMe2Ph)] is described. A dichloro-
4518
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Eur. J. Inorg. Chem. 2004, 4510Ϫ4520

Chalcogenolate Complexes of Palladium(II) and Platinum(II)
FULL PAPER
Table 5. Crystallographic and structure refinement data of complexes [MCl(NʝE)(PR3)]
[PdCl(NʝS**)(PMePh2)] [PtCl{NʝS**}(PMe2Ph)] [PdCl{NʝSe} (PMePh2)] [PtCl{NʝSe**}(PMe2Ph)]
Empirical formula
Formula mass
Crystal system
Space group
C18H25ClNPPdS
460.27
C13H23ClNPPtS
486.89
monoclinic
P21
5.8519(12)
12.932(3)
11.030(2)
90
98.76(3)
90
825.0(3)/2
1.960
8.874/468
0 Յ h Յ 7
0 Յ k Յ 17
Ϫ15 Յ l Յ 14
2083/1910
0.0214
C18H25ClNPPdSe
507.17
monoclinic
P21
11.480(2)
14.025(3)
12.850(3)
90
102.42(3)
90
C13H23ClNPtSe
533.79
monoclinic
P21
5.8716(12)
13.005(3)
11.132(2)
90
100.24(3)
90
triclinic
¯
P1
˚
a [A]
11.434(2)
13.023(3)
13.932(3)
91.75(3)
92.88(3)
108.37(3)
1964.0(7)/4
1.557
1.267/936
Ϫ1 Յ h Յ 17
Ϫ16 Յ k Յ 15
Ϫ17 Յ l Յ 17
8992/8581
0.0270
˚
b [A]
˚
c [A]
α [°]
β [°]
γ [°]
3
˚
V [A ]/Z
2020.5(7)/4
1.667
836.5(3)/2
2.119
ρcalcd. [g·cmϪ3
]
µ [mmϪ1]/F(000)
2.930/1008
Ϫ14 Յ h Յ 13
Ϫ1 Յ k Յ 17
0 Յ l Յ 15
4364/4364
0.0693
10.802/504
0 Յ h Յ 8
0 Յ k Յ 17
Ϫ15 Յ l Յ 14
2259/2086
0.0284
Limiting indices
Refl.collected/unique
Rint
Data/restr./param.
8581/0/457
1.317
1910/0/168
1.177
4364/11/407
1.128
2086/1/168
1.058
Goof on F2
Final R1, wR2 indices
R1, wR2 (all data)
0.0322, 0.0735
0.0443, 0.0771
0.0321, 0.0786
0.0346, 0.0799
2.248/Ϫ1.553
0.0715, 0.1439
0.1074, 0.1619
0.998/Ϫ0.913
0.0271, 0.0677
0.0287, 0.0685
1.138/Ϫ0.962
Largest diff. peak/hole [e·AϪ3] 0.631/Ϫ0.685
˚
[8]
J. A. Ayllon, P. Gonzalez-Duarte, C. Miravittles, E. Molins, J.
Chem. Soc., Dalton Trans. 1990, 1793.
M. Capdevila, W. Clegg, P. Gonzalez-Duarte, I. Mira, J. Chem.
Road, Cambridge CB2 1EZ, UK; Fax: ϩ 44-1223-336-033; E-mail:
deposit@ccdc.cam.ac.uk].
[9]
Supporting Information (see also footnote on the first page of this
article): Further tables with analytical data for all new complexes
and structural details of [PdCl(NʝS**)(PMePh2)], [PtCl(NʝS**)-
(PMe2Ph)], [PdCl(NʝSe)(PMePh2)] and [PtCl(NʝSe**)(PMe2Ph)]
are available. Further figures illustrating the crystal and molecular
structures are also provided.
Soc., Dalton Trans. 1992, 173.
[10]
M. Capdevila, W. Clegg, P. Gonzalez-Duarte, B. Harris, I.
Mira, J. Sola, I. C. Taylor, J. Chem. Soc., Dalton Trans. 1992,
2817.
S. Marchal, V. Moreno, G. Aullon, S. Alvarez, M. Quiros, M.
Font-Bardia, X. Solans, Polyhedron 1999, 18, 3675.
J. Real, M. Pages, A. Polo, J. F. Pinella, A. Alvarez-Larena,
Chem. Commun. 1999, 277.
S. Dey, V. K. Jain, S. Chaudhury, A. Knoedler, F. Lissner, W.
Kaim, J. Chem. Soc., Dalton Trans. 2001, 723.
S. Dey, V. K. Jain, A. Knoedler, A. Klein, W. Kaim, S. Zalis,
Inorg. Chem. 2002, 41, 2864.
S. Dey, V. K. Jain, A. Knoedler, W. Kaim, S. Zalis, Eur. J. Inorg.
Chem. 2001, 2965.
S. Dey, V. K. Jain, A. Knoedler, W. Kaim, Inorg. Chim. Acta
2003, 349, 104.
S. Dey, V. K. Jain, A. Klein, W. Kaim, Inorg. Chem. Commun.
[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
[21]
Acknowledgments
We thank Drs. J. P. Mittal, T. Mukherjee and S. K. Kulshreshtha
for encouragement of this work. We are also grateful to Dr. M.
Sudershanan, Head, Analytical Chemistry Division, BARC for
providing microanalyses of the complexes. Dr. M. Bader (Univer-
sity of Stuttgart) is thanked for collecting single crystal XRD data,
as is Dr. Rudolph Pietschnig (University of Graz) for collecting
NMR spectroscopic data. Support for this work under the Indo-
German bilateral program from the BMBF (Project No. IND 99/
060) is gratefully acknowledged.
2004, 7, 601.
T. Konno, T. Yoshimura, K. Aoki, K. Okamoto, M. Hirotsu,
Angew. Chem. Int. Ed. 2001, 1765.
H. Honda, T. Yoshimura, M. Hirotsu, T. Kawamoto, T.
Konno, Inorg. Chem. 2002, 41, 2229.
T. Konno, H. Honda, Y. Chikamoto, T. Kawamoto, T. Yoshi-
mura, M. Hirotsu, Chem. Lett. 2002, 472.
[1]
M. Bochmann, Chem. Vap. Deposition 1996, 2, 85.
A. Singhal, V. K. Jain, R. Misra, B. Varghese, J. Mater. Chem.
[2]
J. Cheon, S. D. Talaga, J. I. Zink, Chem. Mater. 1997, 9, 1208.
2002, 1121.
[22] [22a]
[3] [3a]
D. Burton, W. D. Ollis, Comprehensive Organic Chemistry,
S. Dey, V. K. Jain, J. Singh, V. Trehan, K. K. Bhasin, B.
[22b]
Varghese, Eur. J. Inorg. Chem. 2003, 744. [3b] S. Dey, V. K. Jain,
Platinum Met. Rev. 2004, 48, 16.
Pergamon Press, Oxford, 1979, vol. 2, pp. 52Ϫ55.
A. K.
Katritzky, O. Meth-Cohn, C. W. Rees, Comprehensive Organic
Functional Group Transformations Pergamon Press, Oxford,
1995, vols. 1 and 2.
[4]
A. M. Malik, P. O’ Brien, N. Revaprasadu, J. Mater. Chem.
2002, 12, 92.
[23]
[24]
[25]
[5] [5a]
[5b]
R. Kaur, H. B. Singh, R. P. Patel, J. Chem. Soc., Dalton Trans.
1996, 2719.
G. Mugesh, A. Panda, H. B. Singh, N. S. Punekar, R. J.
Butcher, Chem. Commun. 1998, 2227.
G. Mugesh, A. Panda, H. B. Singh, R. J. Butcher, Chem. Eur.
I. G. Dance, Polyhedron 1986, 5, 1037.
P. J. Blower, J.
R. Dilworth, Coord. Chem. Rev. 1987, 76, 121.
[6]
[7]
J. Sola, R. Yanez, J. Chem. Soc., Dalton Trans. 1986, 2021.
M. Capdevila, P. Gonzalez-Duarte, C. Foces-Foces, F. H.
Cano, M. Martinez-Ripoll, J. Chem. Soc., Dalton Trans.
1990, 143.
J. 1999, 5, 1411.
Eur. J. Inorg. Chem. 2004, 4510Ϫ4520
www.eurjic.org
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
4519

S. Dey, L. B. Kumbhare, V. K. Jain, T. Schurr, W. Kaim, A. Klein, F. Belaj
FULL PAPER
[26]
[32]
S. Dey, V. K. Jain, A. Knoedler, W. Kaim, Indian J. Chem.
2003, 42A, 2339.
P. P. Phadnis, V. K. Jain, A. Klein, M. Weber, W. Kaim, Inorg.
Chim. Acta 2003, 346, 119.
P. P. Phadnis, V. K. Jain, A. Klein, T. Schurr, W. Kaim, New J.
Chem. 2003, 1584.
K. Herbst, B. Rink, L. Dahlenburg, M. Brorson, Organomet-
allics 2001, 20, 3655.
V. K. Jain, S. Kannan, E. R. T. Tiekink, J. Chem. Soc., Dalton
Trans. 1993, 3625.
V. K. Jain, S. Kannan, E. R. T. Tiekink, J. Chem. Soc., Dalton
Trans. 1992, 2231.
F. Gronvold, E. Rost, Acta Crystallogr. 1962, 15, 11.
F. R. Hartley, The Chemistry of Platinum and Palladium, John
Wiley & Sons, New York, 1973.
[33]
[27]
[28]
[29]
[30]
[31]
[34] [34a] G. M. Sheldrick, SHELXTL, Bruker Analytical X-ray Sys-
[34b]
tems, Madison, Wisconsin, USA, 1998.
G. M. Sheldrick,
SHELXL-97: A program for Crystal Structure Determination,
Universität Göttingen, Göttingen, Germany, 1997.
XABS2: S. Parkin, B. Moezzi, H. Hope, J. Appl. Crystallogr.
1995, 28, 53.
[35]
Received June 16, 2004
Early View Article
Published Online September 9, 2004
4520
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www.eurjic.org
Eur. J. Inorg. Chem. 2004, 4510Ϫ4520