Functionalized 1,1-ethene dithiolates as ligands, V [1]. Synthesis and crystal structure of palladium(II) and platinum(II) complexes with dithioylidene barbituric acid ligands. Molecular structure of a 2,6-diaminopyridine-platinum(II) barbiturate complex

Article abstract of DOI:10.1515/znb-1998-1009

The 1,1-ethene dithiolato ligands (dithioylidene barbituric acids) 2a-f react with palladium(II) and platinum(II) compounds L₂MCl₂ [M = Pd, Pf, L = PEt₃, PBu₃, PPh₃, 1/2 dppe, 1/2 (-)-DIOP, 1/2 2,9-dimethyl phenanthroline] to give the 1,1-ethene dithiolato metal complexes L₂M[S₂C=C-C(O)-NR¹-C(O)-NRZ-C(O)] 3-7. Compound 4a forms a 1:1 adduct (8) with 2,6-diaminopyridine. The compounds were characterised on the basis of their IR and NMR (¹H, ¹³C, ³¹P) spectra. Complexes 4a, 4c, and 5a were further studied by X-ray structural analysis. The barbituric unit in 4a undergoes self-assembly through multiple hydrogen-bonding with complementary 2,6-diaminopyridine yielding the supramolecular complex 8.

Full text of DOI:10.1515/znb-1998-1009

Functionalized 1,1-Ethene Dithiolates as Ligands, V [1].
Synthesis and Crystal Structure of Palladium(II) and Platinum(II) Complexes
with Dithioylidene Barbituric Acid Ligands. Molecular Structure of a
2,6-Diaminopyridine-Platinum(II) Barbiturate Complex
Wolfgang Weigand*,a, Veronika Plener3, Heinrich Nöth#,b, Ingo Krossing#,b,
Jörg Knizek#b, Martin Schmidt#,b
a Institut für Anorganische und Analytische Chemie der Friedrich-Schiller-Universität Jena,
August-Bebel-Straße 2, D-07743 Jena
b Institut für Anorganische Chemie der Ludwig-Maximilians-Universität München,
Meiserstraße 1, D-80333 München
Dedicated to Professor Dr. Dr. h. c. Dieter Seebach on the occasion of his 60th birthday
Z. Naturforsch. 53 b, 1135-1143 (1998); received June 8, 1998
Intermolecular Hydrogen-Bonding, Supramolecular Self-Assembly, Dithioylidene Barbituric
Acid, Palladium Complex, Platinum complexes
The 1,1-ethene dithiolato ligands (dithioylidene barbituric acids) 2a-f react with palla-
dium^) and platinum(II) compounds L2MCI2 [M = Pd, Pt; L = PEt3, PBu3, PPh3, 1/2 dppe,
1/2 (-)-DIOP, 1/2 2,9-dimethyl phenanthroline] to give the 1,1-ethene dithiolato metal com-
plexes L2M[S2C=C-C(0 )-NRI-C(0 )-NR2-C(0 )] 3-7. Compound 4a forms a 1:1 adduct (8)
with 2,6-diaminopyridine. The compounds were characterised on the basis of their IR and
NMR ('H, 13C, 3iP) spectra. Complexes 4a, 4c, and 5a were further studied by X-ray structural
analysis. The barbituric unit in 4a undergoes self-assembly through multiple hydrogen-bonding
with complementary 2,6-diaminopyridine yielding the supramolecular complex 8.
Introduction
Whitesides et al. [7], Hamilton et al. [8], and others
[9]. However, little is known about the coordination
chemistry of these biologically important ligands.
Barbituric acid and its derivatives can coordinate
through one or both of their deprotonated nitrogen
atoms, and the carbonyl oxygen atoms, and the par-
ent barbituric acid through the deprotonated methy-
lene group giving access to a wide range of metal
complexes. So far, most studies have concentrated
on the first-row Transition Metals [10], and rela-
tively few experiments are reported for platinum
group metals [11] or copper, silver, gold and zinc
[12], Very recently platinum(II) complexes of 5,5-
diethyl barbituric acid containing ancillary phos-
phane ligands have been prepared [13]. A number of
transition metal complexes of related ligands such
as orotic acid, 5-aminoorotic acid, and 5-(2-pyridyl
methylene)hydantoin have been reported by Min-
gos et al. [14],
The reactions of ketones as well as of other active
methylene compounds with carbon disulfide in the
presence of a base yielding the 1,1-ethene dithio-
lates are known since 1891 [2]. There is currently
a growing interest in the preparation of metal com-
plexes containing functional 1,1-ethene dithiolato
ligands which allow the synthesis of heterodi- and
-trimetallic compounds [31, complexes exhibiting
fluorescence [4] as well as amphihilic and metal-
lomesogenic [5]. The occurrence of such properties
is usually achieved by subtle changes in the specific
functionalities of a given ligand system.
Barbituric acid is also readily converted into the
1,1-ethene dithiolate by carbon disulfide in the pres-
ence of triethylamine. Its derivatives have attracted
considerable interest as models for molecular self-
assembly processes as shown by Lehn et al. [61,
We aimed at a synthesis of palladium(II) and
platinum(II) complexes with 1,1-ethene dithiolato
derivatives of barbituric acid (dithioylidene barbi-
turic acids) as ligands. These compounds should
* Reprint requests to Prof. Dr. Wolfgang Weigand;
E-mail: c8wewo@rz.uni-jena.de.
# Crystal structure determination.
0932-0776/98/1000-1135 $ 06.00 © 1998 Verlag der Zeitschrift für Naturforschung, Tübingen ■www.znaturforsch.com
K
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W. Weigand et al. • Functionalized 1,1-Ethene Dithiolates as Ligands, V
1136
Q - " "
CS: / NEt,
R
r'-n A n- r2
/ —N
H
2 HNEt ,+
H -N
D M S O / 2 h
° Y °
\
N —^
S ^
PEtj
la -f
.■'0=(
/ Pt\
PE t3
O
h
'
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S
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Et3P \
JS
) - N
,'H
0
R2
R 1
X
x
Et3P
> - N
O
\
H
a
b
c
d
e
f
H
H
H
N -H
CH,
H
H
N—/
H
QH,3
c 12h 25
c h 3
H
c h 3
CH2Ph
CH2Ph
1625-1716 cm-1 assigned to the non-equivalent
carbonyl groups. i/(NH) bands are detected at 3030 -
3435 cm-1 for the A^N'-unsubstituted as well as
the /V-monosubstituted complexes, which indicate
the presence of strong hydrogen-bonds of type
NH 0=C [16].
be able to form two or three strong intermolecular
hydrogen bonds particularly with a complementary
base like 2 ,6 -diamino pyridine.
Results and Discussions
The 1,1-ethene dithiolates 2a-f have been pre-
pared in a one-step synthesis by treating a DMSO
solution of the barbituric acids la - c with carbon
disulfide in the presence of triethylamine at room
temperature [15]. The reactions between the result-
The 31 P {1H} NMR spectra of the platinum com-
plexes 4a-d and 6a-c show singlets with 195Pt
satellites indicating the presence of two equivalent
phosphorus atoms. In contrast, the 31 P {1H} NMR
spectra of the N-monosubstituted complexes 5a - d
ing orange suspensions with (Ph3P)2PdCl2 and the exhibit AB spin patterns for two chemically non-
platinum(II) complexes L2PtCl2 [L = PEt3, PBu3, equivalent phosphorus atoms. The coupling con-
PPhi, 1/2 dppe, 1/2 (-)-DIOP], respectively, pro-
ceed smoothly in DMSO at room temperature to
give the metal complexes 3-6 as yellow air-stable
microcrystalline solids in good yields. Complexes
stants 17(195Pt-31P) are rather similar to each other.
The 1H NMR spectra of 3 - 5d and 7 show in each
case one resonance due to the NH protons. The
chemical shifts of these protons are concentration
3, 4a - c, 5a, b, and 6a, c are isolated by recrystalli- dependent in CDCI3 or CD2CI2 suggesting hydro-
sation from a mixture of dichloromethane / hexane
gen-bond interactions between the barbituric acid
or by chromatography.
fragments.
The IR spectra show three (3-5d, 7) or two
(6a - c) intense bands, respectively, in the range of
In the 13C {1H} NMR spectra of 4a, 5b, c, and
6c the S2C=C resonances appear between 216 and
L
R1
R2
H
Bu3P
\
/ S
-N
PEt3
H
4a
4b
4c
r , - n '
V
r !
'Pd\
'
S
x
0
PBu3
1/2dppe
1/2 (-)-DIOP
PBu3
PBu3
PBu3
PPh,
H
H
B u ,P '
A—NC6H!3
o
LoPtCU
H
H
2a-f
H
H
4d
Sa
5b
Sc
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6a
6b
6c
DMSO
s ' 'S
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c h 3
c 6h ,3
H
Pt
H
/ \
H
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Q ,h 13
c h 3
4-6
H
PBu3
PPh3
c h 3
c h 3
CH2Ph
c h 3
PBu3
CH2Ph
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W. Weigand et al. • Functionalized 1,1-Ethene Dithiolates as Ligands, V
1137
Fig. 1. Part of the hydrogen-bonded zig-zag chain formed by 4a; for the sake of clarity the hydrogen atoms at the
phosphine ligands have been omitted. Selected atom distances [pm] and bond angles [°j: Pt( 1)-S( 1) 234.6(2), Pt( 1)-
S(2) 234.1(2), Pt(l)-P(l) 228.2(3), Pt(l)-P(2) 227.8(2), S(l)-C(l) 174.0(9), S(2)-C(l) 173.2(8), C(l)-C(2) 140.0,
N (6b)-0(5c) 283, N(4e)--0(3a) 280; P(l)-Pt(l)-P(2) 101.86(9), S(l)-Pt(l)-S(2) 73.59(8), S(l)-C(l)-S(2) 107.9(5),
S(l)-C(l)-C(2) 125.9(7), S(2)-C(l)-C(2) 126.2(7).
Fig. 2. Molecular structure
C200
of 4c • 2 DMSO; for the
sake of clarity the hydrogen
atoms at the phosphine lig-
ands have been omitted. Se-
lected atom distances [pm]
and bond angles [°]:
Pt( 1)-S( 1) 234.12 (9),
Pt(l)-S(2) 234.54 (9),
Pt(l)-P( 1)227.30 (9),
Pt(l)-P(2) 226.52(9),
S(l)-C(l) 175.3 (4),
S(2)-C(l) 174.4 (3),
C(l)-C(2) 138.6 (5),
S(20)-0(20) 149.5 (3),
S(30)-0(30) 151.1 (3),
N(2)--0(20) 276,
N (l)-0 (3 0 ) 285;
P(l)-Pt(l)-P(2) 85.80 (3),
S(l)-Pt(l)-S(2) 73.99 (3),
S(l)-C(l)-S(2) 107.9 (5),
S(l)-C(l)-C(2) 126.0(3),
S(2)-C(l)-C(2) 126.4 (3).
of the quaternary S2C=C carbon atom appear for 4a
and 5a, c at b ~ 108 with l95Pt satellites. Complexes
4a and 6c show the expected two, and complexes
5a, c three carbonyl 13C NMR resonances.
220 ppm; in the case of 5a a three-bond cou-
pling to the tributylphosphane phosphorus atom (3.5
Hz) and a two-bond coupling to the 195Pt isotope
(79.3 Hz) are resolvable. The 13C NMR resonances
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1138
W. Weigand et al. ■Functionalized 1,1-Ethene Dithiolates as Ligands, V
Fig. 3. Hydrogen-bonded dimers of
complex 5a; for the sake of clar-
ity the butyl groups at the phos-
phines have been omitted. Selected
atom distances [pm] and bond an-
gles [°]: Pt( 1)-S( 1) 233.6 (3), Pt( 1)-
S(2) 233.8 (3), Pt(l)-P(l) 227.7
(3), Pt(l)-P(2) 227.4 (3), S(l)-C(l)
172.1 (10), S(2)-C(l) 172.8 (9),
C(l)-C(2) 140.6 ( 12), N (6)-0(5)
294; P(l)-Pt(l)-P(2) 101.24 (9),
S( 1)-Pt( 1)-S(2) 73.81 (8), S(l)-
C( 1)-S(2) 108.8 (5), S( 1)-C( 1)-C(2)
124.4(7), S(2)-C(l)-C(2) 126.6 (7).
Molecular Structures of 4a, 4c, 5a and 8
The molecular structure of complexes 4a, 4c • 2
DMSO, 5a and 8 are depicted in Figs. 1- 4 and bond
lengths and angles in the captions to the figures.
Compounds 4a, 4c and 5a crystallise from a mixture
of dichloromethane / DMSO [8:1] at 0°C.
The crystal structure of 5a (Fig. 3) confirms
that lb is acting as a bidendate dianionic ligand.
The molecules 5a form centrosymmetrical dimers
via two equivalent N (6 )-H -0 (5 ) hydrogen bonds;
the N (6)0(5) distance is 294 pm. The platinum(II)
ion resides in a square-planar environment. The
planes Pt(l)P(l)P(2) and Pt(l)S(l)S(2) include an
angle of 5.4°. The plane Pt(l)S(l)S(2)C (l) and the
barbituric acid moiety are slightly tilted with re-
spect to each other, the interplanar angle being
12.3°. The two Pt-S bonds are of equal lengths
[233.6(3) and 233.8(3) pm]; comparable values
are found in (Ph3P)2Pt[S2C=CH-C(0)Ph] [4g]
and(Ph3P)2Pt[S2C=CH-C(0)(C5H4)Fe(C5H5)] [3],
The intramolecular S(l)-- S(2) distance (280.4 pm)
is significantly shorter than the sum of the van
der Waals radii; this corres-ponds with data for
other 1,1-ethene dithiolato platinum(II) complexes
[3, 4g],
Fig. 4. Molecular structure of 8; the hydrogen-bonded
adduct formed between 4a and 2,6-diaminopyridine; for
the sake of clarity the ethyl groups at the phosphines have
been omitted. Selected atom distances [pm] and bond an-
gles [°]: Pt(l)-S(l) 233.3(6), Pt(l)-S(2) 234.0(4), Pt( 1)-
P(l) 228.3(6), Pt(l)-P(2) 227.9(6), S(l)-C(13) 171(2),
S(2)-C(13) 170(2), C(13)-C(14) 144(3), N(la)--0(2b)
287, N(3a)-0(2a) 300, N(2a)-N(5a) 286, N(4a)-0(3a)
306; P(l)-Pt(l)-P(2) 100.2(2), S(l)-Pt(l)-S(2) 73.4(2),
S(l)-C(13)-S(2) 110.0(11), S(l)-C(13)-C(14) 125.0(14),
S(2)-C(l)-C(2) 124.6(14).
Contrary to 5,5-diethylbarbituric acid which forms
six different polymorphs [17], 4a does not show
polymorphism. Further hydrogen-bonding modes
leading to poly-morphism are prevented in 4a by the
bisphosphine platinum(II) complex fragment which
is acting as a blocking group [14a, e].
Unlike 4a and 5a the molecular structure of
compound 4c (Fig. 2) shows that in this complex
the barbituric acid units are not interconnected by
hydrogen-bonds. The reason seems to be the steri-
cally demanding dppe ligand. However, hydrogen-
bonds are formed between the N-H and the 0= S
The molecular structure of 4a (Fig. 1) reveals
a zig-zag like polymeric motif. A folded ribbon
is formed by a continuous array of the barbituric
acid units, each of which is linked via pairs of
N-H - O hydrogen bonds between the imido N-H
atoms and the carbonyl O atoms [N(6)-H - 0(5) /
N(4)-H-- 0(3)]. The distance between N(6b) and
0(5e) as well as 0(5b) and N(6e), respectively is
73.1 pm. The hydrogen-bonding distances between
the barbituric acid ligands indicate strong interac-
tions: N(6) - 0(5) 283 pm, N (4 )-0 (3 ) 280 pm.
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W. Weigand et al. • Functionalized 1,1-Ethene Dithiolates as Ligands, V
1139
groups of the smaller, solvate DMSO molecules
(vide supra) [N (l)-0 (3 0 ) 285 pm, N (2 )-0 (2 0 )
276 pm].
Preparation of 3
At r. t. a mixture of 0.8 mmol (1 ml of the DMSO stock
solution) of 2c was added to a solution of 0.29 g (0.5
mmol) of (Bu3P)2PdCl2 in 10 ml of DMSO. The orange-
yellow mixture was stirred for 2 d at r. t. After addition of
10 ml of water the suspension was extracted with three
20-ml portions of dichloromethane. The combined or-
ganic extracts were washed with 20 ml of water and dried
with sodium sulfate. The solvent was removed in vacuo,
and the resulting orange residue was purified by column
chromatography using hexane/ethyl acetate (2:1) as the
eluent. The main orange-yellow fraction, eluted first, was
collected and the solvent was removed in vacuo. Orange
powder. - Yield 0.24 g (59%), m. p. > 250 °C (dec.). -
IR (KBr): u = 3432 cm-1 (w, br), 3184 (m), 3065 (m)
(OH/NH), 1700 (s), 1673 (s), 1635 (s) (C=0), 1462 (s),
1392 (vs, br) (C=C/C=0). - 1H NMR (JEOL FX 90-Q, 90
MHz, CDC13): <5= 3.81 (m, 2H, NCH2), 8.89 (br. s, 1H,
NH). - 31P NMR (JEOL FX 90-Q, 36.21 MHz, CH2C12):
6 = 8.0.
Suitable single co-crystals of 8 (Fig. 4) were ob-
tained from a dichloromethane solution containing
equimolar amounts of 4a and 2,6-diaminopyridine
at room temperature. Each molecule of 4a is linked
to a 2,6-diaminopyridine molecule via three hydro-
gen-bonds - one shorter [N(2) - N(5) 286 pm] and
two longer [N (3 )-0 (2 ) 300 pm, N (4 )-0 (3 ) 306
pm] linkages. The weakness of the two interactions
N(3)---0(2) as well as N (4)--0(3) is a consequence
of the non-coplanarity of the barbituric acid unit
and the 2,6-diaminopyridine ring which are tilted by
36° with respect to each other. These 1+1 adducts
are associated into 2+2 dimers through two strong
hydrogen-bonds between the amido protons N (l)-
H and the carbonyl 0(2) atoms [N (l)--0 (2 ) 287
pm]. Further oligomerisation of the 2+2 adducts is
prevented by the bisphosphine platinum(II) com-
plex fragment. A similar hydrogen-bonding motif
has been observed between platinum(II) orotate and
2,6-diaminopyridine [14d].
C35H68N20 3P2PdS2 (M = 191.4 g/mol)
Calcd C 52.72 H 8.59 N3.51 S 8.04 %,
Found C 52.79 H 8.33 N 3.54 S 8.70 %.
4a was prepared from 0.8 mmol (1 ml of the
DMSO stock solution) of 2a and 0.25 g (0.5 mmol) of
(Et3P)2PtCl2 in 10 ml of DMSO (reaction time: 2 d,
colour: bright-yellow) and the product was purified as
described for 3. Yellow powder. - Yield 0.21 g (67 %),
m. p. > 250 °C (dec.). - IR (KBr): u = 3436 cm- 1 (w, br),
3194 (m), 3033 (w) (OH/NH), 1748 (m), 1710 (s), 1676
(s), 1635 (s) (C=0), 1451 (s), 1401 (vs, br) (C=C/C=0).
- ‘H NMR (CD2C12): 6 = 7.86 (br. s, 2H, NH). - 13C
NMR (CD2C12): 6 = 107.34 (s, S2C=C), 149.44, 161.70
(s, C=0), 220.81 (s, S2C =C). - 31P NMR (CD2C12): 6 =
4.78 (s, */(195Pt-3,P) = 2862 Hz).
Experimental
Dry DMSO, barbituric acid (la) and 2,6-
diaminopyridine were purchased from Fluka. /V-Methyl
barbituric acid (lb) [18], /V-hexyl barbituric acid (lc)
[18], /V-dodecyl barbituric acid (Id) [18], /V,/V'-dimethyl
barbituric acid (le) [19], /V,/V'-dibenzyl barbituric acid
(If) [19] as well as the complexes (Bu3P)2PdCl2 [20],
(Et3P)2PtCl2[21], (Bu3P)2PtCl2[20], (Ph3P)2PtCl2[20],
(dppe)PtCl2[22], [(-)-DIOP]PtCl2[22] and (2,9-dimethyl-
phenanthroline)PtCl2 [23] were prepared according or
analogously to literature procedures. Chromatography:
Kieselgel 60 (Merck); column length: 40 cm, column
diameter: 4 cm. - IR: Perkin-Elmer 841, Nicolet 520. -
NMR: JEOL GSX 270 (109.37 MHz for31P; H3P04as ex-
ternal standard), JEOL EX 400 (399.78 and 100.53 MHz,
for 1H and 13C, respectively). For 1H and l3C NMR TMS
was used as an internal standard. - Elemental analyses:
Heraeus VT. - Melting and decomposition points (uncor-
rected): Electrothermal Digital Melting-Point-Apparatus.
Ci7H32N20 3P2PtS2 (M = 633.6 g/mol)
Calcd C 32.23 H 5.09 N4.42 S 10.12%,
Found C 33.07 H 5.05 N 3.94 S 10.20%.
4b was prepared from 0.8 mmol (1 ml of the
DMSO stock solution) of 2a and 0.34 g (0.5 mmol) of
(Bu3P)2PtCl2 in 10 ml of DMSO (reaction time: 22 h,
the colour changes from dark red-brownish to red) and
the purification (column chromatography: hexane/ethyl
acetate 5:1) of the product was carried out as described
for 3. Red-orange powder. - Yield 0.28 g (55 %), m. p.
> 250 °C (dec.). - IR (KBr): v = 3184 cm-1 (w, br),
3086 (w), 3050 (w) (OH/NH), 1712 (s), 1679 (m), 1632
(s) (C=0), 1463 (m, br), 1396 (vs, br) (C=C/C=0). - ‘H
NMR (CDC13): 6 = 7.32 (br. s, 2H, NH). - 31P NMR
(CHCI3): 6 = -2.92 (s, ]J(195Pt-31P) = 2860 Hz)
General procedurefor compounds 2a - f
To solutions of 10 mmol of la -f in 10 ml of DMSO
were added triethylamine (2.80 ml, 20 mmol) and carbon
disulfide (0.6 ml, 10 mmol). The solutions were stirred
for 2 h at r. t. During this period they turned orange. These
stock solutions were used for further experiments.
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1140
W. Weigand et al. • Functionalized 1,1-Ethene Dithiolates as Ligands, V
colour changes from red to yellow) and the product was
purified as described for 3 (column chromatography: hex-
ane / ether 5:1). Yellow powder, - Yield 0.16 g (36 %),
m.p. 171 °C. - IR (KBr): v = 3429 cm-1 (w), 3238 (w,
br), 3063 (w) (OH/NH), 1711 (vs), 1675 (s), 1640 (s)
(C=0), 1434 (s), 1401 (vs, br) (C=C/C=0). - 'H NMR
(CDCI3): 6 = 7.36 (s, 1H, NH), 3.09 (m, 2H, NCH2). -
31P NMR (CDCb): 8 = -2.65 / -2.86 (AB spin system,
'7(l95Pt-31P) = 2855 / 2858 Hz, 27(3IP-31P) = 21.5 Hz).
C29H5öN203P2PtS2 (M = 801.9 g/mol)
Calcd C 43.44 H 7.04 N 3.49 S 8.00%,
Found C 42.10 H 6.92 N 3.23 S 9.38%.
4c was prepared from 0.4 mmol (0.5 ml of the DMSO
stock solution) of 2a and 0.12 g (0.3 mmol) of (dppejPtCb
in 10 ml of DMSO (reaction time: 20 h, colour: yellow
suspension). The product was purified as described for
3. Yellow powder. - Yield 0.32 g (81 %), m. p. > 250 °C
(dec.). - IR (KBr): v = 3291 cm“ 1 (w, br), 3191 (w), 3074
(w, br) (OH/NH), 1748 (m), 1724 (s), 1677 (s), 1625 (s)
(C=0), 1435 (s), 1406 (vs, br) (C=C/C=0). - 'H NMR
(CDC13): 6 = 2.35 - 2.48 (m, 4H, PCH2CH2P). - 31P NMR
(CDCb): 6 = 40.48 (s, 'y(,95Pt-3lP) = 2877 Hz).
C35H68N2O3P2PtS2 (M = 886.1 g/mol)
Calcd C 47.44 H 7.74 N3.16 S 7.24 %,
Found C 47.50 H 7.53 N 3.00 S 7.25 %.
5c was prepared from 0.8 mmol (1 ml of the
DMSO stock solution) of 2d and 0.34 g (0.5 mmol) of
(Bu3P)2PtCl2 in 10 ml of DMSO (reaction time: 22 h,
colour: orange-yellow). The purification (column chro-
matography: hexane / ethyl acetate 2:1) of the product
was carried out as described for 3. Yellow powder. -
Yield 0.21 .g (44 %), m. p. 129 °C. - IR (KBr): v = 3338
cm-1 (w), 3163 (w), 3117 (w) (OH/NH), 1716 (s), 1662
(s), 1633 (s) (C=0), 1450 (s), 1406 (vs, br) (C=C/C=0).
- 'H NMR (CDCI3): 6 = 7.38 (s, 1H, NH), 3.83 (m, 2H,
NCH2). - 13C NMR (CDCI3): 6 =40.42 (s, NCH3), 108.85
(s, S2C= 0 , 150.63, 160.92, 162.51 (s, C=0), 217.54 (s,
S2C =C). - 31P NMR (CDC13): 6 = -2.75 / -3.12 (AB
spin system, '7(195Pt-31P) = 2857 / 2859 Hz, 2/(3lP-3lP)
= 21.4 Hz).
C31H26N2O3P2PtS2 (M = 795.7 g/mol)
Calcd C 46.79 H 3.29 N 3.52 S 8.06 %,
Found C 45.96 H 3.29 N3.18 S 8.33 %.
4d was prepared from 0.4 mmol (0.5 ml of the DMSO
stock solution) of 2a and 0.23 g (0.3 mmol) of [(-)-
DIOP]PtCl2 in 10 ml of DMSO (reaction time: 2d, colour
changes from orange to bright yellow). The product was
purified as described for 3. Yellow powder. - Yield 0.26 g
(59 %), m. p. > 250 °C (dec.). - IR (KBr): u = 3429 cm“ '
(m, br), 3208 (w), 3071 (w, br) (OH/NH), 1721 (s), 1681
(s), 1651 (s) (C=0), 1434 (s), 1418 (vs, br) (C=C/C=0).
- 'H NMR (CD2C12): 6 = 1.25 (s, 6H, CH3), 2.64 / 3.27
(m, 6H, CH2), 4.02 (m, 2H, OCH). - 31P NMR (CD2C12):
6 = 2.25 (s, ‘7(l95Pt-31P) = 2853 Hz)
C4iH8oN203P2PtS2 (M = 970.2 g/mol)
Calcd C 50.76 H8.31 N 2.89 S 6.61 %,
Found C 50.86 H8.16 N 2.93 S6.71%.
C36H34N2O5P2PtS2 (M = 895.8 g/mol)
Calcd C 48.27 H 3.83 N3.13%,
Found C 47.26 H 4.ll N 2.87 %.
5a was prepared from 0.8 mmol (1 ml of the
5d: A mixture of 2c (0.8 mmol, 1 ml of the DMSO
DMSO stock solution) of 2b and 0.34 g (0.5 mmol) of stock solution) and of (Ph3P)2PtCl2 (0.40 g, 0.5 mmol) in
(Bu3P)2PtCl2 in 10 ml of DMSO (reaction time: 22 h, 10 ml of DMSO was stirred for 2 d. During this time the
colour: bright-yellow). The product was purified as de- colour of the solution changed from orange to red. After
scribed for 3. Yellow powder. - Yield 0.25 g (60 %), m. p. addition of 10 ml of water the suspension was extracted
> 250 °C (dec.). - IR (KBr): v = 3435 cm“ 1 (w), 3202 (m), with three 20-ml portions of dichloromethane. The com-
20 ml of water
3065 (m) (OH/NH), 1703 (s), 1670 (s), 1645 (s) (C=0), bined organic extracts were washed with
and dried with sodium sulfate. The solvent was removed
6 = 8.28 (s, 1H, NH), 3.09 (s, 3H, NCH3). - l3C NMR in vacuo to leave a yellow powder. - Yield 0.28 g (55 %),
(CD2CI2): 6 = 26AI (s, NCH3), 108.35 (t, 3/( 195Pt-13C) m.p. (dec.) > 250 °C. - IR (KBr): ^ = 3421 cm-1 (m,
1462 (s), 1395 (vs, br) (C=C/C=0). - 1H NMR (CD3CN):
= 37 Hz, 4/(31P-l3C) = 2 Hz, S2C=C), 151.07, 160.89, br), 3238 (w, br), 3063 (w) (OH/NH), 1711 (vs), 1675 (s),
162.00 (s, C=0), 216.50 (s, 2/ ( 195Pt-13C) = 79 Hz, S2C 1640 (s) (C=0), 1434 (s), 1417 (vs, br) (C=C/C=0). - 1H
NMR (CDCI3): 6 = 9.53 (s, 1H, NH), 2.95 (m, 2H, NCH2).
=C). - 31P NMR (CD3CN): 6 = -3.03 / -3.07 (AB spin
systeme,17(195Pt-31P) = 2844 / 2847 Hz, 2/(31P-31P) = 4.0 - 31P NMR (CDCI3): 6 = 17.93 / 18.60 (AB spin system,
' j
(
195P t - 31 _ 2989 / 2885 Hz, 27(31P-31P) = 23.2 Hz).
P
)
Hz).
C30H58N2O3P2PtS2 (M = 816.0 g/mol)
Calcd C 44.16 H7.16 N 3.43 %,
Found C 44.22 H7.19 N 3.34 %.
C47H44N20 3P2PtS2 (M = 1006.0 g/mol)
Calcd C 56.ll H4.41 N 2.78 %,
Found C 55.85 H 4.90 N 3.06 %.
5b was prepared from 0.8 mmol (1 ml of the
6a was prepared from 0.8 mmol (1 ml of the
DMSO stock solution) of 2c and 0.34 g (0.5 mmol) of DMSO stock solution) of 2e and 0.34 g (0.5 mmol) of
(B^PhPtCL in 10 ml of DMSO (reaction time: 2 d, the (Bu3P)2PtCl2 in 10 ml of DMSO (reaction time: 2 d.
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1141
W. Weigand et al. • Functionalized 1,1-Ethene Dithiolates as Ligands, V
Table I. Crystal data and refinement details for complexes 4a, 4c, 5a and 8.
4a
4c
5a
8
Formula
Mr
Cn H39N5O3PtPtSi
742.7
C17H32N2O3P2PtS2
633.6
C 3 9 H 5 ()N 2 0 7 P 2 P tS 6
1108.2
C30H58N2O 3P2PtS2
815.9
0.2 x 0.3 x 0.4
monoclinic
P2\/n
0.6 x 0.5 x 0.5
monoclinic
P2\/c
Crystal size [mm]
Crystal system
Space group
0.32 x 0.3 x 0.22
monoclinic
P2\/c
0.1 x 0.15 x 0.2
monoclinic
P2\/c
10.189(2)
17.035(5)
14.285(3)
103.88(2)
2407(1)
14.345(2)
14.920(2)
20.643(3)
90.973(6)
4417(1)
10.412(2)
21.879(16)
16.834(7)
99.19(1)
3786(3)
14.441(3)
13.446(2)
18.281(3)
107.08(1)
3393(1)
1.509
4
a [A]
b [A]
c [A]
ß [°1
V[A3]
_
1.748
4
1.666
1.432
4
Pealed [g Cm
Z
]
4
1248
213(2)
2232
193(2)
1664
223(2)
1536
293(2)
F(000)[e]
T [K]
0,+16/0,+ 16/±22
3.82 - 53.16
6606
hkl Range
2 0 Range [°]
Measured refl.
0,+121-20,0/± 16
3.78 - 50.00
4476
-12,0/0,+26/±19
3.08 - 50.00
6957
±18/±18/±26
2.84 - 58.38
25042
5982
4224
Unique refl.
8939
6578
2438 [IFI > 4<jlFI]
0.343/0.723
368
0.0877
0.2105
6426 [IFI > 4crlFI]
0.352/0.460
522
0.0243
0.0495
Observed refl.
Min./max. transm.
Refined parameters
fl7[IFI>4<rlFI]
wR2
3204 [IFI > 4<rlFI]
0.132/0.215
242
0.0420
0.1164
4833 [IFI > 4crlFI]
0.077/0.128
361
0.0539
0.1420
Pfin(max/min)[eA-3]
Goodness-of-fit
1.229/-1.590
1.144
1.171/—0.772
1.056
0.747/-0.567
1.147
1,597/-2.395
1.060
colour changes from red to yellow). The product was pu-
rified as described for 3. Yellow powder. - Yield 0.20
6c was prepared from 0.8 mmol (1 ml of the
DMSO stock solution) of 2e and 0.34 g (0.5 mmol) of
g (49 %), m.p. 180 °C. - IR (KBr): v = 1701 cm“ 1 (Bu3P)2PtCl2 in 10 ml of DMSO (reaction time: 22 h,
(vs), 1648 (s), 1640 (s) (C=0), 1454 (s), 1394 (vs, br) colour changes from red to orange). The product was pu-
rified as described for 3. Yellow powder. - Yield 0.28 g
(57 %), m.p. 191 °C. - IR (KBr): u = 1702 cm" 1 (s),
1649 (vs) (C=0), 1445 (s), 1399 (vs, br) (C=C/C=0). -
'H NMR (CD2CI2): ö = 5.21 (s, 4H, NCH2). - 13C NMR
(CD2C12): 6 = 44.18 (s, NCH2), 152.32, 161.53, (s,C=0),
217.78 (s, S2C =C). - 31P NMR (CD2C12): b = -3.23 (s,
'/(195Pt-31P) = 2847 Hz).
(C=C/C=0). - 'H NMR (CD2CI2): 6 = 3.21 (s, 6H,
NCH3). - 31P NMR (CH2CI2): 6 = -3.93 (s, './(195Pt-31P)
= 2845 Hz).
C3iH6oN203P2PtS2 (M = 830.0 g/mol)
Calcd C 44.86 H 7.29 N 3.37 %,
Found C 46.00 H 7.42 N 3.25 %.
6b: A mixture 0.8 mmol (1 ml of the DMSO stock
solution) of 2e and 0.40 g (0.5 mmol) of (Ph^P^PtCL in
10 ml of DMSO was stirred for 20 h. During this time
the colour of the solution changed from orange to dark
red. After addition of 10 ml of water the suspension was
extracted with three 20-ml portions of dichloromethane.
The combined organic extracts were washed with 20 ml
of water and dried with sodium sulfate. The solvent was
removed in vacuo to leave a yellow powder. - Yield 0.26
g (54 %), m. p. (dec) > 250 °C. - IR (KBr): v = 1708 cm" 1
(m), 1648 (s) (C=0), 1448 (s), 1419 (vs, br) (C=C/C=0).
- ‘H NMR (CDCI3): 6 = 3.19 (s, 6H, NCH3). - 31P NMR
(CDCI3): 6 = 18.59 (s, 'y(195Pt-31P) = 2979 Hz).
C43H68N203P2PtS2 (M = 982.3 g/mol)
Calcd C 52.58 H 6.98 N 2.85 S 6.53 %,
Found C 52.18 H 6.72 N 2.96 S 7.00 %.
7: A mixture 0.8 mmol (1 ml of the DMSO stock solu-
tion) of 2c and 0.24 g (0.5 mmol) of (2,9-dimethylphen-
anthroline)PtCl2 in 10 ml of DMSO was stirred for 22
h. During this time the colour of the suspension changed
from dark brown to orange. After addition of 10 ml of
water the suspension was extracted with three 20-ml por-
tions of dichloromethane. The combined organic extracts
were washed with 20 ml of water and dried with sodium
sulfate. The solvent was removed in vacuo to leave a yel-
low powder which was washed with 30 ml of hexane.
C43H36N2O3P2PtS2 (949.9); CHN analysis not satisfying.
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1142
W. Weigand et al. • Functionalized 1,1-Ethene Dithiolates as Ligands, V
Orange powder. - Yield 0.18 g (53 %), dec. > 220 °C. -
IR (KBr): u = 3424 cm-1 (w, br), 3175 (w, br), 3030 (w. diffractometer equipped with a CCD area detector. The
dimensions of the unit cell were derived from the reflec-
(C=C/C=0). - 'H NMR (CDCI3): 6 = 7.58 (s, 1H. NH), tions with / > 10 a(I) on four sets of 15 frames (A<p =
with perfluoroether oil and transferred to a Siemens P4
br), 1710 (s), 1659 (s), 1632 (vs) (C=0), 1410 (vs, br)
0.3°). Data were collected with an exposure time of 10 s
per frame, and 1296 frames were collected at two differ-
ent x settings with A<f> = 0.3° between the next frame.
Data were reduced with the program SAINT, and absorp-
tion correction was performed using all data with / > 10
a {I) in a semiempirical procedure.
The structures were solved by Direct Methods using
the program SHELXL 1993. Anisotropic thermal parame-
ters were applied in the refinement of nonhydrogen atoms.
Hydrogen atoms were placed in calculated positions and
included in the refinement by applying a riding model.
However, hydrogen atoms of NH groups were taken from
difference Fourier peaks, and were freely refined with
fixed isotropic Uj. Selected data of the experimental pro-
cedures are summarised in Table I.
3.88 (m, 2H, NCH2), 3.08 / 3.09 (s, 6H, CH3).
C25H,6N40 3PtS2 (M = 689.7 g/mol)
Calcd C 43.54 H 3.80 N8.12%,
Found C 41.61 H 3.93 N7.51%.
8: Complex 4a (0.063 g, 0.1 mmol) was dissolved in 5
ml of dichloromethane and added to a solution of 2,6-di-
aminopyridine (0.012 g, 0.1 mmol) in 1 ml of DMSO to
give single co-crystals of 8 within 8 d. Yellow plates.
Crystal structure determinations o/4a,c, 5a, and 8 [24]
A single crystal of 4a, 5a and 8, respectively, was
mounted in a glass capillary. After optical alignment 20-
25 reflections were autocentered, and the dimensions of
the unit cell determined on a Siemens P4 instrument oper-
ating with graphite monochromatized Mo-KQradiation.
Data collection was performed in the u;/29 mode with
variable scan speed. The data were then reduced by ap-
plying Lorentz and polarisation correction as well as em-
pirical absorption correction based on ip -scans. A single
crystal of compound 4c was mounted on a glass fiber
Acknowledgements
Generous support by Professor W. Beck, the Deutsche
Forschungsgemeinschaft and the Fonds der Chemieschen
Industrie is gratefully acknowledged. We thank the De-
gussa AG, Hanau, for donation of precious chemicals.
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1143
W. Weigand et al. • Functionalized 1,1-Ethene Dithiolates as Ligands, V
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