Metallacyclic platinum(II) bis(sulfonamides)

Article abstract of DOI:10.1016/S0020-1693(00)00382-0

A series of metallacyclic platinum(II) bis(sulfonamido) complexes have been synthesised by reaction of cis-[PtCl₂L₂] [L = PPh₃ or L₂ = 1,5-cyclo-octadiene (cod)] with the sulfonamides [RSO₂NHCH₂CH₂NHSO₂R, RSO₂NHCH₂CHMeNHSO₂R or RSO₂NHC₆H₄NHSO₂R; R = Ph or p-C₆H₄Me] and Ag₂O. The products have been characterised by NMR spectroscopy, electrospray mass spectrometry, elemental analysis, and for the complexes [Pt{N(SO₂Ph)CH₂CH₂N(SO₂Ph)} (PPh₃)₂] and [Pt{(N(SO₂Ph)C₆H₄N(SO₂Ph)}(cod)], by single-crystal X-ray structure determinations. In both of these complexes, one of the amido nitrogen atoms has the expected approximately planar geometry, but the other nitrogen atom is surprisingly distorted towards a tetrahedral geometry. The more pyramidal nitrogen has a higher trans-influence in the solid state, reflected by a shorter Pt-N bond, and longer cyclo-octadiene Pt-C bond length trans to this nitrogen.

Full text of DOI:10.1016/S0020-1693(00)00382-0

www.elsevier.nl/locate/ica
Inorganica Chimica Acta 314 (2001) 42–48
Metallacyclic platinum(II) bis(sulfonamides)
Cameron Evans, William Henderson *, Brian K. Nicholson
Department of Chemistry, Uni6ersity of Waikato, Pri6ate Bag 3105, Hamilton, New Zealand
Received 16 October 2000; accepted 13 November 2000
Abstract
A series of metallacyclic platinum(II) bis(sulfonamido) complexes have been synthesised by reaction of cis-[PtCl2L2] [L=PPh3
or L2=1,5-cyclo-octadiene (cod)] with the sulfonamides [RSO2NHCH2CH2NHSO2R, RSO2NHCH2CHMeNHSO2R or
RSO2NHC6H4NHSO2R; R=Ph or p-C6H4Me] and Ag2O. The products have been characterised by NMR spectroscopy,
electrospray mass spectrometry, elemental analysis, and for the complexes [P¸t{¹N¹(S¹O¹2¹P¹h)¹C¹H¹2C¹H¹º2N(SO2Ph)}(PPh3)2] and
[P¸t{¹N¹(S¹O¹2¹P¹h)¹C¹6H¹4ºN(SO2Ph)}(cod)], by single-crystal X-ray structure determinations. In both of these complexes, one of the
amido nitrogen atoms has the expected approximately planar geometry, but the other nitrogen atom is surprisingly distorted
towards a tetrahedral geometry. The more pyramidal nitrogen has a higher trans-influence in the solid state, reflected by a shorter
PtꢀN bond, and longer cyclo-octadiene PtꢀC bond length trans to this nitrogen. © 2001 Elsevier Science B.V. All rights reserved.
Keywords: Platinum(II) complexes; Metallacyclic bis(sulfonamide) complexes; X-ray crystal structure
carboxamide ligands and their metal complexes have
also been widely investigated [10] as have platinum and
palladium complexes of other sulfonamide ligands [11].
1. Introduction
Silver(I) oxide has been shown to be a useful reagent
for the synthesis of a wide range of complexes (espe-
cially metallacyclic complexes) of platinum(II) and pal-
ladium(II) [1,2], gold(III) [3], as well as other metals
such as ruthenium(II) [2] and rhodium(I) and (III) [4],
where it acts as both a halide-abstracting reagent and a
strong base. In this paper, we report the synthesis of
some five-membered ring metallacyclic bis(sulfonamide)
complexes of platinum(II) using silver(I) oxide. Gagne´
and co-workers have recently reported some closely
related complexes 1, formed by reaction of the carbon-
ato complex [Pt(CO3)(Ph2PCH2CH2PPh2)] with the chi-
ral sulfonamides RSO2ꢀNHꢀCH(Ph)CH(Ph)ꢀNHꢀ
SO2R [R=CF3 or p-ButC6H4] [5]. These appear to be
the only other examples of five-membered ring plat-
inum bis(sulfonamide) complexes. However, there is
interest in five-membered ring sulfonamide complexes
of other metals [6,8], especially as they are useful chiral
auxiliaries for various reactions [9]. Related chelating
2. Results and discussion
2.1. Syntheses
The reactions of cis-[PtCl2(PPh3)2] or [PtCl2(cod)]
(cod=1,5-cyclo-octadiene) with bis(sulfonamides) of
the general formula RSO2ꢀNHꢀ(X)ꢀNHꢀSO2R [where
R=Ph or p-CH3C6H4 (Tol) and X=CH2CH2,
CHMeCH2 or C6H4] in the presence of excess Ag2O in
refluxing dichloromethane results in the formation of
metallacyclic platinum(II) bis(sulfonamido) complexes,
2–6. The products are isolated as air- and water-stable
white to pale yellow powders. This synthetic route is
complementary to the one described by Gagne´ et al for
the synthesis of complex 1 [5], and should allow access
to a potentially wide range of derivatives by displace-
ment of the labile cod ligand. The attempted synthesis
of the triphenylphosphine and p-toluenesulfonyl ana-
logues of 6 gave materials which had the expected
spectroscopic properties, but which were red in colour,
and did not give good elemental microanalytical data.
* Corresponding author: Tel.: +64-7-8384656; fax: +64-7-
8384219.
E-mail address: w.henderson@waikato.ac.nz (W. Henderson).
0020-1693/01/$ - see front matter © 2001 Elsevier Science B.V. All rights reserved.
PII: S0020-1693(00)00382-0

C. E6ans et al. / Inorganica Chimica Acta 314 (2001) 42–48
43
parable with the values of 3614 and 3520 Hz observed
for complexes la and 1b [5], and is higher than those in
other platinum(II) bis(amide) complexes such as in the
b-propiolactam complex cis-[Pt{NC(O)CH2CH2)2-
(PPh3)2] (7) (3054 Hz) [13], cis-[Pt(isat)2(PPh3)2] (8)
(Hisat=isatin, 2,3-dihydroindol¸e-¹2¹,3¹-d¹io¹nºe) (3284 Hz)
[14] and the ureylene complex [Pt(NPhCONPh)(PPh3)2]
(3337 Hz) [15], and is more comparable to the value for
PPh3 ligand trans to the sulfonamide saccharinate (sac)
in cis-[PtCl(sac)(PPh3)2] (9) (3483 Hz) [16]. This indi-
cates that the sulfonamide ligand has a relatively low
trans-influence compared to other amidate ligands. The
This may be due to oxidation of the ligand occurring,
since complexes containing oxidised o-phenylenedi-
amine-derived ligands have been isolated [7,12], and
silver(I) ions have oxidising characteristics. No further
studies were carried out with these red materials.
1
cod CH groups give characteristic resonances in the H
and 13C-{1H} NMR spectra, showing the expected cou-
pling to 195Pt, e.g. in complex 4 2J(PtH)=64 and
1J(PtC)=145 Hz respectively. The symmetrical com-
plexes 2, 4 and 6 give a single CH resonance, but in 5
there is no plane of symmetry, and four separate CH
resonances are observed as overlapping peaks. In addi-
tion, in complex 5 the asymmetric carbon results in
splitting of the H-2%, H-3% and C-2% signals (Scheme 1),
but the 5% signals were not split, presumably because the
site of asymmetry is too far removed. The H-3% signals
1
were split in the H NMR spectrum, but splitting of the
C-3% signals was not resolved in the 13C spectrum.
The only significant bands in the IR spectra of
complexes 2–6 are those associated with the sulfonyl
groups, which show both symmetric (ca. 1350 cm−1
)
and antisymmetric (ca. 1140 cm−1) modes, similar to
the free sulfonamide ligands. The complexes all give
strong [M+H]+ ions in their positive ion electrospray
(ES) mass spectra.
The NMR spectra of the complexes are as expected.
The phosphine complex 2 shows a single 31P NMR
1
resonance, with J(PtP)=3552 Hz. This is very com-
2.¸2.¹X¹¹-r¹ay¹¹cr¹ys¹ta¹l¹s¹tr¹ucºture determinations of
[Pt{N(SO2Ph)CH2CH2N(SO2Ph)}(PPh3)2] (2) and
¸¹¹¹¹¹¹¹¹¹¹º
[Pt{N(SO2Ph)C6H4N(SO2Ph)}(cod)] (6)
The structures confirm the complexes as bis(sulfon-
amide) metallacycles, containing five-membered
¸¹¹¹¹¹¹º
PtꢀNꢀCꢀCꢀN rings. Complex 2 crystallises with one
molecule of dichloromethane in the lattice, and disorder
was observed, both in the dichloromethane, and in one
half of the metallacyclic ligand. The phenyl ring, C(71)
to C(76), its associated sulfonyl group [S(1), O(1),
O(2)], the nitrogen atom [N(1)], and the metallacyclic
carbon atom [C(1)] adopt two sites in the lattice (in an
approximate 60:40 ratio). The non-disordered portion
and the major component of the disordered fraction of
the structure is shown in Fig. 1, together with the atom
numbering scheme. Selected bond lengths and angles
are given in Table 1. Discussion on the structural
features associated with the disordered portion of the
structure is unwarranted due to the large errors in-
volved with the associated bond lengths and angles.
However, the non-disordered fragment of the structure
is well defined.
F¸ig¹. ¹¹¹¹¹¹¹¹¹¹º
1.
PLUTO
diagram
of
the
structure
of
[Pt{N(SO2Ph)CH2CH2N(SO2Ph)}(PPh3)2] (2) showing the atom
numbering scheme. The minor component of the disordered portion
of the structure has been omitted for clarity.

44
C. E6ans et al. / Inorganica Chimica Acta 314 (2001) 42–48
Table 1
observed in many platinum(II) amide systems, e.g.
,
Selected
bond
¸¹¹¹¹¹¹¹¹¹¹¹lºengths
(A)
and
angles
(°)
for
,
2.050(2) and 2.060(2) A observed in cis-[P(isat)2(PPh3)2]
[Pt{N(SO2Ph)CH2CH2N(SO2Ph)}(PPh3)2] (2)
,
(8), [14] 2.064(6) A in cis-[PtCl(sac)(PPh3)2] (9) [16] and
,
2.09 A observed for cis-[Pt(NPh2)Cl(PEt3)2] [17]. In the
closely related complex la, PtꢀN bond lengths of
2.119(2) and 2.125(2) A are observed, while in the
derivative 10, the PtꢀN bond length is 2.062(6) A,
indicating poorer donor properties of the CF3-substi-
tuted ligand [5].
PtꢀP(1)
PtꢀN(1)
N(2)ꢀC(2)
S(2)ꢀO(3)
2.270(2)
2.24(l)
1.49(1)
1.443(5)
PtꢀP(2)
2.292(2)
2.090(6)
1.615(6)
1.440(6)
a
PtꢀN(2)
N(2)ꢀS(2)
S(2)ꢀO(4)
,
,
P(2)ꢀPtꢀP(1)
97.98(7)
170.1(2)
110.2(5)
107.2(3)
115.9(3)
N(2)ꢀPtꢀN(1)
P(2)ꢀPtꢀN(2)
Pt–N(2)ꢀS(2)
74.8(3) a
91.1(2)
114.1(3)
114.6(3)
P(1)ꢀPtꢀN(2)
PtꢀN(2)ꢀC(2)
N(2)ꢀS(2)ꢀO(3)
O(3)ꢀS(2)ꢀO(4)
Considering the plane defined by Pt(1), N(2), S(2)
and C(2), the nitrogen atom N(2) occupies a position
N(2)ꢀS(2)ꢀO(4)
,
0.337 A above the plane. All other atoms lie below the
a The disorder in this portion of the structure casts doubt on the
accuracy of these values.
,
plane [Pt(1) 0.09, S(2) 0.12, C(2) 0.13 A]. Such geome-
try indicates a significant degree of tetrahedral charac-
ter in the geometry of the N(2) atom. The deviation
from planarity expected for a sp2 hybridised nitrogen
atom is also apparent in the sum of the angles sur-
rounding N(2). The calculated value of 339.3° is inter-
mediate between the expected 360° for trigonal planar
and 328.5° for tetrahedral geometry, and is very differ-
ent to the closely related complex la, where the sums of
the nitrogen bond angles around the (essentially planar)
nitrogens are 358.1 and 358.4° [5]. The geometry about
N(1) appears more planar than N(2) but the disordered
site does not warrant extensive study of its geometry.
However the PtꢀN bond associated with the pyramidal
nitrogen appears substantially shorter [PtꢀN(2) 2.090(6)
,
A] than the PtꢀN bond to the trigonal planar nitrogen
,
[PtꢀN(1) 2.24 A]. As a result of the pyramidal geometry
about N(2), the orientation of the phenyl rings with
respect to the metallacyclic plane is also affected, as
shown in Fig. 2. One phenyl ring [bonded to S(1)ꢀN(1)]
is approximately perpendicular to the P(1), P(2), Pt(1),
N(1), N(2) plane, while the other is almost parallel.
In order to see if the amide pyramidalisation was a
general feature in this type of complex, and to try and
obtain a non-disordered structure for more accurate
Fig. 2. View of 2 bisecting N(1)ꢀPtꢀN(2), illustrating the lack of
planarity of the five-membered metallacycle, the pyramidalisation of
nitrogen N(2), and the different orientations of the phenyl rings.
The platinum coordination plane shows a slightly
distorted square-planar geometry. Deviations from pla-
narity [where the plane is defined by Pt(1), P(1), P(2)
and N(2)] are observed for both sites of N(1), [below
comparisons,
the
molecular
structure
of
[Pt{N(SO2Ph)C6H4SO2Ph)}(cod)] (6) was determined;
the molecular structure and atom numbering scheme
are shown in Fig. 3, with selected bond lengths and
angles in Table 2.
,
,
the plane by 0.64(2) A for N(1) and 1.41(2) A for
N(1A)]. The other atoms within the platinum coordina-
,
tion sphere are within 0.046 A of the least-squares
The overall geometry of 6 is similar to that of 2; one
of the nitrogen atoms [N(1)] is more pyramidal in
nature, while the other [N(2)] is more planar, as shown
by the sum of the bond angles about N(1) (343.35°) and
N(2) (355.6°). Both phenyl substituents are positioned
above the metallacyclic plane, whereas the o-phenylene
ring, which forms part of the metallacycle is positioned
slightly below the plane, as shown in Fig. 4. The angle
between the least-squares plane of the phenylene ring of
the ligand [defined by atoms C(1) to C(6)] and the
platinum least-squares coordination plane [defined by
Pt(1), N(1), N(2) and the midpoints of the C(35)ꢀC(36)
and C(31)ꢀC(32) bonds respectively] is 36.75°. As with
the structure of 2, the bond length between platinum
plane. The distortion from square-planar geometry,
prompted by the steric bulk of the PPh3 ligands and the
bite of the metallacycle, is reflected in the P(1)ꢀPtꢀP(2)
and N(1)ꢀPtꢀN(2) bond angles of 97.98 (7) and 74.8(3)°
respectively, though the disorder casts doubt on the
accuracy of the latter angle.
The P(1)ꢀPt and P(2)ꢀPt bond lengths are 2.270(2)
,
and 2.292(2) A. A similar difference in PtꢀP bond
le¸ng¹t¹hs¹¹w¹a¹s¹ºobserved in the bis(amide) complex
[Pt{NC(O)CH2CH2}2(PPh3)2] (7) [2.291(3) and 2.266(3)
,
A] [13], but not in the complex cis-[Pt(isat)2(PPh3)2] (8)
,
[2.2959(7) and 2.2956 A] [14]. The (non-disordered)
,
PtꢀN(2) bond length of 2.090(6) A is similar to that

C. E6ans et al. / Inorganica Chimica Acta 314 (2001) 42–48
45
,
The reason why one amide nitrogen should undergo
a tetrahedral distortion in both structures is not clear,
especially as there was no indication of tetrahedral
distortion in the closely related complex la. The vast
majority of reported structures of amido complexes
show trigonal planar geometry about the nitrogen
atom. The amide nitrogen of [(h5-C5H5)Re(NO)(PPh3)-
(NHPh)] has a tetrahedrally-substituted arrangement
[18]. The cause of the distortion in the case of com-
plexes 2 and 6 is not known, and pyramidal nitrogen
atoms would be more likely to be associated with
alkyl/aryl-substituted amides rather than sulfonamides
(or carboxamides). Protonation of one of the amido
nitrogen atoms was considered, but can be ruled out on
the basis that (i) no counterion has been located in
either structure and satisfactory elemental microanalyti-
cal data were obtained; (ii) the bond between platinum
and a ‘protonated’ N would be longer than the other
PtꢀN bond, but the opposite is observed; (iii) the
nitrogen of a protonated sulfonamide RSO2NHR% is
extremely weakly basic, and would be expected to
coordinate weakly, if at all, to platinum.
and the pyramidal nitrogen [PtꢀN(1) 2.058(3) A] is
shorter than that to the more planar nitrogen [PtꢀN(2)
,
2.081(3) A]. Concomitantly, the PtꢀC(35) and PtꢀC(36)
bond lengths [trans to N(1)], at 2.201(3) and 2.217(3) A,
are longer than the PtꢀC(31) and PtꢀC(32) bond
lengths [trans to N(2)], which are 2.152(3) and 2.182(3)
,
,
A. This suggests that the more pyramidal N(1) nitrogen
of 6 has a higher trans influence than the more planar
nitrogen; it is noteworthy that the H and 13C NMR
1
spectra show only a single cod CH resonance.
3. Experimental
3.1. General
All reactions were carried out in air. The compounds
silver(I) oxide [19], and the range of bis(sulfonamide)
starting materials used were synthesised using modified
literature procedures, starting from the diamine and
either benzene- or p-toluene-sulfonyl chlorides [7,20].
Dichloromethane and light petroleum (b.p. 40–60°C)
were distilled from calcium hydride, while tetrahydro-
furan and diethyl ether were distilled from sodium/ben-
zophenone ketyl. cis-[PtCl2(PPh3)2] was prepared by
ligand displacement [21] of 1,5-cyclo-octadiene (cod)
from [PtCl2(cod)] [22].
¸¹¹¹¹¹¹¹¹¹º
Fig. 3. Molecular structure of [Pt{N(SO2Ph)C6H4N(SO2Ph)}(cod)]
(6) showing the atom numbering scheme.
Table 2
,
Selected
bond
lengths
(A)
and
angles
for
¸¹¹¹¹¹¹¹¹¹º
[Pt{N(SO2Ph)C6H4N(SO2Ph)}(cod)] (6)
Pt(1)ꢀN(1)
Pt(1)ꢀC(31)
Pt(1)ꢀC(35)
S(1)ꢀO(1)
S(1)ꢀN(1)
S(2)ꢀO(4)
S(2)ꢀN(2)
N(1)ꢀC(1)
C(1)ꢀC(2)
C(35)ꢀC(36)
2.058(3)
2.152(3)
2.201(3)
1.443(2)
1.626(3)
1.438(3)
1.617(3)
1.441(4)
1.407(5)
1.386(5)
Pt(1)ꢀN(2)
2.081(3)
2.182(3)
2.217(3)
1.444(2)
1.777(3)
1.438(3)
1.776(3)
1.432(4)
1.394(5)
1H, 13C-{1H} and 31P-{1H} NMR spectra were
recorded on a Bruker AC300P instrument at 300.13,
75.47 and 121.5 MHz, respectively, in CDCl3. Assign-
ment of individual resonances was achieved by stan-
dard two-dimensional (COSY, C–H correlation, NOE)
and DEPT135 NMR experiments, acquired either on
this instrument or on a Bruker DRX 400 instrument.
1H and 31C NMR spectra are referenced relative to
CHCl3 and 31P NMR spectra are referenced relative to
an external standard of 85% H3PO4. Scheme 1 shows
the atom numbering scheme used for the sulfonamide
ligands; A, B and C refer to the labelling used for
the ethylenediamine-, 1,2-propanediamine- and o-
phenylenediamine-derived ligands respectively. For the
benzenesulfonyl derivatives, no 5% signal occurs, and for
the 1,2-propanediamine ligand the inequivalent aryl
resonances were not distinguished.
Pt(1)ꢀC(32)
Pt(1)ꢀC(36)
S(1)ꢀO(2)
S(1)ꢀC(11)
S(2)ꢀO(3)
S(2)ꢀC(21)
N(2)ꢀC(2)
C(31)ꢀC(32)
N(1)ꢀPt(1)ꢀN(2)
N(1)ꢀPt(1)ꢀC(32)
N(2)ꢀPt(1)ꢀC(36)
O(1)ꢀS(1)ꢀN(1)
N(1)ꢀS(1)ꢀC(11)
O(4)ꢀS(2)ꢀN(2)
C(1)ꢀN(1)ꢀS(1)
S(1)ꢀN(1)ꢀPt(1)
C(2)ꢀN(2)ꢀPt(1)
79.49(10)
94.73(12)
99.07(12)
108.68(15)
110.42(15)
107.13(15)
115.7(2)
N(1)ꢀPt(1)ꢀC(31)
N(2)ꢀPt(1)ꢀC(35) 103.98(12)
91.87(12)
O(1)ꢀS(1)ꢀO(2)
O(2)ꢀS(1)ꢀN(1)
O(4)ꢀS(2)ꢀO(3)
O(3)ꢀS(2)ꢀN(2)
C(1)ꢀN(1)ꢀPt(1)
C(2)ꢀN(2)ꢀS(2)
S(2)ꢀN(2)ꢀPt(1)
118.02(15)
107.47(14)
116.33(17)
112.13(15)
108.86(19)
118.9(2)
118.79(15)
109.6(2)
127.13(15)

46
C. E6ans et al. / Inorganica Chimica Acta 314 (2001) 42–48
Fig. 4. View of 6 bisecting N(1)ꢀPt(1)ꢀN(2). C(1A) and C(2A) are dummy atoms representing the midpoints of the C(35)ꢀC(36) and C(31)ꢀC(32)
bonds respectively.
¸¹¹¹¹¹¹¹¹¹¹¹¹º
3.1.2. [Pt{N(SO2Ph)CH2CH2N(SO2Ph)}(cod)] (3)
IR spectra were recorded as KBr disks on a Perkin–
Elmer 1600 series instrument. Melting points were
recorded on a Reichert Thermopan instrument, and are
uncorrected. Elemental analyses were provided by the
Campbell Microanalytical Laboratory, University of
Otago. Electrospray mass spectra were recorded on a
VG Platform II instrument in positive ion mode, using
MeCN–H2O (1:1 v/v) as the mobile phase. Observed
isotope patterns recorded under high resolution condi-
tions were compared with those theoretically calculated
by the isotope program [23]. Stated m/z values corre-
spond to that of the most intense peak in the isotope
pattern.
A mixture of [PtCl2(cod)] (30 mg, 0.080 mmol), Ag2O
(50 mg, 0.216 mmol) and N,N%-bis(benzenesul-
fonyl)ethylenediamide (27 mg, 0.080 mmol) in
dichloromethane (20 ml) was refluxed for 18 h. The
mixture was filtered to remove silver salts, the filtrate
evaporated to dryness under reduced pressure, and the
product recrystallised from dichloromethane–diethyl
ether to give a white microcrystalline solid (37 mg,
72%). Found: C, 41.4; H, 4.1; N, 4.5. C22H26N2O4S2Pt
requires C, 41.2; H, 4.1; N, 4.4%. M.p. 167–171°C
(dec.). IR: w(SO2) 1301(s) and 1146(s) cm−1. NMR: 1H,
3
l 7.78 [d, 4H, H-2%, J(HH) 9], 7.39–7.50 [m, 6H, H-3%
2
and H-4%], 6.26 [t, 4H, cod CH, J(PtH) 63], 2.93 [m,
¸¹¹¹¹¹¹¹¹¹¹¹¹º
3.1.1. [Pt{N(SO2Ph)CH2CH2N(SO2Ph)}(PPh3)2] (2)
4H, H-1¦], 2.35–2.6 [m, 8H, cod CH2]; 13C-{1H}, l
143.2 (s, C-1%), 131.5 (s, C-4%), 128.9 (s, C-3%), 126.4 (s,
A mixture of cis-[PtCl2(PPh3)2] (50 mg, 0.063 mmol),
Ag2O (100 mg, 0.431 mmol) and N,N%-bis(benzenesul-
fonyl)ethylenediamide (22 mg, 0.063 mmol) in
dichloromethane (20 ml) was refluxed for 16 h. The
mixture was filtered to remove silver salts, the filtrate
evaporated to dryness under reduced pressure, and the
product recrystallised from dichloromethane–diethyl
ether to give a white microcrystalline solid (55 mg,
83%). Found: C, 52.8; H, 4.1; N, 2.7.
C50H44N2O4S2P2Pt·CH2Cl2 requires C, 53.6; H, 4.1; N,
2.5%. M.p. 126–130°C (dec.). IR: w(SO2) 1384(s) and
1
C-2%), 99.1 [t, cod CH, J(PtC) 144], 54.9 (s, C-1¦), 30.3
1
1142(s) cm−1. NMR: H, l 7.1–7.8 (m, Ph), 2.95 (m,
1
H-1¦); 31P-{1H}, l 3.6 [s, J (PtP) 3552]; 13C-{1H}, l
127–135 (m, Ph), 59.2 (s, C-1¦). ESMS (cone voltage 20
V) [M+H]+ (1059, 100%), [M+NH4]+ (1076, 20%).
X-ray quality colourless crystals were grown by va-
pour diffusion of diethyl ether into a dichloromethane
solution at 4°C.
Scheme 1.

C. E6ans et al. / Inorganica Chimica Acta 314 (2001) 42–48
47
(s, cod CH2). ESMS (cone voltage 50 V) [M+H]+
(642, 100%).
77%). Found: C, 45.5; H, 3.6; N, 4.3. C26H26N2O4S2Pt
requires C, 45.3; H, 3.8; N, 4.1%. M.p. 200–205°C
(dec.). IR: w(SO2) 1301(s) and 1146(s) cm−1. NMR: 1H,
l 7.62 [m, 4H, H-2%, 3J(HH) 8], 7.47 (m, 2H, H-4%), 7.35
3.1.3. [P¸t{¹N¹(¹SO¹2¹T¹o¹l)¹C¹H¹2C¹H¹2ºN(SO2Tol)}(cod)] (4)
A mixture of PtCl2(cod)] (40 mg, 0.107 mmol), Ag2O
(50 mg, 0.216 mmol) and N,N%-bis(toluene-
sulfonyl)ethylenediamide (39 mg, 0.107 mmol) in di-
chloromethane (20 ml) was refluxed for 18 h. The
mixture was filtered to remove silver salts, the filtrate
evaporated to dryness under reduced pressure, and the
product recrystallised from dichloromethane–diethyl
ether to give a white microcrystalline solid (49 mg,
69%). Found: C, 43.0; H, 4.4; N, 4.4. C24H30N2O4S2Pt
requires C, 43.0; H, 4.5; N, 4.2%. M.p. 168–172°C
(dec.). IR: w(SO2) 1333(s) and 1142(s) cm−1. NMR: 1H,
l 7.65 [d, 4H, H-2%, 3J(HH) 8], 7.20 [d, 4H, H-3%,
3
[m, 4H, H-3%, J(HH) 8], 7.27 (m, 2H, H-2¦), 6.65 (m,
2H, H-3¦), 6.36 [t, 4H, cod CH, 2J(PtH) 61], 2.6 and 2.3
(m, 8H, cod CH2); 13C-{1H}, l 143.2 (s, C-1%), 142.5 (s,
C-1¦), 131.7 (s, C-4%), 128.9 (s, C-3%), 126.8 (s, C-2%),
122.8 (s, C-3¦), 121.4 (s, C-2¦), 101.5 [t, cod CH,
1J(PtC) 143], 30.2 (s, cod CH2). ESMS (cone voltage 20
V): [M+H]+ (690, 58%), [M+NH4]+ (707, 100%),
[M+K]+ (728, 11%), [2L+NH4]+ (794, 14%), [M+
L+NH4]+
bis(benzenesulfonyl)-o-phenylenediamide.
X-ray quality straw-yellow crystals were grown by
vapour diffusion of diethyl ether into
dichloromethane solution at 4°C.
(1096,
19%),
where
L=N,N%-
a
2
3J(HH) 8], 6.25 [t, 4H, cod CH, J(PtH) 64], 2.90 (m,
4H, H-1¦), 2.32–2.57 (m, 8H, cod CH2), 2.41 (s, 6H,
H-5%); 13C-{1H}, l 142.0 (s, C-4%), 140.2 (s, C-1%), 129.5
3.2. X-ray crystal structure determinations
1
(s, C-3%), 126.5 (s, C-2%), 98.9 [t, cod CH, J(PtC) 145],
¸¹¹¹¹¹¹¹¹¹¹º
55.0 (s, C-1¦), 30.3 (s, cod CH2), 21.5 (s, C-5%). ESMS
3.2.1. [Pt{N(SO2Ph)C2H2N(SO2Ph)}(PPh3)2]·CH2Cl2
(2·CH2Cl2)
(cone voltage 50 V) [M+H]+ (670, 100%).
Crystal data: C50H44N2O4P2PtS2·CH2Cl2, Mr=
¸¹¹¹¹¹¹¹¹¹¹¹¹¹¹º
3.1.4. [Pt{N(SO2Tol)CHMeCH2N(SO2Tol)}(cod)] (5)
1142.95, monoclinic, space group P21/n, a=12.2981(2),
,
A mixture of [PtCl2(cod)] (30 mg, 0.080 mmol), Ag2O
(50 mg, 0.216 mmol) and N,N%-bis(p-toluenesulfonyl)-
1,2-diamidopropane (31 mg, 0.080 mmol) in
dichloromethane (20 ml) was refluxed for 6 h. The
mixture was filtered to remove silver salts, the filtrate
evaporated to dryness under reduced pressure, and the
product recrystallised from dichloromethane–diethyl
ether to give a white microcrystalline solid (34 mg,
62%). Found: C, 43.6; H, 4.6; N, 4.3. C25H32N2O4S2Pt
requires C, 43.9; H, 4.7; N, 4.1%. M.p. 190–196°C
(dec.). IR: w(SO2) 1305(5) and 1146(s) cm−1. NMR:
b=22.7569(4), c=17.0806(3) A, i=97.422(1)°, V=
3
4740.2(1) A , Z=4, Dcalc=1.602 g cm−3, v (Mo Ka)=
,
3.276 mm−1, T=203(2) K, 28593 reflections measured,
10720 unique (Rint=0.0373), 8337 to q=25° used in
calculations. Final wR2=0.1127, R1=0.0650 (all data).
The PhSO2N group associated with N(1) was disor-
dered over two sites. The disorder was modelled as a
major component (60%), and a minor component
(40%) for which only the C(1), N(1), S(1), O(1), O(2)
and C(71) sites could be included since the remainder of
the C(71)–C(76) ring could not be resolved from the
major component.
3
1H, l 7.68 [d, 2H, H-2%, J(HH) 8], 7.58 [d, 2H, H-2%,
3
3J(HH) 8], 7.20 [d, 2H, H-3%, J(HH) 8], 7.16 [d, 2H,
¸¹¹¹¹¹¹¹¹¹¹º
3.2.2. [Pt{N(SO2Ph)C6H4N(SO2Ph)}(cod)] (6)
3
H-3%, J(HH) 8], 6.4 and 6.2 (overlap, 4H, cod CH), 3.5
(m, 1H, H-1¦), 2.6/2.7 (overlap, 10H, cod CH2 and
Crystal data: C26H26N2O4PtS2, Mr=689.70, mono-
3
H-2¦), 2.40 (s, 6H, H-5%), 1.20 [d, 3H, H-3¦), J(HH) 6];
clinic, space group P21/n, a=9.4752(2), b=16.0938(3),
13C-{1H}, l 141.9 (s, C-4%), 141.7 (s, C-4%), 141.4 (s,
C-1%), 139.4 (s, C-1%), 129.3 (m, C-3%), 126.5/127.2 (m,
C-2%), 96.8–101.1 (m, cod CH), 60.3 (s, C-1¦), 59.5 (s,
C-2¦), 32.7 (s, cod CH2), 32.3 (s, cod CH2), 28.3 (s, cod
CH2), 27.9 (s, cod CH2), 22.6 (s, C-3¦), 21.5 (s, C-5%).
ESMS (cone voltage 50 V) [M+H]+ (684, 100%).
c=15.4245(3) A, i=91.654(1)°, V=2351.13(8) A ,
3
,
Z=4, Dcalc=1.948 g cm−3, v(Mo Ka)=6.184 mm−1
,
T=170(2) K, 14456 reflections measured, 5097 unique
(Rint=0.0285) used in calculations. Final wR2=0.0667,
R1=0.0276 (all data).
¸¹¹¹¹¹¹¹¹¹¹º
3.1.5. [Pt{N(SO2Ph)C6H4N(SO2Ph)}(cod)] (6)
4. Supplementary material
A mixture of PtCl2(cod)] (40 mg, 0.107 mmol), Ag2O
(50 mg, 0.216 mmol) and N,N%-bis(benzenesulfonyl)-o-
phenylenediamide (42 mg, 0.107 mmol) in
dichloromethane (20 ml) was refluxed for 22 h. The
mixture was filtered to remove silver salts, the filtrate
evaporated to dryness under reduced pressure, and the
product recrystallised from dichloromethane–diethyl
ether to give a yellow microcrystalline solid (57 mg,
Tables of atomic coordinates, thermal parameters,
bond lengths and bond angles for both structures have
been deposited at the Cambridge Crystallographic Data
Centre (CCDC), Nos. 151 750 (for 2) and 151 749 (for
6). Copies of this information can be obtained free of
charge from The Director, CCDC, 12 Union Road,
Cambridge, CB2 1EZ, UK (fax: +44-1223-336033,

48
C. E6ans et al. / Inorganica Chimica Acta 314 (2001) 42–48
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Acknowledgements
We thank the University of Waikato and the New
Zealand Lottery Grants Board for financial support of
this work, and Johnson–Matthey plc for a generous
loan of platinum. Wendy Jackson and Amu Upreti are
thanked for technical assistance.
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