Platinum (II) and palladium (II) complexes derived from the anion of sulfathiazole; Crystal structure of cis- [Pt (stz) 2 (PPh3) 2] · 3CHCl3

Article abstract of DOI:10.1016/S0277-5387(98)00078-3

Reaction of the complexes cis- [PtCl₂L₂] [L = PPh₃ or L₂ = 1,1′-bis (diphenylphosphino) ferrocene (dppf) ] , or [PdCl₂ (phen) ] [phen = 1,10-phenanthroline] with two mole equivalents of sulfathiazole (stzH) in methanol with excess triethylamine yields the complexes cis- [M (stz) ₂L₂] in good yields. The complexes have been characterised by elemental microanalysis, together with infrared, ¹H and ³¹P NMR spectroscopies. A single-crystal X-ray structure determination on the complex cis- [Pt (stz) ₂ (PPh₃) ₂] 3a shows that both stz ligands coordinate via the thiazole nitrogen atoms. Using positive-ion electrospray mass spectrometry (ESMS) all complexes yield strong molecular ions [M+H] ⁺ at low cone voltages. At higher cone voltages, loss of one stz ligand occurs, giving [L₂M (stz) ] ⁺ ions. The complex cis- [PtCl (stz) (PPh₃) ₂] 4 was also prepared using a 1 : 1 mole ratio of reactants. Functionalisation of both primary arylamine groups of 3a can be accomplished using either acetic anhydride or trifluoroacetic anhydride, in pyridine solvent, and the derivatives 5 were characterised by ³¹P NMR spectroscopy, elemental analysis and ESMS.

Full text of DOI:10.1016/S0277-5387(98)00078-3

Polyhedron Vol[ 06\ No[ 07\ pp[ 2026Ð2033\ 0887
Þ 0887 Elsevier Science Ltd
Pergamon
All rights reserved[ Printed in Great Britain
9166Ð4276:87 ,08[99¦9[99
\
PII ] S9166Ð4276"87#99967Ð2
Platinum"II# and palladium"II# complexes
derived from the anion of sulfathiazole
ð3!amino!N!"thiazol!1!yl#benzenesulfonamide\
stzHŁ ^ crystal structure of cis!
ðPt"stz#1"PPh2#1Ł = 2CHCl2
William Henderson\ꢀ Louise J[ McCa}rey\ Maarten B[ Dinger
and Brian K[ Nicholson
Department of Chemistry\ University of Waikato\ Private Bag 2094\ Hamilton\ New Zealand
"Received 09 October 0886 ^ accepted 07 February 0887#
Abstract*Reaction of the complexes cis!ðPtCl1L1Ł ðL ꢁ PPh2 or L1 ꢁ 0\0?!bis"diphenylphosphino#ferrocene
"dppf#Ł\ or ðPdCl1"phen#Ł ðphen ꢁ 0\09!phenanthrolineŁ with two mole equivalents of sulfathiazole "stzH# in
methanol with excess triethylamine yields the complexes cis!ðM"stz#1L1Ł in good yields[ The complexes have
0
been characterised by elemental microanalysis\ together with infrared\ H and 20P NMR spectroscopies[ A
single!crystal X!ray structure determination on the complex cis!ðPt"stz#1"PPh2#1Ł 2a shows that both stz ligands
coordinate via the thiazole nitrogen atoms[ Using positive!ion electrospray mass spectrometry "ESMS# all
complexes yield strong molecular ions ðM¦HŁ¦ at low cone voltages[ At higher cone voltages\ loss of one stz
ligand occurs\ giving ðL1M"stz#Ł¦ ions[ The complex cis!ðPtCl"stz#"PPh2#1Ł 3 was also prepared using a 0 ] 0
mole ratio of reactants[ Functionalisation of both primary arylamine groups of 2a can be accomplished using
either acetic anhydride or tri~uoroacetic anhydride\ in pyridine solvent\ and the derivatives 4 were characterised
by 20P NMR spectroscopy\ elemental analysis and ESMS[ Þ 0887 Elsevier Science Ltd[ All rights reserved
Keywords] platinum ^ palladium ^ sulfathiazole ^ electrospray ^ crystal structure[
———————————————————————————————————————————————
Sulfonamide compounds\ including sulfanilamide 0 ticularly for ligands which have biological activity
and sulfathiazole 1 have been long known for their ð3\4Ł[ Studies on metal complexes of sulfa drugs is an
antibacterial properties ð0Ł[ The presence of relatively area which has attracted interest in recent years[ While
acidic N0H protons in these compounds "activated a number of complexes of _rst!row transition metals
by the adjacent electron!withdrawing sulfonyl moiety#
suggested that these sulfa drugs should readily form
complexes with platinum group metal complexes\
bonding as their monoanions[ Metal complexes of
such ligands are of importance since the polymeric
silver"I# complex of the related compound sulfa!
diazine\ which contains silverÐamide linkages\ is
widely used clinically for the treatment of severe burns
ð1Ł[ We are interested in the general properties of
platinum!group metalÐamide complexes ð2Ł\ par!
have been described ð5Ð7Ł\ few platinum or palladium
complexes of sulfathiazole have been reported[
However\ some complexes of platinum"II# have been
found to be e}ective bactericides against sulfa!drug
resistant bacteria ð8Ł\ and a platinum"II# complex of
the related sulfa drug sulfadiazine has been found to
show antitumour activity ð09Ł[ A palladium"II# com!
plex of sulfathiazole has been used in the quantitative
analysis of the ligand ð00Ł and stability constants for
a number of metal complexes\ including palladium"II#
have been determined ð01Ł[ Platinum and palladium
complexes of other sulfonamide ligands are known
ð02\03Ł[
In this paper we describe the synthesis of some new
ꢀ Author to whom correspondence should be addressed[
Fax ] 9953 6 727 3108[ E!mail ] w[hendersonÝwaikato[ac[nz[ platinum"II# and palladium"II# derivatives containing
2026

2027
W[ Henderson et al[
deprotonated sulfathiazole ligands[ The application
of electrospray mass spectrometry to the study of this
type of complex is also described[
RESULTS AND DISCUSSION
Syntheses and X!ray crystal structure
Reaction of the complexes cis!ðPtCl1L1Ł ðL ꢁ PPh2
or
L1 ꢁ 0\0?!bis"diphenylphosphino#ferrocene
"dppf#Ł\ or ðPdCl1"phen#Ł ðphen ꢁ 0\09!phen!
anthrolineŁ with two mole equivalents of sulfathiazole
"stzH# 1 with excess triethylamine in hot methanol
yields\ after precipitation with water\ _ltration\ wash!
ing and drying\ the complexes cis!ðM"stz#1L1Ł "2aÐc#[
The complexes are air!stable solids\ poorly soluble in
chlorinated organic solvents\ and insoluble in water[
However they are generally more soluble in dimethyl
sulfoxide\ allowing partial NMR characterisation of
the complexes[ Electrospray mass spectrometry was
also used to characterise these complexes\ this being
a particularly useful technique for the analysis of com!
plexes of low solubility\ and where the reaction centre
"in this case the NH1 groups# is remote from the metal
centre[ The attempted synthesis of 2a using milder
reaction conditions "excess triethylamine in re~uxing
dichloromethane for 3 h# gave a mixture of 2a and the
mono stz complex 3\ identi_ed by 20P!"0H# NMR
spectroscopy[
Subsequent
reaction
of
cis!
ðPtCl1"PPh2#1Ł with one equivalent of stzH in CH1Cl1Ð
MeOH with triethylamine gave crude complex 3 in
65) yield[ The product also contained a small amount
of 2a[
The NH1 groups of the platinum complex 2a can
be acetylated "acetic anhydride:pyridine# or tri!
~uoroacetylated "tri~uoroacetic anhydride:pyridine#
to give the derivatised products 4a and 4b\ respec!
tively[ Attempted sulfonylation of 2a using p!tolu!
enesulfonyl chloride in pyridine gave a mixture of
products\ as shown by ESMS "see below#[ The deri!
vatised products 4 are somewhat more soluble in
dichloromethane and chloroform than 2a[
Unambiguous characterisation of the complexes 2Ð
4 by NMR spectroscopy "vide infra# was not easily
achieved\ and thus a single!crystal X!ray di}raction
study was carried out on one derivative[ The majority
of the complexes did not crystallise well\ however crys!
tals of 2a suitable for a structure determination were
obtained on allowing a saturated chloroform solution
to stand at room temperature for several weeks[ Fig!
ure 0 shows the molecular structure together with
Fig[ 0[ Molecular structure of the complex cis!
ðPt"stz#1"PPh2#1Ł 2a\ showing the atom numbering scheme[
Only the phosphorus!bonded triphenylphosphine carbon
atoms are shown for clarity\ and the three chloroform mol!
ecules of solvation have also been omitted[
Selected bond len`ths "_# and an`les "># ] Pt"0#0N"3#
1[984"6# ^ Pt"0#0N"0# 1[009"6# ^ Pt"0#0P"1# 1[167"1# ^
Pt"0#0P"0# 1[189"1# ^ N"0#0C"0# 0[238"02# ^ N"0#0C"2#
0[247"02# ^ N"3#0C"09# 0[235"01# ^ N"3#0C"01# 0[274"01# ^
N"3#0Pt"0#0N"0# 74[9"2# ^ N"0#0Pt"0#0P"1# 89[8"1# ^
N"3#0Pt"0#0P"0# 78[4"1# ^ P"1#0Pt"0#0P"0# 85[22"8#[
the atom numbering scheme\ and the caption gives There are only three other reported structures of tran!
selected bond lengths and angles[
sition!metal "copper and zinc# complexes containing
The complex contains the expected approximately solely thiazole nitrogen bonded stz ligands ð6\7Ł[ The
square!planar platinum"II# centre\ with two stz thiazole moieties are roughly perpendicular to the
ligands coordinated through their thiazole nitrogen platinum coordination plane\ as shown in Fig[ 1\
atoms\ in a cis!arrangement[ The structure deter! resulting in a trans!disposition of the remainder of the
mination is the _rst of a platinum!group metal sul! stz ligands\ presumably to minimise steric inter!
fathiazole complex bonded via the thiazole nitrogen[ actions[ The coordination plane is twisted so that the

Platinum"II# and palladium"II# complexes
2028
N0Pt0N plane is at 03[1> to the P0Pt0P one "Fig[
1#[
NMR spectroscopy
The 20P!"0H# NMR spectra of the phosphine com!
plexes 2a and 2b show a single resonance\ consistent
with two equivalent phosphine ligands[ The values of
0J"Pt\P# are indicative of the presence of phosphine
ligands trans to relatively low trans!in~uence nitrogen
donor ligands[ Thus\ for the triphenylphosphine com!
0
plex 2a\ the value of J"Pt\P# is 2333 Hz\ which is in
the range expected for nitrogen donor ligands\ and
0
compares well with the J"Pt\P# values of 2943\ 2343
and 2173 Hz found for the amide complexes cis!
ðPt"NCH1CH1CO#1"PPh2#1Ł ð4Ł\ ðPt"NHS"O#1NH#
Fig[ 1[ View of complex 2a along the N0Pt0N plane\ show!
ing the coordination of the thiazole moieties perpendicular "PPh2#1Ł ð02Ł and the isatin!derived complex cis!
to the platinum coordination plane\ resulting in the dis!
position of the bulk of the stz ligands above and below the
plane[
ðPt"isat#1"PPh2#1Ł "isatH ꢁ isatin\ indole!1\2!dione#
ð04Ł\ respectively[
0
The H and 02C!"0H# NMR spectra of the phos!
phine complexes 2a and 2b are relatively unin!
formative\ due to the large number of overlapping
signals in the aromatic region[ However\ unam!

2039
W[ Henderson et al[
of 2849 and 2226 Hz were observed for the phosphines
trans to chloride and amide ligands ð3Ł[ The di}erence
in coupling constants is larger for the asymmetric
complex 3 when compared to the symmetrical species
cis!ðPtCl1"PPh2#1Ł ð0J"Pt\P# 2562 HzŁ and the complex
2a ð0J"Pt\P# 2333 HzŁ\ and this e}ect has been reported
previously ð04\06Ł[
The 20P NMR spectra of the derivatised complexes
4 show little change in the 0J"Pt\P# coupling constant
ð4a 2338 Hz\ 4b 2349 HzŁ from the parent complex 2a
ð2333 HzŁ[ This is not unexpected given the remoteness
of the reactive site from the Pt0P moiety[
Electrospray mass spectrometry
The sulfathiazole complexes 2Ð4 have been inves!
tigated by electrospray mass spectrometry "ESMS#[
This relatively new technique\ which was originally
developed by Fenn and co!workers for the analysis
of large biomolecules\ is _nding increased use in the
characterisation of inorganic complexes ð07Ł[ ESMS
is particularly well!suited for complexes having only
low solubilities and volatilities\ such as those described
in this paper[ Additionally\ the rather complicated
0H and 02C NMR spectra yielded by such complexes
containing multiple aromatic ring systems\ coupled
with remote NH1 functional groups\ makes a simple
mass spectrometric technique the method of choice
for the initial characterisation of complexes of this
type[
ESMS data for complexes 2Ð4 are summarised in
Table 0\ and the complex cis!ðPt"stz#1"PPh2#1Ł 2a is
taken as a representative example for the purposes of
the following discussion[ At a cone voltage of 19 V
the complex yields a strong protonated ion peak
biguous NMR assignment of the complex 2a was ðM¦HŁ¦ at m:z 0118[ Excellent agreement was
achieved using HMBC ðHeteronuclear Multiple Bond observed between the observed and calculated isotope
Correlation "long!range 02C!0H correlation\ optimised distribution patterns[ Additional small peaks were
1
2
for J and J coupling#Ł and HMQC ðHeteronuclear observed due to ðM¦NaŁ¦ and ðM¦KŁ¦\ formed
Multiple Quantum Correlation "short!range 02C!0H\ from traces of the alkali metal cations present in the
0
optimised for J coupling#Ł inverse 1D experiments[ system[ Such adducts from trace cations are well!
0
The aromatic region of the H NMR spectrum of 2a known in electrospray mass spectra[ No higher aggre!
is illustrated in Fig[ 2[ The assignment of hydrogen gates of the type ð1M¦HŁ¦ or ð2M¦HŁ¦ were
atoms 1ý and 2ý "which cannot be easily distinguished observed[ Upon increasing the cone voltage to 29 V\
by standard methods# was made using known assign! an additional species\ having major peaks at m:z 862
ments of the thiazole group in the literature ð05Ł[ No and 863 is observed\ and is assigned to the species
2
1JC\Pt or JC\Pt couplings could be observed for this ðPt"stz#"PPh2#1Ł¦\ i[e[ ðM−stzŁ¦\ formed by loss of a
complex\ even with overnight acquisition periods on sulfathiazole anion ligand[ Upon further increasing
a relatively concentrated solution[ The addition of the cone voltage\ the relative proportion of the
D1O to a d5!DMSO solution of compound 2a resulted ðM−stzŁ¦ species increases at the expense of
in complete exchange of the NH1 protons at d 4[53\ ðM¦HŁ¦ and ðM¦NaŁ¦[ At still higher cone volt!
con_rming their assignment[
ages\ the species ð"o!C5H3PPh1#Pt"PPh2#Ł¦ "m:z 607#\
containing an orthometallated PPh2 ligand\ and its
Complex 3 gives the expected AB pattern in the 20
P
NMR spectrum\ with resonances at d 02[3 and 4[1\ solvated
analogue
ð"o!C5H3PPh1#Pt"PPh2#
showing coupling of 084Pt of 2749 and 2143 Hz\ respec! "NCCH2#Ł¦\ are observed[ We have previously
tively\ consistent with PPh2 ligands trans to chloride observed such cyclometallation in studies of a wide
and N!donor ligands[ For the related complex cis! range of platinum"II# complexes ð3\4\04Ł[
ðPtCl"debarb#"PPh2#1Ł "debarb ꢁ anion of 4\4!
The other stz complexes show generally similar
diethylbarbituric acid# comparable values of 0J"Pt\P# ESMS behaviour to the triphenylphosphine complex

Platinum"II# and palladium"II# complexes
2030
Fig[ 2[ 0H NMR spectrum "399 MHz\ d5!DMSO solution# of the aromatic region of the platinumÐtriphenylphosphine
complex cis!ðPt"stz#1"PPh2#1Ł 2a\ showing the assignment of the various aromatic and NH1 protons[ The inset shows the
atom numbering scheme[
Table 0[ Electrospray mass spectrometric data for the sulfathiazole complexes
Complex
Cone
voltage
Major observed ions "m:z\ )#a
2a
19
39
79
ðM¦HŁ¦ "0118\ 099)#\ ðM¦NaŁ¦ "0140\ 8)#\ ðM¦KŁ¦ "0156\ 0)#
ðM−stzŁ¦ "862:863\ 099)#\ ðM¦HŁ¦ "0118\ 10)#\ ðM¦NaŁ¦ "0140\ 17)#\ ðM¦KŁ¦ "0156\ 1)#
ð"o!C5H3PPh1#Pt"PPh2Ł¦ "607\ 099)#\ ð"o!C5H3PPh1#Pt"PPh2#"NCCH2#Ł¦ "648\ 06)#\ ðM−stzŁ¦
"862:863\ 89)#\ ðM¦HŁ¦ "0118\ 1)#\ ðM¦NaŁ¦ "0140\ 8)#
ð"o!C5H3PPh1#Pt"PPh2#Ł¦ "607\ 099)#\ ð"o!C5H3PPh1#Pt"PPh2#"NCCH2#Ł¦ "648\ 09)#\ ðM−stzŁ¦
"862:863\ 28)#
039
2b
3b
19
59
19
39
19
49
19
49
ðM¦HŁ¦ "0147\ 099)#\ ðM¦NaŁ¦ "0179\ 4)#
ðM−stzŁ¦ "0992\ 0993\ 099)#\ ðM¦HŁ¦ "0147\ 4)#\ ðM¦NaŁ¦ "0179\ 4)#
ðM−stzŁ¦ "863#\ ðM−stz¦NH2Ł¦ "880#\ ðM¦HŁ¦ "0909#
ðM−stzŁ¦ "863#
4a
4b
ðM−stzAcŁ¦ "0904\ 4)#\ ðM¦HŁ¦ "0202\ 099)#
ðM−stzAcŁ¦ "0904\ 099)#\ ðM¦HŁ¦ "0202\ 07)#
ðM¦HŁ¦ "0311\ 099)#
ðM−stzCOCF2Ł¦ "0958\ 099)#\ ðM¦HŁ¦ "0311\ 099)#
a Identi_cation of ions is by means of the most intense peak or peaks in the isotope distribution pattern[
b Weak ions also observed due to the small amount of impurity 2a present in this sample[
2a[ All complexes yield a strong ðM¦HŁ¦ molecular stz− ligand appears to provide an alternative ion!
ion\ though di}erent propensities to form the isation process "to protonation# at moderate cone
ðM"stz#L1Ł¦ ion were observed[ The observation of voltages[
ðM−stzŁ¦ ions up to high cone voltage suggests that
For complex 3 containing one chloride and one
the platinum!amide bond in the monocationic species stz ligand\ the ESMS spectrum of a freshly prepared
possess considerable stability\ though cyclo! solution showed a large ðM¦HŁ¦ peak at m:z 0909[
metallation of the PPh2 ligands provides an apparent The presence of both multi!isotopic platinum and di!
route for fragmentation[ In contrast\ loss of the _rst isotopic chlorine leads to a highly distinctive isotope

2031
W[ Henderson et al[
distribution pattern for this species\ and excellent prior puri_cation\ while triethylamine was distilled
agreement was found between observed and cal! from KOH pellets prior to use[
culated patterns[ The aromatic amine group present
in the complex is expected to be the most basic in the stage apparatus and are uncorrected[ Elemental analy!
complex\ and is thus the likely site of protonation[
ses were performed by the Campbell Microanalytical
Melting points were recorded on a Reichert hot!
The acetylated complex 4a shows a strong ðM¦HŁ¦ Laboratory\ University of Otago[ IR spectra were rec!
ion at m:z 0202 in the 19 V ESMS spectrum\ con! orded as KBr disks on a Perkin!Elmer 0599 Series or
_rming acetylation of both primary amine groups[ BioRad FTS!39 FTIR spectrophotometers[ 20P!"0H#
When the cone voltage is increased to 49 V\ one of the NMR spectra were recorded "unless otherwise stated#
acetylated sulfathiazole ligands "stzAc# is lost\ giving in CDCl2 solution\ to which ca 19) of DMSO was
ðM−stzAcŁ¦ "m:z 0904# as the base peak\ thus par! added\ either on a JEOL JNM!FX89 spectrometer\ at
elleling the behaviour of the parent 2a[ Identical 25[12 MHz\ or on a Bruker AC299P spectrometer at
behaviour was shown by the tri~uoroacetylated com! 010[40 MHz[ Spectra were recorded with external
plex 4b[ However\ the product "4c# from the attempted 74) H2PO3 as the reference "d 9[9#[ 0H NMR spectra
reaction of 2a with p!toluenesulfonyl chloride "Tol! were recorded in d5!DMSO solution on a Bruker DRX
SO1Cl# in pyridine was shown by ESMS to be a mix! spectrometer at 399[02 MHz\ or on a Bruker AC299P
ture of products\ with both mono! and di!sulfonylated instrument at 299[02 MHz\ chemical shifts being rela!
complexes giving their respective ðM¦HŁ¦ ions in the tive to SiMe3 "d 9[9#[ 02C!"0H# NMR spectra were
19 V positive!ion spectrum[ The major peak\ at m:z recorded on a Bruker AC299P spectrometer at 64[36
0196\ is assigned as ðPt"stz!SO1Tol#"pyridine# MHz[
"PPh2#1Ł¦ apparently formed by loss of one stz ligand
Electrospray mass spectra were obtained in posi!
and coordination of a pyridine ligand\ the solvent used tive!ion mode with a VG Platform II mass spec!
in the synthesis of this product[ However\ 20P!"0H# trometer\ with MeCHÐH1O "0 ] 0# as the mobile phase[
NMR of this mixture of products yielded only a single Cone voltages were typically varied from 09 to 099 V\
0
resonance ðd 1[6\ J"PtP# 2349Ł\ suggesting that the in order to investigate the e}ect of higher voltages on
neutral complexes 2a and 4c "and the mono!deri! fragmentation of the parent ions[ Excellent agreement
vatised complex# have a lower ionisation e.ciencies between observed and calculated isotope distribution
than the cationic ðPt"stz!SO1Tol#"pyridine#"PPh2#1Ł¦[ patterns was observed for all major ions[ Theoretical
The NH1 group is located some distance from the isotope patterns were calculated using the Iosotope
PPh2 ligands\ and 20P NMR is therefore insensitive to program ð11Ł[
changes at this position[ Despite the lack of success of
Melting point\ microanalytical and IR spec!
the synthesis of 4c\ the study demonstrates that ESMS troscopic data for complexes 2Ð4 are presented in
provides a valuable characterisation technique for Table 1[
rapid identi_cation of reaction products in this
0
system\ where H and 02C NMR is of limited diag!
nostic value[
Synthesis of cis!ðPt"stz#1"PPh2#1Ł 2a
In conclusion\ a number of platinum"I# and pal!
ladium"II# complexes containing deprotonated sul!
A suspension of cis!ðPtCl1"PPh2#1Ł "199 mg\ 9[142
fathiazole ligands have been prepared ^ a structure mmol# and stzH 1 "022 mg\ 9[410 mmol# was heated
determination of the bis"triphenylphosphine# to re~ux in methanol "19 cm2# with triethylamine "9[3
platinum complex 2a shows the ligands to be coor! cm2# for 0[4 h to give a white suspension[ The mixture
dinated through the thiazole nitrogen atoms[ Elec! was cooled and water "29 cm2# added[ The product
trospray mass spectrometry is demonstrated to be a was _ltered\ washed with water "4 cm2# and dried in
useful technique for investigating the chemistry of this vacuo to yield 2a "159 mg\ 73)#[ NMR ] 20P!"0H#
class of compound[
"010[4 MHz#\ d 2[37 ðs\ 0J"Pt\P# 2333Ł[ 02C!"0H# ]
"CDCl2# d 057[4 "s\ 0ý#\ 040[3 "s\ C!3?#\ 022[7 "d\ C!
11\ 51#\ 022[1 "s\ C!1ý#\ 020[0 "d\ C!31#\ 029[1 "s\ C!
0?#\ 017[2 "d\ C!21\ 41#\ 016[3 "d\ C!1?\ 5?#\ 015[8 ðs\
"dd\ second!order\ 0JC\P 57[42\ 2JC\P 4[76#\ C!01Ł\ 001[2
EXPERIMENTAL
The compound ðPdCl1"phen#Ł ð08Ł was synthesised "d\ C!2?\4?#\ 094[7 "d\ C!2ý#[
via the literature procedure[ The complexes cis!
ðPtCl1"PPh2#1Ł and ðPtCl1"dppf#Ł were prepared by
ligand substitution ð19Ł of the cyclo!octa!0\4!diene Synthesis of cis!ðPt"stz#1"dppf#Ł 2b
"cod# ligand of the complex ðPtCl1"cod#Ł ð10Ł[ The
following compounds were either prepared via the
A suspension of ðPtCl1"dppf#Ł "090 mg\ 9[012
literature procedure or used as supplied from com! mmol# and stzH 1 "52 mg\ 9[136 mmol# in methanol
mercial sources ] PPh2 "Pressure Chemical Company#\ "29 cm2# with triethylamine "0 cm2# was re~uxed for
dppf and tri~uoroacetic anhydride "Aldrich#\ sul! 0[4 h[ The yellow suspension was cooled to room
fathiazole 1 and p!toluenesulfonyl chloride "BDH#[ temperature\ and the product _ltered\ washed with
Methanol was of LR grade and used without any methanol "4 cm2# and dried in vacuo to give 2b "007

Platinum"II# and palladium"II# complexes
2032
Table 1[ Melting point\ microanalyticala and IR spectroscopic data for the sulfathiazole complexes 2Ð4
Microanalytical data
Complex m[pt[ ">C#
C
H
N
IR nmax "cm−0
#
2a
2d
2f
×129
×129
×129
41[5"41[7#
38[5"38[6#
34[1"34[2#
2[6"2[7#
2[4"2[4#
2[9"2[9#
5[8"5[7#
5[7"5[6#
03[2"03[0#
0341 "vs#\ 0029 "s#\ 0989 "s#
0341 "vs#\ 0018 "s#\ 0978 "s#\ 577 "s#
0486 "s#\ 0349 "vs#\ 0303 "s#\ 0216 "s#\ 0186 "s#\ 0156
"vs#\ 0060 "s#\ 0012 "vs#\ 0989 "vs#\ 0963 "vs#\ 824 "vs#\
603 "s#\ 572 "vs#\ 543 "s#\ 458 "vs#
3
4a
4b
n[d[
×129
084Ð199
41[2"42[5#
42[2"42[0#
37[7"38[0#
2[7"2[7#
3[0"2[7#
2[1"2[0#
3[0"3[1#
5[8"5[3#
5[9"4[8#
0348 "vs#\ 0021 "s#\ 0978 "s#\ 581 "s#\ 449 "s#\ 418 "s#
0341 "vs#\ 0026 "s#\ 0989 "s#
0629 "s#\ 0341 "vs#\ 0189 "s#\ 0054 "vs#\ 0980 "vs#\ 831
"s#\ 578 "vs#
a Calculated values are given in parentheses[
n[d[ ] This sample was of low purity "20P NMR# and melting point was therefore not determined[
mg\ 65)#[ 20P!"0H# NMR "010[4 MHz#\ d 2[7 ðs\ ture[ The resulting solid was _ltered\ washed with
0J"Pt\P# 2424Ł[
water "09 cm2# and ether "09 cm2# and dried in vacuo[
Complex 4a[ Reaction of 2a "053 mg\ 9[022 mmol#
with acetic anhydride gave 4a "097 mg\ 51)# as a
white powder[ 20P!"0H# NMR "010[4 MHz#\ d 2[2
ð0J"Pt\P# 2338Ł[
Complex 4b[ Reaction of 2a "059 mg\ 9[029 mmol#
with tri~uoroacetic anhydride gave 4b "018 mg\ 69)#
as a pale pink powder[ 20P!"0H# NMR "010[4 MHz\
CDCl2#\ d 1[1\ 0J"Pt\P# 2349[
Complex 4c[ Reaction of 2a "043 mg\ 9[014 mmol#
with p!toluenesulfonyl chloride gave 4b "85 mg# as a
white powder\ which was shown to be a mixture of
products by ESMS[ 20P!"0H# NMR "010[4 MHz\
CDCl2# showed a single major peak at d 1[6 ð0J"Pt\P#
2349Ł[
Synthesis of ðPd"stz#1"phen#Ł 2c
The complex ðPdCl1"phen#Ł "014 mg\ 9[249 mmol#
with stzH 1 "068 mg\ 9[690 mmol# in methanol "29
cm2# with added triethylamine "0 cm2# was re~uxed
for 05 h to give an orange suspension[ Complex 2c was
_ltered o}\ washed with methanol "4 cm2#\ acetone "4
cm2# and dried in vacuo to give an orange powder "133
mg\ 77)#[
Synthesis of cis!ðPtCl"stz#"PPh2#1Ł 3
To a solution of cis!ðPtCl1"PPh2#1Ł "032 mg\ 9[070
mmol# and stzH 1 "36 mg\ 9[073 mmol# in methanol
"09 cm2# and dichloromethane "19 cm2# was added
triethylamine "0 cm2#\ and the mixture stirred over!
night at room temperature[ The resulting colourless
solution was rotary evaporated to dryness at 39>C to
a}ord a white solid\ which was found to be complex
3\ with a small quantity "ca 2)# of the bis"stz# com!
plex 2a[ The solid was washed with isopropanol "19
cm2# to remove triethylammonium chloride\ and dried
in vacuo to give crude 3 "028 mg\ 65)#[ 20P!"0H#
Crystal structure determination of 2a
Crystals of 2a suitable for an X!ray structure deter!
mination were obtained by allowing a saturated
CHCl2 solution of the complex to stand at 3>C for
several weeks[ Unit cell dimensions and intensity data
were obtained on a Seimens SMART di}ractometer[
The data collection nominally covered over a hemi!
sphere of reciprocal space\ by a combination of three
sets of exposures ] each set had a di}erent f angle for
the crystal and each exposure covered 9[2> in v[ The
crystal to detector distance was 4[9 cm[ The data set
was corrected using SADABS ð12Ł\ including an
0
1
NMR "25[1 MHz#\ d 02[3 ðs\ J"Pt\P# 2749\ J"P\P#
06Ł and 4[1 ðs\ 0J"Pt\P# 2143Ł[
Reaction of 2a with acetic anhydride\ tri~uoroacetic empirical absorption correction "Tmax\min 9[72\ 9[28#[
anhydride and p!toluenesulfonyl chloride Crystal data[ C43H35N5O3P1S3Pt[2CHCl2\
Mr ꢁ 0475[23 "including solvent of crystallisations#\
¹
General method[ To a stirred solution of complex triclinic\ P0\ a ꢁ 00[9886"0#\ b ꢁ 03[6086"1#\
2a "ca 049 mg\ 9[011 mmol# in pyridine "4 cm2# was c ꢁ 10[2900"1# _\ a ꢁ 67[238"0#\ b ꢁ 66[313"0#\
added acetic anhydride or tri~uoroacetic anhydride g ꢁ 60[905"0#>\ U ꢁ 2068[32"5# _2\ Dcalcd 0[546 g
"39 drops# or p!toluenesulfonyl chloride "099 mg#\ cm−2
\
Z ꢁ 1\ F"999# ꢁ 0479\ Mo0Ka X!rays
and stirred for 59 min[ The mixture was poured onto "l ꢁ 9[60962 _#\ m"MoÐKa# ꢁ 1[71 mm−0\ crystal
crushed ice and allowed to warm to room tempera! 9[39×9[00×9[09 mm2[

2033
W[ Henderson et al[
B[ K[ and Wilkins\ A[ L[\ J[ Or`anomet[ Chem[\
0855\ 415\ 292[
A total of 20\946 re~ections in the range 1>³u³17>
were collected at 192 K\ with 02\791 unique "Rint
9[976#[ The structure was solved by Patterson methods
"SHELXS!85 ð13Ł# and developed routinely[ One of
the three CHCl2 molecules in the lattice was partially
disordered with two of the chlorine atoms each dis!
tributed over two sites\ while another showed high
temperature factors suggesting at least partial dis!
order:occupancy[ In the _nal cycles of least!squares
re_nement based on F1 "SHELXL!85 ð13Ł# all non!
hydrogen atoms were anisotropic and hydrogen atoms
were included in calculated positions[ The re_nement
converged with R0 ꢁ 9[9743 for 8616 data with
I×1s"I#\ 9[0129 for all data\ wR1 ꢁ 9[0849 "w ꢁ ðs1
"F1o #¦9[0032P1Ł−0 where P ꢀ "Fo1¦1F1c #:2# and
GoF 0[936[ A _nal di}erence map showed somewhat
3[ Fawcett\ J[\ Henderson\ W[\ Kemmitt\ R[ D[ W[\
Russell\ D[ R[ and Upreti\ A[\ J[ Chem[ Soc[\
Dalton Trans[\ 0885\ 0786[
4[ Henderson\ W[ and Sabat\ M[\ Polyhedron\ 0886\
05\ 0552[
5[ Casanova\ J[\ Alzuet\ G[\ Latorre\ J[ and Borras\
ꢂ
J[\ Inor`[ Chem[\ 0886\ 25\ 1941 and references
therein ^ Casanova\ J[\ Alzuet\ G[\ Borras\ J[\ Lat!
tore\ J[\ Sanau\ M[ and Garcia!Granda\ S[\ J[
Inor`[ Biochem[\ 0884\ 59\ 108 ^ Bult\ A[\ Pharm[
Weekbl\ 0865\ 000\ 274[
6[ Casanova\ J[\ Alzuet\ G[\ Borras\ J[ and Carugo\
O[\ J[ Chem[ Soc[\ Dalton Trans[\ 0885\ 1128[
7[ Casanova\ J[\ Alzuet\ G[\ Ferrer\ S[\ Borras\ J[\
Garcia!Granda\ S[ and Perez!Carreno\ E[\ J[
Inor`[ Biochem[\ 0882\ 40\ 578[
8[ Yamashita\ S[\ Japanese Patent 6\819\010\ 0868 ^
Chem[ Abstr[\ 0868\ 80\ 702[
09[ Pasini\ A[ and Zunino\ F[\ An`ew[ Chem[ Int[ Ed[
En`l[\ 0876\ 15\ 504 ^ Pasini\ A[\ Bersanetti\ E[\
Zunino\ F[ and Savi\ G[\ Inor`[ Chim[ Acta\ 0872\
79\ 88[
00[ Agrawal\ Y[ K[\ Menon\ S[ K[ and Giridhar\ R[\
Anal[ Lett[\ 0876\ 19\ 718[
large residual features of ¦6[10 and −2[55 e _−2
\
within 0 _ of the platinum atom\ which could not
be improved upon by reprocessing the data[ This\
together with the higher than usual R factors\ suggests
that the data were not of the best quality\ a problem
exacerbated by the disorder in the CHCl2 molecules
in the crystal[ Detailed discussion of bond parameters
is therefore deemed inappropriate[
Further details of the structure investigation\ tog!
ether with lists of _nal atomic coordinates\ thermal
parameters\ and complete bond distances and angles\
and structure factors may be obtained from the Cam!
bridge Crystallographic Data Centre\ or from the
authors on request[
01[ Agrawal\ Y[ K[\ Giridhar\ R[ and Menon\ S[ K[\
J[ Pharm[ Sci[\ 0876\ 65\ 892[
02[ Parkin\ I[ P[ and Woollins\ J[ D[\ J[ Chem[ Soc[\
Dalton Trans[\ 0889\ 408[
03[ Kemmitt\ R[ D[ W[\ Mason\ S[\ Moore\ M[ R[
and Russell\ D[ R[\ J[ Chem[ Soc[\ Dalton Trans[\
0881\ 398 ^ Corradi\ A[ B[\ Gozzoli\ E[\ Menabue\
L[\ Saladini\ M[\ Battaglia\ L[ P[ and Sgarabotto\
P[\ J[ Chem[ Soc[\ Dalton Trans[\ 0883\ 162 ^
Corradi\ A[ B[\ Coord[ Chem[ Rev[\ 0881\ 006\ 34 ^
Schaad\ D[ R[ and Landis\ C[ R[\ Or`an!
ometallics\ 0881\ 00\ 1913[
04[ Law\ J[ M[\ Henderson\ W[ and Nicholson\ B[ K[\
J[ Chem[ Soc[\ Dalton Trans[\ 0886\ 3476[
05[ Kalinowski\ H[\ Berger\ S[ and Braun\ S[\ Carbon!
02 NMR Spectroscopy[ John Wiley and Sons\
0877[
Acknowled`ements*The University of Waikato and the
New Zealand Lottery Grants Board are acknowledged for
_nancial support[ We also thank Johnson Matthey PLC for
a generous loan of platinum\ Assoc[ Prof[ C[ E[ F[ Rickard
and A[ G[ Oliver "University of Auckland# for collection of
the X!ray data set\ and Wendy Jackson and Amu Upreti for
technical assistance[
06[ Andrews\ M[ A[\ Gould\ G[ L[\ Klooster\ W[ T[\
Koenig\ K[ S[ and Voss\ E[ J[\ Inor`[ Chem[\ 0885\
24\ 4367[
07[ Colton\ R[\ D|Agostino\ A[ and Traeger\ J[ C[\
Mass Spectrum Rev[\ 0884\ 03\ 68 ^ Hop\ C[ E[ C[
A[ and Bakhtiar\ R[\ J[ Chem[ Educ[\ 0885\ 62\
A051[
08[ Wimmer\ F[ L[\ Wimmer\ S[ and Castan\ P[\
Inor`[ Synth[\ 0881\ 18\ 074[
19[ Oliver\ D[ L[ and Anderson\ G[ K[\ Polyhedron\
0881\ 00\ 1304[
10[ McDermott\ J[ X[\ White\ J[ F[ and Whitesides\
G[ M[\ J[ Am[ Chem[ Soc[\ 0865\ 87\ 5410[
11[ Arnold\ L[ J[\ J[ Chem[ Educ[\ 0881\ 58\ 700[
12[ Blessing\ R[ H[\ Acta Cryst[\ 0884\ A40\ 22[
13[ Sheldrick\ G[ M[\ SHELX!85\ Programs for solv!
ing and re_ning crystal structures[ University of
GoÃttingen\ 0885[
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