Complex of cis-(NH3)2PtCl2 with guanylyl(3′-5′)-cytidine

The predominant complex formed by the reaction of cis-(NH₃)₂PtCl₂ and guanylyl(3′-5′)cytidine has been isolated. The molar ratio of the binding of cis-(NH₃)₂PtCl₂ to guanylyl(3′-5′)-cytidine is 1:2. The values of proton dissociation constant due to guanine and cytosine bases provide useful information for determining the binding site of the isolated complex. In addition, nmr and ir spectral data were used to determine the binding site. cis-(NH₃)₂PtCl₂ coordinates to guanylyl(3′-5′)cytidine through N(7) position of the guanine base, but cytosine base does not participate in the binding to cis-(NH₃)₂Pt²⁺. Interbase crosslink has not been detected. The binding specificity of cis-(NH₃)₂PtCl₂ to guanine base is discussed.     

Novel palladium(II) and platinum(II) complexes of biocidal benzisothiazolinone (Bit); X-ray crystal structures of co-crystallised Bit/BitO and cis-Pd(en)(Bit−1H)2·H2O

Reaction of benzisothiazolinone (Bit), a well-known biocide, with the Pd(II) and Pt(II) am(m)ine precursors cis-[Pd(en)(H₂O)₂](NO₃)₂ and cis-[Pt(NH₃)₂(H₂O)₂](NO₃)₂ yielded cis-Pd(en)(Bit_−1H)₂ and cis-Pt(NH₃)₂(Bit_−1H)₂, respectively. Bit is bound to the metal centres in both cases through the deprotonated isothiazolinone N. The crystal structures of a Bit/BitO co-crystal and cis-Pd(en)(Bit_−1H)₂·H₂O are also described.     

Preparation of methyl cis-9,cis-12-octadecadienoate-16,16,17,17-d4

An eight-step synthesis is described which gives an overall yield of ～30% methyl cis-9,cis-12-octadecadienoate-16,16,17,17-d₄. The preparation utilizes easily obtainable starting materials. Tris(triphenylphosphine)chlororhodium (I) catalyst is used for incorporation of the deuterium isotopes. The double bond in the 9 position is created by the Wittig coupling of 1-non-3-enyl-d₄-triphenylphosphonium bromide to methyl 8-formyloctanoate. Various methods for preparation of the intermediate and final products are discussed. Partial argentation resin chromatography was used to remove the ～9% trans/cis, cis/trans, and trans/trans isomers also produced. Analysis of the final product by mass spectrometry (MS) indicated 96%-d₄.     

The reaction of the cis-dioxorhenium(V) core with N,O-donor ligands: mono and bidentate coordination of 3-methyl-2-aminophenol

The reaction of cis-[ReO₂I(PPh₃)₂] with 3-methyl-2-aminophenol (H₂map) in ethanol led to the formation of trans-[Re(map)(Hmap)I(PPh₃)₂]I. The X-ray crystal structure shows that the ligand map is coordinated monodentately through the doubly deprotonated amino nitrogen and is therefore present as an imide. The chelate Hmap is coordinated via the neutral amino nitrogen and the singly deprotonated phenolate oxygen, which is coordinated trans to the imido nitrogen. In benzene equimolar quantities of cis-[ReO₂I(PPh₃)₂] and 4-methyl-2-aminophenol (H₂amp) produced the five-coordinate cis-[ReO₂(Hamp)(PPh₃)]. A twofold molar excess of 2-aminophenol (H₂ap) yielded the six-coordinate [ReO(Hap)(ap)(PPh₃)]. The chelate ap is coordinated through the deprotonated phenolate oxygen and the singly deprotonated amino nitrogen (amide).     

Microbiological Hydroxylation of Cinerone to Cinerolone

Cinerone [2-(2′-cis-butenyl)-3-methyl-2-cyclopenten-1-one] is hydroxylated to cinerolone [2-(2′-cis-butenyl)-3-methyl-4-hydroxy-2-cyclopenten-1-one] by a number of streptomycetes, bacteria, and fungi. Aspergillus niger ATCC 9,142 and Streptomyces aureofaciens ATCC 10,762 were found to be the most effective hydroxylators. The optical activity of the product was found to range from [α]_D²⁵ 0° to -8.6°, depending on the organism and conditions of culture. Two additional hydroxylated products of cinerone have been isolated and identified as 2-n-butyl-4-hydroxy-3-methyl-2-cyclopenten-1-one and 2-(2′-cis-butenyl-4′-hydroxy)-3-methyl-2-cyclopenten-1-one, respectively.     

Structure and reactivity of [Ru(2,3-Medpp)2Cl2]

The structure and reactivity of the complex [Ru(2,3-Medpp)₂Cl₂](PF₆)₂ (2,3-Medpp⁺=2-[2-(1-methylpyridiniumyl)]-3-(2-pyridyl)pyrazine) was investigated by X-ray diffraction (XRD), ¹H NMR, redox, and UV-Vis absorption measurements. X-ray analysis shows that crystals obtained from an acetonitrile-toluene solution contain the trans-Cl₂, trans-pyrazine isomeric form, while ¹H NMR and redox measurements on the main product of the synthetic workup indicate the presence of the trans-Cl₂, cis-pyrazine isomer. In the dark at 70 °C, the complex [Ru(2,3-Medpp)₂Cl₂]²⁺ reacts slowly in acetonitrile isomerizing to the cis-[Ru(2,3-Medpp)₂(CH₃CN)Cl]³⁺ species. Under ambient light in the presence of excess AgNO₃ the cis-[Ru(2,3-Medpp)₂(CH₃CN)₂]⁴⁺ species is obtained.     

Cis-dichlorodiammineplatinum(II) has a binding specificity for adjoining guanine bases

Self complementary deoxyribooctanucleotides, [5′-d(GpGpTpCpGpApCpC)-3′]₂ and [5’-d(CpGpGp- ApTpCpCpG)-3’]₂, were allowed to react with cis- PtCl₂(NH₃)₂, and the reaction mixture was treated with exonuclease (snake venom phosphodiesterase and/or calf spleen phosphodiesterase). Semi-quantitative analysis by HPLC showed that the adjoining guanine bases have a specific binding affinity to cis-PtCl₂(NH₃)₂.     

Seasonal variations in trans-2-hexenal and linolenic acid in homogenates of Thea sinensis leaves

The seasonal variations in the amounts of C₆-volatile components cis-3-hexenal trans-2-hexenal n-hexanal) and their precursors (linoleic and linolenic acid) in homogenates of Thea sinensis leaves were quantitatively analyzed throughout the year. Formation of trans-2-hexenal began in the middle of April and reached a maximum during July. Towards autumn the aldehyde gradually decreased and, in winter (December to March), was virtually absent. The levels of cis-3-hexenol remained constant during May–December. cis-3-Hexenal showed a similar variation pattern to that of trans-2-hexenal. The major fatty acids in the leaves were palmitic, palmitoleic, oleic, linoleic and linolenic acid, and occurred in non-ionic lipids and phospholipid fractions. The amounts of linoleic and linolenic acid did not show any marked variation except for a big peak in October.     

Crystal and molecular structure of Δ-cis-α-ethylenebis-S-prolinato(1,2-diamino-ethane)cobalt(III) perchlorate dihydrate, Δ-cis-α-[Co(ss-EBP)(en)] ClO4·2H2O

The crystal and molecular structure of Δ- cis-α- ethylenebis-S-prolinato(1,2-diaminoethane)cobalt(III) perchlorate dihydrate, Δ-cis-α-[Co(SS-EBP)(en)] ClO₄· 2H₂O, was determined from three-dimensional X-ray diffractometer data. The complex crystallizes in the orthorhombic system, space group P2₁2₁2₁ with a = 7.879(4) Å, b = 13.738(9) Å, c = 19.445(2) Å, V = 2104(2) ų. With Z = 4, the observed and calculated densities are 1.60(2) and 1.605 g cm^?3, respectively. The structure was refined by the block- diagonal least-squares technique to a final R = 0.0560 for 1604 observed reflections. The geometry about the cobalt atom is roughly octahedral with the tetradentate SS-EBP (= ethylenebis-S-prolinate ion), assuming cis-α configuration in which the complex possesses two out-of-plane amino acidate (R) rings and the backbone ethylenediamine (E) ring. The E ring conformation is δ. On the other hand, the R rings have λ conformation as well as the en ring. Δ-R_NR_N?(δ_E  λ_R1  λ_R2)(λ_en)-cis-α-[Co(SS-EBP)(en)]⁺ is one of two possible isomers of this compound which have been isolated and whose absolute configurations have been tentatively assigned by spectroscopy. The crystal and molecular structure determination confirms these assignments.     

Synthesis of [17,18-3H]trans-13-azaprostanoic acid. A labeled probe for the PGH2/TXA2 receptor

Because of its highly unstable nature, TXA₂, produced by platelet metabolism of arachidonic acid, does not lend itself to use as a receptor probe for its own receptor. As such, the stable TXA₂/PGH₂ antagonist, trans-13-azaprostanoic acid (trans-13-APA, 12b), was prepared as the [17,18 ³H] derivative ([³H] trans-13-APA, 12c) to study this receptor and to better evaluate the mechanism of action of these azaprostanoids. Tritiated trans-13-APA, 12c, was prepared in nearly theoretical specific activity (57 Ci/mmole) from (17z)-trans-13-azaprost-17-enoic acid (11b) by catalytic tritiation. The unsaturated 11b was prepared by condensation of cis-7-amino-3-heptene (8) with 2-(6-carboxyhexyl) cyclopentanone (9), NaBH₄ reduction, chromatography, and hydrolysis of the trans isomer so isolated. The olefins 11a and b were also of biochemical interest because of the unsaturation in the lower side chain. The presence of similar unsaturation in PGH₃ (4) and TXA₃ (3) renders these prostaglandins inactive as proaggregatory agents. Evaluation of the antiaggregatory activity of 11a and b indicated it to be about the same potency in inhibiting human platelet aggregation as the parent cis and trans-13-APAs, suggesting that introduction of a double bond at the 17 position in platelet prostaglandin antagonists is unlikely to result in enhanced antiplatelet activity.     

Multinuclear NMR study and crystal structures of complexes of the types cis- and trans-Pt(amine)2I2

Complexes of the types cis- and trans-Pt(amine)₂I₂ were studied by spectroscopic methods, especially by multinuclear NMR spectroscopy. In ¹⁹⁵Pt NMR, the cis diiodo compounds with primary amines were observed between −3342 and −3357 ppm in acetone, while the trans compounds were found between −3336 and −3372 ppm. For the secondary amines, the chemical shifts were observed at lower fields. In ¹H NMR, the trans complexes were observed at higher fields than the cis compounds, while in ¹³C NMR, the reverse was observed. The ²J(¹⁹⁵Pt-¹H) and ³J(¹⁹⁵Pt-¹H) coupling constants are larger for the cis compounds (ave. 67 and 45 Hz, respectively) than for the trans isomers (ave. 59 and 38 Hz). In ¹³C NMR, the values of ²J(¹⁹⁵Pt-¹³C) and ³J(¹⁹⁵Pt-¹³C) were also found to be larger for the cis complexes (ave. 17 and 39 Hz versus 11 and 28 Hz). There seems to be a slight dependence of the pK_a values of the protonated amines or the proton affinity in the gas phase with the δ(Pt) chemical shifts. The crystal structures of eight diiodo complexes were determined. These compounds are cis-Pt(CH₃NH₂)₂I₂, cis-Pt(n-C₄H₉NH₂)₂I₂, cis-Pt(Et₂NH)₂I₂, trans-Pt(n-C₃H₇NH₂)₂I₂, trans-Pt(iso-C₃H₇NH₂)₂I₂, trans-Pt(n-C₄H₉NH₂)₂I₂, trans-Pt(t-C₄H₉NH₂)₂I₂ and trans-Pt(Me₂NH)₂I₂. The Pt-N bond distances located in trans position to the iodo ligands were compared to those located in trans position to the amines. The Pt-N bond in cis-Pt(Et₂NH)₂I₂ are much longer than the others, probably caused by the steric hindrance of the two very bulky ligands located in cis positions.     

The structural and electrochemical consequences of hydrogenating copper N2S2 Schiff base macrocycles

A series of cis and trans tetradentate copper macrocyclic complexes, of ring size 14-16, that employ amine and thioether donor groups are reported. Apart from 5,6,15,16-bisbenzo-8,13-diaza-1,4-dithia-cyclohexadecane copper(I) (cis-[Cu(H₄N_buS_en)]⁺) all of the complexes are obtained in the copper(II) form. Crystallographic analysis shows that the copper(II) complexes all adopt a distorted planar geometry around the copper. In contrast, cis-[Cu(H₄N_buS_en)]⁺ is found to adopt a distorted tetrahedral geometry. The complexes were subjected to electrochemical analysis in water and acetonitrile. The effect of the solvent, positions of the donor atoms (cis/trans) on E^1/2 is discussed as is the comparison of the electrochemical behaviour of these complexes with their parent Schiff base macrocycles.     

Synthesis and study of Pt(II)-aromatic amines complexes of the types cis- and trans-Pt(amine)2(NO3)2 and cis-Pt(amine)2(R(COO)2)

Complexes of the types cis- and trans-Pt(amine)₂(NO₃)₂ with amines containing a phenyl group were synthesized and studied mainly by IR and multinuclear magnetic resonance spectroscopies. The cis complexes could be synthesized pure only with the amines of the type Ph-R-NH₂ (R = alkyl), while pure trans compounds were synthesized with all the studied amines. In ¹⁹⁵Pt NMR spectroscopy, the dinitrato complexes of the amines Ph-R-NH₂ were observed around −1700 ppm for the cis isomers and at about −1580 for the trans complexes. For the other amines, where a phenyl ring is directly attached to the amino group, the signals were observed at lower fields, −1528 ppm for cis-Pt(PhNH₂)(NO₃)₂ and around −1450 ppm for all the trans isomers. There is a linear relationship between the δ(Pt) of the Pt(amine)₂(NO₃)₂ complexes and the pK_a of the protonated amines. The coupling constants ²J(¹⁹⁵Pt-¹HN) are larger in the cis compounds (ave. 76 Hz) than in the trans isomers (ave. 63 Hz). The complexes cis-Pt(amine)₂(R(COO)₂) with bidentate dicarboxylato ligands were also synthesized and characterized mainly by IR spectroscopy. The compounds apparently decompose in DMF and are too insoluble in other solvents for solution studies.     

Synthesis, structure and properties of TTF-carboxylate bridged paddlewheel dirhodium complexes, Rh2(BuCO2)3(TTFCO2) and Rh2(BuCO2)2(TTFCO2)2

Reaction of tetrathiafulvalene carboxylic acid (TTFCO₂H) with paddlewheel dirhodium complex Rh₂(Bu^tCO₂)₄ yielded TTFCO₂-bridged complexes Rh₂(Bu^tCO₂)₃(TTFCO₂) (1) and cis- and trans-Rh₂(Bu^tCO₂)₂(TTFCO₂)₂ (cis- and trans-2). Their triethylamine adducts [1(NEt₃)₂] and cis-[2(NEt₃)₂] were purified and isolated with chromatographic separation, and characterized with single crystal X-ray analysis. Trans-[2(NEt₃)₂] is not completely separated from a mixture of cis- and trans-[2(NEt₃)₂], but its single crystals were obtained from a solution of the mixture. A three-step quasi-reversible oxidation process was observed for 1 in MeCN. The first two steps correspond to the oxidation of the TTFCO₂ moiety and the last one is the oxidation of the Rh₂ core. The oxidation of cis-2 is observed as a two-step process with very similar E_1/2 values to those of the first two processes for 1. Both 1⁺ and cis-2²⁺ in MeCN at room temperature show isotropic ESR spectra with a g value of 2.008 and a_H = 0.135 mT for two equivalent H atoms and a_H = 0.068 mT for one H atom. The redox and ESR data of cis-2 suggest that the intramolecular interaction between the TTF moieties is very small.     

Study of Pt(II)-cyclic amines complexes of the types cis- and trans-Pt(amine)2I2 and cis- and trans-Pt(amine)2(NO3)2 and their aqueous products by

Complexes of the types cis- and trans-Pt(amine)₂I₂ containing cyclic amines were synthesized and studied mainly by IR and multinuclear NMR spectroscopies. The compounds were converted to cis- and trans-Pt(amine)₂(NO₃)₂, which were also investigated. The hydrolysis and the aquation reactions of the latter compounds were then studied in D₂O in different conditions of pH. In acidic medium, the aqueous product is [Pt(amine)₂(D₂O)₂]²⁺ and for a few amines, [Pt(amine)₂(D₂O)(NO₃)]⁺ was detected. In basic pH, the main product is Pt(amine)₂(OD)₂ and Pt(amine)₂(OD)(NO₃) was detected for several compounds. In neutral pH, the cis isomers form between two and four species in fresh solutions. The most shielded species in ¹⁹⁵Pt NMR is the monoaqua-monohydroxo complex cis-[Pt(amine)₂(D₂O)(OD)]⁺ and the less shielded compound is the dihydroxo-bridged dimer [Pt(amine)₂(μ-OD)₂Pt(amine)₂]²⁺, which were observed for all the compounds. For a few amines, the monohydroxo-bridged dimer [Pt(D₂O)(amine)₂(μ-OD)Pt(OD)(amine)₂]²⁺ was detected and for cyclohexylamine, a fourth signal was assigned to a cyclic hydroxo-bridged trimer [(Pt(amine)₂(μ-OD))₃]³⁺. ¹⁹⁵Pt NMR spectroscopy has shown that the concentration of the monomer decreases with time, while the concentration of the dimers increases. Only one product was observed for the trans isomers in neutral pH. The signal was assigned to the monoaqua-monohydroxo species trans-[Pt(amine)₂(D₂O)(OD)]⁺. The ¹³C and ¹H NMR spectra of most of the complexes were measured. All the coupling constants ^2,3J(¹⁹⁵Pt-¹H) and ^2,3J(¹⁹⁵Pt-¹³C) are larger in the cis compounds than in the trans isomers.     

Synthesis, characterization and kinetic studies of the cis-[RuCl2(cyclen)] complex

We report here the synthesis, characterization and kinetic studies of cis-[RuCl₂(cyclen)]⁺ in aqueous solution, where cyclen is the macrocyclic ligand 1,4,7,10-tetraazacyclododecane. The complex releases one Cl⁻ producing cis-[RuCl(OH)(cyclen)]⁺ in aqueous solution at pH 4.60. The product of this reaction was characterized by Ultraviolet-Visible (UV-Vis) spectrum in comparison to the synthesized cis-[RuCl(OH)(cyclen)](BF₄)·2H₂O. The electrochemical data showed that E_pc of the Ru(III/II) peak increases as the macrocycle ring size decreases and also when the trans conformation is changed to cis. The chloride affinity of Ru(III) depends on the macrocycle ring size since cis-[RuCl₂(cyclam)]⁺ (cyclam=1,4,8,11-tetraazacyclotetradecane) does not release chloride for at least 12 h. The overall effect between cyclam and cyclen reflects the fact that the electron involved in the reduction enters a nonbonding π-d orbital and its energy is affected by the macrocyclic ligand.     

Different reaction mechanisms for cis- and trans-prenyltransferases

Octaprenyl diphosphate synthase (OPPs) and undecaprenyl diphosphate synthases (UPPs) catalyze consecutive condensation reactions of farnesyl diphosphate (FPP) with 5 and 8 isopentenyl diphosphate (IPP) to generate C₄₀ and C₅₅ products with trans- and cis-double bonds, respectively. In this study, we used IPP analogue, 3-bromo-3-butenyl diphosphate (Br-IPP), in conjunction with radiolabeled FPP, to probe the reaction mechanisms of the two prenyltransferases. Using this alternative substrate with electron-withdrawing bromo group at the C3 position to slow down the condensation step, trapping of farnesol in the OPPs reaction from radiolabeled FPP under basic condition was observed, consistent with a sequential mechanism. In contrast, UPPs reaction yielded no farnesyl carbocation intermediate under the same condition with radiolabeled FPP and Br-IPP, indicating a concerted mechanism. Our data demonstrate the different reaction mechanisms for cis- and tran-prenyltransferases although they share the same substrates.     

Studies of the reaction products of adenosine with [Pt(NH3)3Cl]Cl and cis-Pt(NH3)2Cl2 by high performance liquid chromatography

The reaction products of adenosine with [Pt(NH₃)₃Cl]Cl or cis-Pt(NH₃)₂Cl₂ have been studied using high performance liquid chromatography and uv spectroscopy. The reaction of [Pt(NH₃)₃Cl]Cl with adenosine (pH = 7.0, Pt/base = 0.5) gives four products. Two of them, mononuclear complexes in which platinum is bound to adenosine through N(7) or N(1), comprise more than 90% of all the products. The N(1) and N(7) sites on adenosine indicate almost equal binding affinity for [Pt(NH₃)₃Cl]Cl. The reaction of cis-Pt(NH₃)₂Cl₂ with adenosine has been studied in the presence of a large excess of adenosine (Pt/base ? 0.05). The reaction gives four products. One is the monomeric 2:1 complex with cis-Pt(NH₃)₂²⁺ bound to two adenosine molecules through the N(7) site and the N(1) site, and another is the monomeric 2:1 complex with cis-Pt(NH₃)₂²⁺ bound to two adenosine molecules through the N(7) sites. cis-Pt(NH₃)₂Cl₂ is stronger affinity to the N(7) site than of adenosine to the N(1) site.     

Solvent exchange, solvent interchange, aquation and isomerisation reactions of cis- and trans-[Co(tmen)2(NCMe)2] in water, Me2SO and MeCN: kinetics and stereochemistry

The synthesis and characterisation of cis- and trans-[Co(tmen)₂(NCCH₃)₂](ClO₄)₃ are described. Solvolysis rates have been measured by both ¹H NMR spectroscopy and UV-Vis spectrophotometry in dimethyl sulfoxide at 298.2 K. The cis isomer undergoes solvolysis by consecutive first-order reactions, k₁=5.61 × 10⁻⁴ and k₂=5.35 × 10⁻⁴ s⁻¹, each with steric retention. The measured solvolysis rate (single step reaction) for the trans isomer is k=1.54 × 10⁻⁵ s⁻¹. The solvent exchange rates have been measured by ¹H NMR spectroscopy in CD₃CN at 298.2 K: k_ex(cis)=k_ct + k_cc=2.0 × 10⁻⁵ and k_ex(trans)=k_tc + k_tt=4.56 × 10⁻⁶ s⁻¹. From these data, the measured cis-trans isomerisation rate (1.71 × 10⁻⁶ s⁻¹) and equilibrium position in CH₃CN (17% trans), the steric course for substitution in the exchange processes has been determined: trans reactant - 69% trans product; cis reactant - 99% cis product. Aquation rates for cis- and trans-[Co(tmen)₂(NCCH₃)₂](ClO₄)₃ have also been determined spectrophotometrically and by NMR; k_cis=1.3 × 10⁻⁴ and k_trans=2.7 × 10⁻⁵ s⁻¹. In both cases the steric course for the primary aquation step is indeterminate because the subsequent steps are faster. Where data are available, the [Co(tmen)₂X₂]ⁿ⁺ complexes are found to be consistently much more reactive than their [Co(en)₂X₂]ⁿ⁺ analogues.     

Synthesis and multinuclear magnetic resonance spectroscopy of the novel ionic Pt(II) mixed-ligands complexes cis- and trans-[Pt(amine)2(pyrimidine)2](NO3)2

Novel ionic mixed-ligands complexes of the types cis- and trans-[Pt(amine)₂(pm)₂](NO₃)₂ (where pm = pyrimidine) were synthesized and studied in the solid state by IR spectroscopy and in aqueous solution by multinuclear (¹⁹⁵Pt, ¹H and ¹³C) magnetic resonance spectroscopy. The results of the solution NMR characterization have shown that the isolated compounds are pure. In ¹⁹⁵Pt NMR, the cis RNH₂ complexes were observed at slightly lower fields (ave. −2441 ppm) than the equivalent trans analogues (ave. −2448 ppm). For Me₂NH, the difference between the two isomers is larger (29 ppm). The complexes are observed at lower fields (difference of 100 ppm) than the corresponding [Pt(amine)₄]²⁺ complexes, which might indicate the presence of π-backdonation in the Pt-pm bond. In ¹H NMR, the coupling constants ³J(¹⁹⁵Pt-¹H_amine) are larger in the cis compounds (38-48 Hz) than in the trans analogues (30-36 Hz). The ³J(¹⁹⁵Pt-¹H_pm) values are also larger for the cis isomers. In ¹³C NMR spectroscopy, the coupling constants ³J(¹⁹⁵Pt-¹³C_amine) are 36 Hz (ave.) for the cis complexes and 26 Hz (ave.) for the trans isomers, while the ²J(¹⁹⁵Pt-¹³C_amine) are 18 Hz (cis) and 14 Hz (trans), respectively. The ³J(¹⁹⁵Pt-¹³C_5(pm)) values are 36 Hz (cis) and 28 Hz (trans). A few ²J(¹⁹⁵Pt-¹³C_pm) couplings were observed (7-10 Hz).