Cis Compounds Research Articles

Endocyclic Enamides Derived from Aza‐Diketopiperazines as Olefin Partners in Povarov Reaction: An Access to Tetracyclic N‐Heterocycles

Original endocyclic enamides based on a bicyclic aza‐diketopiperazine (aza‐DKP) structure have been used as dienophile partners in the Povarov reaction. The reported method represents a successful strategy for the structural diversification of the aza‐DKP scaffold, giving access to a new family of fused tetracyclic N‐heterocycles, which contain at least four nitrogen atoms in the heterocyclic structure. Depending on the nature of the aldehyde partner, the cycloadditions have been performed either as a two‐component or a three‐component Povarov reaction (2CPR or 3CPR), in the presence of BF3 as a Lewis acid catalyst. With aliphatic aldehydes the reaction proceeds with high diastereoselectivities in favor of the cis compounds. Some mechanistic aspects of this cycloaddition have been examined computationally.

DFT calculations of the neighboring groups effects on cheletropic reaction of 2,5-Dihydrothiophene sulfone

In this research DFT calculations were used to investigate the neighboring effects on cheletropic reaction of 2,5-Dihydrothiophene sulfone(1). Structural properties and stereoelectronic behavior in the activation energy and enthalpy of cheletropic reaction was performed for 2,5-Dihydrothiophene sulfone where substitutions of CF3; CCl3 and CBr3 that were placed on Sulfolen were investigated by using DFT-B3LYP/6-311+G** level of theory. The Results of calculations using B3LYP, HF and MP2 [basic 6-311+G**] showed that the trend of electronic effects on the cis and trans state is different. Reaction rate and activation energy in cis compounds showed that increasing electronegativity and decreasing the band length reduced the reaction speed. Trend of reaction rate and activation energy in Trans compounds showed that in cheletropic reaction rate and activation energy not only electronic effects but also the Steric effects play a main role. DFT/B3LYP/6-311+G** calculation results also confirm these results. In cis compounds, 2,5- three Floro metyl Sulfolen(2) has the highest activation energy about (12.25 kcal/mol) and the lowest rate of reaction. In trans compounds, Trans-2,5- three chloro metyl Sulfolen(7) has the highest activation energy about (12.99 kcal/mol) and the lowest rate of reaction.

Effect of chain length and donor–acceptor substitution on the electrical responsive properties of conjugated biphenyls: a DFT-based computational study

ABSTRACTThe effect of donor–acceptor (D-A) substituent and chain length on the electrical polarisabilities and first hyper polarisability of cis and trans biphenyl oligomeric compounds have been investigated using density functional theory-based hybrid functional CAM-B3LYP with 6-311G (2d,2p) basis set. Our extensive computational study reveals that both average polarisability and first hyper polarisability of the studied compounds increase with the increasing ethylene spacer chain length. Again the substitution of donor (NMe2) and acceptor (C≡N) at the para position of the phenyl rings to each oligomer shows order of magnitude increase of both αav and βav value compared to the unsubstituted one. This increased αav and βav values have been explained due to increasing charge transfer contribution resulting from decreasing optical energy gap (ΔE = S1 − S0) upon D-A substitution. It is also observed that the charge transfer contribution to first hyperpolarisability (βCT) is more than the polarisability (αCT) for the studied molecules. The electronic spatial extent (<R2>) which is a measure of electron density volume around the molecule is found to play a major role along with the intramolecular charge transfer character to explain the non-linear variation of first hyperpolarisability (βav) as a function of ethylene spacer chain length (n) and D-A substitution.

Water-soluble Ru(II)- and Ru(III)-halide-PTA complexes (PTA = 1,3,5-triaza-7-phosphaadamantane): Chemical and biological properties

Four structurally related Ru(II)-halide-PTA complexes, of general formula trans- or cis-[Ru(PTA)4X2] (PTA=1,3,5-triaza-7-phosphaadamantane, X=Cl (1, 2), Br (3, 4), were prepared and characterized. Whereas compounds 1 and 2 are known, the corresponding bromo derivatives 3 and 4 are new. The Ru(III)-PTA compound trans-[RuCl4(PTAH)2]Cl (5, PTAH=PTA protonated at one N atom), structurally similar to the well-known Ru(III) anticancer drug candidates (Na)trans-[RuCl4(ind)2] (NKP-1339, ind=indazole) and (Him)trans-[RuCl4(dmso-S)(im)] (NAMI-A, im=imidazole), was also prepared and similarly investigated. Notably, the presence of PTA confers to all complexes an appreciable solubility in aqueous solutions at physiological pH. The chemical behavior of compounds 1–5 in water and in physiological buffer, their interactions with two model proteins – cytochrome c and ribonuclease A – as well as with a single strand oligonucleotide (5′-CGCGCG-3′), and their in vitro cytotoxicity against a human colon cancer cell line (HCT-116) and a myeloid leukemia (FLG 29.1) were investigated. Upon dissolution in the buffer, sequential halide replacement by water molecules was observed for complexes 1–4, with relatively slow kinetics, whereas the Ru(III) complex 5 is more inert. All tested compounds manifested moderate antiproliferative properties, the cis compounds 2 and 4 being slightly more active than the trans ones (1 and 3). Mass spectrometry experiments evidenced that all complexes exhibit a far higher reactivity towards the reference oligonucleotide than towards model proteins. The chemical and biological profiles of compounds 1–5 are compared to those of established ruthenium drug candidates in clinical development.

Pure enantiomers of benzoylamino-tranylcypromine: LSD1 inhibition, gene modulation in human leukemia cells and effects on clonogenic potential of murine promyelocytic blasts

The pure enantiomers of the N-(2-, 3-, and 4-(2-aminocyclopropyl)phenyl)benzamides hydrochlorides 11a–j were prepared and tested against LSD1 and MAO enzymes. The evaluation of the regioisomers 11a–j highlighted a net increase of the anti-LSD1 potency by shifting the benzamide moiety from ortho to meta and mainly to para position of tranylcypromine phenyl ring, independently from their trans or cis stereochemistry. In particular, the para-substituted 11a,b (trans) and 11g,h (cis) compounds displayed LSD1 and MAO-A inhibition at low nanomolar levels, while were less potent against MAO-B. The meta analogs 11c,d (trans) and 11i,j (cis) were in general less potent, but more efficient against MAO-A than against LSD1. In cellular assays, all the para and meta enantiomers were able to inhibit LSD1 by inducing Gfi-1b and ITGAM gene expression, with 11b,c and 11g–i giving the highest effects. Moreover, 11b and 11g,h strongly inhibited the clonogenic potential of murine promyelocytic blasts.

The cis–trans transformation of cyclohexane formic acid ester compounds

Trans-alkyl cyclohexane formic acid phenol ester compounds are synthesised by reaction of trans-cyclohexane formic acid and phenols. This process also produces many harmful cis-alkyl cyclohexane formic acid phenol ester compounds that are harmful to the environment. Using p-toluenesulphonic acid as the catalyst in this experiment, these cis compounds were transformed to their trans form. The yields of trans-alkyl cyclohexane formic acid phenol ester compounds were more than 70%, which was significantly higher when compared to the yields of 40–60% obtained using the control method. The effects of catalyst, reaction time and reaction temperature on cis–trans transformation were investigated. The possible mechanism of cis–trans transformation has been discussed in this report.

Efficient and Stereoselective Nitration of Mono- and Disubstituted Olefins with AgNO2 and TEMPO

Nitroolefin is a common and versatile reagent. Its synthesis from olefin is generally limited by the formation of mixture of cis and trans compounds. Here we report that silver nitrite (AgNO2) along with TEMPO can promote the regio- and stereoselective nitration of a broad range of olefins. This work discloses a new and efficient approach wherein starting from olefin, nitroalkane radical formation and subsequent transformations lead to the desired nitroolefin in a stereoselective manner.

Cellular accumulation and DNA interaction studies of cytotoxic trans-platinum anticancer compounds

Fortyyears after the discovery of the anticancer effects of cisplatin, scientists are still pursuing the development of platinum complexes with improved properties regarding side effects and resistance, which are two main problems in cisplatin treatment. Among these compounds, trans-configured platinum complexes with oxime ligands emerged as a new class with features distinct from those of established anticancer agents, including different DNA binding behavior, increased cellular accumulation, and a different pattern of protein interaction. We report herein on the reactivity with biomolecules of three novel pairs of cis- and trans-configured acetone oxime platinum(II) complexes and one pair of 3-pentanone oxime platinum(II) complexes. Cellular accumulation experiments and in vitro DNA platination studies were performed and platinum contents were determined by inductively coupled plasma mass spectrometry. The trans-configured complexes were accumulated in SW480 cells in up to 100 times higher amounts than cisplatin and up to 50 times higher amounts than their cis-configured counterparts; r (b) values (number of platinum atoms per nucleotide) were more than tenfold increased in cells treated with trans complexes compared with cells treated with cisplatin. The interaction of the complexes with DNA was studied in cell-free experiments with plasmid DNA (pUC19), in capillary zone electrophoresis with the DNA model 2-deoxyguanosine 5'-monophosphate, and in in vitro experiments showing the degree of DNA damage in the comet assay. Whereas incubation with cis compounds did not induce degradation of DNA, the trans complexes led to pronounced strand cleavage.

Hydrolysis mechanism of anticancer Pd(II) complexes with coumarin derivatives: a theoretical investigation

The hydrolysis reaction mechanisms of a new generation Pd(II) anticancer drugs containing coumarin derivatives have been investigated combining density functional theory with the conductor-like dielectric continuum model approach. The first and the second aquation processes have been explored for the cis and trans counterpart of title PdL2 complex. Two possibilities for the second hydrolysis process have been analyzed for both compounds. From our data emerge that cis and trans PdL2 compounds have a different behavior in water. cis-isomer readily undergo first hydrolysis process generating a mono-aqua complex while both the pathways investigated for the second aquation reaction are more energetically demanding, suggesting that the mono-aqua complex could act as active species. On the contrary, for trans-compound, both the investigated reactions for the second aquation process occur by overcoming activation barriers comparable with that found for the first hydrolysis reaction. According to our data, trans-oriented PdL2 drug could undergo degradation process generating non-active compounds with the consequent lack of pharmacological activity.

ChemInform Abstract: Tetracyclic Analogues of (+)-S 14297: Synthesis and Determination of Affinity and Selectivity at Cloned Human Dopamine D3 vs D2 Receptors.

Abstract Starting from the structure of the preferential D3 antagonist S 14297 (1), we have prepared a series of cis and trans tetracyclic derivatives of general formula I in order to improve potency and selectivity for D3 receptors. The trans oxazino derivative 2c, showed slightly increased affinity at D3 receptors and double the selectivity for D3 over D2 receptors, in comparison to S 14297. Cis derivatives and compounds where R1 is aralkyl were totally devoid of activity.

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

Abstract 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–1Hamine) are larger in the cis compounds (38–48 Hz) than in the trans analogues (30–36 Hz). The 3J(195Pt–1Hpm) values are also larger for the cis isomers. In 13C NMR spectroscopy, the coupling constants 3J(195Pt–13Camine) are 36 Hz (ave.) for the cis complexes and 26 Hz (ave.) for the trans isomers, while the 2J(195Pt–13Camine) are 18 Hz (cis) and 14 Hz (trans), respectively. The 3J(195Pt–13C5(pm)) values are 36 Hz (cis) and 28 Hz (trans). A few 2J(195Pt–13Cpm) couplings were observed (7–10 Hz).

Synthesis and NMR characterization of the novel mixed-ligands Pt(II) complexes Pt(amine)(pyrimidine)X2 and trans,trans-X2(amine)Pt(μ-pyrimidine)Pt(amine)X2 (X=I and Cl)

Abstract Mixed-ligand complexes of the type Pt(amine)(pm)I 2 , (pm = pyrimidine) were synthesized and characterized by IR spectroscopy and by multinuclear ( 195 Pt, 1 H and 13 C) magnetic resonance spectroscopy. The cis compounds were prepared from the reaction of I(amine)Pt(μ-I) 2 Pt(amine)I with pyrimidine (1:2 proportion) in water, while the trans isomers were synthesized from the isomerization of the cis complexes in acetone. The cis isomers could not be isolated with several amines, especially the more bulky ones. In 1 H NMR, the pyrimidine protons of the cis compounds were found at lower fields than those of the trans analogs and the J ( 195 Pt– 1 H) coupling constants are slightly larger in the cis geometry. For n -butylamine, the reaction produced also I 2 ( n -butylamine)Pt(μ-pm)Pt( n -butylamine)I 2 . No such dimer could be isolated with the other amines. The compounds Pt(amine)(pm)Cl 2 were also prepared (amine = methylamine and t -butylamine) from the ionic complex K[Pt(amine)Cl 3 ] using an excess of pyrimidine. The IR and NMR characterization showed that the methylamine compound was a cis – trans mixture, while only the trans isomer was isolated with t -butylamine. When the same reaction was performed using a Pt:pm ratio of 2:1, Cl 2 (amine)Pt(μ-pm)Pt(amine)Cl 2 was isolated. The pyrimidine-bridged dimers were identified by IR and multinuclear magnetic resonance spectroscopies as the trans – trans isomers. The trans monomers and dimers showed only one ν (Pt–Cl) band. The 195 Pt NMR signals of the dimers were found close to those of the monomer trans -Pt(amine)(pm)Cl 2 .

Insight into cis‐to‐trans Olefin Isomerisation Catalysed by Group 4 and 6 Cyclopentadienyl Compounds

AbstractIntramolecular isomerisation of the pendant allyl unit present in the model compound [MoH(η5‐C5H4SiMe2CH2CH=CH2)(CO)3] reported before was investigated by DFT calculations. The coordination of CO and the splitting of the agostic Mo–H interactions found in metallacyclic transition states stabilise the cis and trans hydride compounds [MoH(η5‐C5H4SiMe2CH=CHCH3)(CO)3] relative to the corresponding tricarbonyl molybdenum alkyl metallacycles. A comparison with an analogous zirconium system is included. To contrastthese results with the behaviour of metal hydride cyclopentadienyl compounds, which have no intramolecular alkene functionality, group 4 and 6 derivatives such as [Zr(η5‐C5H4SiMe2‐η1‐NtBu)(η5‐C5H4SiMe2CH2CH2‐η1‐CH2)] (2), [MH(η5‐C5HMe4)(CO)3] [M = Mo (3), W (4)], and [ZrH(η5‐C5H4SiMe2‐η1‐NtBu)(η5‐C5H4R)] [R = H (5), SiMe3 (6)] were examined as selective catalysts for the intermolecular isomerisation of the terminal olefins allyltrimethylsilane (A) and 4‐methyl‐1‐pentene (B). Zirconium hydride compounds were the most efficient catalysts. Compound 4 catalysed the same reaction but required heating at 140 °C, whereas compound 3 was inactive due to a dehydrogenation process, which produced the dinuclear compound [Mo(η5‐C5HMe4)(CO)3]2 (7). Reaction of 4 and 5 with the internal alkenes trimethyl(1‐propenyl)silane (C) and 4,4‐dimethyl‐2‐pentene (D) favoured cis‐to‐trans isomer conversion with poor production of the corresponding terminal olefins. (© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2009)

Synthesis, Characterization, and In Vitro Antitumor Activity of New Amidineplatinum(II) Complexes Obtained by Addition of Ammonia to Coordinated Acetonitrile

AbstractNew cis‐ and trans‐dichloridoplatinum(II) complexes, which contain two amidine ligands or one amidine and one ammine ligand, cis‐ and trans‐[PtCl2{(Z)‐HN=C(NH2)CH3}2] (1) and cis‐ and trans‐[PtCl2(NH3){(Z)‐HN=C(NH2)CH3}] (2), have been prepared from the corresponding nitrile complexes by amminolysis in thf solution. All synthesized compounds were characterized by elemental analysis, ESI‐MS, and IR and NMR spectroscopy. Amidines are isosters of iminoethers and ketimines. The trans isomers of the platinum complexes of the latter are endowed with an unexpectedly high antitumor activity. An important feature of complexes 1 and 2, as compared to iminoethers, is the exclusive preference for the Z configuration of the amidine ligand(s). The tumor cell growth inhibitory potency of the amidine compounds was tested towards a pair of human ovarian tumor cell lines A2780 (cancer cells sensitive to cisplatin) and A2780cisR (cancer cells with acquired resistance to cisplatin), and compared to that of cisplatin. From the obtained results it appears that the resistance factor is lower for cis‐amidine complexes as compared to cisplatin, and for trans compounds it is lower as compared to cis compounds.(© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2008)

Synthesis and NMR characterization of the novel mixed-ligand Pt(II) complexes cis- and trans-Pt(Ypy)(pyrimidine)Cl 2 and trans, trans-Cl 2(Ypy)Pt(μ-pyrimidine)Pt(Ypy)Cl 2 (Ypy = pyridine derivative)

Mixed-ligand complexes of the type cis- and trans-Pt(Ypy)(pm)Cl 2 where Ypy = pyridine derivative and pm = pyrimidine were synthesized and characterized by IR spectroscopy and by multinuclear ( 195Pt, 1H and 13C) magnetic resonance spectroscopy. The cis compounds were prepared from the reaction of K[Pt(Ypy)Cl 3] with pyrimidine (1:1 proportion) in water, while most of the trans isomers were synthesized from the isomerization of the cis compounds. The cis isomers could not be isolated with the Ypy ligands containing two –CH 3 groups in ortho positions. When the aqueous reaction of K[Pt(Ypy)Cl 3] with pyrimidine was performed in a Pt:pm ratio = 2:1, the pyrimidine-bridged dinuclear species were formed. Only the most stable trans– trans isomers could be isolated pure. In IR spectroscopy, the cis monomers showed two ν(Pt–Cl) bands, while the trans monomers and dimers showed only one ν(Pt–Cl) band. The 195Pt NMR signals of the cis monomers were found at slightly higher fields than those of the corresponding trans isomers. The δ( 195Pt) of the dimers were found close to those of the trans monomers. The NMR results were interpreted in relation to the solvent effect, which seems important in these complexes. The coupling constants J( 195Pt– 1H) and J( 195Pt– 13C) are larger in the cis geometry. The crystal structures of the compounds cis-Pt(2,4-lut)(pm)Cl 2, trans-Pt(2,6-lut)(pm)Cl 2 and trans, trans-Cl 2(2,6-lut)Pt(μ-pm)Pt(Ypy)Cl 2 were studied by X-ray diffraction methods and the results have confirmed the configurations suggested by IR and NMR spectroscopies.

Novel platinum(II) compounds with N-benzylidenebenzylamines: Synthesis, crystal structures and the effect of cis or trans geometry on cycloplatination

Coordination compounds with a trans-stereochemistry were prepared for ligands (4-ClC 6H 4)CH NCH 2(4′-ClC 6H 4) ( L a), (2,4,6-Me 3C 6H 2)CH NCH 2(4′-ClC 6H 4) ( L b) and (2,6-Cl 2C 6H 3)CH NCH 2(4′-ClC 6H 4) ( L c) and were shown to be precursors of the corresponding cyclometallated compounds. The reactions between cis-[PtCl 2(dmso) 2] and ligands ArCH NCH 2(4′-ClC 6H 4) (Ar = 2-BrC 6H 4 ( L d); 2-ClC 6H 4 ( L e); C 6F 5 ( L f); 2,6-F 2C 6H 3 ( L g)) under previously described conditions for cycloplatination of N-benzylidenebenzylamines gave a cyclometallated compound only for imine L f; the other imines produced coordination compounds with a cis arrangement from which cyclometallation could not be achieved. Formation of either cis or trans coordination compounds [PtCl 2( L)dmso] ( L = N-benzylidenebenzylamine) can be related to steric effects and to the E/ Z configuration of the C N bond. All compounds were fully characterized including structure determinations for trans-[PtCl 2{(4-ClC 6H 4)CH NCH 2(4′-ClC 6H 4)}SOMe 2] ( 2a), trans-[PtCl 2{(2,6-Cl 2C 6H 3)CH NCH 2(4′-ClC 6H 4)}SOMe 2] ( 2c) and the amine derivative trans-[PtCl 2(4-ClC 6H 4CH 2NH 2)SOMe 2] ( 2) obtained as a by-product.

The infrared and Raman spectra of trans- and cis-tetrachloro-tetramethylbicyclopropylidene

The title compounds trans- and cis-2,2,2′,2′-tetrachloro-3,3,3′,3′-tetramethyl-bicyclopopylidene were synthesized, and their infrared and Raman spectra were recorded. Non-coincidence between the IR and Raman bands of the trans compound suggested C 2h symmetry and a planar ring system. In the cis compound most of the IR and Raman bands coincided and a C 2v symmetry seems likely. The exocyclic C C double bond gave rise to a medium/weak Raman band at 1847 cm −1 in the trans compound. In the cis derivative IR and Raman bands both at 1825 cm −1 were observed. From similarities with related molecules, the ring breathing, the antisymmetric ring stretch, the CCl 2 out-of-phase and in-phase stretch and the out-of-plane ring bending modes have been tentatively assigned for the trans and cis compounds.

Cis/trans isomers of PtX 2 L 2 (X = halogen, L = neutral ligand); the crystal structures of two polymorphs of cis-dichlorobis(dibenzyl sulfido-κS)platinum(II) in the temperature range 100–295 K

The structures of two polymorphs, one triclinic and one monoclinic, of cis-dichlorobis(dibenzyl sulfido-kappaS)platinum(II), cis-PtCl(2)(Bz(2)S)(2), have been determined at 295, 250, 200, 150 and 100 K. In both polymorphs the complex has a structure where platinum(II) coordinates two dibenzyl sulfide molecules and two chloro ligands, forming a complex with pseudo-square-planar coordination geometry. The triclinic polymorph shows disorder at all temperatures. Both polymorphs have a packing arrangement involving centrosymmetric structural dimers. cis-PtCl(2)(Bz(2)S)(2) belongs to a group of complexes with the general formula PtX(2)L(2), where X is a halogen and L is a ligand with a donor atom from groups 14, 15 or 16. The distribution of structural classes among 173 cis-PtX(2)L(2) compounds found in the Cambridge Structural Database (CSD, Version 5.28, November 2006) has been investigated. The predominant structural class [notation according to Belsky & Zorkii (1977). Acta Cryst. A33, 1004-1006] among the cis compounds is P2(1)/c, Z = 4 (1) (73 structures, 42%), followed by P\bar 1, Z = 2 (1) (33 structures, 19%). Inversion centres combined with the screw-axis/glide plane are the dominating packing operators (56%) followed by the inversion centre (21%). The cis and trans influence in cis/trans-PtCl(2)L(2) compounds has been investigated using data from the CSD. The cis influence is small for donor atoms in groups 15 and 16. The trans influence is small for group 16 donor atoms and for nitrogen, but for phosphorus it is significantly greater than the other donor atoms studied.

Comparison of cis and trans-Platinum Mononucleobase Compounds with DNA and Protein Models

Reactions of 5′-guanosine monophosphate (5′-GMP) and N-acetylmethionine (N-ac-l-Met) with the mononucleobase compounds, cis-[PtCl(L)n(9-EtGH)]+ (L = NH3, 4-pic, n = 2; L = en, n = 1) in a 1:1 molar ratio have been studied in aqueous solutions at pH 7.3 using 1H and 195Pt NMR spectroscopy. There is a high kinetic preference for sulfur over nitrogen binding. These results are compared with the trans isomers. Based on low cytotoxicity and a high sulfur/nitrogen preference the cis isomers may also present suitable features for antiviral activity through interaction with specific proteins.

Synthesis and study of Pt(II)-aromatic amines complexes of the types cis- and trans-Pt(amine) 2(NO 3) 2 and cis-Pt(amine) 2(R(COO) 2)

Complexes of the types cis- and trans-Pt(amine) 2(NO 3) 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–NH 2 (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–NH 2 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(PhNH 2)(NO 3) 2 and around −1450 ppm for all the trans isomers. There is a linear relationship between the δ(Pt) of the Pt(amine) 2(NO 3) 2 complexes and the p K a of the protonated amines. The coupling constants 2 J( 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.