Diamminedichloroplatinum , trans

SYNS trans-DIAMMINEDICHLOROPLATINUM(II) trans-PLATINUM(II)DIAMMINEDICHLORIDE... 

DIAMINO-s-TRIAZOLE see DCF200 1,3-DIAMINOUREA see CBS500 ds-DIAMMINEDICHLOROPLATINUM see PJDOOO trans-DIAMMINEDICHLOROPLATINUM(II) see DEXOOO... 

In geometric isomers, or cis-trans isomers, of coordination compounds, the same ligands are arranged in different orders within the coordination sphere. Geometric isomerism occurs when atoms or groups of atoms can be arranged on two sides of a rigid structure. Cis means adjacent to and trans means on the opposite side of. Cis- and trans-diamminedichloroplatinum(II) are shown below. 

The DNA damage produced by Pt(II)-coordination complexes can be included in such a schema. This discussion will be limited to damage produced by cis- and trans-Diamminedichloroplatinum... 

Drug Treatments. Cis-Diamminedichloroplatinum(II) (NSC 119875) and trans-Diamminedichloroplatinum(II) (NSC 131558) were obtained from the National Cancer Institute and were always constituted in isotonic, aqueous solution Just prior to use. L-phenylalanine mustard (NSC 8806) was dissolved in 0.1 N HCl and stored frozen. 

If Reiset s first chloride is heated at250°Cvuitil no further NH3 is given off, the product is trans-diamminedichloroplatinum (II) ... 

Two milestones in chemistry may be addressed to the geometric isomers of diamminedichloroplatinum(II). About 100 years ago Alfred Werner laid down the principles of modem coordination chemistry with the help of isomeric [PtCl2(NH3)2] [1]. About 70 years later Barnett Rosenberg and co-workers discovered that the cis isomer is antitumor active, whereas the trans isomer is not [2,3]. Today m-[PtCl2(NH3)2] (cisplatin) is routinely used as a drug, particularly effective against testicular and ovarian cancer [4],... 

The presence of large deposits of platinum ores in Russia led to an intensive study of the coordination compounds of platinum early in the development of coordination chemistry. As a result of these studies by the Russian school, the first stereospecific displacement reaction (and first example of the trans effect) was discovered. Consider two means of forming diamminedichloroplatinum(ll) (1) displacement of Cl ions from [PtCl4] by NH, (2) displacement of NH3 from [Pt(NH3)4]" by CP ions. It is found that two different isomers are formed ... 

FIGURE 9.5 cis and trans Isomers of Diamminedichloroplatinum(ll), [PtCljtNHjlj]. The cis isomer, also known as cisplatin, is used in cancer treatment. 

Maleic copolymers were proved to form chelates with platinum-containing anticancer drugs (cis-diamminedichloroplatinum(II), trans-l,2-diaminocyclohexane platinum) through a monocarboxylato and a 0->Pt coordination linkage. These complexes self-assembled into nanoparticles with an increased in-vivo tumors inhibition due to their internalization into the cancer cells. The release of the platinum-containing drug was pH dependent [211,212]. 

Cisplatin, cw-diamminedichloroplatinum(II), is an extremely potent antitumor agent. Show how it can be prepared in high purity to the exclusion of the trans geometric isomer by employing the kinetic trans effect. 

It is important to underline the fact that a tetrahedral complex, which would have the same global formula as the preceding one, cannot exhibit this isomerism. Hence, for example, the isolation of two isomers of the diamminedichloroplatinum(II) complex [Pt (Cl)2(NH3)2] has been a very strong argument in favor of its planar stmcture. The octahedral hexacoordinated complex dichlorobis(ethylenediamine)cobalt(III) [Co (Cl2)(en)2]+ exists in the cis and trans forms (Fig. 23.4). 

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