Trans-PtCl

Release of coordinated chloride from trans-Pt(NH3)2Cl2 is much harder and requires heating trans-PtCl(OH)(NH3)2 (Pt-O 1.989 A Pt—N 2.024 and 2.048 A) and trans-Pt(OH)2(NH3)2 have been isolated from such mixtures [72]. 

In the case of complexes such as (21) and (23) which have an extended planar ligand, a significantly higher proportion of interstrand cross-links in DNA is formed in comparison to either cis- or trans-platin.172 The steric effects of these planar ligands result in the formation of structurally unique 1,2-interstrand cross-links like those formed by cisplatin, a unique example of how steric effects may alter a nonactive lesion into an active one (Figure 13).173,174 Model studies predicted this outcome by preparation of the monofunctional models trans-[PtCl(9-ethylguanine) (NH3)(quinoline)] and comparison of substitution rates of the Pt—Cl bond by G or C mononucleotides.175 176 Interestingly, the iminoether compound (25) appears to form predominantly monofunctional adducts with DNA.177... 

PtMe(C00H)(diphos) (diphos=Ph2PCH2CH2PPh2) (8) and trans-PtCl-(COgH)(PEt )2 (9) are thermally quite stable whereas trans-[PtH-(COOH)La] in solution is unstable manifests a dramatic trans-ef-... 

The diaqua form of czs-DDP can be easily obtained from the dichloro compound by using Aq+, whereas the corresponding trans-DDP derivative requires more forcing conditions [15]. Neither of these species have been isolated, however. Various procedures have been employed to obtain solutions of the first hydrolysis or solvolysis product of czs-DDP and related compounds including chromatographic methods [15] and treatment of the dichloro compound [16] with 1 equiv Aq+ in DMF. With trans-DDP, controlled hydrolysis of the parent compound in basic solution gives trans-[PtCl(OH)(NH3)2]-H20 and trans-[Pt(OH)2(NH3)2] ... 

In acidic aqueous solution the complexation of the chloroaqua derivatives of cis- and trans-DDP involves substitution of the aqua ligand with the nucleobase [15]. The trans derivative reacts 10 times faster than the cis isomer with inosine at pH 3, in line with the trans-effect Cl" > NH3. It has been shown that trans- [PtCl(NH3)2(H20)]+ behaves like a mono-... 

A well-studied reaction yielding a metal hydride is that of trans-[PtCl(CO)-(PEt3)2]+ with water to yield C02 and rram-[PtCl(H)(PEt3)2], (35) (95). 

Figure 8. Graph of1JPt-P cis to C Xn in cis- [PtCl(C Xn)(PPh3)2] against 2J pt-pds to CXnin trans-[PtCl(C Xn)(PPh3)2 ] (41)...

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