Platinum II Complexes

Differences are also observed in the reactivity of platinum(II) complexes of [82X2] and [802X2] towards halogens. In the former case oxidative addition to give platinum(IV) complexes occurs, with retention... 

Several N-(chloromethyl)pyridinium platinum complexes have been described in the literature [89JOM255 92JCR(S)296 92JOM155]. Interestingly, 2-pyridyl platinum(II) complexes 11 and 12, having been dissolved in dichloromethane, are slowly N-alkylated by the solvent, yielding the N-(chloromethyl)pyridinium compounds 13 (76%) and 14 (77%) (Scheme 3). 

Oxidative addition reactions of platinum(II) complexes with N-heterocyclic ligands 97CRV1735. 

Since n bonding is believed to be more important in low oxidation states, as d orbitals contract with increasing oxidation state leading to poorer dw-pw overlap, this would not be expected on the basis of a 7r-bonding mechanism. Similarly, one can compare /(Pt-P) for pairs of isomers in the +2 and +4 states in a planar platinum(II) complex, the platinum 6s orbital is shared by four ligands whereas in an octahedral platinum(IV) complex it is shared by six ligands. Therefore, the 6s character is expected to be only 2/3 as much in the platinum(IV) complexes, correlating well with the 7(Pt-P) values, which can be taken to be a measure of the a-character in the bond. 

Complexes are similarly formed by polydentate phosphine and arsine ligands synthetic routes involve oxidation of the platinum(II) complex, either with the halogen or with nitric acid ... 

In addition to the methods already outlined for platinum(II) complexes, simultaneous crystallization can be used to prepare mixed complex halides (Figure 3.105). 

Halogen oxidation of platinum(II) complexes generally occurs trans, as does reaction with H202 to afford dihydroxy complexes (Figure 3.106). 

Table 3.27 shows bond lengths for a number of platinum(IV) and related platinum(II) complexes. 

Anomalies in ligand exchange reactions for platinum(II) complexes. D. S. Martin, Inorg. Chim. Acta, Rev., 1967,1, 87-97 (40). 

Application of the principle of microscopic reversibility can be used to eliminate a mechanism suggested at one time for the nucleophilic substitution reactions of square-planar platinum(II) complexes. For the sake of specificity, we take PtCl - as a typical... 

Particular use was made of conductivity measurements of cobalt(iii) and platinum(ii) complexes which allowed a facile determination of the number and type of ions present in solution. For example, the compounds Co(NH3) Cl3 would give a monocation and an monoanion (n=4), a dication and two monoanions (n = 5) and a trication and three monoanions (n=6) respectively. In some cases, it was also possible to distinguish chemically between inner and outer sphere chloride by precipitation of the outer sphere species as AgCl. 

The electronic spectra and magnetic susceptibility of [Ni(21)Cl2] were found to be consistent with a five-coordinate high spin complex. This complex has greater antitumor activity against P388 lymphocytic leukemia test system in mice than cobalt(II), copper(II), zinc(II) and platinum(II) complexes of 21 [187],... 

Schemes 6-18 A plausible mechanism of hydration of acetonitrile catalyzed by unhindered hydridobis(phosphine)platinum(II) complexes...

For transition-metal catalyzed hydroxylation of alkane C-H bonds, the reactions of alkanes with platinum(II) complexes were the most successful. In an aqueous solution of hexachloroplatinic acid and Na2PtCl4, alkanes were converted into a mixture of isomeric alkyl chlorides, alcohols, and ketones, and the platinum(IV) is reduced to platinum(II).7 The kinetics of the reaction with methane as the alkane have been described in detail.8... 

Two main mechanisms may be proposed for the first step of the alkane interaction with platinum(II) complexes (1) oxidative addition... 

Platinum(II) Complexes with Carbonyl and Silicon-donor Ligands 688... 

Platinum(II) Complexes with Phosphorus-, Arsenic-, and Antimony-donor Ligands 706... 

Platinum(II) Complexes with Sulfur- and Selenium-donor Ligands 715... 

Platinum(II) Complexes with Hydrido and Dihydrogen Ligands 718... 

Platinum(II) Complexes with Mixed Donor-atom Ligands 720... 

There are relatively few examples of the reaction of platinum(O) with tertiary silanes. A novel example is the reaction of [Pt(PEt3)4] with the rhodium complex [RhCl(H)(SiAr3)(P(Pr1)3)2], which results in silane transfer to give the platinum(II) complex cis- [PtHtSiArsXPCPr1) ].64... 

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