Arylplatinum complexes

Several arylplatinum complexes of Tl+ have been reported (Table 15). The anionic /rreacts with T1N03 to produce a chain polymer 120, in which successive Pt atoms are bridged to each other by two Tl+ ions (Scheme 28).112 The compound is an acetone solvate, and there also appear to be weak Tl F interactions in the solid-state structure. Upon irradiation (A = 441 nm), the complex exhibits an intense emission with a maximum at 678 nm. The luminescence is attributed to MLCT transitions. 

The reaction of arylsilanol with hromoplatinum(II) complexes in the presence of Ag20 leads to arylplatinum complexes via transmetalation from Si to Pt, as shown in Eq. 5.21 [88],... 

Two classes of stabihzed arylplatinum complexes have played a major role in the discovery and the development of Pt M donor-acceptor braids metallacyclic compounds and complexes incorporating pentafluoro- and pentachlorophenyl ligands. In contrast, the use of phenylplatinum complexes for that purpose is only very recent. In this section, we discuss selected recent developments for these three classes of compounds. 

Nearly all alkyl and aryl transition metal compounds are cleaved by hydrogen halides. Even arylplatinum complexes stabilized by phosphine ligands are rapidly cleaved by hydrogen chloride in methanol or benzene. The reaction... 

Most of the preparative reactions of arylplatinum complexes, such as oxidative addition of organic halides, trans-metallation, and exchange of the auxiliary ligands, are common to those of alkylplatinum complexes. Aromatic C-H bond activation promoted by Pt(0) and Pt(n) complexes is the unique preparation method of arylplatinum complexes. Cationic methylplatinum(ll) complexes with A -ligands promote C-H activation of aromatic hydrocarbons to form cationic arylplatinum complexes, as mentioned in Section 8.08.3.1.3. 

Oxidative addition of G-H bonds to Pt(0) is utilized in the preparation of arylplatinum complexes. Furan, benzoxazole, and benzothiazole react with Pt(PEt3)4 to cause selective oxidative addition of a G-H bond, giving hydrido(aryl)platinum complexes 208-210. ... 

Reaction of diphosphines with the complex of a 6",iV,iV-tridentate ligand leads to the /i 6 -coordinated arylplatinum complex 634 or the dinuclear complex with the diphosphine ligand that bridges two Pt centers coordinated by bidentate arylimine ligands (635, Scheme 88). ... 

Several square-planar arylpalladium and arylplatinum complexes have been examined, and results are also collected in Table XIX. These THG studies at 1.91 pm revealed that metal replacement in tra s- MI(C6H4-4-N02)(PEt3)2] (M = Pd, Pt) had no effect on nonlinearity y values are larger than in related carbonyl complexes, although data are low in absolute terms. Replacing triethylphosphine by triphenylphosphine, replacing 4-formyl by 4-nitro substituent, and proceeding from iodo to bromo, all result in a 50% increase in nonlinearity. 

Thallium Adducts of Arylplatinum and -gold Complexes 3.08.9.5.1 Platinum aryl complexes... 

Poly(phenyl ester) dendrimers with six terminal platinum chelate complex units were used as highly selective sensors for sulphur dioxide, considered partly responsibly for the formation of smog and acid rain. In the presence of hydrogen peroxide or sunlight and ozone, S02 is oxidised to S03. The latter reacts spontaneously with water to form sulphuric acid. That is the reason why detection of minimal concentrations of sulphur dioxide with appropriate sensors is necessary. The arylplatinum(II) complexes attached to the molecular periphery of the dendrimers absorb sulphur dioxide with formation of a pentacoordi-... 

Intramolecular transmetallation of arylpalladium(ll) and arylplatinum(ll) complexes with silanes and stannanes has been studied by Echavarren and co-workers (Scheme 11) <19980M3661>. 

The proposed [43, 44e] mechanism of the reaction between PtCla and the arene to afford/ ara and meta isomers of the a-arylplatinum(IV) complex (VII-14 and VII-14m in Scheme VII.8) involves the formation of a weak 7i-arene complex of platinum(IV) VII-11 which is transformed into an intermediate Wheland-type complex. The isomerization of the Wheland complexes VII-12p and VH-12/n possibly proceeds though the transition state VII-13, and/or is due to the reversibility, to some extent, of the stage of VII-12 formation. The transarylation mentioned above (equation VII.6) is perhaps also due to the reversibility of the Wheland complex formation. 

Albrecht M, van Koten G (1999) Gas sensor materieils based on meteillodendrimers. Adv Mater 11(2) 171-174 Albrecht M, Gossage RA, Lutz M, Spek AL, van Koten G (2000) Diagnostic organometallic and metallodendritic materials for SO gas detection reversible binding of sulfur dioxide to Arylplatinum(II) complexes. Chem Eur J 6 1431-1445... 

In another example, the loss of N2 from arylazo platinum complexes provides a method for the formation of arylplatinum compounds not accessible by the usual Grignard route (57). 

Transmetallation, involving intermolecular transfer of the aryl ligand, also provides convenient routes for synthesis of arylplatinum(ii) complexes. Reactions of 2-methoxyphenyllithium with Pt complexes having optically active diphosphines, DIOP, BINAP, and chiraphos, produce the corresponding diarylplatinum complexes. NMR spectra show the presence of isomers due to restricted rotation around the Pt-G bond of the 2-methoxyphenyl ligand. Anionic... 

Ligand exchange is another important method to convert reported arylplatinum(ii) complexes into new ones, and [PtAr2(//-SMe2)] z is a convenient precursor of diarylplatinum complexes with various auxiliary ligands. 

Cationic dinuclear complexes 341 and 342 have l,l-(2-pyridyl)ethene and 4,7-phen as the respective bridging ligands between the two arylplatinum fragments. ... 

Chelating Alkyl- and Arylplatinum(ii) Complex 8.08.3.4.1 Platinacycles with two Pt-C cj-bonds... 

---