Platinum trimethyl complexes

A more complex intramolecular hydrogen bond system is built in the platinum(II) complex 33 (O Fig. 8) in which the central f/trco-configured diol is the chelation site. A y and a S hydrogen bond, each starting at one of the terminal donor hydroxyl functions, end at one and the same alkoxido function. The other one is an acceptor in a more strained p hydrogen bond [22]. Affirmed by DPT calculations, the completion of an octahedral coordination sphere of trimethyl-platinum(n) in a dinuclear complex is accomplished with facial tridentately bonded D-mannitol (coordination mode , 0, 0 k 0, 0, 0 ) [38]. 

OjSCjH4, Acetic acid, 2-mercaptocobalt complex, 21 21 03CH2, Carbonic acid platinum chain complex, 21 153, 154 cobalt complex, 21 120 OjPCjH, Trimethyl phosphite iron complex, 21 93... 

For instance, a cationic aqua complex/<2c-[PtMe3(OH2)3]" is indefinitely stable in aqueous solutions at elevated temperatures, whereas diphosphine - supported trimethyl platinum(lV) complexes such as/<2c-(dppbz)Pt Me3(OR) and/ac-(dppe) Pt MesCOR) shown in Fig. 5 undergo concurrent C-C and C-O reductive elimination at 120°C [21, 23, 24]. 

A second t q)e of 3-carbon-bonded acetylacetonate complex is illustrated by the trimethyl(acetylacetonato)platinum(IV) dimer. Although the X-ray crystal structure analysis has not been carried out for this specific complex, both X-ray and neutron diffraction studies have been done for the analogous trimethyl(nonane-4,6-dionato)platinum(IV) complex (25, 26). This and other similarities suggest that the acetylacetonate complex has the same structure. The structure of the nonane-4,6-dionate complex is illustrated in Fig. IE along with some selected bond lengths. Compounds of this kind have been referred to as bridgebonding complexes by Gibson (23). 

The chloro(trimethyl)platinum(iv) complex with bipy 951 reacts with SnCl2 in GH2GI2 to form the trimethyl-platinum complex with an SnGl3 ligand (952, Equation (182)). " ... 

Unsubstituted tris(pyrazolyl)borate has been used to stabilize trimethyl, dimethylhydrido, dimethyl(hydroxido), dimethyl(carboxylato), and dimethylthiolato complexes 983-9857 The dimethyl(hydrido)platinum(iv) complex 986 was characterized by comparison of the NMR data with the above-related complexes, and theoretical calculations of a tris(iminoamino)borate complex provided reasonable results for the Pt(iv) complex with a hydride ligand 987 rather than a potential Pt(ii) hydrogen-bonded species 9887 ... 

The dimethyl(hydrido)platinum(iv) complex with tris(3,5-dimethylpyrazolyl)borate (Tp ) as a ligand 992 can be obtained as a stable complex by protonolysis of the anionic dimethylplatinum(ii) complex (Equation (185))7 Similar reactions of HCl and Mel with the dimethyl and diphenyl complexes produce trimethyl-, diphenyl(hydrido)-, and diphenyl(methyl)platinum(iv) complexes. Addition of B(G6F5)3 to the platinate in hydrocarbon solvents leads to a dialkyl(hydrido)platinum(iv) complex 993, probably via abstraction of a methyl ligand followed by oxidative addition of the solvent to the Pt(ii) center (Equation (186)). ... 

The dimethylplatinum(ll) complex with a bidentate iV,iV,iV -trimethyl-A -(2-picolyl)ethylenediamine ligand undergoes methylation by Mel and protonation by several protic acids to produce cationic trimethylplatinum(iv) complex 1018 and methylplatinum(ll) complex 1019, respectively (Scheme 129). The protonation involves an intermediate cationic hydrido(dimethyl)platinum(lv) complex 1020. Scrambling of hydrogen atoms between hydride and methyl ligands during the reaction indicates an intermediate complex with methane as a ligand. 

A dimethylplatinum(ii) complex with a chelating A,T-ligand reacts with MeCl to form chloro(trimethyl)platinum(iv) complex 1036 as the oxidative addition product (Equation (191))/ This contrasts with the fact that PtMe2(dppe) does not undergo oxidative addition of MeCl under the same conditions. 

Bayler A, Canty AJ, Edwards PG et al (2000) Trimethyl-palladium(IV) and -platinum(IV) complexes containing phosphine donor ligands, including studies of l,5,9-triethyl-l,5,9-triphosphacyclodecane and X-ray structural studies of palladium(II) and palladium(IV) complexes. J Chem Soc Dalton Trans 3325-3330... 

C9H21N3, N,N, N"-Trimethyl-1,4,7-triazacyclo-nonane, Megtacn complexes with chromium(lll), 34 151—154 C9H23Cl2N3Pt, Platinum(ll),... 

In the related compound a-a -dipyridyl-acetylacetonato trimethyl platinum, which is monomeric, five of the coordination positions are taken up by the dipyridyl nitrogen atoms and the methyl groups. The sixth position is occupied by the central carbon atom of the acetylacetone, not by one of the oxygen atoms 242a). The oxygen atoms then remain uncoordinated, and the rest of the acetylacetone group is considerably distorted from the highly symmetrical form it normally has in complexes. This is the only... 

CkH.jP, Phosphine, dimethylphenyl-ruthenium complex 26 273 C HU, Cyclooctene platinum complex, 26 139 C,H,N, Benzene, 2-isocyano-1,3-dimethyl-iron complexes, 26 53, 57 C H N, Benzenemethanamine, N,N,2-trimethyl-... 

Alkylplatinum(IV) complexes exhibit considerable stability. When /ac-trimethyl-platinum(IV) species are heated, however, they eliminate ethane cleanly ... 

NdC4jHj9, Neodymium, tris(2,6-dwert-butyl-4-methylphenoxo)-, 27 167 O3PC3H, Trimethyl phosphite, cobalt and rhodium complexes, 28 283,284 iron complexes, 28 171, 29 158 nickel complex, 28 101 O3PCJH15, Triethyl phosphite, iron complexes, 28 171, 29 159 nickel complex, 28 101 nickel, palladium, and platinum complexes, 28 104-106 03PC,H2i, Isopropyl phosphite, nickel complex, 28 101... 

Alternatively, since the platinum atom in trimethyl(nonane-2,4-dione)platinum(IV) is directly above the carbon atom, one could conceive of this as a pseudo-n-allylic complex over the three ring carbon atoms. A final description of bonding in these bridge-bonded complexes can be given in terms of valence-bond theory which suggests that there is a predominence of a third resonance contributing form (II) which enhances the donor ability of the unique ring carbon atom 27). 

A study of a platinum /3-diiminate (nacnac) complex provides evidence for oxidative addition to C-H bonds. Starting with a stable Pt(rv) trimethyl adduct, loss of ethane produces a reactive Pt(ll) intermediate that metallates the ligand (Pt(ll) — Pt(iv)) and reductively eliminates methane(Pt(lv) —> Pt(ll)). / -Elimination then generates an observable pendant olefin hydride complex. This species serves as a reversible source of the unsaturated Pt(ll) intermediate, which can reversibly add to alkane solvent C-H or C-D bonds, permitting deuteration of the isopropyl groups of the ligand (Equation (14)). ... 

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