Platinum carbonyl anions

Platinum carbonylate anion clusters like [Pt3(CO)6] can be obtained by alkaline reduction of [PtCh] in a CO atmosphere. From [Pt3(CO)s] other higher nuclear-ity anions can be obtained. In this context, several examples have been reported in which this type of anionic cluster is used in the preparation of catalysts by impregnation or exchange methods. Salts of [Pt3 (CO)6 ] (n = 3, 5) have been used to prepare, by impregnation, dispersed platinum on ZnO and MgO [49] and, by ion exchange methods, to prepare Pt3 /C electrodes for the electrocatalytic oxidation of methanol [50]. A salt of [Pti2(CO)24] has recently been used to prepare... 

Homoleptic platinum carbonyl anions, characteristics, 8, 410 Homoleptic tantalum complexes, preparation and characteristics, 5, 108... 

Transition metals with odd atomic numbers cannot achieve the expected FAN in monomeric compounds. In cases where carbonyls of these elements are known, the compormds contain more than one metal atom and metal-metal bonds these effectively contribute one extra electron to each metal Mn2(CO)io, Co2(CO)s. Many polynuclear metal carbonyls are known. The largest metal cluster that has been characterized is a polynuclear platinum carbonyl anion,... 

Iron enneacarbonyl reacts smoothly with 1,1-dimethylsilacyclobutane to insert into the ring Si—C bond with complete regiospecificity (76JCS(D)910). The ferrosilacyclopentane (54) is thermally stable but reacts with HCl, and can also be prepared from 3-chIoropropyI-dimethylchlorosilane and Fe(CO)42. Carbonyl anions will substitute at silicon if this atom bears chlorine, and platinum will insert into the Si—H bond (Scheme 79) (72CC445, 78JOM( 144)317). 

Fig. 12. Infrared spectra of rhodium and platinum polynuclear carbonyl anions in the carbonyl stretching region (tetrasubstituted ammonium or phosphonium salts in THF). MA/NC, ratio of number of metal atoms to the number of negative charges.

Figure 4. Synthesis of platinum cluster anions, [Pt3(CO)3(/i-CO)3] , in solution, on the basic surface of MgO and in the Micro/mesoporous cages of NaY(12 A) and FSM-16 (28, 48 The chemistry on MgO and in micro/mesoporous cages is quite similar to that occurring in the basic solution. However, the cavities afford the templating micro reactor for the synthesize of the selected clusters owing to their chemical properties and confinement of the micro cavities. By contrast, a wide distribution of Pt cluster anions having different sizes was formed on the MgO surface by the surface-mediated carbonylation reaction.

The infrared spectrum of CO adsorbed on a vapor derived < 1.0 nm platinum colloid stabilized by iro-butylaluminoxane in methylqrclohexane showed only a linear CO stretch at 2035 cm. This particle size is witliin the range for the larger molecular platinum carbonyl duster anions, and the colloidal platinum can in fact be hydrolysed to mixtures of [Pt9(CO)ig] and [Pti2(CO)24] after CO adsorption. [229]... 

In this section, we consider polynuclear carbonyl compounds that contain only platinum we consider polynuclear carbonyls that contain platinum and other metals in Section 8.07.1.6. We further split up the discussion on the platinum only compounds into three groupings the homoleptic carbonyl anions, the mixed ligand triangular compounds and assorted others. 

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