Ruthenium carbonyl clusters rhenium

Platinum nanoparticles, preparation, 12, 78 Platinum-nitrogen bonds, in platinacycles, 8, 508 Platinum-osmium carbonyl clusters, characteristics, 8, 420 Platinum-oxygen bonds, in platinacycles, 8, 505 Platinum particles, surface reactivity, 12, 542 Platinum-phosphorus bonds, in platinacycles, 8, 508 Platinum-rhenium carbonyl clusters, characteristics, 8, 420 Platinum(II)-ruthenium(II) binary complexes, preparation,... 

The UPS spectra for these clusters reveal the general appearance of a 3-4 eV wide metal d band lying immediately below the Fermi level which is separated by 2-3 eV from an intense peak due to the CO 5intense peak at 3-4 eV below the 5a and l r features is due to the CO 4a levels. These spectra exhibit a remarkable qualitative similarity to the corresponding spectra of CO adsorbed on metal surfaces. More important for the present discussion is that they can be directly compared with the ionization energies obtained from theoretical calculations. For instance, the calculated spectra for a series of tetracobalt carbonyl clusters using the DV-Xa method have been compared with the He(I) UPS spectrum of [Co4(CO)i2]. [150] The transition state procedure [41] used in these calculations also accounted for the final state effects, that is, for the effects of orbital relaxation following the ionization process. This relaxation is typically about 2 eV for the valence orbitals of transition metal carbonyls and the calculated IP s compare well with the experimental ones. In a similar way, ruthenium, osmium, and rhenium carbonyl cluster UPS spectra have been calculated and reproduce the general trends and positions of the... 

Rearrangements of clusters, i.e. changes of cluster shape and increase and decrease of the number of cluster metal atoms, have already been mentioned with pyrolysis reactions and heterometallic cluster synthesis in chapter 2.4. Furthermore, cluster rearrangements can occur under conditions which are similar to those used to form simple clusters, e.g. simple redox reactions interconvert four to fifteen atom rhodium clusters (12,14, 280). Hard-base-induced disproportionation reactions lead to many atom clusters of rhenium (17), ruthenium and osmium (233), iron (108), rhodium (22, 88, 277), and iridium (28). And the interaction of metal carbonyl anions and clusters produces bigger clusters of iron (102, 367), ruthenium, and osmium (249). 

Pyrolysis reactions of mononuclear carbonyls and low-nuclearity cluster compounds have been used extensively in the syntheses of HNCC of osmium (54, 72,80,95,108), ruthenium (18,20,29), and, more recently, rhenium (2-4). The reactions have been carried out either in inert solvents or, to facilitate the ejection of CO or other volatile ligands, in the solid state under vacuum. Condensation processes under pyrolytic conditions are rarely specific and, as such, lead to the formation of a wide range of products. In order to obtain optimum yields of a particular HNCC, the reaction conditions must be carefully screened. Solution reactions offer advantages such as the ability to monitor the progress of the reaction using IR spectroscopy. As they often give... 

C, Carbide iron complex, 26 246 ruthenium cluster complexes, 26 281-284 CHF,02, Acetic acid, trifluoro-tungsten complex, 26 222 CHFjOjS, Methanesulfonic acid, trifluoro-iridium, manganese, and rhenium complexes, 26 114, 115, 120 platinum complex, 26 126 CH2O2, Formic acid rhenium complex, 26 112 CH, Methyl iridium complex, 26 118 manganese complex, 26 156 rhenium complexes, 26 107 CHjO, Methanol platinum complexes, 26 135 tungsten complex, 26 45 CNajOuRusCn, Ruthenate(2- )ns-carbido-tetradecacarbonyl-disodium, 26 284 CO, Carbonyls chromium, 26 32, 34, 35 chromium, molybdenum, and tungsten, 26 343... 

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