Clusters metalloborane

The polyhedral metalloboranes, Part I metalloborane clusters with seven vertices and fewer. J. D. Kennedy, Prog. Inorg. Chem., 1984, 32, 519 (312). 

To conclude, we shall mention some metal-atom reactions with boranes (172) and carboranes (173). When cobalt atoms reacted with pentaboraneO) and cyclopentadiene, a number of new metalloborane clusters were formed (172), two of which were 65115003(17-05115)3 and cyclopentyl-B5H40o2(i7-05H5)3. Possible structures for the former are shown in Fig. 42. The reaction of cyclopentadiene, pentaboraneO), and 2-butyne with cobalt atoms yielded the metallocarborane species illustrated in Fig. 43 (173). 

Synthetic routes to metalloboranes are briefly summarized. Two specific aspects of the field are selected for more detailed comment (i) the occurrence of exopolyhedral cycloboronation of P-phenyl groups (ii) oxidative cluster closure reactions. These topics are illustrated by reference to reactions of closo-BioHio nido-B9H12 and arachno-BoHiU" with a variety of Ir1 complexes, and several novel metalloborane cluster geometries (as determined by X-ray diffraction analysis) are described, notably nido-TIr(BoHi )H (PPh3)2], i so-ni do-[ IrC(OH)B8H6(OMe) (CgH PPh )... 

U. Expansion, degradation, or modification of a preformed metalloborane cluster. 

APPENDIX I NUCLEAR MAGNETIC RESONANCE SPECTROSCOPIC DATA AND AVAILABILITY OF STRUCTURAL DATA FOR METALLOBORANE CLUSTERS WITH A RATIO OF M AND B ATOMS OF AT LEAST 1 1... 

APPENDIX II SELECTED BOND DISTANCES FOR STRUCTURALLY CHARACTERIZED METALLOBORANE CLUSTERS WITH A... 

The asymmetric cluster in Figure 16 is representative of the structures in which the chirality properties of the structure are not associated with any atomic site in the molecule. Metalloborane clusters with this type of symmetry properties have also been reported. The stereochemical notation for asymmetric clusters will have to specify cluster chirality. And when clusters with more complex ligand substitution patterns and chiral ligands are prepared, the configurations of all metal centers and the chiralities of the associated ligands must be given. 

Several similar examples are reported including metalloborane clusters . A review of metal-atom-alkyne reactions has appeared . 

Mathematical cluster chemistry/Metal-metal interactions in transition metal clusters with donor ligands/Electron count versus structural arrangement in clusters based on a cubic transition metal core with bridging Main Group elements/Metalloboranes/ Clusters with interstitial atoms from the p-block How do Wade s rules handle them /Diverse naked clusters of the heavy Main Group elements Electronic regularities and analogies... 

The initial crystal structures of borohydride complexes of transition metals were obtained in 1967 for Cu(BH4)(PPh3)2 and Zr(BH4)4. The X-ray data for the latter show beautifully symmetric triple hydrogen (tt ) bridges from four borons that tetrahedrally surround M (Figure 13.1). Metalloborane cluster con )lexes of the type [Fe(CO)3]5- B H +4 and HFe(CO)9(BH4) (3) along with [Cp Ru] moieties connected to B H +4 clusters n = 2-A) provide an elegant borane analogy. The... 

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