Small heteroborane cluster systems. 3. Characterization, deprotonation, and transition-metal chemistry of the small phosphorus-bridged pentaborane(9) system (.mu.-diphenylphosphino)pentaborane

Polyhedral azaborane chemistry. Nitrogen-vertex incorporation in metallaazaborane formation from 4-(NHEt2)B9H13. Two isomers of [(η5-C5Me5)RhB9H12(NEt2)]

“…The bonding behaviour within the nitrogen bridges in compounds 1 and 2 is of interest. A non-hydrogen main-group atom bridging this type of nido-decaboranyl position is well 29 the bridged interboron distances are 2.080(4) and 2.683(5) Å respectively. Of all these, the two {PPh 2 }-bridged interboron distances of 2.683(5) and 2.69(2) Å are clearly non-bonding, suggesting two two-electron twocentre phosphorus-boron bonds in the bridge, 30 whereas the other phosphorus-, oxygen-and carbon-bridged interboron distances of 1.839(7)-1.872(2) Å are within normal deltahedral borane ranges that perhaps suggest essentially three-centre two-electron involvement of the two bridged boron atoms with the bridging heteroatom.…”

Small Heteroborane Cluster Systems. 6. Mössbauer Effect Study of Iron Substituted Small Metallaborane Clusters

“…It is useful to compare the observed Mössbauer spectral parameters for the metallaborane complexes with their X-ray crystallographically determined bond distances and angles. The crystal structures for compounds 1 , 5 , and 6 have been reported previously. ,,7b Particularly useful in comparison with these complexes, however, is the crystallographic data for compound 2 , because it represents the direct analogue of compound 1 in which the μ-2,3-(P(C 6 H 5 ) 2 ) unit of 1 has been replaced by a bridging μ-B−H−B unit in compound 2 . The X-ray structure of compound 2 has not been reported previously.…”

“…nido -Pentaborane(9) was taken directly from our laboratory stock. The compounds [Fe(η 5 -C 5 H 5 )(CO) 2 B 5 H 7 P(C 6 H 5 ) 2 ] ( 1 ), [(Fe(η 5 -C 5 H 5 )(CO) 2 ) 2 B 5 H 7 ] ( 3 ), [Fe(η 5 -C 5 H 5 )(CO)B 4 H 6 (P(C 6 H 5 ) 2 )] ( 4 ), [Fe(η 5 -C 5 H 5 )(CO)B 3 H 7 (P(C 6 H 5 ) 2 )] ( 5 ), and [Fe(η 5 -C 5 H 5 )(CO)B 5 H 8 ] ( 6 ) 7 were prepared and purified according to previously reported literature methods. The spectroscopic data for these compounds matched those previously reported.…”

“…Numerous organoiron complexes, such as [Fe(η 5 -C 5 H 5 )(CO)LX], where L = CO and PPh 3 and X = halides, pseudohalides, alkyls, silyls, and boranes, and [Fe(CO) 4 L x ] species, have been investigated using Mössbauer spectroscopy. − We have recently reported on the structures and photochemistry of a series of small metallaborane complexes of the type [Fe(η 5 -C 5 H 5 )(CO) x L] (where x = 1 or 2 and L is a borane cage with between three and five boron vertices). − Issues of particular interest in these metallaborane complexes have related to how the metal−cage bonding is affected by changes in coordination mode of the cage to the iron center (terminal, bridged, inserted, etc. ), how the cage size modifies these interactions, and what role exopolyhedral cage substitution plays in the nature of this iron−cage interaction.…”

Chemistry of Pentaborane(9). A Review

“…In these compounds the phosphorus atom has taken the position of a boron atom in the cluster, which now has the geometry of B 6 H 10 . The same compound, (Me 3 Si) 2 CPB 5 H 8 , was also produced by the direct reaction of (Me 3 Si) 2 52 ). MNDO calculations for this compound suggest that the interaction between the phosphorus atom and the boron cage is best described by two two-electron, two-center bonds.…”