Electron Deficient Molecules Boron Hydrides

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Electron Deficient MoleculesBoron Hydrides

• Edward A. Mottel
• Department of Chemistry
• Rose-Hulman Institute of Technology

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Electron Deficient Molecules
Non-transition metal atoms in a molecule or
ion which do not have a filled electron shell are
referred to as electron deficient.
These species often undergo unusual bonding in an
attempt to fill their empty shells.
The effect is especially noteworthy in
elements which form covalent bonds.
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The Players
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Boron Is Electron Deficient
filled p-orbital of fluorine overlaps empty
p-orbital of boron
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Boron Is Electron Deficient
diborane
hydrogen doesnt have any filled p-orbitals
draw an orbital overlap diagram of diborane
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Boron Is Electron Deficient
119 pm
97
122
137 pm
diborane
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Boron HydridesCloso Structures
closo-pentaborane(5)
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Boron HydridesCloso, Nido and Arachno Structures
closo
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Boron HydridesPrincipal Hydrides
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B5H9 pentaborane-9
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B10H14 decaborane-14
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Dicarba-closo-dodecaborane
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Boron HydridesCloso Structures