Borane Derivatives: A New Class as
Super and Hyperhalogens
Super and hyperhalogens are a class of highly electronegative species
whose electron affinities far exceed those of halogen atoms.
And are important to chemical industry as oxidizing agents, bio-catalysts,
and building blocks of salts.
Wade-Mingos rule well known for describing the stability of closo-
boranes (BnHn2-)
A new class of super and hyperhalogens, guided by Wade-Mingos rule,
can be formed by tailoring the size and composition of borane
derivatives.
Conventional superhalogens which have a metal atom at the core
surrounded by halogen atoms, the superhalogens formed using the Wade-
Mingos rule do not have to have either halogen or metal atoms.
We demonstrate this by using B12H13 and its isoelectronic cluster,
CB11H12 as examples.
conventional superhalogens containing alkali atoms require at least two
halogen atoms, only one borane-like moiety is sufficient to give
M(B12H12) (M=Li, Na, K, Rb, Cs) clusters superhalogen properties.
Hyperhalogens can be formed by using the above superhalogens as
building blocks.
Examples M(B12H13)2 and M(C-B11H12)2 (M=Li - Cs).
Electron counting rules play an important role in describing the stability
and chemistry of atoms and compounds.
, The octet rule
The octet rule states that an atom needs eight electrons to close its s and p
shells, is responsible not only for the inertness of noble gas atoms but
also for the reactivity of elements such as alkali metals and halogens.
The 18-electron rule
18 electrons are needed to close s, p, and d shells.
It is mainly associated with compounds composed of transition metal
atoms such as Cr(C6H6)2 and Fe(C5H5)2
Wade-Mingos rule
The stability of boranes (BnHn2-) is governed by the Wade-Mingos rule.
Wade-Mingos rule states that in polyhedral borane clusters with n
vertices (n+1) pairs of electrons are needed for cage bonding.
New class of superhalogens can be created by using the Wade-Mingos
rule without the benefit of either a metal or a halogen atom. In addition,
hyperhalogens can also be created with these superhalogens as building
blocks.
Superhalogens
A conventional superhalogen has the formula MXn+1 where n is the
maximal valence of the metal atom M and X represents a halogen atom.
Super and Hyperhalogens
Super and hyperhalogens are a class of highly electronegative species
whose electron affinities far exceed those of halogen atoms.
And are important to chemical industry as oxidizing agents, bio-catalysts,
and building blocks of salts.
Wade-Mingos rule well known for describing the stability of closo-
boranes (BnHn2-)
A new class of super and hyperhalogens, guided by Wade-Mingos rule,
can be formed by tailoring the size and composition of borane
derivatives.
Conventional superhalogens which have a metal atom at the core
surrounded by halogen atoms, the superhalogens formed using the Wade-
Mingos rule do not have to have either halogen or metal atoms.
We demonstrate this by using B12H13 and its isoelectronic cluster,
CB11H12 as examples.
conventional superhalogens containing alkali atoms require at least two
halogen atoms, only one borane-like moiety is sufficient to give
M(B12H12) (M=Li, Na, K, Rb, Cs) clusters superhalogen properties.
Hyperhalogens can be formed by using the above superhalogens as
building blocks.
Examples M(B12H13)2 and M(C-B11H12)2 (M=Li - Cs).
Electron counting rules play an important role in describing the stability
and chemistry of atoms and compounds.
, The octet rule
The octet rule states that an atom needs eight electrons to close its s and p
shells, is responsible not only for the inertness of noble gas atoms but
also for the reactivity of elements such as alkali metals and halogens.
The 18-electron rule
18 electrons are needed to close s, p, and d shells.
It is mainly associated with compounds composed of transition metal
atoms such as Cr(C6H6)2 and Fe(C5H5)2
Wade-Mingos rule
The stability of boranes (BnHn2-) is governed by the Wade-Mingos rule.
Wade-Mingos rule states that in polyhedral borane clusters with n
vertices (n+1) pairs of electrons are needed for cage bonding.
New class of superhalogens can be created by using the Wade-Mingos
rule without the benefit of either a metal or a halogen atom. In addition,
hyperhalogens can also be created with these superhalogens as building
blocks.
Superhalogens
A conventional superhalogen has the formula MXn+1 where n is the
maximal valence of the metal atom M and X represents a halogen atom.
