Describe the bonding in boron hydrides
Answers
Hyy,
Here is your answer--
Boranes is the name given to the class of synthetic hydrides of boron with generic formula BxHy. In the past, borane molecules were often labeled " electron-deficient" because of their multicenter bonding (in which a pair of bonding electrons links more than two atoms, as in 3-center-2-electron bonds); this was done in order to distinguish such molecules from hydrocarbons and other classically bonded compounds. However, this usage is incorrect, as most boranes and related clusters such as carboranes are actually electron-precise, not electron-deficient. For example, the extremely stable icosahedral B12H122- dianion, whose 26 cluster valence electrons exactly fill the 13 bonding molecular orbitals, is in no actual sense deficient in electrons; indeed it is thermodynamically far more stable than benzene.
Boranes is the name given to the class of synthetic hydrides of boron with generic formula BxHy. In the past, borane molecules were often labeled " electron-deficient" because of their multicenter bonding (in which a pair of bonding electrons links more than two atoms, as in 3-center-2-electron bonds); this was done in order to distinguish such molecules from hydrocarbons and other classically bonded compounds. However, this usage is incorrect, as most boranes and related clusters such as carboranes are actually electron-precise, not electron-deficient. For example, the extremely stable icosahedral B12H122- dianion, whose 26 cluster valence electrons exactly fill the 13 bonding molecular orbitals, is in no actual sense deficient in electrons; indeed it is thermodynamically far more stable than benzene.While some boranes are highly reactive with respect to electron-pair donors, others are not, e.g., the BnHn2- dianions (n = 6-12) as well as many neutral boranes such as B18H22. Some lower boranes are pyrophoric in air and react with water. The boranes belong to the class of cluster compounds which have been the subject of developments in chemical bonding theory. A large number of the related anionic hydridoborates have also been synthesized.
☆☆HOPE IT MAY HELP YOU.☆☆
Answer:
Boron hydrides are called Boranes with generic formula BnHn+4 or BnHn+6. Boranes are also classified as electron deficient due to their multicenter bonding in which a pair of bonding electrons links more than two atoms. Some boranes are highly reactive as well as neutral boranes. B2H6 is called diborane. Boranes can be present as solids, liquids or gases. Their boiling and melting points increase with increasing molecular weight and complexity.
Boranes exhibit multicenter bonding where three or more atoms share a pair of bonding electrons due to electro deficiency. E.g. Diborane B2H6 contains three-center Bridge bonding where one electron pair is shared between three atoms (two boron and one hydrogen atom) as compared to two atoms. Complex polyhedral boranes are formed because of three-center Bridge ability along with normal covalent bonds.