BCl_3 exists as monomer whereas AlCl_3 is dimerized through halogen bridging. Give reason. Explain the structure of the dimer of AlCl_3 also.

BCl_3 exists as monomer whereas AlCl_3 is dimerized through halogen br

1.	BCl_3 exists as monomer whereas AlCl_3 is dimerized through halogen bridging. Give reason. Explain the structure of the dimer of AlCl_3 also.
Answer» Solution :`BCl_3` does not dimerize because of its SMALL size. `BCl_3` do not exist as a DIMER. BORON cannot ACCOMMODATE FOUR large sized chloride ions. `AlCl_3` exist as a dimer in which Al uses its vacant 3p-orbital by coordinate with Cl to complete their octet by forming dimer. `AlCl_3` achieves stability by forming a dimer.