question_answer 1)

What are electron deficient compounds? Are \[BC{{l}_{3}}\]and \[SiC{{l}_{4}}\] electron deficient species? Explain.

Answer:

The compounds in which the central element possesses incomplete octet, i.e., less than 8 electrons in the valence shell are termed electron deficient compounds. \[BC{{l}_{3}}\] Is an electron deficient compound as the central boron atom has six electrons in its valence shell. It can accept two more electrons to complete its octets It reacts with \[_{\centerdot }^{\centerdot }N{{H}_{3}}\] to form an addition compound. \[C{{l}_{3}}B+N{{H}_{3}}\to C{{l}_{3}}B\leftarrow N{{H}_{3}}\] \[SiC{{l}_{4}}\]is not an electron deficient compound as silicon atom has complete octet in its valence shell. However, due to the presence of d-orbitals, it can expand its octet and forms species like\[{{[SiC{{l}_{6}}]}^{2-}}\].