Question

Which of the following statement is correct for two carbenes $\ddot{C{F}_2}$ and $\ddot{C}C{l}_2$?

• A. $C{F}_2$ is more stable than $CC{l}_2$ in triplet state
• B. $C{F}_2$ is more stable than $CC{l}_2$ in singlet state
• C. Both are equally stable whether it is singlet or triplet state
• D. None of the statement above is correct

Answer 1

The correct option is B $C{F}_2$ is more stable than $CC{l}_2$ in singlet state

$C{F}_2$ is more stable than $CC{l}_2$ in singlet state because of effective $2p\pi -2p\pi$ interaction in $C{F}_2$ as compared to $2p\pi -3p\pi$ in $CC{l}_2$.