Chemistry - Complete P-block Question with Solution | TestHub

For d$\pi$-d$\pi$ bonding, the ligand must have vacant d-orbitals. Nitrogen in N(CH₃)₃ is from the second period and lacks vacant d-orbitals. Phosphorus in P(C₂H₅)₃ and Arsenic in As(C₆H₅)₃ are from the third and fourth periods, respectively, and possess vacant d-orbitals suitable for d$\pi$-d$\pi$ bonding with transition metals. Therefore, both options 2 and 3 can form d$\pi$-d$\pi$ bonds.