Question

2. Octahedral transition metal complexes containing strong a acceptor ligands obey the 18- electron rule much more often than complexes containing n donor ligands. Why?

Answer 1

Solution 2
Ans 2 In Octabedral transition metal complesees there are five d-orbitals of metal (day dyz dzn driya dz). In octahedral field they were splitted into two sets. dry dz² day dyz dzu dry dz o Ang day dyz dzu - In absence of oh field In presence of oh field crystal field splitting 7- acceptor ligands such as co and en@elo which are strong field ligands. have a large a octahedral Splitting (Cao) large), lwhich means Ang orbital is low energy bonding orbital e I and eg is higher in energy, and is autibonding ou to large energy difference in energy befeueen Itzy and et orbitals, elections only occupy up to the trg. The ego which is autibonding is left unoccupied, Hence the most stable 18 electron configuration is obeyed.

. While in case of I donor ligands which are weak field ligands such as NH₂, FO H.O etc which are located - un low o lo medium to medium fast of Spectrochemical Series part of spect = have a small octahedral splitting hence to small). - hence due to increased energies of tag orbitals, 3 Because of which these molecular orbitals become weakly antibonding orbitals, Hence adelition or removal of electron has little effect 3 on complen stability, 3 small to makes filling of eat possible Hence EANY ISE 2 and a donor ligands can make tzy antibonding (<18€). Hence octahedral transition metal complenes having strong a acceptor ligands obey 18e - Rule more often than complex having a donor ligands