Grade 12th passInorganic Chemistry

Co(NH3)6-dimagnetic but [Co(F6)]is paramagnetic why

Megha

9 Years agoGrade 12th pass

4 Answers

Shramana Kar

9 Years ago

In both compound Co^3+(3d6) ion is present. But NH3 is a strong field ligand. So in 1st compound 6 electrons of 3d orbital pair and 2 d orbital becomes empty and the hybridization is d2sp3, inner orbital complex. As there is no unpaired electron the compound is diamagnetic. In 2nd compound F^- is a weak field ligand. So 3d electrons do not pair. Here the hybridization is sp3d2, outer orbital complex. So there are 4 unpaired electrons in 3d orbital & it is paramagnetic.Please approve my answer if you find it helpful...

abhishek mishra

9 Years ago

All octahedral comlexes of Co+3 are low spin, diamagnetic except [CoF6]3- and [Co(H2O)3F3], and it cant be explained by VBT.

if you use concept of weak field and strong field then how will you explain that [Co(OX)3]3- is diamagnetic whether oxalate is a weak field ligand.

Onkar Susladkar

9 Years ago

Because NH3 is strong field legand and F is week field legand that`s way NH3 can push the electron in the inner shell of the central metal atom as this also due to the NH3 can form inner orbital complex

ankit singh

5 Years ago

As you can see, the 4 unpaired electrons remain as it is and give [CoF6]3- a 'PARAMAGNETIC' nature. ... As you can see due to pairing up NO unpaired electrons remain in the d-orbitals, and hence [Co(NH3)6]3+ is 'DIAMAGNETIC'