Chemistry - STEREO ISOMERISM Question with Solution | TestHub
Consider the following :-
(1) Diamminedichloridoplatinum(II)
(2) Tris(ethylenediamine)iron(III) chloride
(3) Potassium trioxalatoiridate(III)
(4) Diaquadiiodidodinitrito-O-palladium(IV)
(5) Dichloridobis(ethylenediamine)cobalt(III) sulphate
(6) Sodium ethylenediaminetetraacetatonickelate(II)
Number of diamagnetic complex species , having correct IUPAC name , show optical isomerism as well as geometrical isomerism only in given condition (not in other structural isomeric form).
Answer:
Solution:
(1) [Pt(NH₃)₂Cl₂] – Diamminedichloroplatinum(II)
Square planar → can show geometrical isomerism (cis/trans).
No optical isomerism for square planar.
Diamagnetic (d⁸, low spin).
Geometrical only.
(2) [Fe(en)₃]Cl₃ – Tris(ethylenediamine)iron(III) chloride
Octahedral with three bidentate ligands → can show optical isomerism.
No geometrical isomerism for fac/mer concept here (all ligands same).
Paramagnetic (Fe³⁺ d⁵, high spin) → not diamagnetic.
(3) K[Ir(C₂O₄)₃] – Potassium trioxalatoiridate(III)
Octahedral with 3 bidentate oxalate ligands → optical isomerism possible.
No geometrical isomerism in given structure.
Diamagnetic (Ir³⁺ d⁶ low spin)
Optical only.
(4) [Pd(H₂O)₂I₂(NO₂)₂] – Diaquadiiodidodinitrito-O-palladium(IV)
Octahedral: two H₂O, two I⁻, two NO₂⁻ → can show both geometrical (cis/trans) and optical isomerism.
Diamagnetic (Pd⁴⁺ d⁶ low spin)
Optical + geometrical → counts.
(5) [Co(en)₂Cl₂]SO₄ – Dichloridobis(ethylenediamine)cobalt(III) sulphate
Octahedral: 2 en, 2 Cl → can show cis/trans (geometrical)
Cis form → optical isomerism.
Diamagnetic (Co³⁺ d⁶ low spin)
Optical + geometrical → counts.
(6) Na[Ni(EDTA)] – Sodium ethylenediaminetetraacetatonickelate(II)
EDTA = hexadentate → no geometrical/optical isomerism possible.
Paramagnetic (Ni²⁺ d⁸, high spin)
Not counted.
Diamagnetic complexes showing both optical + geometrical isomerism:
- [Pd(H₂O)₂I₂(NO₂)₂]
- [Co(en)₂Cl₂]SO₄