IUPAC + Isomerism in Coordination Compounds
Coordination Compounds
58
JEE Qs
20%
Hard
90
min
Systematically apply IUPAC rules by breaking down the complex into its components and draw all possible isomeric structures to identify and verify each type, paying close attention to symmetry elements for optical activity.
๐งฎ Key Formulas
โ Key Points for JEE
- 1Master the systematic IUPAC nomenclature for both cationic, anionic, and neutral coordination complexes, including prefixes for number of ligands (di, tri, tetra, bis, tris, tetrakis) and the use of '-ate' suffix for anionic complexes.
- 2Accurately determine the oxidation state of the central metal atom, as it is crucial for both naming and understanding the complex's properties, including isomerism.
- 3Distinguish clearly between structural isomerism (ionization, linkage, hydrate, coordination) and stereoisomerism (geometric, optical), understanding the specific structural differences that define each type.
- 4For stereoisomerism, always consider the coordination number and geometry (especially square planar and octahedral) to predict the possibility and types of geometric isomers (cis/trans, fac/mer) and optical isomers (enantiomers).
- 5Chelating ligands significantly influence isomerism; they often restrict rotations, favoring certain geometries and are key to developing chirality for optical isomerism.
โ ๏ธ Common Mistakes
- โIncorrectly calculating the oxidation state of the central metal, leading to errors in both naming and isomerism identification.
- โConfusing the rules for naming anionic ligands with neutral ones, or failing to apply the '-ate' suffix for central metals in anionic complexes.
- โOverlooking or misidentifying isomers, especially subtle differences in linkage or ionization isomers, or failing to draw all possible stereoisomers for a given formula.
- โIncorrectly determining the presence or absence of a plane/center of symmetry for optical isomerism, particularly in octahedral complexes with bidentate ligands.
๐ Practice Questions
See allQ74.In the Claisen-Schmidt reaction to prepare, dibenzalacetone from 5.3 g of benzaldehyde, a total of 3.51 g of product was obtained. The percentage yield in this reaction was ______ %.
Q61.The calculated spin-only magnetic moments of K3 [Fe(OH)6] and K4 [Fe(OH)6] respectively are : (1) 3.87 and 4.90 B.M. (2) 4.90 and 5.92 B.M. (3) 4.90 and 4.90 B.M. (4) 5.92 and 4.90 B.M.
Q54.Identify the homoleptic complexes with odd number of d electrons in the central metal : (A) [FeO4]2โ (B) [Fe(CN)6]3โ (C) [Fe(CN)5NO]2โ (D) [CoCl4]2โ (E) [Co(H2O)3 F3] Choose the correct answer from the options given below : (1) (A), (B) and (D) only (2) (C) and (E) only (3) (B) and (D) only (4) (A), (C) and (E) only
Q68.In which of the following complexes the CFSE, ฮo will be equal to zero? (1) [Fe(en)3]Cl3 (2) K4 [Fe(CN)6] (3) [Fe(NH3)6]Br2 (4) K3 [Fe(SCN)6]
Q70.From the magnetic behaviour of [NiCl4]2โ (paramagnetic) and [Ni(CO)4] (diamagnetic), choose the correct geometry and oxidation state. (1) [NiCl4]2โ: NiII , tetrahedral [Ni(CO)4] : NiII , (2) [NiCl4]2โ : NiII , square planar [Ni(CO)4] : Ni(0) square planar , square planar (3) [NiCl4]2โ: NiII , tetrahedral [Ni(CO)4] : Ni(0), (4) [NiCl4]2โ: Ni(0), tetrahedral [Ni(CO)4] : Ni(0), tetrahedral square planar
Q53.The correct order of the following complexes in terms of their crystal field stabilization energies is : (1) [Co(NH3)4]2+ < [Co(NH3)6]2+ < [Co(en)3]3+ < [Co(NH3)6]3+ (2) [Co(NH3)6]2+ < [Co(NH3)6]3+ < [Co(NH3)4]2+ < [Co(en)3]3+ (3) [Co(en)3]3+ < [Co(NH3)6]3+ < [Co(NH3)6]2+ < [Co(NH3)4]2+ (4) [Co(NH3)4]2+ < [Co(NH3)6]2+ < [Co(NH3)6]3+ < [Co(en)3]3+
NCERT Chapters
- Class 12 Chemistry Ch 9: Coordination Compounds