Coordination Compounds

NCERT-based; corner-to-corner; for low-time high yield revision

First chemist to formulate the structures of Coordination Compounds

Alfred Werner

Other name for valency of central atom in Coordination sphere

Primary valence

Other name for Coordination number in Coordination sphere

Secondary valence

Meaning of Coordination Polyhedra

Ions/groups bound by secondary linkages to the metal having characteristic spatial arrangements corresponding to different coordination numbers (C.N.)

Which geometrical shapes are more common in coordination compounds?

Octahedral, Tetrahedral and Square planar

Difference between Double Salt and Complex

Double Salt: Dissociate into simple ions completely
Complex Salt: Don’t dissociate into simple ions completely

Meaning of Coordination Entity

Constitutes a central metal atom or ion bonded to a fixed number of ions or molecules

Meaning of Central atom

The atom/ion to which a fixed number of ions/groups are bound in a definite geometrical arrangement around it

Central atoms/ions in a coordination entity are referred as

Lewis acids

Meaning of Ligands

Ions/molecules bound to the central atom/ion in the coordination entity

Structure of EDTA^4-

Chelate ligand

When a di- or polydentate ligands uses two/more donor atoms to bind with metal atom simultaneously

Meaning of Denticity

No. of chelating groups

Compare stability of complexes:
Chelated Complex and Unidentated Complex

Chelated Complex > Unidentated Complex

Meaning of Ambidentate Complex

Ligands which possess two different donor atoms and either of the two ligetes in the complex

The number of ligand donor atoms to which the metal is directly bonded is called:

Coordination Number or Secondary Valence

To determine Coordination number, we only count no. of Sigma bonds True/False

True and we don’t count and Pi bonds involved (if any)

In K₄[Fe(CN)₆],
1) [Fe(CN)₆]^4- is:
2) K⁺ is:
3) CN^- is:
4) Fe⁺² is:
5) 6 in (CN)₆ is:
6) +2 in Fe⁺² is:

1) Coordination Sphere
2) Counter ion
3) Ligand
4) Central atom
5) Coordination number/Secondary valence
6) Oxidation number of central atom/Primary valence

The spatial arrangement of the ligand atoms which are directly attached to the central atom/ion is _____________ about the central atom.

Coordination Polyhedron

Name these different coordination polyhedra:

Octahedral; Tetrahedral; Square Planar; Trigonal bipyramidal; Square pyramidal

[Co(NH₃)₆]⁺³ is __________ complex while [Co(NH₃)₄Cl₂]⁺³ is is __________ complex. (in terms of kind of donor groups attached)

Homoleptic; Heteroleptic

IUPAC of:
1) [Pt(NH₃)₂Cl(NO₂)]
2) K₃[Cr(C₂O₄)₃]
3) [CoCl₂(en)₂]Cl
4) [Co(NH₃)₅(CO₃)]Cl
5) Hg[Co(SCN)₄]

1) Diamminechloridonitrito-N-platinum(II)
2) Potassium trioxalatochromate(III)
3) Dichloridobis(ethane-1,2-diamine)cobalt(III) chloride
4) Pentaamminecarbonatocobalt(III) chloride
5) Mercury (I) tetrathiocyanato-S-cobaltate(III)

Formulas of:
1) Tetraammineaquachloridocobalt(III) chloride
2) Potassium tetrahydroxidozincate(II)
3) Potassium trioxalatoaluminate(III)
4) Dichloridobis(ethane-1,2-diamine)cobalt(III)
5) Tetracarbonylnickel(0)

1) [Co(NH₃)₄(H₂O)Cl]Cl
2) K₂[Zn(OH)₄]
3) K₃[Al(C₂O₄)₃]
4) [Co(en)₂Cl₂]⁺
5) [Ni(CO)₄]