coordination compounds Flashcards
moleculare compounds
2 or more simple salt combined together in a fixed proportion by their WEIGHT
DOUBLE SALT
dissociate into ions completely when dissolved in water
e.g: potash alum. karnalite , mohrs salt
complex compounds
it doesn’t dissociate into ions completely when dissolvwd in water
WERNERS THEORY OF CC
- Metals have two types of links (valences) in coordination compounds: primary and secondary
- Negative ions satisfy the primary valances, which are generally ionisable
- Secondary valences cannot be ionised. Neutral molecules or negative ions satisfy these needs. For a metal, the secondary valence is equal to the coordination number and is constant
- Ions/groups coupled to the metal by secondary connections have distinct spatial configurations that correspond to different coordination numbers
Coordination entity
a CMA/i BOUNDED TO A FIXED NO. OF IONS OR MOLECULES
CMA/I
LIGAND
CMA also reffered to as LEWIS ACID
- the atom which has fixed no. of atoms or molecule bounded to it in a definite geometric arrangements
- the ions or molecules bounded to the CMA/i
UNIDENTATE
AND EXAMPLE
WHEN ligand is bounded to CMA/i through **single donor atom **
Cl, H2O, NH3
DIDENTATE
AND EXAMPLE
WHEN ligand is bounded to CMA/i THROUGH two donor atom
en or C2O42-
ethane - 1,2- diammine
POLYDENTATE AND EXAMPLE
WHEN LIGAND is bounded to CMA/i thru more than 2 donor atom
EDTA4-
ethylenediamminetetraacetate
hexadendate
2 N2 and 4O2
CHELATE LIGAND
chelate ring
WHEN di or polydendate ligand uses 2 or more donor atoms to bind to the CMA/I simultaneously
if they form ring
chelate ring = cordination no, - 1
DENTICITY
No, of ligating grp
AMBIDENDATE LIGAND
LIGETES
Ligand which have 2 different donor atom and either one of the 2 ligetes in the complex
e.g: 1. NO2
M<-ON=O or M<-NO2
NITRITO-O AND NITRITO-N
2. SCN
M<-SCN or M<-NCS
THIOCYANATO -S AND THIOCYANATO - N
COORDINATION NO.
THE NO. of ligands directly attached to the CMA/i
find the CN of:
- [PtCl6]^2-
- [Ni(NH3)4]+2
- [Fe(C2O4)3]3-
- [Co(en)3]3+
C2O42- and en are didendate
CN= denditicity * ligands
- 6
- 4
- 6
- 6
ONLY SIGMA BONDS
COORDINATION SPHERE
COUNTER ION
the CMA/ion and the ligand attached to it are enclosed in a square bracket
the ionisable group written outside the brackett
COORDINATION POLYHEDRON
THE spatial arrangement of ligands which are directly bounded to the CMA/i
name the spatial arrangement of the following
- [Ni(Co)4]
- PtCl4
- [Co (NH3)6]
3 most common spatial arrangement
- tetrahedral
- square planar
- octahedral
HOMOLEPTIC AND EXAMPLE
WHEN THE metal is bounded to only one kind of donor grp
[Co(NH3)6]3+
HETEROLEPTIC AND EXAMPLE
COMPLEXES IN WHICH METAL IS bounded to more than one kind of donor grp
[Co(NH3)4Cl2]+
Write the formulas for the following coordination compounds:
(i)Tetraamminediaquacobalt(IlI) chloride
(ii)Potassium tetracyanidonickelate(II)
(iii)Tris(ethanp-1,2-diamine) chromium(III) chloride
(iv)Amminebromidochloridonitrito-N- platinatc(II)
(v)Dichloridobis(ethane-l ,2-diamine) platinum (IV) nitrate
(vi)Iron(III)hexacyanidoferrate(II)
- [Co(NH3)4(H20)]Cl2
- K2[Ni(CN)4]
- [Cr(en)3]Cl3
- [Pt(NH3)BrClNO2]-
- [Pt Cl2(en)2] (NO3)2
- Fe4[Fe(CN)6]3