Complex Ions - PowerPoint

Document Sample
Complex Ions - PowerPoint Powered By Docstoc
					Complex
  Ions
 Complex Ion
•An ion formed when a
positive central element
binds with multiple ions
   or polar molecules
  Complex Ion
   •The central
 element is almost
always a positively
   charged metal
Describe or
  define a
Complex Ion
  Anion
•Negatively
charged ion
  Cation
•Positively
charged ion
Metal Ion Examples
Cu +2   Cu +   Au +



Ag +    Zn+2   Ni +2



Pt +2   Co+2   Al +3
     Ligands
•The negative ions or
polar molecules bound
by the central element
   in a complex ion
  Ligand Examples
•Cl -   F -    H2 O
•NH3    CN -   Br-

•NO     O2     OH -
 Polydentate
  Ligands
•Ligands that can
bind to more than
    one point
   Bidentate
   Ligands
•Ligands that can
bind to two points
 in a complex ion
  Bidentate
  Examples
H2N-CH2-CH2-NH2

   -O    C-CO2-
        2
Tridentate Ligands
 •Ligands that can
 bind to three points
  in a complex ion
Tridentate
Examples
 H2-C-COO-

HO-C-COO -

 H2-C-COO-
   Chelates
  •Polydentate
ligands that bind
 to metal ions in
     solution
Coordination Number
•The number of points
 in which ligands bind
 to the central element
    in a complex ion
 Coordinate
Covalent Bond
 •Covalent bonds in
which both electrons
involved are donated
    by one atom
  Complex Ions
•The bonds formed in
  a complex ion are
 coordinate covalent
       bonds
  Coordination
   Complex
•A complex ion and
   its counter ion
  Complex Ions
•The bonds formed in
  a complex ion are
 coordinate covalent
       bonds
  Complex Ion
•Because of the type
  bonding, they are
  sometimes called
coordinate complexes
1) Name cations
 before anions
Naming Complexes
 2) Name ligands
before metal in the
   complex ion
2) Naming Ligands
  a) give neutral
  compds normal
   names except:
H2O   aqua
NH3   amine
CO    carbonyl
NO    nitrosyl
2) Naming Ligands
  b) change -ide
 endings to -o for
    all anions
2) Naming Ligands
  d) use geometric
     prefixes for
    monodentate
       ligands
2) Naming Ligands
 e) use bis- for 2 &
      tris- for 3
polydentate ligands
3) Naming Metal
 a) use the normal
    name if the
complex ion is (+)
3) Naming Metal
b) make the metal
ending -ate if the
complex ion is (-)
 3) Naming Metal
   d) use Roman
  numerals in () to
indicate metal ox #
Name the Following:
  [Pt(NH3)4]Cl2
 [Co(H2O)2Cl4] -2

[Cu(H2O)2(en)2]I2
Predict # of isomers
     of each:
  [Pt(NH3)4 Cl2]
 [Co(H2O)3Cl3]
Complex Ion Shapes
      2-linear
4-tetrahedral or sq pl
   6-octahedral
Geometric Isomers
Square planar vs
  tetrahedral
  cis vs trans
Geometric Isomers
 Bunched octa-
 T-shaped octa-
 bis: cis vs trans
Optical Isomers
Tri-bis mirror
   images
 Field Strength
CN - > NO - > en >
         2
 NH3 > NCS    ->

 H 2O > F - > Cl-
 Field Strength
CN - is strong field

 Cl- is weak field
 Field Strength
Determines d-level
   splitting or
Do(splitting energy)
Field Strength
Large Do yields
 low spin or
 diamagnetic
   compds
Field Strength
Small Do yields
  high spin or
 paramagnetic
    compds
  [Pt(NH3)2I4]-2

    Determine:
 Name, shape, &
possible isomerism
[Co(NH3)6 ] +3       yellow
[Co(NH3)5NCS]   +2   orange
[Co(NH3)5H2O]   +2   red
[Co(NH3)5Cl] +2      purple
t-[Co(NH3)4Cl2] +1   green
  Complex Ion Equilibria
Cu +2   + 4 NH3       [Cu(NH3)4   ]+2



                  [Cu(NH3)4 ] +2
   Kf =           [Cu +2][NH ]4
                            3
 Calculate the ratio of
 [Cu +2]/ [Cu(NH ) ]+2
                   3 4
when Cu   +2 is added to a

 0.10 M NH3 solution:
    Kf = 2.0 x 10   12
Common Ion Equilibria
 •The larger the Kf,
 the more likely the
 complex will form
Common Ion Equilibria
•Kf for [Ag(NH3)2] +1

   = 1.7 x 107

•Kf for [Ag(CN)2]-1

   = 2.0 x 1020
Common Ion Equilibria
•Kf for [M(NH3)2]+2

   = 1.7 x 107

•Kf for [M(CN)4]-2

   = 2.0 x 1020
Common Ion Equilibria
   CN-will replace
    NH3 in the
 complex with silver
       Calculate:
   a) coordination #
 b) number of isomers
c) oxidation # of metal
  [Zn(NH3)2H2  OF] +1

   [Co(NH3)3ClFI] -1

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:26
posted:10/3/2012
language:Unknown
pages:51