Shape depends on coordination number.
Six Coordinate Complexes: If complex ion has coordination number of 6, gives octahedral shape
so 90 bond angles around central metal ion.
When MnSO4 is dissolved in water. Forms complex ion with octahedral shape.
Learn these examples above. Pay attention the type of bond angle.
Four Coordinate Complexes: Coordination number of four gives tetrahedral or square planar.
Tetrahedral Complexes: Tetrahedral shape more common. Bond angles of 109.5 around central
metal ion.
Square Planar Complexes: Square planar shapes occurs when transition metal of complex ion
has eight d- electrons in highest energy d- sub- shell. Such as platinum (II), nickel, palladium (II)
and gold (III). Bond angle is 90.
When drawing, the position and type of bond matters.
Also when drawing make sure bond from the central metal ion comes to the atom with the lone
pair e.g. nitrogen or oxygen. Make sure LHS and RHS are different.
If asked to draw an unknown structure, break up its name e.g. hexachloroplatinate.
[Au(CN)2]
–
, with a bond angle of 180° is linear shape.
