1. Transition Metals - The Basics + Complex Ions

Transition Metal definition

A transition metal is a metal that can form one or more stable ions with an incomplete d sub-shell.

What are the two elements in the d block which aren’t transition metals?

Scandium and zinc

Why aren’t Scandium and zinc transition metals?

Their stable ions don’t have incomplete d sub-levels.

Physical properties - 2

• high density

• high melting and boiling points

Chemical Properties of transition metals - 4

• They form complexes

• They form coloured ions

• Variable oxidation states

• Good catalysts

what causes the special chemical properties of transition metals?

their incomplete d sub-levels.

what is a complex?

These form from transition metals, consisting of a central metal ion, surrounded by ligands.

What are ligands?

An atom, ion or molecule that donates a pair of electrons to a central metal ion.

list the monodentate ligands

What are the bidentate ligands

• ethane-1,2-diamine

• ethandioate ions

What are the multidentate ligands

• EDTA4-

• Haem groups

Coordination number

The number of co-ordinate bonds that are formed with the central metal ion. (usually 6 and 4)

equation for the oxidation state of the metal ion

the oxidation state of the metal ion = The total charge of the complex - The sum of the charges of the ligands.

Ti ions, oxidation state and colour

Ti2+ → +2 → violet

Ti3+ → +3 → purple

V ions, oxidation state and colours

V2+, +2, violet

V3+, +3, green

VO(2+), +4, blue

VO2 (+), +5, yellow

Cr ions, oxidation state and colours

Cr3+, +3, green

Cr2O7 (2-), +6, orange

Mn ions, oxidation state and colours

Mn2+, +2, very pale pink/ colourless

MnO4 (2-), +6, green

MnO4 (-), +7, purple

Fe ions, oxidation state and colours

Fe2+, +2, pale green

Fe3+, +3, yellow/purple

Co ions, oxidation state and colours

Co2+, +2, pink

Ni ions, oxidation state and colours

Ni2+, 2+, green

Cu ions, oxidation state and colours

Cu2+, +2, pale blue