Transition Metals Flashcards
what is a transition metal
A transition metal is an element that has an incomplete d sub shell in either of its atoms or one of its common ions
what are the properties of transition metals
- In solution the ions of transition metals from complex ions
- Variable oxidation states
- Formation of coloured ions
- Effective catalysts (e.g Fe in Haber process to make ammonia, or an alloy of rhodium, palladium and platinum in a catalytic converter used to convert NO into N2)
what is a complex ion
A complex ion is a transition metal ion bonded to one or more ligands by coordinate bonds
what is a ligand
A ligand is a molecule or ion that can donate a pair of electrons to the transiton metal ion to form a coordinate bond to a metal ion
what is a monodentate ligand
A monodentate ligand is a molecule or ion that can donate one pair of electrons to the transition metal ion to form one coordinate bond
what are some examples of simple ligands and their charges
- Water, H2O : 0
- Ammonia, NH3 : 0
- Chloride ion, Cl- : 1-
- Hydroxide, OH- : 1-
- Cyanide, CN- : 1-
what do ligands act as when they bond to transition metals
They act as Lewis bases as they donate a lone pair to form a co-ordinate bond - the metal ion acts as a Lewis acid as it accepts lone pairs
what is the coordination number
Coordination number is the total number of coordinate bonds formed between a central metal ion and its ligands
what is a bidentate ligand and what are the 2 examples
A bidentate ligand has two atoms with lone pairs and can form two coordinate bonds per ligand
- 1,2 - diaminoethane (en)
- ethanedioate ion (C2O4^2-)
what is a multidentate ligand
A multidentate ligand has more than two atoms with lone pairs and can form more than two coordinate bonds to a metal ion
what shapes would a six-fold and four-fold coordination have
- six-fold coordination = octahedral shape
- four-fold coordination = tetrahedral shape or square planar
