Transition Metal Chemistry and Coordination Compounds

Vocabulary flashcards covering the fundamental concepts of transition metal coordination chemistry, including ligand types, naming conventions, isomerism, and crystal field theory.

Complex ion

A central metal cation bonded to one or more molecules or ions.

Coordination compound

A compound that typically consists of a complex ion and a counter ion.

Ligand

The molecules or ions that surround the metal in a complex ion; they possess at least one unshared pair of valence electrons.

Donor atom

The specific atom in a ligand that is bound directly to the metal atom.

Coordination number

The number of donor atoms surrounding the central metal atom in a complex ion.

Monodentate ligand

A ligand that contains only one donor atom.

Bidentate ligand

A ligand that contains two donor atoms, such as ethylenediamine ($NH_2CH_2CH_2NH_2$).

Polydentate ligand

A ligand that contains three or more donor atoms; for example, ethylenediaminetetraacetate ion (EDTA) which has six donor atoms.

Chelating agents

A term used to describe bidentate and polydentate ligands.

Ammine

The systematic name used for the neutral ligand Ammonia ($NH_3$) in coordination compounds.

Aquo

The systematic name used for the neutral ligand Water ($H_2O$) in coordination compounds.

Carbonyl

The systematic name used for the neutral ligand Carbon monoxide ($CO$) in coordination compounds.

-ate

The suffix added to the end of a complex name if the complex is an anion.

Stereoisomers

Compounds made up of the same types and numbers of atoms bonded together in the same sequence but with different spatial arrangements.

Geometric isomers

Stereoisomers that cannot be interconverted without breaking a chemical bond, characterized by cis or trans arrangements.

Optical isomers

Nonsuperimposable mirror images of a molecule.

Chiral

Molecules that are nonsuperimposable mirror images and are optically active.

Achiral

Molecules that are superimposable on their mirror images and are not optical isomers.

Crystal field splitting ($\Delta$)

The energy difference between two sets of d orbitals in a metal atom when ligands are present.

Spectrochemical Series

A list of ligands arranged in order of their ability to split d-orbital energies: $I^- < Br^- < Cl^- < OH^- < F^- < H_2O < NH_3 < en < CN^- < CO$.

Strong field ligands

Ligands that produce a large energy difference ($\Delta$) between the sets of d orbitals.

Weak field ligands

Ligands that produce a small energy difference ($\Delta$) between the sets of d orbitals.