Transition Metals and Coordination Chemistry

This set of flashcards covers key concepts related to transition metals, their properties, electron configurations, coordination chemistry, and bonding.

Periodic Table Categories

Elements are divided into four categories: Main-group elements, Transition metals, Lanthanides, Actinides.

Main-group metals

Malleable and ductile, conduct heat and electricity, form positive ions.

Transition metals

More electronegative than main-group metals, likely to form covalent compounds, easily form complexes, and have incompletely filled d orbitals.

Electron configuration of transition-metal ions

Electrons are generally removed from the valence shell s orbitals before d orbitals during ionization.

Cobalt oxidation states

Cobalt can form complexes with Co2+ and Co3+ ions, with corresponding electron configurations [Ar] 3d7 and [Ar] 3d6 respectively.

Coordination Chemistry

A coordination compound contains a central metal ion surrounded by oppositely charged ions or neutral molecules known as ligands.

Ligands

Molecules or ions that coordinate to a central metal atom or ion, usually with lone pairs of electrons.

Coordination number

The total number of sites occupied by ligands on a central metal atom or ion.

Chelating ligands

Ligands that can form more than one bond with a metal, leading to ring structures called chelates.

Isomers in coordination complexes

Different arrangements of ligands that can result in various types of isomers, including ionization and geometric isomers.

Geometric isomers

Isomers with the same formula but different spatial arrangements, like cis and trans configurations.

Oxidation states of transition metals

Transition metals exhibit various oxidation states, with +2 being relatively stable compared to +3 in aqueous solutions.

Soft and hard acids and bases

Soft acids react faster with soft bases; hard acids react faster with hard bases, influencing the stability of complexes.

Metal carbonyls

Compounds with metal bonded to carbon monoxide, demonstrating unique properties due to back-bonding.

Back-bonding

The overlap of metal d orbitals with ligand π* orbitals, enhancing the metal-ligand bond strength.

IR spectroscopy in coordination compounds

Infrared spectra indicate the strength of bonding; lower stretching frequencies suggest stronger back-bonding.