Chapter 23 - Transition Metals Chemistry and Coordination Compounds

23.1 - Properties of the Transition Metals

Strong metallic bonding result from the combination of tight packing and small atomic size.
- As a result, transition metals have greater densities, melting points, boiling points, and fusion and vaporization temps.
Transition metal complexes have a wide range of oxidation states
- It's worth noting that each element's usual oxidation states are +2, +3, or both.
- The +3 oxidation states are more stable towards the start of the series, whereas the +2 oxidation levels are more stable toward the end.
The nuclear numbers increase, the outer shell is filled with electrons and by adding protons the nuclear charge increases.
The external electrons weakly protect each other from the extra nuclear charge in the third period – sodium to argon.
- Therefore, atomic radiation rapidly decreases from sodium to argon, with increasing energy from electronegativities and ionizations.

Iron is the second most prevalent metal in the Earth's crust, behind aluminum.
- It can be found in a variety of ores, including hematite (Fe2O3), siderite (FeCO3), and magnetite (Fe3O4).
Copper, a rare element that makes up 6.8% of the Earth's crust by mass, can be found in its natural state as well as in ores like chalcopyrite, CuFeS2.
Unclean copper can be electrolysically purified.
Copper has the highest electrical conductivity after silver, too expensive for large-scale use. It's also a good heat pipeline.
- In alloys, electrical cables, tubes, and coins copper is used.

A coordination compound is made up of a complexion and a counter ion in most cases.
Ligands are the molecules or ions that surround the metal in a complexion.
The donor atom is the atom in a ligand that is directly bonded to the metal atom.
- The number of donor atoms surrounding the core metal atom in a complexion is known as the coordination number in coordination compounds.
Ligands are characterized as monodentate, bidentate, or polydentate depending on the number of donor atoms present.
- H2O and NH3 are monodentate ligands, meaning they each have only one donor atom.
Because of their claw-like capacity to hold the metal atom, bidentate and polydentate ligands are also known as chelating agents.

Stereoisomers that cannot be interconverted without breaking a chemical link are known as geometric isomers.
- Geometric isomers are commonly seen in pairs.
- To identify one geometric isomer of a chemical from the other, we use the terms "cis" and "trans."
- Cis denotes that two atoms are next to each other in the structural formula, while trans denotes that the atoms are on opposing sides.
- Colors, melting temperatures, dipole values, and chemical reactivities of cis and trans isomers of coordination compounds are often considerably different.
Optical isomers are mirror images that cannot be superimposed.
Plane-polarized light vibrates only in one plane, unlike conventional light, which vibrates in all directions.
- The rotation of polarized light by optical isomers is measured using a polarimeter.

When ligands are present, the crystal field splitting is the energy difference between two sets of d orbitals in a metal atom.
Chemists calculated the crystal splitting for each ligand using spectroscopic data for several complexes with the same metal ion but different ligands, and established a spectrochemical series, which is a list of ligands arranged in increasing order of their ability to split the d orbital energy levels.

A complexion that conducts very sluggish exchange reactions is called an inert complex.
It demonstrates that a chemically reactive species is not always thermodynamically unstable.
- The energy of activation, which is considerable in this situation, determines the rate of reaction.
The labile complex is known to complexes such as tetracyanonickelate(II) because they are subjected to rapid reactions of the ligand.
- A thermodynamically stable species is therefore not unreactive.

Coordination compounds are found in biological systems and are used in a variety of settings, including the household, industry, and medicine.
The tripolyphosphate ion is an effective, stability and solubility of chelating agent with Ca2+ ions. The detergent industry has revolutionized sodium tripolyphosphate.
- But because the phosphates are plant nutrients, phosphate-based waste water released in rivers and lakes leads to the development of algae, which leads to oxygen depletion.
Most or all water life eventually succumbs under these conditions. This is known as eutrophication.
- As a result, since the 1970s, many States have prohibited phosphate detergents and producers have rewritten their products for the purpose of phosphates removal.