Inorganic

• Main group elements


  • Group 1-13 elements
• Periodic properties of the elements

  • Valence electron configurations
  • Atomic parameters
  • Occurrence
  • Metallic character
  • Oxidation states

  
• Valence electron configurations


  The electron configuration of the main group elements can be predicted from their position in the periodic table. The n − 1 orbitals are being filled in the d block and the n − 2 orbitals are being filled in the f block.

  
• Elements


  • Group 14
  • Group 15
  • Group 16
  • Group 17
  • Group 18
• The valence electron configuration of the ground state of an atom of an element can be inferred from its group number.

  
• Electron configurations in the d block

  Slightly less systematic, but involve the filling of the ( n − 1)d orbitals.
• Group 14 elements


  • Carbon providing the basis for life on Earth
  • Silicon being vital for the physical structure of the natural environment in the form of crustal rocks
• In this chapter, the focus with carbon is on its inorganic chemistry
• Electron configurations in the f-block

  Involve filling of the ( n − 2)f orbitals.
• Silicon is widely distributed in the natural environment, and tin and lead find widespread applications in industry and manufacturing
• Atomic radii


  • Increase down a group and, within the s and p blocks, decrease from left to right across a period.
• Group 14 elements


  • The lightest elements of the group are nonmetals
  • Tin and lead are metals
  • All the elements except lead exist as several allotropes
  • Electron configuration: ns2np2
  • The +4 oxidation state is dominant in the compounds of the elements
  • The major exception is lead, for which the most common oxidation state is +2
  • Carbon and silicon are strong oxophiles and fluorophiles
• Ionization energy


  The energy required to remove an electron from a gas-phase atom. Increases across a period and decreases down a group.
• Simple binary compounds formed by Group 14 elements

  • With hydrogen
  • With oxygen
  • With the halogens
  • With nitrogen
  • Carbon and silicon also form carbides and silicides with metals
• Electronegativity


  The power of an atom of the element to attract electrons to itself when it is part of a compound. Increases across a period and decreases down a group.
• Diamond


  Electrical insulator, very hard, transparent
• van Arkel−Ketelaar triangle


  Used to predict covalent or ionic bonds in binary compounds based on the difference in electronegativities (Δ χ ) of the elements and their average electronegativity ( χ mean ).

  
• Graphite


  Good conductor, soft, black
• NaCl and HCl can be predicted to be covalent or ionic based on the van Arkel−Ketelaar triangle.

  
• Hardness and softness


  Helps to rationalize the type of compound that an element forms in nature.
• The conversion of diamond to graphite at room temperature and pressure is spontaneous (ΔtrsG < = 2.90 kJ mol−1 ) but does not occur at an observable rate under ordinary conditions: diamonds older than the solar system have been isolated from meteorites
• Graphite can act as either an electron donor or an electron acceptor towards atoms and ions that penetrate between its sheets and give rise to an intercalation compound

  
• Goldschmidt classification of elements

  • Lithophiles
  • Chalcophiles
  • Siderophiles
  • Atmophiles
• An example of an oxidation of graphite by the removal of electrons from the π band is the formation of graphite bisulfates by heating graphite with a mixture of sulfuric and nitric acids
• Metallic character


  Decreases across a period and increases down a group.
• The halogens show an alternation effect in their tendency to form intercalation compounds with graphite

  
• Coordination numbers


  • Low coordination numbers generally dominate for small atoms; high coordination numbers are possible as a group is descended. The 4d- and 5d-series elements often exhibit higher coordination numbers than their 3d-series congeners; compounds of d metals in high oxidation states tend to have covalent structures.
• Fullerenes


  • Formed when an electric arc is discharged between carbon electrodes in an inert atmosphere
  • The molecule consists of five- and six-membered carbon rings, and the overall symmetry is icosahedral in the gas phase
  • Fullerenes can be reduced to form [60]fulleride salts, C60n− (n=1 to 12)

  
• Coordination numbers


  • NH3, PCl3, PCl5, Pd(PPh3)4, [Mo(CN)8]3-
• Fullerene–metal complexes undergo reversible multielectron reduction and form complexes with d-metal organometallic compounds

  
• Bond enthalpy trends


  For an atom E that has no lone pairs, the E–X bond enthalpy decreases down the group; for an atom that has lone pairs, it typically increases between Periods 2 and 3, and then decreases down the group. Smaller atoms form stronger bonds because the shared electrons are closer to each of the atomic nuclei.

  
• Carbon nanotubes


  • Closely related to both fullerenes and graphene
  • Consist of one or more concentric cylindrical tubes conceptually formed by rolling graphene sheets
  • The ends of the nanotubes are often capped by hemispheres of fullerene-like caps containing six five-membered rings of atoms

  
• Types of hydrides


  • Molecular hydrides
  • Saline hydrides
  • Metallic hydrides
• Types of carbides


  • Saline carbides: Groups 1 and 2 metals
  • Metallic carbides: metallic conductivity; d-block elements
  • Metalloid carbides: hard covalent solids formed by boron and silicon
• Molecular hydrides


  Electron precise compounds, basic covalent hydrides, weak-acid covalent hydrides, strong acids, electron deficient hydrides, anionic hydrides
• Methylchlorosilanes are important starting materials for the manufacture of silicone polymers; the properties of silicone polymers are determined by the degree of cross-linking and may be liquids, gels, or resins
• Electron precise


  All valence electrons of the central atom are engaged in bonds
• The tetraalkyl and tetraaryl germanium (IV) compounds are chemically and thermally stable

  
• Electron deficient


  There are too few electrons available to fill the bonding and nonbonding orbitals
• Germylene


  Organosilicon compounds