Encyclopedia of Metalloproteins

2013 Edition
| Editors: Robert H. Kretsinger, Vladimir N. Uversky, Eugene A. Permyakov

Barium, Physical and Chemical Properties

Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-1533-6_167



The heaviest nonradioactive member of the alkaline-earth elements (atomic number 56), barium is a soft, silvery, highly reactive metal. Its compounds have various uses, particularly in drilling fluids, paints, glasses, and pyrotechnics, but all soluble compounds of barium are toxic to mammals. The insoluble barium sulfate is used as a radiocontrast agent in medical imaging.


Barium is a member of the alkaline-earth family of metals (Group 2 in the periodic table). It is a relatively common element, ranking approximately 14th in natural abundance in the Earth’s crust; it is more plentiful than, for example, sulfur or zinc. The free metal does not occur in nature, but is found combined in minerals such as barite (barium sulfate, BaSO 4) (Fig.  1), or less commonly, in witherite (barium carbonate, BaCO 3). The density of such compounds (i.e., BaSO 4, 4.5 g cm −3; BaCO 3, 4.3 g cm −3) has long been reflected in their names;...
This is a preview of subscription content, log in to check access.


  1. Braithwaite N, Weaver G (1990) Electronic materials. Butterworth, LondonGoogle Scholar
  2. Diefenbach M, Schwarz H (2005) High-electron-density C6H6 units: stable ten-electron benzene complexes. Chem Eur J 11:3058–3063PubMedCrossRefGoogle Scholar
  3. Drake SR et al (1993) Group IIA metal β-diketonate complexes; the crystal structure of [Sr3(tmhd)6(Htmhd)]•C6H5Me•C5H12 and [Ba4(tmhd)8] (Htmhd = 2,2,6,6-tetramethylheptane-3,5-dione). J Chem Soc, Dalton Trans 2883–2890Google Scholar
  4. Hanusa TP (2007) Alkaline-earth metals: beryllium, magnesium, calcium, strontium, and barium. In: Crabtree RH, Mingos DMP (eds) Comprehensive organometallic chemistry-III, vol 2. Elsevier, Oxford, pp 67–152CrossRefGoogle Scholar
  5. Hargittai M (2000) Molecular structure of metal halides. Chem Rev 100:2233–2301PubMedCrossRefGoogle Scholar
  6. Himmel K, Jansen M (1998) Synthesis and single-crystal structure analysis of [Ba(NH3)7]C60•NH3. Inorg Chem 37:3437–3439CrossRefGoogle Scholar
  7. Kaupp M, Schleyer PVR (1992) The structural variations of monomeric alkaline earth MX2 compounds (M = Ca, Sr, Ba; X = Li, BeH, BH2, CH3, NH2, OH, F). An ab initio pseudopotential study. J Am Chem Soc 114:491–497CrossRefGoogle Scholar
  8. Murugavel R et al (2001) Reactions of 2-mercaptobenzoic acid with divalent alkaline earth metal ions: synthesis, spectral studies, and single-crystal X-ray structures of calcium, strontium, and barium complexes of 2,2´-dithiobis(benzoic acid). Inorg Chem 40:6870–6878PubMedCrossRefGoogle Scholar
  9. Pierson HO (1999) Handbook of chemical vapor deposition: principles, technology, and applications. Noyes, NorwichGoogle Scholar
  10. Westerhausen M (1998) Synthesis, properties, and reactivity of alkaline earth metal bis[bis(trialkylsilyl)amides]. Coord Chem Rev 176:157–210CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2013

Authors and Affiliations

  1. 1.Department of ChemistryVanderbilt UniversityNashvilleUSA