Germanium
Main page |
| Other names/abbreviations: | Ge Ekasilicon |
| Element no: | 32 |
| Element group: | 14 (IUPAC) IV A (American labelling) IV B (European labelling) |
| Element type: | Metals |
| CAS-Number: | 7440-56-4 |
| EINECS-Number: | 231-164-3 |
Chemical properties
SolubilityWater: Insoluble (20 °C) [5]
Uses
- alloying agent [1]
- a catalyst [1]
- germanium and germanium oxide are transparent to the infrared and are used in infrared spectroscopes and other optical equipment, including extremely sensitive infrared detectors. Also for wide-angle camera lenses and microscope objectives [1].
Biological properties
GeO2 can inhibit the growth of the diatom Phaeodactylum tricornutum [1]. The effect has been suggested to be from inhibition of silica shell formation [1]. High levels of Ge(OH)4 has been reported to inhibit silicon uptake, chlorophyll synthesis and photosynthetic carbon fixation by diatoms [1].The organogermanium compounds bis(D,L-lactato)germanium(IV), bis(L-lactato)germanium(IV), bis (thiolactato)germanium(IV) and bis(thioglycolato)germanium(IV) were tested for their antimutagenic activity in Salmonella typhimurium. Each compound showed moderate activity against the mutagenic effect of nitroaromatic compounds and weak effects against the mutagenic activity of ethylmethane sulfonate. No inhibition of mutagenicity was observed against the indirect acting promutagens benzo(a)pyrene and 2-aminoanthracene [2].
Safety
Symbol: -R-phrases: -
S-phrases: -
Physical properties
Appearance | ||
| Physical state @ 20°C: | Solid [5] | |
| Color: | Gray [5] | |
| Odor: | Odourless [5] | |
Bulk properties | ||
| Molecular weight (g/mol): | 72.61(2) [3] | |
| Melting point (°C): | 945 [3] | |
| Boiling point (°C): | 2850 [3] | |
| Density (g/cm3): | 5.323 (alpha form) [3] 6.71 (beta form) [3] | |
| Molar volume (cm3): | 13.60 (20 °C) [4] | |
| Elastic properties: Young's modulus (GPa): Rigidity modulus (GPa): Bulk modulus (GPa): Poisson ratio: |
80 [4] 30 [4] 80 [4] 0.34 [4] | |
| Hardness: Mineral hardness: |
1.5-2.5 [4] | |
Thermodynamic properties | ||
| ΔfH°gas (kJ/mol): | 283 (Monoatomic) [3] 372.0 [6] | ΔfH°solid (kJ/mol): | 0.0 [6] | ΔH°fusion (kJ/mol): | 36.94 [6] | ΔH°vaporization (kJ/mol): | 328 [3] |
S°gas (J/K·mol): | 167.9 [6] | S°solid (J/K·mol): | 31.1 [6] |
ΔfG°gas (kJ/mol): | 331.2 [6] |
Cp (gas) (J/K·mol): | 30.7 (25 °C) [6] | Cp (solid) (J/K·mol): | 23.222 (25 °C) [6] |
Crystal structure | ||
| Crystal type: | DC [4] | |
Electronic properties | ||
 |
Electron configuration: | 1s2-2s2-2p6-3s2-3p6-3d10-4s2-4p2 |
| Ionic radius (Å): | Ge(IV): 0.53 [3] Ge(II): 0.73 [3] | |
Conductivity | ||
| Electrical resisitvity (μΩ·cm): | 4.7·10-5 (approximately, 20 °C) [3] | |
References
1: Slawson,R.M., Van Dyke,M.I., Lee,H., Trevors,J.T. Germanium and silver resistance, accumulation, and toxicity in microorganismsPlasmid (1992) 27 (1) 72-79
2: Schimmer,O., Eschelbach,H., Breitinger,D.K., Grutzner,T., Wick,H. Organogermanium compounds as inhibitors of the activity of direct acting mutagens in Salmonella typhimurium
Arzneimittelforschung (1997) 47 (12) 1398-1402
3: Greenwood,N.N., Earnshaw,A. Chemistry of the elements
2nd edition (1997) Edited by Greenwood,N.N., Earnshaw,A. pp. 1-1340, Butterworth-Heinemann. Oxford. Great Britain
4: Buch,A. Pure Metals Properties. A Scientific-Technical Handbook
1st edition (1999) Edited by Buch,A. pp. 1-306, ASM International and Freund Publishing House Ltd. Ohio. USA
5: Merck. ChemDAT The Merck Chemical Database Ver. 1.1.5
6: CRC Handbook of Chemistry and Physics
75th edition (1994) Edited by Lide,D.R. , CRC Press Inc. Boca Raton, USA
© Michael Pilgaard
Created: September 29, 2008
Last update: October 8, 2008