RHENIUM

Introduction

Atomic Number: 75
Group: 7 or VII B
Atomic Weight: 186.207
Period: 6
CAS Number: 7440-15-5

Classification

Chalcogen
Halogen
Noble Gas
Lanthanoid
Actinoid
Rare Earth Element
Platinum Group Metal
Transuranium
No Stable Isotopes
Solid
Liquid
Gas
Solid (Predicted)

Description • Uses/Function

Discovery of rhenium is generally attributed to Noddack, Tacke, and Berg, who announced in 1925 they had detected the element in platinum oresand columbite. They also found the element in gadolinite and molybdenite. By working up 660 kg of molybdenite they were able in 1928 to extract1 g of rhenium. The price in 1928 was $10,000/g. Rhenium does not occur free in nature or as a compound in a distinct mineral species. It is, however,widely spread throughout the earth’s crust to the extent of about 0.001 ppm. Commercial rhenium in the U.S. today is obtained from molybdeniteroaster-flue dusts obtained from copper-sulfide ores mined in the vicinity of Miami, Arizona, and elsewhere in Arizona and Utah. Some molybdenitescontain from 0.002 to 0.2% rhenium. More than 150,000 troy ounces of rhenium are now being produced yearly in the United States. The total estimatedFree World reserve of rhenium metal is 3500 tons. Natural rhenium is a mixture of two isotopes, one of which has a very long half-life. Thirty nineother unstable isotopes are recognized. Rhenium metal is prepared by reducing ammonium perrhenate with hydrogen at elevated temperatures. Theelement is silvery white with a metallic luster; its density is exceeded only by that of platinum, iridium, and osmium, and its melting point is exceededonly by that of tungsten and carbon. It has other useful properties. The usual commercial form of the element is a powder, but it can be consolidatedby pressing and resistance-sintering in a vacuum or hydrogen atmosphere. This produces a compact shape in excess of 90% of the density of the metal.Annealed rhenium is very ductile, and can be bent, coiled, or rolled. Rhenium is used as an additive to tungsten and molybdenum-based alloys to impartuseful properties. It is widely used for filaments for mass spectrographs and ion gages. Rhenium-molybdenum alloys are superconductive at 10 K.Rhenium is also used as an electrical contact material as it has good wear resistance and withstands arc corrosion. Thermocouples made of Re-W areused for measuring temperatures up to 2200°C, and rhenium wire has been used in photoflash lamps for photography. Rhenium catalysts areexceptionally resistant to poisoning from nitrogen, sulfur, and phosphorus, and are used for hydrogenation of fine chemicals, hydrocracking, reforming,and disproportionation of olefins. Rhenium costs about $12/g (99.99% pure). Little is known of its toxicity; therefore, it should be handled with careuntil more data are available. 1

Physical Properties

Melting Point:2*  3186 °C = 3459.15 K = 5766.8 °F
Boiling Point:2* 5596 °C = 5869.15 K = 10104.8 °F
Sublimation Point:2 
Triple Point:2 
Critical Point:2 
Density:3  20.8 g/cm3

* - at 1 atm

Electron Configuration

Electron Configuration: [Xe] 6s2 4f14 5d5
Block: d
Highest Occupied Energy Level: 6
Valence Electrons: 

Quantum Numbers:

n = 5
ℓ = 2
m = 2
ms = +½

Bonding

Electronegativity (Pauling scale):4 1.9
Electropositivity (Pauling scale): 2.1
Electron Affinity:5 0.15 eV
Oxidation States: +7,4,6
Work Function:6 4.95 eV = 7.9299E-19 J

Ionization Potential   eV 7  kJ/mol  
Ionization Potential   eV 7  kJ/mol  
Ionization Potential   eV 7  kJ/mol  
1 7.8335    755.8

Thermochemistry

Specific Heat: 0.137 J/g°C 8 = 25.510 J/mol°C = 0.033 cal/g°C = 6.097 cal/mol°C
Thermal Conductivity: 47.9 (W/m)/K, 27°C 9
Heat of Fusion: 33.2 kJ/mol 10 = 178.3 J/g
Heat of Vaporization: 715 kJ/mol 11 = 3839.8 J/g
State of Matter Enthalpy of Formation (ΔHf°)12 Entropy (S°)12 Gibbs Free Energy (ΔGf°)12
(kcal/mol) (kJ/mol) (cal/K) (J/K) (kcal/mol) (kJ/mol)
(s) 0 0 8.81 36.86104 0 0
(g) 184.0 769.856 45.131 188.828104 173.2 724.6688

Isotopes

Nuclide Mass 13 Half-Life 13 Nuclear Spin 13 Binding Energy
160Re 159.98212(43)# 860(120) μs [0.82(+15-9) ms] (2-) 1,251.36 MeV
161Re 160.97759(22) 0.37(4) ms 1/2+ 1,268.75 MeV
162Re 161.97600(22)# 107(13) ms (2-) 1,276.82 MeV
163Re 162.972081(21) 390(70) ms (1/2+) 1,284.89 MeV
164Re 163.97032(17)# 0.53(23) s high 1,292.96 MeV
165Re 164.967089(30) 1# s 1/2+# 1,310.35 MeV
166Re 165.96581(9)# 2# s 2-# 1,318.42 MeV
167Re 166.96260(6)# 3.4(4) s 9/2-# 1,326.49 MeV
168Re 167.96157(3) 4.4(1) s (5+,6+,7+) 1,334.56 MeV
169Re 168.95879(3) 8.1(5) s 9/2-# 1,351.95 MeV
170Re 169.958220(28) 9.2(2) s (5+) 1,360.02 MeV
171Re 170.95572(3) 15.2(4) s (9/2-) 1,368.09 MeV
172Re 171.95542(6) 15(3) s -5 1,376.16 MeV
173Re 172.95324(3) 1.98(26) min (5/2-) 1,384.23 MeV
174Re 173.95312(3) 2.40(4) min 1,392.31 MeV
175Re 174.95138(3) 5.89(5) min (5/2-) 1,400.38 MeV
176Re 175.95162(3) 5.3(3) min 3+ 1,408.45 MeV
177Re 176.95033(3) 14(1) min 5/2- 1,416.52 MeV
178Re 177.95099(3) 13.2(2) min (3+) 1,424.59 MeV
179Re 178.949988(26) 19.5(1) min (5/2)+ 1,441.98 MeV
180Re 179.950789(23) 2.44(6) min (1)- 1,440.73 MeV
181Re 180.950068(14) 19.9(7) h 5/2+ 1,448.80 MeV
182Re 181.95121(11) 64.0(5) h 7+ 1,456.88 MeV
183Re 182.950820(9) 70.0(14) d 5/2+ 1,464.95 MeV
184Re 183.952521(5) 38.0(5) d 3(-) 1,473.02 MeV
185Re 184.9529550(13) STABLE 5/2+ 1,481.09 MeV
186Re 185.9549861(13) 3.7186(5) d 1- 1,489.16 MeV
187Re 186.9557531(15) 41.2(2)E+9 a 5/2+ 1,497.23 MeV
188Re 187.9581144(15) 17.0040(22) h 1- 1,505.30 MeV
189Re 188.959229(9) 24.3(4) h 5/2+ 1,513.38 MeV
190Re 189.96182(16) 3.1(3) min (2)- 1,512.13 MeV
191Re 190.963125(11) 9.8(5) min (3/2+,1/2+) 1,520.20 MeV
192Re 191.96596(21)# 16(1) s 1,528.27 MeV
193Re 192.96747(21)# 30# s [>300 ns] 5/2+# 1,536.35 MeV
194Re 193.97042(32)# 2# s [>300 ns] 1,535.10 MeV
Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses. 13

Abundance

Earth - Source Compounds: oxides 14
Earth - Seawater: 0.000004 mg/L 15
Earth -  Crust:  0.0007 mg/kg = 0.00000007% 15
Earth -  Total:  60 ppb 16
Mercury -  Total:  46 ppb 16
Venus -  Total:  64 ppb 16
Chondrites - Total: 0.046 (relative to 106 atoms of Si) 17

Compounds

Safety Information


Material Safety Data Sheet - ACI Alloys, Inc.

For More Information

External Links:

Sources

(1) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:25-4:26.
(2) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:132.
(3) - Lide, David R. CRC Handbook of Chemistry and Physics, 84th ed.; CRC Press: Boca Raton, FL, 2002; p 4:39-4:96.
(4) - Dean, John A. Lange's Handbook of Chemistry, 11th ed.; McGraw-Hill Book Company: New York, NY, 1973; p 4:8-4:149.
(5) - Lide, David R. CRC Handbook of Chemistry and Physics, 84th ed.; CRC Press: Boca Raton, FL, 2002; p 10:147-10:148.
(6) - Speight, James. Lange's Handbook of Chemistry, 16th ed.; McGraw-Hill Professional: Boston, MA, 2004; p 1:132.
(7) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 10:178 - 10:180.
(8) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:133.
(9) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:193, 12:219-220.
(10) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:123-6:137.
(11) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:107-6:122.
(12) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.
(13) - Atomic Mass Data Center. http://amdc.in2p3.fr/web/nubase_en.html (accessed July 14, 2009).
(14) - Silberberg, Martin S. Chemistry: The Molecular Nature of Matter and Change, 4th ed.; McGraw-Hill Higher Education: Boston, MA, 2006, p 965.
(15) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 14:17.
(16) - Morgan, John W. and Anders, Edward, Proc. Natl. Acad. Sci. USA 77, 6973-6977 (1980)
(17) - Brownlow, Arthur. Geochemistry; Prentice-Hall, Inc.: Englewood Cliffs, NJ, 1979, pp 15-16.