Molybdenum(II) acetate: Difference between revisions
Pansygrower (talk | contribs) No edit summary |
Reverted to revision 358127601 by Rifleman 82; content removed in later edits. (TW) |
||
| Line 28: | Line 28: | ||
}} |
}} |
||
}} |
}} |
||
'''Molybdenum(II) acetate''' [Mo<sub>2</sub>(O<sub>2</sub>CCH<sub>3</sub>)<sub>4</sub>] is a [[coordination compound]] with a metal-metal [[quadruple bond]] between two [[Molybdenum|Mo(II)]] atoms<ref name="rauchfuss">Girolami, G. S.; Rauchfuss, T. B. and Angelici, R. J., "Synthesis and Technique in Inorganic Chemistry third edition", University Science Books: Mill Valley, CA, 1999, ISBN 0-935702-48-2</ref>. This yellow solid is insoluble in most common solvents. Other diacetate metal complexes such as rhodium(II) acetate [Rh<sub>2</sub>(O<sub>2</sub>CCH<sub>3</sub>)<sub>4</sub>], [[copper(II) acetate]] [Cu<sub>2</sub>(O<sub>2</sub>CCH<sub>3</sub>)<sub>4</sub>], and chromium(II) acetate [Cr<sub>2</sub>(O<sub>2</sub>CCH<sub>3</sub>)<sub>4</sub>] exist with the same [[Chinese lantern structure]] as Mo<sub>2</sub>(O<sub>2</sub>CCH<sub>3</sub>)<sub>4</sub>.<ref>Cotton, F. A.; Hillard, E.A.; Murillo, C. A.; Zhou, H.-C.; J. Am. Chem. Soc., 2000, 122, 416-417"After 155 Years, A Crystalline Chromium Carboxylate with a Supershort Cr-Cr Bond".</ref> |
'''Molybdenum(II) acetate''' [Mo<sub>2</sub>(O<sub>2</sub>CCH<sub>3</sub>)<sub>4</sub>] is a [[coordination compound]] with a metal-metal [[quadruple bond]] between two [[Molybdenum|Mo(II)]] atoms<ref name="rauchfuss">Girolami, G. S.; Rauchfuss, T. B. and Angelici, R. J., "Synthesis and Technique in Inorganic Chemistry third edition", University Science Books: Mill Valley, CA, 1999, ISBN 0-935702-48-2</ref>. This yellow solid is insoluble in most common solvents. Other diacetate metal complexes such as rhodium(II) acetate [Rh<sub>2</sub>(O<sub>2</sub>CCH<sub>3</sub>)<sub>4</sub>], [[copper(II) acetate]] [Cu<sub>2</sub>(O<sub>2</sub>CCH<sub>3</sub>)<sub>4</sub>], and chromium(II) acetate [Cr<sub>2</sub>(O<sub>2</sub>CCH<sub>3</sub>)<sub>4</sub>] exist with the same [[Chinese lantern structure]] as Mo<sub>2</sub>(O<sub>2</sub>CCH<sub>3</sub>)<sub>4</sub>, but only Cr<sub>2</sub>(O<sub>2</sub>CCH<sub>3</sub>)<sub>4</sub>(H<sub>2</sub>O)<sub>2</sub> has a metal-metal quadruple bond present.<ref>Cotton, F. A.; Hillard, E.A.; Murillo, C. A.; Zhou, H.-C.; J. Am. Chem. Soc., 2000, 122, 416-417"After 155 Years, A Crystalline Chromium Carboxylate with a Supershort Cr-Cr Bond".</ref> |
||
==Structure== |
==Structure== |
||
Mo<sub>2</sub>(O<sub>2</sub>CCH<sub>3</sub>)<sub>4</sub> is a [[diamagnetic]] compound with an eclipsed ligand geometry containing a quadruple bond between two Mo(II) centers . Each Mo(II) atom in Mo<sub>2</sub>(O<sub>2</sub>CCH<sub>3</sub>)<sub>4</sub> has four d [[valence electrons]] with a total of eight for the compound. These eight valence electrons form one [[sigma bond|σ]], two [[pi bond|π bonds]], and one [[delta bond|δ bond]], creating an [[electron configuration]] of σ2π4δ2. Each of these bonds is formed by the overlapping of two d orbitals.<ref name="rauchfuss" /><ref name="blaudeau">Blaudeau, J.P.; Pitzer, R.M.; J.Phys. Chem. 1994, 98, 4575-4579. “ Ab Initio Studies of Ligand Effects on the Metal-Metal Bond in Dimolybdenum Complexes”. </ref> Each of the four acetate groups acts as bridges between the two metal centers.<ref name="rauchfuss" /> The Mo-O bond between each Mo(II) center and O atom from acetate has a [[bond length|distance]] of 2.119Å, and the Mo-Mo distance between the two metal centers is 2.0934Å.<ref name="handa">Handa, M.; Mikuriya, M.; Kotera, T.; Yamada, K.; Nakso, T.; Matsumoto, H.; Kasuga, K.; Bull. Chem. Soc. Jpn., 1995,68, 2567-2572. “Linear Chain Compounds of Molybdenum(II) Acetate Linked by Pyazine, 4,4’-Bipyridine,and 1,4- Diazabicyclo[2.2.2]octane”. </ref> |
Mo<sub>2</sub>(O<sub>2</sub>CCH<sub>3</sub>)<sub>4</sub> is a [[diamagnetic]] compound with an eclipsed ligand geometry containing a quadruple bond between two Mo(II) centers . Each Mo(II) atom in Mo<sub>2</sub>(O<sub>2</sub>CCH<sub>3</sub>)<sub>4</sub> has four d [[valence electrons]] with a total of eight for the compound. These eight valence electrons form one [[sigma bond|σ]], two [[pi bond|π bonds]], and one [[delta bond|δ bond]], creating an [[electron configuration]] of σ2π4δ2. Each of these bonds is formed by the overlapping of two d orbitals.<ref name="rauchfuss" /><ref name="blaudeau">Blaudeau, J.P.; Pitzer, R.M.; J.Phys. Chem. 1994, 98, 4575-4579. “ Ab Initio Studies of Ligand Effects on the Metal-Metal Bond in Dimolybdenum Complexes”. </ref> Each of the four acetate groups acts as bridges between the two metal centers.<ref name="rauchfuss" /> The Mo-O bond between each Mo(II) center and O atom from acetate has a [[bond length|distance]] of 2.119Å, and the Mo-Mo distance between the two metal centers is 2.0934Å.<ref name="handa">Handa, M.; Mikuriya, M.; Kotera, T.; Yamada, K.; Nakso, T.; Matsumoto, H.; Kasuga, K.; Bull. Chem. Soc. Jpn., 1995,68, 2567-2572. “Linear Chain Compounds of Molybdenum(II) Acetate Linked by Pyazine, 4,4’-Bipyridine,and 1,4- Diazabicyclo[2.2.2]octane”. </ref> An unidentate ligand such as water(H<sub>2</sub>O) attaches to the Mo(II) center to complete the octahedral conformation of each atom. |
||
==Preparation== |
==Preparation== |
||
Revision as of 23:21, 25 April 2010
| Names | |
|---|---|
| Other names
Dimolybdenum tetraacetate,
tetra (aceto) dimolybdenum , Molybdenum(II) acetate dimer, | |
| Identifiers | |
| ECHA InfoCard | 100.034.611 |
CompTox Dashboard (EPA)
|
|
| Properties | |
| C8H12Mo2O8 (dihydrate) | |
| Molar mass | 432.08784 g/mol |
| Appearance | Yellow solids |
| Boiling point | decomposes |
| not soluble | |
| Related compounds | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
| |
Molybdenum(II) acetate [Mo2(O2CCH3)4] is a coordination compound with a metal-metal quadruple bond between two Mo(II) atoms[1]. This yellow solid is insoluble in most common solvents. Other diacetate metal complexes such as rhodium(II) acetate [Rh2(O2CCH3)4], copper(II) acetate [Cu2(O2CCH3)4], and chromium(II) acetate [Cr2(O2CCH3)4] exist with the same Chinese lantern structure as Mo2(O2CCH3)4, but only Cr2(O2CCH3)4(H2O)2 has a metal-metal quadruple bond present.[2]
Structure
Mo2(O2CCH3)4 is a diamagnetic compound with an eclipsed ligand geometry containing a quadruple bond between two Mo(II) centers . Each Mo(II) atom in Mo2(O2CCH3)4 has four d valence electrons with a total of eight for the compound. These eight valence electrons form one σ, two π bonds, and one δ bond, creating an electron configuration of σ2π4δ2. Each of these bonds is formed by the overlapping of two d orbitals.[1][3] Each of the four acetate groups acts as bridges between the two metal centers.[1] The Mo-O bond between each Mo(II) center and O atom from acetate has a distance of 2.119Å, and the Mo-Mo distance between the two metal centers is 2.0934Å.[4] An unidentate ligand such as water(H2O) attaches to the Mo(II) center to complete the octahedral conformation of each atom.
Preparation
Mo2(O2CCH3)4is synthesized by heating molybdenum hexacarbonyl (Mo(CO)6) in solution with acetic acid. The process strips CO ligands from Mo(CO)6 and allows for the oxidation of Mo0 atoms by acetic acid. [1][5][6][7]
- 2 Mo(CO)6 + 4 HO2CCH3 → Mo2(O2CCH3)4 + 12 CO + 2 H2
Different arrangements of trinuclear cluster compounds with a molybdenum metal center have been found as byproducts during the reaction of HO2CCH3 and Mo(CO)6. Three Mo(II) atoms bond to each other in an equilateral triangle formation. [8]
The reaction of HO2CCH3 and Mo(CO)6 was first investigated by Bannister et al. in 1960. At the time, quadruple metal-metal bonds had not yet been discovered, so these authors proposed a tetrahedral geometry around each Mo(II) center.[6][9] The discovery of quadruple bonds was made by F.A. Cotton in 1964 with the synthesis and characterization of potassium octachlorodirhenate(III).[10]
Applications
Mo2(O2CCH3)4 is generally used as an intermediate compound in a process to form other quadruple bonded Molybdenum compounds.[1][5][6][7][9][4] The acetate ligands can be replaced with wanted ligands to create new compounds such as Mo2Cl4[P(C4H9)3]4.[1][7][3] Recent studies have started to use quadruple bonded molybdenum complexes such as Mo2(O2CCH3)4 to form quintuple bonded molybdenum complexes.[11]
References
- ^ a b c d e f Girolami, G. S.; Rauchfuss, T. B. and Angelici, R. J., "Synthesis and Technique in Inorganic Chemistry third edition", University Science Books: Mill Valley, CA, 1999, ISBN 0-935702-48-2
- ^ Cotton, F. A.; Hillard, E.A.; Murillo, C. A.; Zhou, H.-C.; J. Am. Chem. Soc., 2000, 122, 416-417"After 155 Years, A Crystalline Chromium Carboxylate with a Supershort Cr-Cr Bond".
- ^ a b Blaudeau, J.P.; Pitzer, R.M.; J.Phys. Chem. 1994, 98, 4575-4579. “ Ab Initio Studies of Ligand Effects on the Metal-Metal Bond in Dimolybdenum Complexes”.
- ^ a b Handa, M.; Mikuriya, M.; Kotera, T.; Yamada, K.; Nakso, T.; Matsumoto, H.; Kasuga, K.; Bull. Chem. Soc. Jpn., 1995,68, 2567-2572. “Linear Chain Compounds of Molybdenum(II) Acetate Linked by Pyazine, 4,4’-Bipyridine,and 1,4- Diazabicyclo[2.2.2]octane”.
- ^ a b Brignole, A.G.; Cotton, F.A., Inorg. Synth.; 1972, 13, 81-89. “Rhenium and Molybdenum compounds containing quadruple compounds”.
- ^ a b c Bannister, E.; Wikinson, G. ; Chem. Ind. 1960, 319. “Molybdenum(II) carboxylates”
- ^ a b c Pence, L.E.; Weisgerber, A.M.; Maounis, F.A.; J.Chem.edu.,1999, 76, 404-405. “Synthesis of Molybdenum-Molybdenum Quadruple Bonds”.
- ^ Bino,A.; Cotton, F.A.; Dori, A.; Jour. Am. Chem. Soc.1981, 103, 243-244. “A Aqueous New Chemistry of Organometallic, Trinuclear Cluster Compounds of Molybdenum”.
- ^ a b Stephenson, T.A.; Bannister, E.; Wilkinson, G.; J. Chem. Soc., 1964, 2538. “Molybdenum(II) Carboxylates”.
- ^ Cotton, F. A.; Walton, R. A. “Multiple Bonds Between Metal Atoms” Oxford University Press: New York, 1993, ISBN 0-19-855649-7.
- ^ Tsai, Y.C.; Chen H.Z.; Chang, C.C.; Yu, J.K.; Lee, G.H.; Wang, Y.; Kuo, T.S.; J. Am. Chem. Soc.,2009,131, 12534-12535. “ Journey from Mo-Mo Quadruple Bonds to Quintuple Bonds”