The Organometallic and Metal-Organic Chemistry of Molybdenum
About: This article is published in Studies in Inorganic Chemistry.The article was published on 1994-01-01. It has received 3 citations till now. The article focuses on the topics: Molybdenum.
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21 May 2020
TL;DR: In this article, the authors present a survey of the Molybdenum chemistry and its application in various areas of industry, such as mining, automotive, agriculture, and economic aspects.
Abstract: The article contains sections titled:
1. Introduction
2. Properties
3. Occurrence
3.1. Minerals
3.2. Deposits
4. Production
4.1. Concentration
4.2. Processing of Concentrate
4.3. Recovery from Spent Petroleum Catalysts
4.4. Recovery during Production of Tungsten Ores
4.5. Production of Molybdenum Metal Powder
4.6. Production of Compact Molybdenum Metal
4.7. Processing of Molybdenum
4.8. Molybdenum-Base Alloys
5. Uses
6. Production of Ferromolybdenum
6.1. Ferromolybdenum Grades
6.2. Raw Materials
6.3. Submerged Arc Furnace Carbothermic Reduction
6.4. Metallothermic Reduction
7. Molybdenum Compounds
7.1. Overview of Molybdenum Chemistry
7.2. Molybdenum Oxides
7.3. Molybdenum Chalcogenides
7.4. Molybdenum Halides
7.5. Molybdates, Isopolymolybdates, and Heteropolymolybdates
7.6. Other Molybdenum Compounds
8. Uses of Molybdenum Compounds
8.1. Catalysis
8.2. Lubrication
8.3. Corrosion Inhibition
8.4. Flame Retardancy and Smoke Suppression
8.5. Pigments
8.6. Agriculture
9. Analysis
10. Economic Aspects
11. Environmental Aspects
12. Toxicology and Occupational Health
35 citations
TL;DR: The heteroleptic molybdenum complexes have been analyzed quantitatively by means of linear solvation energy relationships based on Kamlet-Taft solvatochromism parameters, as well as on Drago's "unified scale of solvent polarity".
Abstract: The heteroleptic molybdenum complexes [{Mo(NO)Tp*X}n(L-L)] [Tp* = HB(3,5-Me2C3HN2)3; X = Cl, I; L-L = 4-NC5H4(CHCH)4C5H4N-4‘, n = 1, 2; X = Cl; L-L = {4,4‘-NC5H4CHCHC(Me)CHCH=}2, n = 2] have a low energy absorbance in their electronic spectra which exhibits solvatochromic shifts. These have been analyzed quantitatively by means of linear solvation energy relationships based on Kamlet−Taft solvatochromism parameters, as well as on Drago's “unified scale of solvent polarity”. Each of these approaches leads to satisfactory linear models, in qualitative agreement with one another. The solvatochromism is due to a combination of increased solvent dipolarity/polarizability and solvent-to-solute hydrogen bonding, each preferentially stabilizing polar ground states compared with less polar excited states. The latter originate from metal-to-ligand charge transfer. Quantitatively, the Drago and Kamlet−Taft models differ somewhat. The former are statistically slightly better than those based on Kamlet−Taft parameters.
15 citations
Journal Article•
TL;DR: In this paper, the reaction between [WBr 3 (CO) 2 (η 5 -C 5 H 5 )] and excess of Tl(SC 6 F 5 ) affords Tl[WBr 2 (CO), η 5 −C 5H 5 )] (2b) as the major product and [W(SC6F 5 ) 3 ( CO), Δ − 5 − C 5 H5 )] (3) as minor product.
Abstract: The reaction between [WBr 3 (CO) 2 (η 5 -C 5 H 5 )] and excess of Tl(SC 6 F 5 ) affords Tl[W(SC 6 F 5 ) 4 (η 5 -C 5 H 5 )] (2b) as the major product and [W(SC 6 F 5 ) 3 (CO)(η 5 -C 5 H 5 )] (3) as the minor product. Complex (3) has been structurally characterised as its 0.5 CH 2 Cl 2 solvate by X-ray diffraction
References
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TL;DR: In this article, the photochemical reactions of allyl complexes with allene, 1,3-butadiene, 2-methyl-1, 3-cyclohexadiene and 1-3-cycloenadiene have been studied.
Abstract: The photochemical reactions of [Mo2(η5-C5H5)2(µ-H)(µ-PR2)(CO)4](R = Ph or Me) with allene, 1,3-butadiene, 2-methyl-1,3-butadiene, and 1,3-cyclohexadiene have been studied. In each of these reactions allyl complexes of general formula [Mo2(η5-C5H5)2(µ-PR2)(η3-allyl)(CO)3] are obtained as major products. The 1H n.m.r. spectra of these allyl complexes indicate that they exist in solution as an equilibrium mixture of exo and endo isomers. In the reactions with 1,3-butadiene the allyl complexes are accompanied by very low yields of other species which are assigned the formula [Mo2(η5-C5H5)2O(µ-vinyl)(µ-PR2)(CO)] on the basis of spectroscopic evidence. The reaction of [Mo2(η5-C5H5)2(µ-H)(µ-PMe2)(CO)4] with allene gives as a major product, in addition to the allyl species, the complex [Mo2(η5-C5H5)2{µ-σ:η2-C(Me)=CH2}(µ-PMe2)(CO)3].
12 citations
TL;DR: In this article, triphenylcyclopropenyl bromide has been used for X-ray structure determination, yielding a series of products [MoBr(CO)2(η3-C3Ph3)L2] and [MoCl(C4Ph3O(bipy))L2].
Abstract: Reactions of triphenylcyclopropenyl bromide with [Mo(CO)4L2][L2= 2,2′-bipyridine (bipy), 1,10-phenanthroline (phen), or 2,2′-dipyridylamine (dpa)] yield the two series of products [MoBr(CO)2(η3-C3Ph3)L2] and [MoBr(CO)2(η3-C4Ph3O)L2]. The cyclopropenyl complexes were also prepared from [MoBr(CO)2(η3-C3Ph3)(NCMe)2] by reaction with L2 in MeCN, which yielded crystalline solvates suitable for an X-ray structure determination. Crystals of [MoBr(CO)2(η3-C4Ph3O)(bipy)]·thf, (1), are monoclinic, a= 9.87(1), b= 20.36(1), c= 16.23(1)A, β= 92.2(1)°, Z= 4, space group P21/c. Crystals of [MoBr(CO)2(η3-C3Ph3)(bipy)]·MeCN, (2), are triclinic, a= 10.552(8), b= 11.607(9), c= 13.801(11)A, α= 67.1(1), β= 100.4(1), γ= 89.5(1)°, Z= 2, space group P. 2 832 and 1 804 above background reflections were collected on a diffractometer and refined by full-matrix least squares to R 0.072 and 0.082 for (1) and (2) respectively. In both structures the molybdenum atoms are in octahedral environments, with the mutually cis carbonyl groups and the bipy ligand occupying an equatorial plane. In trans positions are a bromine atom and in (1) a η3-oxocyclobutenyl group and in (2) a η3-cyclopropenyl group.
12 citations
TL;DR: In this article, the tetraphenylborato ligand was used as a catalysts for the reduction of olefins in a transition metal transition complex with (q7-cycloheptatrienyl) and (q6-tetrameryl)-molybdenum.
Abstract: Early in 1974, this research consortium began an exploratory study of the feasibility of synthesis of low-valent, stable, high-molecular-weight organometallic derivatives of the transition elements which, due to their respective structures and electronic configurations, might exhibit a series of stable oxidation states. It was anticipated that low-valent transition metal complexes incorporating formal charge separation would possess the requisite stability and, in addition, would offer the chance of providing oxidation-reduction catalysis for organic transformations.' Initial success in the synthesis of derivatives of the large, $-bonding tetraphenylborato ligand, coupled with the rich electrochemistry of these complexes, led to further investigations. By the summer of 1976, the first of these derivatives capable of effecting reduction of olefins had been prepared, characterized, and its intimate structure determined.',' Although a few compounds containing the tetraphenylborato ligand bonded to transition metals had been reported previous to, or concurrent with, our work, none of these complexes had been shown to act as catalysts for mediating organic syntheses.\"' In this report are described several new complexes containing the tetraphenylborato ligand, as well as some of the details of the catalytic activity exhibited by one of these molecules, (q7-cycloheptatrienyl)(q6-tetraphenylborato)molybdenum, the only sandwich complex of molybdenum containing both a seven-carbon and a six-carbon ligand.
12 citations
TL;DR: The binding of Na+ to cyclic polyether sites incorporated in molybdenum complexes has been shown to shift the reduction potentials of the {Mo(NO)3+ centers present to more anodic potentials by up to 320 mV as mentioned in this paper.
Abstract: The binding of Na+ to cyclic polyether sites incorporated in molybdenum complexes has been shown to shift the reduction potentials of the {Mo(NO)}3+ centres present to more anodic potentials by up to 320 mV.
12 citations
TL;DR: In this paper, the cyclopentadienyl salt (C5H5) was charcterised by X-ray crystallography, and it was shown that it can readily rearrange to [Mo2(µ-HC2Ph)(CO)4(η-C5h5)2], whereas methylation (CF3SO3Me) in CH2Cl2 or tetrahydrofuran affords [Mo 2{µ -η1,η2-CC(Ph(Ph)R}(CO
Abstract: Addition of PhCCLi to [Mo2(CO)4(η5-CmHn)2](n=m= 5; n= 7, m= 9) or ButLi to [Mo2(µ-HC2Ph)(CO)4(η5-CmHn)2] affords Li[Mo2(µ-C2Ph)(CO)4(η5-CmHn)2] characterised as [(Ph3P)2N]+ salts, protonation of the cyclopentadienyl salt affords [Mo2(µ-η1,η2-CCHPh)(CO)4(η-C5H5)2] which readily rearranges to [Mo2(µ-HC2Ph)(CO)4(η-C5H5)2], whereas methylation (CF3SO3Me) in CH2Cl2 or tetrahydrofuran affords respectively [Mo2{µ-η1,η2-CC(Ph)R}(CO)4(η-C5H5)2][R = Me or (CH2)4OMe] the latter being charcterised by X-ray crystallography; thermolysis of [Mo2{µ-η1,η2-CC(Ph)Me}(CO)4(η-C5H5)2] gives [Mo2{µ-η1,η3-CH.C(Ph)CH2}(CO)4(η-C5H5)2].
12 citations