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 electrochemical behavior of [W{HB(Me2pz)3}(NO)(CO)2] and [Mo{HB[Me2Pz]3} (NO)I2{Li(OEt2)2}] has been examined.
Abstract: Cyclic voltammetric (c.v.), coulometric, and e.s.r. spectroscopic studies have established that [Mo{HB(Me2pz)3}(NO)I2], (A)(Me2Pz = 3,5-dimethylpyrazolyl), can be reduced reversibly to a paramagnetic monoanion in tetrahydrofuran (thf) solution, and that (A)– dissociates I– giving [Mo{HB(Me2pz)3}(NO)I(solvent)], (B). The latter undergoes a reversible one-electron oxidation process. The electrochemical behaviour (c.v.) of [W{HB(Me2pz)3}(NO)(CO)2] and [Mo{HB(Me2pz)3}(NO)L2]z(L = NCMe, z=+1; L = CO, z= 0) has also been briefly examined. Reduction of complex (A) by Li(C6H4Me-p) in diethyl ether afforded the complex [Mo{HB(Me2pz)3}(NO)I2{Li(OEt2)2}], (E), whose characterisation and properties are described. It is thought that (E) contains the {Mo–(µ-I)2Li+} group.
17 citations
TL;DR: The methanediazo ligands act as bridging ligands via their basic nitrogen atoms in the methandiazo-komplexes as mentioned in this paper. But they do not act as a bridging function.
Abstract: Die Methandiazo-Komplexe (η5-C5H5)M(CO)2 (N2CH3) (MMo: 1a; MW: 1b) reagieren mit Cr(CO)5THF (2) und (η5-C5H5)Mn(CO)2THF (3) im Zuge einer substituierenden Metallkoordination der basischen Stickstoff-Funktion unter Bildung der thermisch sehr stabilen heterodinuklearen Organometall-Verbindungen (η5-C5H5)M(CO)2[N2 (CH3){Cr(CO)5}] (4a, b) bzw. (η5-C5H5)M(CO)2[N2 (CH3){(η5-C5H5Mn(CO)2}] (5a, b), in denen der Methandiazo-Ligand unter Erniedrigung der NN-Bindungsordnung eine Bruckenfunktion uber seine beiden Stickstoffatome ausubt.
Complex Chemistry of Reactive Organic Compounds, XXXIII. The Methanediazo Ligand as Bridging Function in Stable Organometallic Compounds
The methanediazo complexes (η5-C5H5)M(CO)2(N2CH3) (MMo: 1a; MW: 1b) react with Cr(CO)5THF (2) and (η5-C5H5)Mn(CO)2THF (3) via metal coordination of the basic nitrogen function with concomitant decrease of the nitrogen-nitrogen bond order to yield the thermally very stable heterodinuclear organometallic compounds (η5-C5H5)M(CO)2 [N2(CH3){Cr(CO)5}] (4a, b) and (η5-C5H5)M(CO)2[N2 (CH3){(η5-C5H5)Mn(CO)2}] (5a, b), respectively, which contain methanediazo groups acting as bridging ligands via their basic nitrogen atoms.
17 citations
TL;DR: Tris(substituted butadiene) complexes of molybdenum and tungsten have been prepared by the reduction of the metal halides with anthracene-activated magnesium in the presence of the appropriate diene.
17 citations
TL;DR: In this paper, the molecular structure of [CrRh(µ-CO)2(CO) 2(η-C5Me5) 2 (C6H7) was established by an X-ray diffraction study: crystals are orthorhombic, space group Pnma(no. 62), in a unit cell with a= 10.635(4), b= 11.690(3), c= 15.275(5)A, and Z= 4.5σ(I).
Abstract: Irradiation with u.v. light of mixtures of [Cr(CO)3(η-arene)](arene = C6H6, C6H3Me3-1,3,5, or C6Me6) and [Rh(CO)2(η-C5Me5)] in tetrahydrofuran (thf) affords the dimetal compounds [CrRh(µ-CO)2(CO)2(η-C5Me5)(η-arene)]; the complex [CrRh(µ-CO)2(CO)2(η-C9H7)(η-C6H3Me3-1,3,5)](C9H7= indenyl) has been similarly prepared from [Rh(CO)2(η-C9H7)] and [Cr(CO)2(thf)(η-C6H3Me3-1,3,5)]. The i.r. and n.m.r. data for these species are reported and discussed in relation to the molecular structure of [CrRh(µ-CO)2(CO)2(η-C5Me5)(η-C6H6)] which has been established by an X-ray diffraction study : crystals are orthorhombic, space group Pnma(no. 62), in a unit cell with a= 10.635(4), b= 11.690(3), c= 15.275(5)A, and Z= 4. The structure has been refined to R 0.051 from 1 584 independent intensities [I 2.5σ(I)]. The molecule is constrained crystallographically to Cs, symmetry, the mirror plane being defined by the terminal carbonyl ligand on each metal atom, the Rh–Cr bond [2.757(2)A], and the centroids of the two cyclic ligands. The pentamethylcyclopentadienyl ligand on the Rh atom is in a trans relationship to the η6-benzene ligand on the Cr atom, and both lie astride (perpendicular to) the mirror plane. The two other carbonyl ligands are terminal to the Cr atom, but are strongly semi-bridging to the Rh atom [Cr–C 1.902(7), Rh–C 2.200(7)A], and define planes which are nearly perpendicular to the mirror plane. Some distortion of the Rh–C5 geometry towards a ‘diolefin’ type attachment is noted and discussed. Reaction of the compounds [M(CO)5(thf)](M = Cr or W) and [Mo(NCMe)(CO)5] with [Rh2(µ-CO)2(η-C5Me5)2] affords the heteronuclear trimetal cluster complexes [MRh2(µ-CO)2(CO)5(η-C5Me5)2] in high yield. These species may be regarded as molecules in which an M(CO)5 fragment, isolobal with CH2, is ‘complexed’ by an ethylene-like [Rh2(µ-CO)2(η-C5Me5)2] fragment.
17 citations
TL;DR: The alkylidyne-molybdenum complex [NEt4][Mo(CC6H4Me-4)(CO){P(OMe)3}(η5-C2B9H9Me2)] has been prepared, and used to prepare compounds with bonds between moly bdenum and gold, rhodium, and iron as discussed by the authors.
Abstract: The alkylidyne–molybdenum complex [NEt4][Mo(CC6H4Me-4)(CO){P(OMe)3}(η5-C2B9H9Me2)] has been prepared, and used to prepare compounds with bonds between molybdenum and gold, rhodium, and iron. Reactions of the molybdenum compound with [AuCl(PPh3)],[Rh(cod)(PPh3)2][PF6](cod = cyclo-octa-1,5-diene), and [Fe2(CO)9] afford, respectively, the complexes [MoAu(µ-CC6H4Me-4)(CO){P(OMe)3}(PPh3)(η5-C2B9H9Me2)], [MoRh(µ-CC6H4Me-4)(µ-CO){P(OMe)3}(PPh3)2(η5-C2B9H9Me2)], and [NEt4][MoFe2(µ3-CC6H4Me-4)(µ-σ : σ′ : η5-C2B9H7Me2)(CO)8]. The structure of the latter has been established by X-ray diffraction. There are two crystallographically independent anions with their associated cations in the asymmetric unit but with overall very similar geometries. In the anions a triangle of metal atoms is symmetrically capped on one side by the alkylidyne ligand. On the other side of the triangle the molybdenum atom is η5-ligated by the C2B9cage, but two boron atoms in the pentagonal face are σ bonded to the two iron atoms. The molybdenum carries two carbonyl groups and each of the iron atoms is bonded by three of these ligands. The reaction between [Fe2(CO)9] and [NEt4][Mo(CC6H4Me-4)(CO){P(OMe)3}(η5-C2B9H9Me2)] also affords the novel mononuclear molybdenum compound [NEt4][Mo{σ,η5-CH (C6H4Me-4)C2B9H8Me2}(CO)3]. Protonation (HBF4·Et2O) of CO-saturated CH2Cl2solutions of the latter gives the neutral complex [Mo(CO)4{η5-C2B9H8(CH2C6H4Me-4)Me2}]. Protonation in the presence of an excess of PMe3 gives a mixture of the two compounds [Mo(CO)3(L){η5-C2B9H8(CH2C6H4Me-4)Me2}](L = PMe3 or CO). The n.m.r. data (1H, 13C-{1H},11B-{1H}, and 31P-(1H}) for the new compounds are reported and discussed.
17 citations