Carbonyl halides of the Group VI transition metals. XII. Isolation of halocarbonyls and halocarbonyl anions of molybdenum and tungsten

1968 ◽  
Vol 21 (11) ◽  
pp. 2657 ◽  
Author(s):  
JA Bowden ◽  
R Colton
Keyword(s):  
Transition Metals ◽  
Group Vi ◽  
Tetraethylammonium Salts ◽  
And Tungsten

Dibromotetracarbonylmolybdenum, Mo(CO)4Br2, and the dihalotetracarbonyltungsten compounds, W(CO)4X2 (where X = Cl, Br), have been isolated and characterized. These highly reactive compounds are all diamagnetic. The trihalotetracarbonyl anions [M(CO)4X3]- (M = Mo, W) have been isolated as their tetraethylammonium salts from the parent halocarbonyls. These yellow diamagnetic compounds are the first tetracarbonyl derivatives to be prepared from the parent halocarbonyls.

Carbonyl halides of the Group VI transition metals. XI. Dithiocyanatocarbonyl derivatives of molybdenum and tungsten(II)

1968 ◽  
Vol 21 (6) ◽  
pp. 1435 ◽  
Author(s):  
R Colton ◽  
GR Scollary
Keyword(s):  
Transition Metal ◽  
Transition Metals ◽  
Ammonium Chloride ◽  
Pure State ◽  
Ammonium Thiocyanate ◽  
Donor Ligands ◽  
Group Vi ◽  
Derivatives Of ◽  
And Tungsten

Reaction of ammonium thiocyanate with dihalocarbonyls of molybdenum and tungsten(11) leads to the elimination of ammonium chloride and the formation of a dithiocyanatocarbonyl complex of the transition metal. Although the thiocyanatocarbonyls themselves have not been isolated in a pure state, a number of substituted derivatives with phosphorus donor ligands have been prepared and characterized. In general these complexes are less stable than the corresponding carbonyl halide derivatives.

Carbonyl halides of the Group VI transition metals. VII. Nitrosyl halide derivatives of molybdenum and tungsten(II)

1968 ◽  
Vol 21 (5) ◽  
pp. 1149 ◽  
Author(s):  
MW Anker ◽  
R Colton ◽  
IB Tomkins
Keyword(s):  
Nitric Oxide ◽  
Transition Metals ◽  
New Method ◽  
Natural Explanation ◽  
Group Vi ◽  
New Feature ◽  
Derivatives Of ◽  
And Tungsten

The previously reported dihalodinitrosylbis(triphenylphosphine)molybdenum and tungsten(11) type complexes, M(NO)2L2X2 (M = Mo, W; L = PPh3, AsPh3, SbPh3; X = Cl, Br), have been prepared by a new method involving the action of nitric oxide on the corresponding tricarbonyl derivatives. The new feature of this method is that, unlike the previous methods, it is not stereospecific, and in some cases all three possible cis isomers are formed. The identification of the various isomers has given a natural explanation of the apparently anomalous order of π-bonding effects in these complexes previously reported by Cotton and Johnson.

Carbonyl halides of the Group VI transition metals. XIX. Iodocarbonyl complexes of molybdenum and tungsten with Bis(diphenylarsino)methane

1970 ◽  
Vol 23 (3) ◽  
pp. 441 ◽  
Author(s):  
R Colton ◽  
CJ Rix
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Carbon Monoxide ◽  
Magnetic Resonance ◽  
Transition Metals ◽  
Direct Interaction ◽  
Acetone Solution ◽  
Group Vi ◽  
First Time ◽  
And Tungsten ◽  
Nuclear Magnetic

Complexes of the general formulae M(CO)3(dam)I2, M(CO)3(dam)2I2, and M(CO)2(dam)2I2 have been prepared and characterized [M = Mo, W; dam = bis(diphenylarsino)methane]. All of the compounds are diamagnetic and non-electrolytes in acetone solution. The tungsten derivatives were prepared by direct interaction of dam with diiodotetracarbonyltungsten(11), but the molybdenum analogues were obtained by iodine oxidation of the zero-valent complex Mo(CO)4(dam)2 whose preparation is reported for the first time in this paper. The bis(dam)tricarbonyl complexes, M(C0)3(dam)2I2, are unstable in solution giving M(CO)2(dam)I2 and free dam in equilibrium with undissociated complex. The bis(dam)tricarbonyl complexes also readily lose carbon monoxide, especially in the case of molybdenum, to give M(CO)z(dam)2I2. These dicarbonyl complexes readily absorb carbon monoxide to re-form the tricarbonyl complexes to give a reversible carbon monoxide carrying system. Overall, these systems may be represented by the general equations : M(CO)3(dam)I2 + dam ↔ M(CO)3(dam)2I2 + CO These equilibria have been studied using both infrared and nuclear magnetic resonance techniques.

Carbonyl halides of the Group VI transition metals. XXVI. Nitrosyl halide complexes of molybdenum(II) and tungsten(II) with Bis(diphenyl-phosphino)methane and Bis(diphenylarsino)methane

1972 ◽  
Vol 25 (7) ◽  
pp. 1393 ◽  
Author(s):  
JA Bowden ◽  
R Colton ◽  
CJ Commons
Keyword(s):  
Nitric Oxide ◽  
Transition Metals ◽  
Direct Interaction ◽  
Group Vi ◽  
Halide Complexes ◽  
Derivatives Of ◽  
And Tungsten

The known polymeric molybdenum nitrosyl halides [Mo(NO)2X2 (X = Cl, Br) have been prepared by the action of nitric oxide on Mo(CO)4X2. Derivatives of these complexes with bis(diphenylarsino)methane (dam) and its phosphine analogue (dpm) were prepared by direct interaction. In addition, complexes containing dam were formed by the action of nitric oxide on M(CO)2(dam)2X2 (M = Mo, W; X = Cl,Br,I). All compounds isolated were of the form M(NO)2LX2 and M(NO)2L2X2 (L = dam or dpm). Differences between the nitrosyl halide derivatives and the corresponding carbonyl halide complexes are interpreted on the basis of a steric argument.

An investigation on the adhesive behaviour between transition metals titanium, niobium, tantalum, and tungsten

1991 ◽  
Vol 164 (2) ◽  
pp. 387-394 ◽  
Author(s):  
Kebin Li ◽  
Jiansan Sun ◽  
Ling Liu ◽  
Zhenzhong Qi
Keyword(s):  
Transition Metals ◽  
And Tungsten

First Principles Calculations of Helium Solution Energies in BCC Transition Metals

2006 ◽  
Vol 981 ◽  
Author(s):  
François Willaime ◽  
Chu Chun FU
Keyword(s):  
Transition Metals ◽  
Density Functional ◽  
Tetrahedral Site ◽  
Density Functional Theory Calculations ◽  
Interstitial Site ◽  
Group Vi ◽  
Functional Theory ◽  
Group V ◽  
Substitutional Site ◽  
Exchange Correlation

AbstractDensity functional theory calculations of the solution energies of helium in substitutional, tetrahedral and octahedral sites have been performed for all BCC transition metals: V, Nb, Ta, Cr, Mo, W and Fe. The effects of exchange correlation functional and of pseudopotential have been investigated in Fe; they are relatively small. The solution energies are found to be weakly dependent on the element for the substitutional site whereas for the interstitial sites they are much smaller in group V than in group VI and they decrease from 3d to 4d and 5d metals. As a result an inversion is observed from V, Nb and Ta - which tend to favor the interstitial site - to Mo and W, which favor the substitutional one, with an intermediate behavior for Cr and Fe. Finally, the results indicate that the tetrahedral site is always energetically more favorable than the octahedral one by 0.2 to 0.3 eV.

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