Carbonyl halides of the Group VI transition metals. XIII. Diiodotetracarbonyls of molybdenum and tungsten and some of their derivatives

1969 ◽  
Vol 22 (2) ◽  
pp. 305 ◽  
Author(s):  
R Colton ◽  
CJ Rix
Keyword(s):  
Carbon Monoxide ◽  
Room Temperature ◽  
Direct Interaction ◽  
Radiation Reaction ◽  
Donor Ligands ◽  
Group Vi ◽  
Dicarbonyl Compound ◽  
Molybdenum Compound ◽  
First Time ◽  
And Tungsten

Diiodotetracarbonyls of molybdenum and tungsten(II) have been prepared for the first time by the direct interaction of the parent hexacarbonyls with iodine at room temperature under the influence of ultraviolet radiation. Reaction of the iodocarbonyls with donor ligands such as triphenylphosphine, triphenylarsine, and triphenylstibine generally gives neutral substitution products, but the reaction between the molybdenum compound and triphenylphosphine yielded the previously reported triphenylphosphonium salt of the triiodotricarbonyl(triphenylphosphine)-molybdate(II) ion. ��� Diiodotricarbonylbis(triphenylphosphine)tungsten(II) loses carbon monoxide on heating under vacuum to give the corresponding blue dicarbonyl compound. The dicarbonyl dissolved in dichloromethane readily absorbs carbon monoxide to reform the tricarbonyl and the compounds therefore represent a further carbon monoxide carrying system. ��

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. 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.

Carbony1 halides of the Group VI transition metals. XV. Complexes with Bis(1,2-diphenylphosphino)ethane

1969 ◽  
Vol 22 (7) ◽  
pp. 1341 ◽  
Author(s):  
MW Anker ◽  
R Colton ◽  
CJ Rix ◽  
IB Tomkins
Keyword(s):  
Carbon Monoxide ◽  
Transition Metals ◽  
Room Temperature ◽  
Conductivity Measurements ◽  
Group Vi ◽  
Complex Series ◽  
Reversible Reactions ◽  
New Type ◽  
Temperature And Pressure

Compounds of the general formulae M(CO)3(dpe)X2, [M(CO)2(dpe)1.5X2]2, and M(CO)2(dpe)2X2 have been prepared and characterized (M = Mo, W; dpe = bis- (1,2-diphenylphosphino)ethane; X = Cl, Br, I). All of the compounds are diamagnetic and most of them are non-electrolytes. However, conductivity measurements indicate that, for the iodo derivatives only, the bis(dpe) compounds should be formulated as 1 : 1 electrolytes, [M(CO)2(dpe)2I]I. ��� For the iodo series of compounds only, there is a complex series of reversible reactions including a new type of carbon monoxide carrying system. In addition, the dimeric dpe derivatives are cleaved by carbon monoxide at room temperature and pressure to give equal quantities of [M(CO)2(dpe)2I]I and M(CO)3(dpe)I2.

Carbonyl halides of the Group VI transition metals. IX. Complexes with Bis(diphenylarsino)methane: Some further carbon monoxide carriers

1968 ◽  
Vol 21 (5) ◽  
pp. 1159 ◽  
Author(s):  
MW Anker ◽  
R Colton ◽  
IB Tomkins
Keyword(s):  
Carbon Monoxide ◽  
Transition Metals ◽  
Room Temperature ◽  
Bidentate Ligand ◽  
The Other ◽  
Group Vi ◽  
Mixed Coordination ◽  
Temperature And Pressure

Complexes of the types MX2(CO)3(dam)2 and MX2(CO)2(dam)2 [M = Mo, W; X = Cl, Br; dam = bis(diphenylarsino)methane] have been prepared and characterized. The compounds are all non-electrolytes; in the tricarbonyls both of the potentially bidentate arsenic ligands are in fact acting only as monodentates, but in the dicarbonyls there is mixed coordination with one ligand monodentate and the other bidentate. The dicarbonyl complexes absorb carbon monoxide in solution at room temperature and pressure, a metal-arsenic bond of the bidentate ligand is broken, and the corresponding tricarbonyl compound is produced. The reaction is readily reversible; thus the system is an example of a carbon monoxide carrier.

Carbonyl halides of the Group VI transition metals. XVI. Reactions of Bis(diphenylphosphino)methane with Diiodotetracarbonyltungsten(II)

1969 ◽  
Vol 22 (12) ◽  
pp. 2535 ◽  
Author(s):  
R Colton ◽  
CJ Rix
Keyword(s):  
Carbon Monoxide ◽  
Transition Metals ◽  
Molecular Species ◽  
Direct Interaction ◽  
Ionic Species ◽  
Reaction Scheme ◽  
Simple System ◽  
Tricarbonyl Complex ◽  
Group Vi ◽  
Unusual Type

Compounds of the general formulae W(CO)3dpmI2 and W(CO)2(dpm)2I2 [dpm = bis(diphenylphosphino)methane] have been prepared by direct interaction of the ligand with diiodotetracarbonyltungsten(II). However, this apparently simple system is complicated by the existence of two isomers of the tricarbonyl complex and three isomeric forms of the dicarbonyl. The various isomers have been separated and characterized individually and the interconversions between all the complexes have been investigated. The overall reaction scheme contains a partial carbon monoxide carrying system and an example of an unusual type of isomerism: �������������������� W(CO)2(dpm)2I2 → [W(CO)2(dpm)2I]I that is, isomerism of a molecular species to an ionic species.

Carbonyl halides of the Group VI transition metals. V. Carbon monoxide carriers and some sulphur and nitrogen derivatives of molybdenum halocarbonyls

1968 ◽  
Vol 21 (1) ◽  
pp. 15 ◽  
Author(s):  
R Colton ◽  
GR Scollary ◽  
IB Tomkins
Keyword(s):  
Carbon Monoxide ◽  
Transition Metals ◽  
Direct Interaction ◽  
Group Vi ◽  
Derivatives Of

The blue compounds MX2(CO)2(Ph3P)2 (M = Mo and W, X = Cl and Br) have been shown to absorb carbon monoxide very readily indeed to form the corresponding tricarbonyls, and as reported earlier, the tricarbonyls may be easily converted into the dicarbonyls. The dicarbonyl is therefore a carbon monoxide carrier. The compounds Mo(CO)3 dtc2 and Mo(CO)2 dtc2 (dtc = diethyldithiocarbamate) also represent a carbon monoxide carrying system, but in this case both compounds are rather unstable. The compounds MoX2(CO)2 btp2 (btp = N-n-butylthiopicolinamide; X = Cl, Br) have been prepared by direct interaction of the ligand and the appropriate halocarbonyl. Although these compounds are believed to be monomeric they do not absorb carbon monoxide.

Carbonyl halides of the Group VI transition metals. XXIII. An N.M.R. study of a series of Bis(diphenylarsino)methane derivatives of molybdenum(II) and tungsten(II)

1971 ◽  
Vol 24 (6) ◽  
pp. 1157 ◽  
Author(s):  
MW Anker ◽  
R Colton ◽  
CJ Rix
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Fine Structure ◽  
Room Temperature ◽  
Variable Temperature ◽  
Nuclear Magnetic Resonance Study ◽  
Magnetic Resonance Study ◽  
Group Vi ◽  
Temperature Exchange ◽  
Derivatives Of ◽  
And Tungsten

A variable temperature nuclear magnetic resonance study of a series of molybdenum(II) and tungsten(II) complexes of the general formula M(CO)2(dam)2X2 (M = Mo, W; X = Cl, Br, I; dam = bis(diphenylarsino)methane) has been carried out. These compounds have previously been shown to be seven-coordinate non-electrolytes containing one chelated and one monodentate dam ligand. The detailed study of their N.M.R. spectra reported here shows that, near room temperature, exchange occurs between the non-equivalent dam molecules. At lower temperatures this exchange ceases, but further fine structure appears in the spectra due to the freezing-in of particular conformation of the molecules. On warming, this fine structure disappears as a result of the inherent non-rigid character of the ligand. ��� The experimental spectra have been compared with a set of computed spectra based on the model of an exchanging system to determine the various exchange rate constants, and the observed spectra have been interpreted m terms of the molecular stereochemistry about the metal.

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.

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