MoCl, Molybdenum chloride

For both modern reagents PIFA and MoCls an inner-sphere radical transfer is expected, as depicted in Scheme 7. The Lewis acidic additives involved in the PIFA-mediated transformation create an iodonium species that forms a Jt-com-plex 26 with the substrate this subsequently leads to an electron transfer. In contrast, the electrophilic molybdenum chloride most probably coordinates to the oxygen atoms of the donor functions which will then start the transformation. Smooth conversions are obtained if the substituent R" adjacent to the donor (27) is another methoxy group or a bulky moiety. 

Reaction with potassium chloride in fused state or in the presence of iodine monochloride forms molybdenum hexachloride anion, MoCle , which forms salts such as K2M0CI6 ... 

Specific procedures for the synthesis of M0CI4, MoCl, and M0CI2 are described in the sections that follow. Other methods of synthesis are also summarized in these sections. Procedures for the synthesis of M0CI5 have been given in Inorganic Syntheses 7, 167 (1963) and 9, 135 (1967). The industrial method is the direct chlorination of metal and is recommended in some laboratories.12-18 A convenient laboratory technique is the liquid-phase reaction system that uses refluxing thionyl chloride and molybdenum (VI) oxide.14... 

Molybdenum (III) chloride, MoCl, has a molecular weight of 202.32. The dark red compound is stable when protected from... 

Antimony(V) chloride (SbQj) and molybdenum(V) chloride (MoCls) can react spontaneously with alkenes to give predominantly the corresponding c/s-1,2-dichlorides (equation 11). The reaction probably proceeds through a successive insertion and reductive elimination sequence. The chlorination of butadiene with SbCls and copper(II) chloride results preferentially in the formation of (Z)- and ( )-1,4-dichloro adducts, while the reaction with chlorine gives an 1 1 mixture of 1,2- and 1,4-adducts, as shown in Table 2 and equation (12). The formation of (Z)-l,4-dichloro-2-butene may be ascribed to a transition state as shown in Scheme 3. 

Two Mo-Cl bonds of molybdenum(V) chloride are ammonolysed at —33° and four Mo-Cl bonds at room temperature to give MoCl(NH) (NH2)2, which is scarcely soluble and probably polymeric. 

Molybdenum pentachloride dissolved in high-temperature alkali chloride-based melts, and concentrations of Mo(V) up to 0.2mol/dm were obtained. Its dissolution process was studied in LiCl-KCl, NaCl-KCl, NaCl-KCl-CsCl and NaCl-CsCl melts between 450 and 850 °C and in all the systems resulted in the formation of molybdenum(V) chloro-ions, which we show to be MoCl ". The symmetry of this species complies with ligand field theory as octahedral but some distortions may be present. 

Molybdenum.— An oxidative-elimination reaction takes place when the complexes [Mo(CO)4(5-X-phen)] (X = H, Me, Cl, or NO2) are treated with mercuric chloride in acetone. The products are [MoCl(HgCl)(CO)3(5-X-phen)). Kinetic studies, using stopped-flow techniques, indicate that the reactions proceed via initial formation of adducts of stoicheiometry [Mo(CO)4(5-X-phen)],-HgCla and [Mo(CO)4(5-X-phen)],2HgCla. These adducts are of the metal donor-metal acceptor type which were first characterized for some iron(0) and cobalt(i) complexes. - Consistent with this formulation, the rate of initial attack of HgCla on the molybdenum complexes increases as the substituent X becomes more electron-releasing. Donor-acceptor complex formation is also apparent in the reactions of iodine with the compounds [FeCCOsP and [R(acac)a]. ... 

MoCl. Solid-state metathesis reactions are best performed with high-quality molybdenum(V) chloride. M0CI5 can be obtained commercially (Aesar)... 

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