Molybdenum cyclopentadienyl tricarbonyl

Fig. 7. Representive stmctures for compounds of molybdenum(0) (a) Mo(CO)g (b) tris(acetonitrile)tris(carbonyl)molybdenum(0) (c) bis(l,2-diphenylphosphinoethane) bis (dinitrogen) molybdenum(0), [R2PCH2CH2PR2]2Mo(N2)2, where R = CgH, also known as Mo(dppe)2(N2)2, where dppe = 1,2 — diphenylphosphinoethane (d) cyclopentadienyl tricarbonyl molybdenum(0) anion, CpMo(CO)3, where Cp = cyclopentadienyl (e)...

The cyclopentadienyl tricarbonyl molybdenum and tungsten dimers also react with [(7r-Ph4C4)PdX2]2 (X = Cl, Br) complexes but by transfer of the tetraphenylcyclobutadiene group 182). 

Cyclopentadienyl-tricarbonyl-technelium(I) was prepared by reacting TeCU in the presence of copper powder with CO under a pressure of 325 atm to yield technetium carbonylchloride which was then heated in ethyleneglycoldimethylether with sodium cyclopcntadienyl. The sublimable, colorless, and diamagnetic [(C5H5)Tc(CO)3]° melts at 87.5 °C [662]. Irradiation of the dimeric compound [(C5Hs)Mo(CO)3]2° with Iher-mal neutrons produced [(C5H5) " Tc(CO)3]° by nuclear transformation of molybdenum to technetium [663] ... 

Trichloro(tripyridine)chromium(III), synthesis 36 Tris(3-bromoacetylacetonato)chromium(III), synthesis 37 Cyclopentadienyl tricarbonyl hydrides of chromium, molybdenum, and tungsten, synthesis 38 Trichloro(tripyridine)molybdenum(III), synthesis 39 Potassium octacyanotungstate(IV) 2-hydrate, synthesis 40 Chlorine(CP )-labeled thionyl chloride, silicon tetrachloride, boron chloride, germanium (IV) chloride and phosphorus(III) chloride, synthesis 44 Unipositive halogen complexes, synthesis 46 Monopyridineiodine(I) chloride, synthesis 47 Manganese(III) acetylacetonate, synthesis 49 Triiron dodecacarbonyl, synthesis 52... 

Cyclopentadienyl tricarbonyl hydrides of chromium, molybdenum, and tungsten can be prepared by reaction of Institute for Inorganic Chemistry, The University, Munich, Germany, t Union Carbide Chemicals Company, South Charleston, W.Va. 

Cyclopentadienyl-tricarbonyl-tetracyanoethylene molybdenum follows C11M0N4O5 CjgHigMoN04... 

C3iH29Cl3NbP2 2 C7H8, [1,2-Bis(diphenylphosphino)ethane]trichloro-(Tj -cyclopentadienyl)niobium(IV) bistoluene solvate, 45B, 983 C3 2H2oAgBF, 14O12W4, Tetrakis(cyclopentadienyliodotungsten-tricarbon-yDsilver tetrafluoroborate, 43B, 1090 C3 2H2oHg4MOaOi2, (T -Cyclopentadienyl-tricarbonyl-molybdenum)-mercury-molybdenum tetramer, 45B, 984... 

A. Chaloyard and N. El Murr, Inorg. Chem., 1980, 19, 3217. Synthesis of ring-substituted derivatives of cyclopentadienyl tricarbonyl complexes of molybdenum and tungsten. 

Most preparations of the intermediate racemic 3-allyl(dicarhonyl)cyclopentadieny molybdenum complexes7 2 start from sodium or potassium tricarbonyl(cyclopentadienyl)molybdate8 9 10 (4) for a simple preparation see ref 11, p 493. The allylation of 4 hy homoallylic halides, such as 4-hromo-l-butene, is accompanied by rearrangement and decarhonylationI2. (Z)-if-2-butenyl(dicarbonyl)cyclopentadienylmolybdenum (5), like other comparable complexes, exists as a mixture of endo/exo- conformers, which interconvert rapidly at room temperature12. 

Similarly, acetylene itself gave ferrocene. Cyclopentadienyl(methyl)molybdenum tricarbonyl reacted with diphenylacetylene to produce some tetraphenylcyclopentadiene. The corresponding ethylmolybdenum derivative gave some tetraphenyl-methylcyclopentadiene. The cyclizations involved in these reactions and the trimethylchromium reaction above are quite unusual and certainly deserve further study. 

BF4MoOPCwH](), Molybdenum(l +), car-bonyl-(-n5-cyclopentadienyl)-(diphenylacetylene)-(triphenylphosphine)-tetrafluoroborate(l -), 26 104 BF4MoO2PC25H20, Molybdenum, dicarbonyl-(T) -cyclopentadienyl)-[tetrafluoroborato(l -)] (triphenylphosphine)-, 26 98 BF4MoOjCbH5, Molybdenum, tricarbonyl-(ry -cyclopentadienyl) [tetrafluorobor-ato (1-)]-, 26 96... 

HglOoRujCijH, Ruthenium, nonacarbonyl-(3,3-dimethyl-l-butynyl)-(iodomercury)-/Wangu/o-tri-, 26 330 HgMo012Ru3C23Hi4, Ruthenium, nonacar-bonyl-( x3-3,3-dimethyl-1 -butynyl) p.-[tricarbonyl(-ri -cyclopentadienyl)-molybdenum]mercury -/riangu/o-tri-, 26 333... 

A number of readily reversible cr-7r rearrangements have been observed wherein a labile ligand such as carbon monoxide is lost by pyrolysis or photolysis, producing a coordinatively unsaturated metal center, which then regains coordinative saturation by means of a tr-n rearrangement. For example, irradiation of o--alkyl-7r-cyclopentadienyl-molybdenum tricarbonyl (15) produces the rr-allene complex (16) (25). These... 

In contrast to 73, the related tricarbonyl [2-(>/5-cyclopentadienyl)ethyI]-molybdenum (83) (107) forms fairly stable diene complexes with la-Ic in a stepwise reaction, first tj2- and, after prolongated irradiation, -coordinated [Eq. (44)]. Only to a minor extent is insertion of the dienes la and lb into the Mo—C [Pg.338]

Penta(isopropyl)- and penta(neopentyl)-Cp cobalticinium salts, on the other hand, have a high enough barrier to interconversion (AG% 17.1 and 19.4 kcal/mol, respectively) with coalescence temperatures of 65° and 100°C, respectively, in the NMR (14). Thus, both enantiomers can coexist at 20°C with only a slow interconversion between them. In tricarbonyl-methyl-penta(isopropyl)cyclopentadienyl molybdenum the activation energy has been estimated to 13 1 kcal/mol (211) (cf. comment in Section IV, C, 2). 

TRICARBONYL-(ii5-CYCLOPENTADIENYL)SILYL COMPLEXES OF CHROMIUM, MOLYBDENUM, AND TUNGSTEN... 

In (r-methyl-ir-cyclopentadienylmolybdenum tricarbonyl, the methyl group is attached to the molybdenum by a metal-to-carbon tr-bond, and the cyclopentadienyl group is attached by TT-type bonding, as in sandwich compounds. The material forms yellow crystals, m.p. 124° (decomp.), that are soluble in organic solvents and slowly oxidized by air. Purification is readily effected by vacuum sublimation. The infrared and n.m.r. spectra have been described. ... 

The cyclodimerization of 3,3-dimethylcyclopropene to form 3,3,6,6-tetramethyl-exo-tri-cyclo[3.1.0.0 ]hexane (4) can also be achieved with pentacarbonyliron in toluene at 95"C in 3 hours (no yield given) or in tetrahydrofuran at 60 °C with catalytic amounts of hexacarbonyl-molybdenum (77% yield, 93% conversion) or hexacarbonyltungsten (86.5% yield). With nonacarbonyldiiron a stoichiometric ring-opening reaction and formation of tricarbonyl(2-methyl-l-propenylketene)iron has been observed (see Section 2.C. for details). A 40% yield of the tricyclic dimer 4 is obtained under the catalytic action of ( / -cycloocta-l,5-diene)(t -cyclopentadienyl)cobalt(I). ... 

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