Cyclopentadienyl complexes reactions

Cyclopentadienyl complexes reactions of, 700-703 structures of, 673-678 synthesis of, 680-681 Cytochromes, 569-572, 891-895... 

Seven publications centre on the chemistry of triruthenium cyclopentadienyl complexes. Reaction of [Cp Ru(p -Cl)]4 with Li2S yields [Cp 3Ru3(p -Cl)(p -S)], however with a mixture of Li2S/NaSPri the related thiolate-capped cluster [(2p 3Ru3(p -SPr )(p -S)] results . Somewhat related is [Cp 3Ru3(S4)] which reacts with a variety of electrophiles (R" ) to afford thiolate-... 

The isotopic method has been used in conjunction with a flow apparatus by Stranks, to measure the exchange between the cyclopentadienyl complexes of iron (III) and iron (II) in methanol. Separation was based on the insolubility of Fe(C5H5) in petroleum ether at —80 °C. Using Fe(II) and Fe(III) 10 M and short reaction times ( msec), a rate coefficient 8.7 x 10 l.mole .sec at — 75 °C was obtained. The rate of exchange in the presence of chloride ions and inert electrolytes was found to be more rapid. Calculations using Marcus Theory showed reasonable agreement with the experimental observations. In deuterated acetone, line broadening measurements have led to an estimate of this rate coefficient of > 10 l.mole . sec at 26 °C. 

Isomerizations are another category of reaction where Co complexes act as catalysts. Mixed S,P donor complexes Co(SCN)2(PR3)2 catalyze the isomerization of 1-butene to 2-butene in the presence of NaBH4, with CoH(SCN)(PR3)2 proposed as the active species.1366 A cyclopentadienyl complex (272) is active in the isomerization of quadricyclene to norbornadiene. 

Derivatization of some mono(cyclopentadienyl) complexes to yield new monosubstituted species can often be accomplished by metathetical exchange (Equation (26)) or protonation reaction.295 Protonolysis of (CsPr 4H)Ca[N(SiMe3)2](THF) with several terminal alkynes HC CR in either toluene or hexanes produces the... 

Insertions of isocyanide into niobium-carbon bonds follow a path similar to that with vanadium, resulting in the formation of the 7]2-iminoacyl complexes, which can then be involved in further chemistry.175 176 The reaction of acetone with cyclopentadienyl complex 110 under a carbon monoxide atmosphere gives the if -acetone compound 111. Complex 111 subsequently undergoes either stepwise insertion of two isocyanides via 112 or double insertion of the isocyanide to give complex 113 (Scheme 48).177... 

This review deals with metal-hydrocarbon complexes under the following headings (1) the nature of the metal-olefin and -acetylene bond (2) olefin complexes (3) acetylene complexes (4) rr-allylic complexes and (5) complexes in which the ligand is not the original olefin or acetylene, but a molecule produced from it during complex formation. ir-Cyclopentadienyl complexes, formed by reaction of cyclopentadiene or its derivatives with metal salts or carbonyls (78, 217), are not discussed in this review, neither are complexes derived from aromatic systems, e.g., benzene, the cyclo-pentadienyl anion, and the cycloheptatrienyl cation (74, 78, 217), and from acetylides (169, 170), which have been reviewed elsewhere. 

Manganese carbonyl, Mn2(CO)io, when treated with tetracyclone at 140-150°, gives an air-sensitive product which on hydrolysis gives the T-cyclopentadienyl complex (LII) 215). Manganese carbonyl does not react with dimcthylacetylene in sunlight, but duroquinone was formed in a similar reaction of the alkyne with [Mn(CO)6] 1 155). Mn(—1) is iso-electronic with Fe(0), and it is suggested that the unstable quinone com-... 

Organosilyl substituted 7)5-cyclopentadienyl complexes may be prepared by two main procedures (a) reactions of silylated cyclopenta-dienes or their alkali metal derivatives, with an appropriate transition metal compound (carbonyl or halide) with formation of ir-bonds (b) metalation of a preformed 7j5-cyclopentadienyl complex, followed by treatment with an organohalosilane. 

A very versatile preparation seems to be the elimination of organotin halides in the reaction of organostannyl-organosilylcyclopentadienes with metal carbonyl halides. This reaction is very selective and only Sn—C bonds are cleaved with formation of 7)5-cyclopentadienyl complexes (7) ... 

Complexes 74 and 75 do not interconvert during prolonged reflux in xylene solution, nor do they isomerize to the 1,2,5,6-i/4-OFCOT complex 72. However, when the reaction of [RhCl(i/2-olefin)2] 2 with OFCOT was carried out in refluxing benzene, the brown residue afforded only the cyclopentadienyl complex 75 on derivatization. Both cyclopentadienyl complexes retain the IR band at 1770 cm-1, which is clearly due to the strained fluorocyclo-... 

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