Cyclopentadienyl carbonyl complexes with alkynes

Two commonly used synthetic methodologies for the synthesis of transition metal complexes with substituted cyclopentadienyl ligands are important. One is based on the functionalization at the ring periphery of Cp or Cp metal complexes and the other consists of the classical reaction of a suitable substituted cyclopentadienyl anion equivalent and a transition metal halide or carbonyl complex. However, a third strategy of creating a specifically substituted cyclopentadienyl ligand from smaller carbon units such as alkylidynes and alkynes within the coordination sphere is emerging and will probably find wider application [22]. 

Alkynyl complexes with copper, 2, 160 with Cp Re(CO) (alkyne), 5, 916 with dicarbonyl(cyclopentadienyl)hydridoirons, 6, 175 with diiron carbonyls, 6, 232-233 donor-free, with gold(I), 2, 255 with gold(I)... 

Heterometal alkoxide precursors, for ceramics, 12, 60-61 Heterometal chalcogenides, synthesis, 12, 62 Heterometal cubanes, as metal-organic precursor, 12, 39 Heterometallic alkenes, with platinum, 8, 639 Heterometallic alkynes, with platinum, models, 8, 650 Heterometallic clusters as heterogeneous catalyst precursors, 12, 767 in homogeneous catalysis, 12, 761 with Ni—M and Ni-C cr-bonded complexes, 8, 115 Heterometallic complexes with arene chromium carbonyls, 5, 259 bridged chromium isonitriles, 5, 274 with cyclopentadienyl hydride niobium moieties, 5, 72 with ruthenium—osmium, overview, 6, 1045—1116 with tungsten carbonyls, 5, 702 Heterometallic dimers, palladium complexes, 8, 210 Heterometallic iron-containing compounds cluster compounds, 6, 331 dinuclear compounds, 6, 319 overview, 6, 319-352... 

In contrast to the inertness of bisalkynebisdithiocarbamate complexes, alkyne displacement from bisalkyne cyclopentadienyl derivatives is common. An extensive series of cationic [CpMo(CO)L(RC=CR)][BF4] complexes has been prepared from [CpMo(CO)(RC=CR)2][BF4] reagents by substitution of one of the coordinated alkynes [Eq. (19)] (72). Reaction of the carbonyl reagent with phosphines occurs smoothly at room temperature in methylene chloride to form monoalkyne products in high yields... 

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-... 

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