1,3-Cyclopentadiene molybdenum complexes

C4H 2OSi, Silane, methoxytrimethyl-, 26 44 CH4N, Propane, 2-isocyant-2-methyl-ruthenium complex, 26 275 C][l,4]-dithiin-2-thione, 26 389 CHfc, 1,3-Cyclopentadiene cobalt complex, 26 191-197, 309 chromium, molybdenum, and tungsten complexes, 26 343 iron complex, 26 232-241 mercury-molybdenum-ruthenium complex, 26 333... 

Aryl and alkenyl chromium carbene complexes react with HCaC(CH2)3CH=CHCH=CHR (R = C02Et, CH=CHC02Et) by insertion of carbon monoxide to give hydroquinones. Aryl molybdenum carbene complexes give hexahydroazulenes while alkenyl substituted molybdenum complexes generate hydroquinones or cyclopentadiene derivatives. ... 

Perhaps chemists will be able to mimic nature without duplicating the iron-sulfur-molybdenum structure. For example, a zirconium complex with tetramethyl cyclopentadiene can bind dinitrogen in a manner that breaks the NON bond, as shown below. Treatment with hydrogen gas results in formation of small amounts of ammonia. Although the yields are too low to make this a viable commercial process, researchers hope to make the process more efficient through chemical modifications and changes in conditions. 

Upon UV irradiation in hydrocarbon solution, the hexacarbonyls of chromium, molybdenum, and tungsten react differently with conjugated dienes like 1,3-butadiene (la), ( )-l,3-pentadiene (lb), 2-methyl-1,3-butadiene (lc), ( , )-2,4-hexadiene (Id), ( )-2-methyl-l,3-pentadiene (le), 2-ethyl-1,3-butadiene (If), or 1,3-cyclohexadiene (Ig). Chromium hexacarbonyl (2) yields, with the acyclic dienes la-lf, tetracarbonyl-r/2-dienechromium(0) complexes (3a-3f) in a smooth reaction (8-10). With 1,3-cyclohexadiene, in addition to 3g, dicarbonylbis(>/4-l,3-cyclohexadiene)chromium(0) (4g) is obtained [Eqs. (7) and (8)j. During chromatography on silica gel, the 1,3-cyclohexadiene complex 3g dismutates readily to [Cr(CO)6] and 4g [Eq. (9)]. Under the same conditions with 2 1,3-cyclopentadiene (lh) yields, in a hydrogen-transfer reaction, the stable dicarbonyl- / 5-cyclopentadienyl-r/ 3-cyclopent-enylchromium (5) (11-13) [Eq. (10)]. 

C,2H, )N2, Azobenzene, cobalt and palladium complexes, 26 175,176 manganese complex, 26 173 C,2H N, Pyridine, 2-(phenylmethyl)-, palladium complex, 26 208-210 C,2H, P, Phosphine, diphenyl-, manganese complex, 26 158,226-230 ruthenium complex, 26 264 C 2H,2, Toluene, a-2,4-cyclopentadiene-l-yl-, chromium, molybdenum and tungsten hexacaibonyl complexes, 28 148... 

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