ISSN:
0009-2940
Keywords:
Bond formation, C - C, metal-mediated
;
Hexatrienediyl ligands
;
hexadienediyl ligands
;
Molybdenum complexes
;
Tungsten complexes
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Photoreaktion von (μ-η]2:2-Acetylen)tetracarbonylbis(η5-cyclopentadienyl)-dimolybdenum and -tungsten with Acetylene and 1,3-Butadiene[Mo2(η5-C5H5)2(CO)4(μ-η2:2-C2H2)] (1) and [W2(η5-C5H5)2(CO)4-(μ-η2:2-C2H2)] (2) react upon UV irradiation with acetylene, 1,3-butadiene, and isoprene. Main products of the reactions with acetylene are the fly-over complexes [M2(η5-C5H5)2(CO)2(η1:3:3:1-1,3,5-hexatriene-1,6-diyl)] (8: M = Mo; 9: M = W). There is some IR evidence for the formation of [Mo2(η5-C5H5)2(CO)(η5η1:4:1-1,3-butadiene-1,4-diyl)] (10). In addition [Mo3(η5-C5H5)6(μ-η1:2-ethynyl)] (12) is obtained. 1 reacts with 1,3-butadiene with C - C bond formation to give [Mo2(η5-C5H5)2〉(CO)(μ-η1:2-CO)(μ-η1:2:3-1,5-hexadiene-1,4-diyl)] (15) and [Mo2(η5-C5H5)2 (CO)4[μ-η1:3-E,Z-2,4-hexadiene-1-ylidene)] (18). With isoprene [Mo2(η5-C5H5)2(CO)4[μ-η1:3-E,Z-5-methyl-2,4-hexadiene-1-ylidene)] (18a) is obtained. The reaction of 2 with 1,3-butadiene yields six complexes. Beside thermolabile [W2 [W2(η5-C5H5)2(CO) (μ-η1:2:1-3-oxo-1-propene-1, 3-diyl)(η4-1,3-butadiene)] (21), (η5-C5H5)2(CO) (μ-η1:4-3-methylene-1,4-pentadiene-1-yl)] (20), the tungsten homologue of 15, [W2(η5-C5H5)2(CO) (μ-η1:2:3-1,5-hexadiene-1,4-diyl)] (16), its isomer [W2(η5-C5H5)2(CO)2(μ-η1:2:3-1,5-hexadiene-1,4-diyl)] (23) with a W - W double bond, and [W2(η5-C5H5)2(CO)2(μ-η1:2:1-1,4-hexadiene-1,6-diyl)] (17) are isolated. Furthermore, [W2(η5-C5H5)2(CO)2 (μ-η1:2-vinylidene)] (11) is obtained. In solution 21 rearranges to 23. The crystal and molecular structures were determined for 15 and 18. The constitutions of the other products were deduced from the IR and 1H-NMR spectra.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19921250215
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