ISSN:
0009-2940
Keywords:
(η2-Alkene)(η5-cyclopentadienyl)organylnickel(II) complexes, stability and reactivity of
;
Cyclopentadienyl ligands, substituted
;
Chelating alkenylcyclopentadienyl
;
Nickel complexes
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Various Coordinations in (η2-Alkene)(η5-cyclopentadienyl)organylnickel(II) ComplexesA series of (η2-alkene)(η5-cyclopentadienyl)organylnickel(II) complexes with substituted cyclopentadienyl ligands is synthesized in order to compare the structures, the thermal stabilities, and chemical reactivities. In (allyl)(η5-Cp')Ni compounds the allyl moiety is η3-coordinated when Cp'=C5H5, C5Me5 (1), C5Ph5 (2), indenyl (3), [Hydridotri(pyrazolyl)borato] (4) (as an equivalent of the cyclopentadienyl ligand), and [C5H4((CH2)3CH=CH2)] (22). It is found that the [(η2-alkene)alkyl(η5-Cp')nickel] compounds [Cp'=C5Me5; alkene=C2H4, alkyl=Me (10), Et (9) or alkene=(1 - 2-η2)-1,3-butadiene, alkyl=Me (11); Cp'=C5Ph5; alkene=C2H4, alkyl=Me (12)] are thermally more stable and less reactive than their η5;- C5H5 analogues; the largest increase in thermal stability is observed when the η5-Cp' and the η2-alkene functions are connected by substitution of the cyclopentadienyl ligand with an alkenyl group of suitable chain length. In the case of compounds of the general type [(η5-C5R4((CH2)nCH=CH2))-(ligand)Ni(II)] with Ph3P as the ligand these complexes are cationic [R=H, n=3 (14+) or R=Me, n=2 (17+)]. On the other hand, the compounds with anionic ligands are neutral complexes (R=H, n=3, ligand=methyl (19), ethyl (20), isopropyl (21) or R=Me, n=3 and ligand=iodide (24), bromide (25), methyl (26), ethyl (27)]. In 14+, 17+, 19 - 21 and 24 - 27 the C=C bond of the alkenyl group is η2-coordinated to the nickel atom. X-ray structures have been determined for 4 and 25.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19911240306
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