ISSN:
1572-8862
Keywords:
Rhenium
;
metallocycle
;
cluster
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Abstract The compound (n-Bu4N)2[Re4Cl8(μ-Cl)2(μ-O)2 · 2THF] has been prepared from (n-Bu4N)2 Re2Cl8 by refluxing it in wet trifluoroacetic acid. It forms brown, block-shaped crystals in space group P $$\bar 1$$ , withZ = 2 in a cell of dimensions:a = 11.748(1) Å,b = 16.847(3) Å,c = 16.953(3) Å, α = 97.53(1)°β = 106.49(1)° γ = 101.25(1)°V = 3093(1) Å3. There are two independent but practically identical tetranuclear anions, each on a crystallographic inversion center. The short, unbridged Re-Re edges, to which triple bonds are assigned have lengths of 2.280(1) Å and 2.276(1) Å and the longer edges, each with a μ-Cl and a μ-O atom have lengths of 2.611(1) Å and 2.615(1) Å, for molecules 1 and 2 respectively. This anion completes a series going from [Re4Cl8(μ-O)2(μ-OMe)2]2− through [Re4Cl8(μ-O)2(μ-OMe)(μ-Cl)]2− to the present [Re4Cl8(μ-O)2(μ-Cl)2]2−. These metallocyclobutadiynes can be viewed as products of the 2,2-cycloaddition of two Re-Re quadruple bonds, but the mechanistic details of how they arise remain obscure.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01165470
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