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Borole Derivatives. 24. Synthesis of Cationic (Arene)(phenylborole)rhodium Complexes. Structures of the Trinuclear Complex (η5-C4H4BPh)Rh(μ3-I)3-Rh(μ,η5:η6-C4H4BPh)Rh(η5-C4H4BMe)·CH2Cl2 and of the Polymeric catena-(μ,η5:η6-1-Phenylborole)rhodium Tetrafluoroborate
journal contribution
posted on 1998-02-16, 00:00 authored by Gerhard E. Herberich, Hartmut J. Eckenrath, Ulli EnglertThe heterocubane
[Rh(μ3-I)(C4H4BPh)]4
(1) reacts with Ag+ salts in acetonitrile to
give
the labile salt
[Rh(NCMe)3(C4H4BPh)]BF4
(2). This salt 2 reacts with
hexamethylbenzene
(hmb) to give the arene complex
[Rh(C4H4BPh)(hmb)]BF4
(3), and with mesitylene [Rh(1,3,5-C6H3Me3)(C4H4BPh)]BF4
(4) is obtained. Complex 2 loses
acetonitrile under vacuum to
produce the polymeric salt
catena-[{Rh(μ,η5:η6-C4H4BPh)}BF4]x
(5). Insight into the essential
structural features of this polymer provided its radial distribution
function obtained from a
wide-angle X-ray scattering experiment. When treated with
acetonitrile, complex 5 regenerates 2 and with pyridine affords
[Rh(py)3((C4H4BPh)]BF4
(6). Crystallization from a solution of
[Rh(μ3-I)(C4H4BPh)]4
(1) and the corresponding methylborole complex
[Rh(μ3-I)(C4H4BMe)]4 (1/1) in
CH2Cl2 produces the trinuclear complex
(η5-C4H4BPh)Rh(μ3-I)3Rh(μ,η5:η6-C4H4BPh)Rh(η5-C4H4BMe)·CH2Cl2
(7) with a bridging
μ,η5:η6-C4H4BPh
ligand; complex
7 was characterized by an X-ray structure determination.
The resulting molecular structure
was used to create a structure model for the monomeric building block
of polymer 5.