ic202089p_si_002.cif (69.07 kB)

From Solid State to Solution: Advancing Chemistry of Bi–Bi and Bi–Rh Paddlewheel Carboxylates

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posted on 02.01.2012, 00:00 by Alexander S. Filatov, Margaret Napier, Volodimir D. Vreshch, Natalie J. Sumner, Evgeny V. Dikarev, Marina A. Petrukhina
The first successful high-yield solution synthesis of homobimetallic Bi2(O2CCF3)4 (1), as well as heterobimetallic BiRh­(O2CCF3)4 (2) and BiRh­(O2CCF2CF3)4 (3), complexes is reported. It is based on one-pot reduction reactions starting from Bi­(III) and Rh­(II) carboxylates and using Bi metal as a reducing agent. The presence of small amounts of diphenyl ether was found to facilitate this reaction, most probably because of its good solubilizing and π-stabilizing abilities. The latter is illustrated by the isolation and structural characterization of a π-adduct of 1 with diphenyl ether, [Bi2(O2CCF3)4·1/2Ph2O]. Importantly, the new approach expands to solution the chemistry of Bi­(II) that was previously limited to the solid state only. The solution procedure developed for the preparation of heterometallic BiRh­(O2CCF3)4 is now one step shorter and gives the product in excellent yield compared with the previously reported method based on sublimation-deposition technique. It is also performed on a greater scale (∼10–20 times) and makes further scale-up feasible, if needed. Moreover, it eliminates the isolation of the hard-to-handle unsolvated Bi­(II) trifluoroacetate used earlier as a starting material. A new polymorph of BiRh­(O2CCF3)4 (2) was crystallized from solution in this work. The solution approach was also applied to the synthesis of a new heterobimetallic carboxylate with perfluorinated propionate ligands, BiRh­(O2CCF2CF3)4 (3). All products are fully characterized by spectroscopic and single crystal X-ray diffraction methods. Complexes 2 and 3 exhibit similar solid state structures based on heterobimetallic paddlewheel units forming infinite 1D chains through intermolecular Rh···O interactions.