[TDNQ][CoCp*2] and [TDNQ]3[CoCp2]2; Radical Anions of a 1,2,5-Thiadiazolo-naphthoquinone
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- 作者：Ian S. Morgan ; Michael Jennings ; Alessandro Vindigni ; Rodolphe Cle虂rac ; Kathryn E. Preuss
- 刊名：Crystal Growth & Design
- 出版年：2011
- 出版时间：June 1, 2011
- 年：2011
- 卷：11
- 期：6
- 页码：2520-2527
- 全文大小：972K
- 年卷期：v.11,no.6(June 1, 2011)
- ISSN：1528-7505
文摘
The first crystal structure of a quinone[1,2,5]thiadiazole radical anion is presented. Reduction of naphtha[2,3-c][1,2,5]thiadiazole-4,9-dione (TDNQ) with outersphere electron transfer agents, decamethylcobaltocene (CoCp*2) and cobaltocene (CoCp2), by slow mixing of solutions, generates two species: [TDNQ][CoCp*2] and [TDNQ]3[CoCp2]2, respectively. The [TDNQ][CoCp*2] is soluble in a wide variety of organic solvents, whereas [TDNQ]3[CoCp2]2 is generally insoluble. The radical anion oxidation state, TDNQp>鈥⑩€?/sup>, in [TDNQ][CoCp*2] is confirmed by lengthened C鈥揙 bond distances in the (solvated) crystal structure, as compared to neutral TDNQ, shifting of the 谓(C鈥揙) stretch in the IR absorption spectrum, and the presence of a solution electron paramagnetic resonance (EPR) signal. In the [TDNQ]3[CoCp2]2 species, copacking of single-molecule radical anions, TDNQp>鈥⑩€?/sup>, and bimolecular radical anion units, (TDNQ)2p>鈥⑩€?/sup>, with cobaltocenium cations is observed. The magnetic measurements highlight the presence of dominating antiferromagnetic interactions between TDNQp>鈥⑩€?/sup> and (TDNQ)2p>鈥⑩€?/sup> spins in this cobaltocene salt.