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An electrochemical cell consisting of cobalt ([Co[sup II/III](P[sub 3]O[sub 9])[sub 2]][sup 4-/3-]) and vanadium ([V[sup III/II]-(P[sub 3]O[sub 9])[sub 2]][sup 3-/4-]) bistrimetaphosphate complexes as catholyte and anolyte species, respectively, was constructed with a cell voltage of 2.4 V and Coulombic efficiencies >90% for up to 100 total cycles. The [Co(P[sub 3]O[sub 9])[sub 2]][sup 4-] (l) and [V(P[sub 3]O[sub 9])[sub 2]][sup 3-] (2) complexes have favorable properties for flow-battery applications, including reversible redox chemistry, high stability toward electrochemical cycling, and high solubility in MeCN (1.09 ± 0.02 M, [PPN][sub 4][1]·2MeCN; 0.77 ± 0.06 M, [PPN][sub 3][2]·DME). The [PPN][sub 4]-[1]·2MeCN and [PPN][sub 3][2]·DME salts were isolated as crystalline solids in 82 and 68% yields, respectively, and characterized by [sup 31]P NMR, UV/vis, ESI-MS(-), and IR spectroscopy. The [PPN][sub 4][1]-2MeCN salt was also structurally characterized, crystallizing in the monoclinic P2[sub 1]/c space group. Treatment of 1 with [(p-BrC[sub 6]H[sub 4])[sub 3]N][sup +] allowed for isolation of the one-electron-oxidized spin-crossover (SCO) complex, [Co(P[sub 3]O[sub 9])[sub 2]][sup 3-] (3), which is the active catholyte species generated during cell charging. The success of the 1-2 cell provides a promising entry point to a potential future class of transition-metal metaphosphate-based all-inorganic non-aqueous redox-flow battery electrolytes. [ABSTRACT FROM AUTHOR]

The article reports on the formation of Cyclopentadienone derivatives by the reaction of 1,4,-Dilithio-1,3-dienes or Zirconacyclopentadienes with Oxalyl Chloride in the presence of CuCI. The article reports the first 1,1-cycloaddition of oxalyl chloride with 1,4-dilithio-1,3-dienes or zirconcyclopentadienes to afford cyclopentadienone derivatives in the presence of CuCl, in which the carbon-carbon bond of 1 ,2-dicarbonyl cleaved during nucleophilic addition. To avoid the high reactivity of organodilithium compound, a proper tuning of the reactivity of organodimetallic reagents and oxalyl chloride is possible.