Reversible Thermochromism and Stable Resistance Switching Behaviors Based on a Co(III)-Complex-Linked Polyoxoniobate

A 3DCo(III)-complex hybrid polyoxoniobate framework Na-10(H2O)(36)[Co-2(phen)(2)(4,4 & PRIME;-bipy)(Nb6O19)(2)]& BULL;19H(2)O (1) has been constructed from [Co-2(phen)(2)(4,4 & PRIME;-bipy)(Nb6O19)(2)](10-) dimer units and 2D inorganic Na-O clusterlayers. The Co(III) centers are coordinated with {Nb6O19}, 4,4 & PRIME;-bipy and phen simultaneously. The [Co-2(phen)(2)(4,4 & PRIME;-bipy)(Nb6O19)(2)](10-) fragments link the Na-Ocluster layers to generate a 3D metal complex-modified hybrid polyoxoniobateframework with & pi;-& pi; interactions between phenanthrolinerings. Compound 1 shows reversible thermochromic behaviorresulting from electron transfer from {Nb6O19} to 4,4 & PRIME;-bipy and subsequent formation of radical products,which is first observed in polyoxoniobates. Furthermore, the compoundexhibits stable nonvolatile storage behavior and rewritable resistiveswitching with a low switching voltage (1.12 V) and high current on/offratio (1.18 x 10(3)) along with stable cyclic performanceduring stability test for 200 cycles. Charge-transfer mechanism hasbeen studied by analyzing the relationship between current and voltagein the process of resistance switching. A3D Co(III)-complex hybrid polyoxoniobate framework Na-10(H2O)(36)[Co-2(phen)(2)(4,4 & PRIME;-bipy)(Nb6O19)(2)]& BULL;19H(2)O (1) has been constructed from [Co-2(phen)(2)(4,4 & PRIME;-bipy)(Nb6O19)(2)](10-) dimer units and 2D inorganicNa-O cluster layers. Compound 1 shows reversiblethermochromic behavior resulting from electron transfer from {Nb6O19} to 4,4 & PRIME;-bipy and subsequent formationof radical products, which is first observed in polyoxoniobates. Furthermore,the compound exhibits stable nonvolatile storage behavior.

Automated summary

A 3D Co(III)-complex hybrid polyoxoniobate framework has been constructed and it shows reversible thermochromic behavior. The framework also exhibits stable nonvolatile storage behavior and rewritable resistive switching performance. The charge-transfer mechanism has been studied.