Reversible iodine absorption of nonporous coordination polymer Cu(TCNQ)
Reversible iodine absorption of nonporous coordination polymer Cu(TCNQ)
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DOI：
10.1039/c3nj01290e
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发表时间：
2014-01-01
影响因子：
3.3
通讯作者：
Uruichi, Mikio
中科院分区：
文献类型：
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作者：
Miyao, Koji;Funabiki, Akira;Uruichi, Mikio
Cu(TCNQ)（TCNQ = 7,7',8,8'-四氰基醌二甲烷）的多晶粉末在与碘进行固体研磨或浸入碘的己烷溶液中时吸收碘形成Cu(TCNQ)I-4。在Cu(TCNQ)的两种多晶型物中，在液相反应中，II相Cu(TCNQ)的碘吸收速率比I相Cu(TCNQ)慢得多，而固体研磨反应导致两相均有效吸收。含碘盐的价态为[Cu+I-(TCNQ(0))](I-2)(1.5)，其中铜离子与碘阴离子和中性TCNQ配位。该盐是一种半导体（sigma(RT) = 3 x 10(-3) S cm(-1)，压实颗粒），其电导率比 Cu(TCNQ) 低一个数量级。该盐通过退火释放碘，通过中间 Cu(TCNQ) I 态再生 Cu(TCNQ) 的原始相。 TCNQ、CuI 和碘的固态反应也会产生含碘盐。 Cu(TCNQ)的碘吸收-解吸机制与我们之前报道的碱金属TCNQ盐不同。
Polycrystalline powders of Cu(TCNQ) (TCNQ = 7,7',8,8'-tetracyanoquinodimethane) absorb iodine to form Cu(TCNQ)I-4 upon solid grinding with iodine or immersion in a hexane solution of iodine. Of the two polymorphs of Cu(TCNQ), phase II Cu(TCNQ) exhibits a much slower iodine-absorption rate than that of phase I Cu(TCNQ) in the liquid-phase reaction, whereas the solid grinding reaction results in efficient absorption for both phases. The valence state of the iodine-containing salt is [Cu+I-(TCNQ(0))](I-2)(1.5), where the copper ion is coordinated with an iodide anion and neutral TCNQ. The salt is a semiconductor (sigma(RT) = 3 x 10(-3) S cm(-1), compaction pellet) with an electrical conductivity one order lower than that of Cu(TCNQ). The salt releases iodine by annealing to regenerate the original phases of Cu(TCNQ) via an intermediate Cu(TCNQ) I state. A solid-state reaction of TCNQ, CuI, and iodine also produces the iodine-containing salt. The iodine absorption-desorption mechanism of Cu(TCNQ) differs from that of alkali-TCNQ salts that we reported previously.