Nakabayashi Keita, Nishio Masaki, Miyasaka Hitoshi
Department of Chemistry, Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University , Kakuma-machi, Kanazawa 920-1192, Japan.
Institute for Materials Research, Tohoku University , 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan.
Inorg Chem. 2016 Mar 7;55(5):2473-80. doi: 10.1021/acs.inorgchem.5b02858. Epub 2016 Feb 15.
The stepwise neutral-ionic (N-I) phase transition found in the alternating donor/acceptor (DA) chain [Ru2(2,3,5,6-F4PhCO2)4(DMDCNQI)]·2(p-xylene) (0; 2,3,5,6-F4PhCO2(-) = 2,3,5,6-tetrafluorobenzoate; DMDCNQI = 2,5-dimethyl-N,N'-dicyanoquinonediimine) was tuned by partly substituting the acceptor DMDCNQI with 2,5-dimethoxy-N,N'-dicyanoquinonediimine (DMeODCNQI), which displays a poorer electron affinity in an isostructural series. The site-doped series comprised [Ru2(2,3,5,6-F4PhCO2)4(DMDCNQI)1-x(DMeODCNQI)x]·2(p-xylene) for doping rates (x) = 0.05 (0.05-MeO), 0.10 (0.10-MeO), 0.15 (0.15-MeO), and 0.20 (0.20-MeO). The neutral chain [Ru2(2,3,5,6-F4PhCO2)4(DMeODCNQI)]·4(p-xylene) (1), which only contained DMeODCNQI, was also characterized. All site-doped compounds were isostructural to 0 except 1 despite their identical DA chain motif. Except at an x value of 0.20, they displayed a two-step N-I transition involving an intermediate phase. This transition occurred at high temperatures in 0 but shifted to lower temperatures in a parallel manner with increasing doping rate. Simultaneously, each transition broadened with increasing doping rate, leading to a convergence of two transitions at an x value approximating 0.2. Donor/acceptor-site-doping techniques present somewhat different impacts in terms of interchain Coulomb effects.
在交替供体/受体（DA）链[Ru2(2,3,5,6-F4PhCO2)4(DMDCNQI)]·2(对二甲苯)（0；2,3,5,6-F4PhCO2(-)=2,3,5,6-四氟苯甲酸根；DMDCNQI=2,5-二甲基-N,N'-二氰基对苯二亚胺）中发现的逐步中性-离子（N-I）相变，通过用2,5-二甲氧基-N,N'-二氰基对苯二亚胺（DMeODCNQI）部分取代受体DMDCNQI进行调节，在同构系列中DMeODCNQI显示出较差的电子亲和力。位点掺杂系列包括[Ru2(2,3,5,6-F4PhCO2)4(DMDCNQI)1-x(DMeODCNQI)x]·2(对二甲苯)，掺杂率（x）=0.05（0.05-MeO）、0.10（0.10-MeO）、0.15（0.15-MeO）和0.20（0.20-MeO）。还对仅含有DMeODCNQI的中性链[Ru2(2,3, ,5,6-F4PhCO2)4(DMeODCNQI)]·4(对二甲苯)（1）进行了表征。除1外，所有位点掺杂化合物与0同构，尽管它们具有相同的DA链基序。除x值为0.20外，它们显示出涉及中间相的两步N-I转变。这种转变在0中发生在高温下，但随着掺杂率的增加以平行方式转移到较低温度。同时，每个转变随着掺杂率的增加而变宽，导致在x值接近0.2时两个转变收敛。供体/受体位点掺杂技术在链间库仑效应方面呈现出有些不同的影响。
