Intrinsic Carrier Doping in Antiferromagnetically Interacted Supramolecular Copper Complexes with (Pyrazino)tetrathiafulvalene (Pyra-TTF) as the Ligand, [Cu^IICl₂(pyra-TTF)] and (Pyra-TTF)₂[Cu^I₃Cl₄(pyra-TTF)]

New supramolecular copper complexes with pyrazinotetrathiafulvalene (pyra-TTF) as the ligand, [CuIICl2(pyra-TTF)] (1) and (pyra-TTF)2[CuI3Cl4(pyra-TTF)] (2), have been synthesized by the diffusion method. Complex 1 is a black block crystal with a three-dimensional (3-D) supramolecular network; the linear chain [−CuIICl2−(pyra-TTF)−]n extends along the b axis, where the coordinated pyra-TTF donors are stacked in a head-to-tail and ring-over-bond configuration to construct two-dimensional (2-D) sheets, and between the sheets, there are C···Cl− or H···Cl− contacts. Even though the electron spin resonance (ESR) measurement reveals the nearly CuII state, complex 1 is a semiconductor with σRT = 1.0 × 10−4 S cm−1 and Ea = 0.33 eV. The high-frequency conductivity measurement also confirmed the intrinsic slight carrier doping from CuII to the pyra-TTF donor. This slight doping enhances not only the real and imaginary dielectric constants but also the antiferromagnetic interaction between CuII spins following the 2-D Heisenberg model with 2J = −20 K. In contrast, complex 2 is a very thin black needle. This needle crystal has two crystallographically independent pyra-TTF molecules, which are coordinated and noncoordinated donors. The coordinated donors composed a supramolecular chain [CuI3Cl4(pyra-TTF)0]n, whereas the noncoordinated donors formed conducting α′′-type pyra-TTF+0.5 sheets. This complex is semiconducting with σRT = 0.1 S cm−1 and Ea = 0.15 eV. Both complexes 1 and 2 demonstrate that the pyra-TTF molecule works not only as an oxidized donor by CuII to construct conducting sheets but also as a ligand coordinated to a Cu cation to form supramolecuar chains.以吡嗪并四硫富瓦烯（pyrazinotetrathiafulvalene, pyra-TTF）为配体的新型超分子铜配合物[CuIICl₂(pyra-TTF)]（1）与(pyra-TTF)₂[CuI₃Cl₄(pyra-TTF)]（2）通过扩散法合成。配合物1为黑色块状晶体，具有三维（3-D）超分子网络结构；沿b轴延伸的链状结构[−CuIICl₂−(pyra-TTF)−]ₙ中，配位的pyra-TTF给体以头对尾且环盖键的堆叠构型构筑二维（2-D）片层，片层之间存在C···Cl⁻或H···Cl⁻相互作用。尽管电子顺磁共振（electron spin resonance, ESR）测试显示其近乎二价铜离子（CuII）状态，但配合物1仍为半导体，室温电导率σ_RT = 1.0 × 10⁻⁴ S·cm⁻¹，活化能E_a = 0.33 eV。高频电导率测量进一步证实，CuII向pyra-TTF给体发生了本征轻微载流子掺杂。这种轻微掺杂不仅提升了材料的实部与虚部介电常数，还依据二维海森堡模型（2J = −20 K）增强了CuII自旋间的反铁磁相互作用。与之相反，配合物2为极细的黑色针状晶体。该针状晶体包含两个晶体学独立的pyra-TTF分子，分别为配位给体与非配位给体。配位给体构成了超分子链[CuI₃Cl₄(pyra-TTF)₀]ₙ，而非配位给体则形成了导电α''型pyra-TTF⁺0.5片层。该配合物同样为半导体，室温电导率σ_RT = 0.1 S·cm⁻¹，活化能E_a = 0.15 eV。配合物1与2均证明，pyra-TTF分子既可被CuII氧化为给体以构筑导电片层，也可作为配体与铜阳离子配位形成超分子链。