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Updated: Sep 9, 2025
Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives
Published on: February 7, 2017
Polymorphism and Thermally Induced Structural Transformation in Semiconducting Cd(II) Coordination Polymers
Ryohei Akiyoshi1, Honoka Motokawa1, Asuka Nishibe1
1Department of Chemistry, School of Science, Kwansei Gakuin University, 1 Gakuen Uegahara, Sanda, Hyogo 669-1330, Japan.
Abstract:
Three polymorphs of a semiconducting Cd(II)-thiolate coordination polymer with the formula [Cd(2-SNPh)2]n (2-HSNPh = 2-naphthalenethiol) have been reported. Single-crystal X-ray structural analysis revealed that KGF-51 adopts a one-dimensional (1D) structure composed of single-strand (-Cd-S-)n ladder chains, whereas KGF-71 adopts a 1D architecture with double-strand (-Cd-S-)n chains assembled through S···S interactions. In contrast, microcrystal electron diffraction analysis demonstrated that KGF-79, obtained through thermal treatment of KGF-51 and KGF-71, exhibits the formation of a 1D structure comprising triple-strand (-Cd-S-)n chains, also formed via S···S interactions. This thermally induced, irreversible structural transformation to KGF-79 is accompanied by a transition from a nonpolar structure to a polar structure, leading to the emergence of second harmonic generation activity. Furthermore, time-resolved microwave conductivity measurements and first-principles calculations demonstrated that all three polymorphs exhibit photoconductivity, which is attributed to charge transport along the inorganic (-Cd-S-)n chains via a hopping mechanism.
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