Magnetic and Optical Properties of Layered (Me4P+)[MIVO(Pc•3–)]•–(TPC)0.5·C6H4Cl2 Salts (M = Ti and V) Composed of π-Stacking Dimers of Titanyl and Vanadyl Phthalocyanine Radical Anions

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• 作者：Dmitri V. KonarevYoshiaki Nakano ; Salavat S. Khasanov ; Alexey V. Kuzmin ; Manabu Ishikawa ; Akihiro Otsuka ; Hideki Yamochi ; Gunzi Saito ; Rimma N. Lyubovskaya
• 刊名：Crystal Growth & Design
• 出版年：2017
• 出版时间：February 1, 2017
• 年：2017
• 卷：17
• 期：2
• 页码：753-762
• 全文大小：650K
• ISSN：1528-7505

文摘

Two isostructural salts with radical anions of titanyl and vanadyl phthalocyanines (Me₄P⁺)[M^IVO(Pc^•3–)]^•–(TPC)_0.5·C₆H₄Cl₂ (M = Ti (1), V (2)), where TPC is triptycene, were obtained. These salts contain phthalocyanine layers composed of the {[M^IVO(Pc^•3–)]^•–}₂ dimers with strong π–π intradimer interaction. The reduction of metal phthalocyanines was centered on the Pc macrocycles providing the appearance of new bands in the near infrared range and a blue shift of Q- and Soret bands. That results in the alternation of shorter and longer C–N_imine bonds in Pc^•3–. Only one S = 1/2 spin is delocalized over Pc^•3– in 1 providing a χ_MT value of 0.364 emu K mol^–1 at 300 K. Salt 1 showed antiferromagnetic behavior approximated by the Heisenberg model for isolated pairs of antiferromagnetically interacting spins with exchange interaction of J/k_B = −123.0 K. The χ_MT value for 2 is equal to 0.617 emu K mol^–1 at 300 K to show the contribution of two S = 1/2 spins localized on V^IV and delocalized over Pc^•3–. Magnetic behavior of 2 is described by the Heisenberg model for a four-spin system with strong intermolecular coupling between Pc^•3– in {[V^IVO(Pc^•3–)]^•–}₂ (J_inter/k_B = −105.0 K) and weaker intramolecular coupling between the V^IV and Pc^•3– (J_intra/k_B = −15.2 K).