The Salts of Copper Octafluoro- and Hexadecafluorophthalocyanines Containing [CuII(F8Pc)4-]2- Dianions and [CuF16Pc]- Monoanions

Dmitri V Konarev; Sergey I Troyanov; Alexey V Kuzmin; Yoshiaki Nakano; Manabu Ishikawa; Maxim A Faraonov; Salavat S Khasanov; Alexey L Litvinov; Akihiro Otsuka; Hideki Yamochi; Gunzi Saito; Rimma N Lyubovskaya

doi:10.1021/acs.inorgchem.6b01932

The Salts of Copper Octafluoro- and Hexadecafluorophthalocyanines Containing [Cu^II(F₈Pc)^4-]^2- Dianions and [CuF₁₆Pc]^- Monoanions

Inorg Chem. 2017 Feb 20;56(4):1804-1813. doi: 10.1021/acs.inorgchem.6b01932. Epub 2017 Feb 6.

Authors

Affiliations

¹ Institute of Problems of Chemical Physics RAS , Chernogolovka, Moscow Region, 142432 Russia.
² Chemistry Department, Moscow State University , Leninskie Gory,119991 Moscow, Russia.
³ Institute of Solid State Physics RAS , Chernogolovka, Moscow Region, 142432 Russia.
⁴ Division of Chemistry, Graduate School of Science, Kyoto University , Sakyo-ku, Kyoto 606-8502, Japan.
⁵ Research Center for Low Temperature and Materials Sciences, Kyoto University , Sakyo-ku, Kyoto 606-8501, Japan.
⁶ Faculty of Agriculture, Meijo University , 1-501 Shiogamaguchi, Tempaku-ku, Nagoya 468-8502, Japan.
⁷ Toyota Physical and Chemical Research Institute , 41-1 Yokomichi, Nagakute, Aichi 480-1192, Japan.

PMID: 28165230
DOI: 10.1021/acs.inorgchem.6b01932

Abstract

Crystalline anionic salts with copper octafluoro- and hexadecafluorophthalocyanines, (Bu₄N⁺)₂[Cu^II(F₈Pc)^4-]^2-·2C₆H₄Cl₂ (1) and (PPN⁺)₃[CuF₁₆Pc]₃^3-·2C₆H₅CN (2), where PPN⁺ is bis(triphenylphosphoranylidene)ammonium and Pc is phthalocyanine, have been obtained. The absence of noticeable absorption in the NIR range and DFT calculations for 1 indicate that both negative charges are mainly localized on the Pc ligand, and that the [Cu^II(F₈Pc)^4-]^2- dianions are formed without reduction of Cu^II. The magnetic moment of 1.60 μ_B corresponds to the contribution of one S = 1/2 spin per dianion. The spin is localized on the Cu^II atom, which shows an EPR signal characteristic of Cu^II. Dianions are isolated in 1, providing only weak magnetic coupling of spins with a Weiss temperature of -4 K. Salt 2 contains closely packed π-π stacks built of [CuF₁₆Pc]^- anions of types I and II, and the interplanar distances are 3.187 and 3.275 Å. According to the DFT calculations, the [CuF₁₆Pc]^- anions of types I and II can have different charge distributions, with localization of an extra electron on the copper atoms to form diamagnetic [Cu^I(F₁₆Pc)^2-]^- monoanions or delocalization of an extra electron on the F₁₆Pc ligand to form [Cu^II(F₁₆Pc)^•3-]^•- having an S = 1/2 (Cu^II) + 1/2 (F₁₆Pc^•3-) spin state. In fact, at 300 K, the magnetic moment of 2 of 3.25 μ_B per formula unit is rather close to the contribution from two [Cu^II(F₁₆Pc)^•3-]^•- (calculated μ_eff is 3.46 μ_B). The Weiss temperature of -21.5 K indicates antiferromagnetic coupling of spins, which can be modeled by stronger intermolecular coupling between (F₁₆Pc)^•3- with J₁/k_B = -23.5 K and weaker intramolecular coupling between Cu^II and (F₁₆Pc)^•3- with J₂/k_B = -8.1 K. This interaction is realized in the {[Cu^II(F₁₆Pc)^•3-]^•-}₂ dimers separated by diamagnetic [Cu^I(F₁₆Pc)^2-]^- species. In spite of the stacking arrangement of phthalocyanine macrocycles in 2, the inhomogeneous charge distribution and nonuniform distances between the macrocycles should suppress electrical conductivity.