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Tetrabutylammonium Salts of Aluminum(III) and Gallium(III) Phthalocyanine Radical Anions Bonded With Fluoren-9-olato

Dmitri V Konarev, Salavat S Khasanov, Manabu Ishikawa, Yoshiaki Nakano, Akihiro Otsuka, Hideki Yamochi, Gunzi Saito, Rimma N Lyubovskaya

Chem Asian J. 2017 Apr 18;12(8):910-919.

PMID: 28205420

Abstract:

Reduction of aluminum(III), gallium(III), and indium(III) phthalocyanine chlorides by sodium fluorenone ketyl in the presence of tetrabutylammonium cations yielded crystalline salts of the type (Bu4 N+ )2 [MIII (HFl-O- )(Pc.3- )].- (Br- )⋅1.5 C6 H4 Cl2 [M=Al (1), Ga (2); HFl-O- =fluoren-9-olato- anion; Pc=phthalocyanine] and (Bu4 N+ ) [InIII Br(Pc.3- )].- ⋅0.875 C6 H4 Cl2 ⋅0.125 C6 H14 (3). The salts were found to contain Pc.3- radical anions with negatively charged phthalocyanine macrocycles, as evidenced by the presence of intense bands of Pc.3- in the near-IR region and a noticeable blueshift in both the Q and Soret bands of phthalocyanine. The metal(III) atoms coordinate HFl-O- anions in 1 and 2 with short Al-O and Ga-O bond lengths of 1.749(2) and 1.836(6) Å, respectively. The C-O bonds [1.402(3) and 1.391(11) Å in 1 and 2, respectively] in the HFl-O- anions are longer than the same bond in the fluorenone ketyl (1.27-1.31 Å). Salts 1-3 show effective magnetic moments of 1.72, 1.66, and 1.79 μB at 300 K, respectively, owing to the presence of unpaired S=1/2 spins on Pc.3- . These spins are coupled antiferromagnetically with Weiss temperatures of -22, -14, and -30 K for 1-3, respectively. Coupling can occur in the corrugated two-dimensional phthalocyanine layers of 1 and 2 with an exchange interaction of J/kB =-0.9 and -1.1 K, respectively, and in the π-stacking {[InIII Br(Pc.3- )].- }2 dimers of 3 with an exchange interaction of J/kB =-10.8 K. The salts show intense electron paramagnetic resonance (EPR) signals attributed to Pc.3- . It was found that increasing the size of the central metal atom strongly broadened these EPR signals.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP13450889 Gallium(III) bromide Gallium(III) bromide 13450-88-9 Price
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