Dianionic Titanyl and Vanadyl (Cation+)2[MIVO(Pc4−)]2− Phthalocyanine Salts Containing Pc4− Macrocycles |
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| Authors: | Dr Dmitri V Konarev Dr Alexey V Kuzmin Dr Salavat S Khasanov Alexey L Litvinov Dr Akihiro Otsuka Prof Hideki Yamochi Prof Hiroshi Kitagawa Prof Rimma N Lyubovskaya |
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| Affiliation: | 1. Institute of Problems of Chemical Physics RAS, Chernogolovka, Moscow region, Russia;2. Institute of Solid State Physics RAS, Chernogolovka, Moscow region, Russia;3. Division of Chemistry, Graduate School of Science, Kyoto University, Kyoto, Japan;4. Research Center for Low Temperature and Materials Sciences, Kyoto University, Kyoto, Japan |
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| Abstract: | In this study, the titanyl and vanadyl phthalocyanine (Pc) salts (Bu4N+)2MIVO(Pc4?)]2? (M=Ti, V) and (Bu3MeP+)2MIVO(Pc4?)]2? (M=Ti, V) with MIVO(Pc4?)]2? dianions were synthesized and characterized. Reduction of MIVO(Pc2?) carried out with an excess of sodium fluorenone ketyl in the presence of Bu4N+ or Bu3MeP+ is exclusive to the phthalocyanine centers, forming Pc4? species. During reduction, the metal +4 charge did not change, implying that Pc is an non‐innocent ligand. The Pc negative charge increase caused the C?N(pyr) bonds to elongate and the C?N(imine) bonds to alternate, thus increasing the distortion of Pc. Jahn–Teller effects are significant in the eg(π*)]2 dianion ground state and can additionally distort the Pc macrocycles. Blueshifts of the Soret and Q‐bands were observed in the UV/Vis/NIR when MIVO(Pc2?) was reduced to MIVO(Pc . 3?)] . ? and MIVO(Pc4?)]2?. From magnetic measurements, TiIVO(Pc4?)]2? was found to be diamagnetic and (Bu4N+)2VIVO(Pc4?)]2? and (Bu3MeP+)2VIVO(Pc4?)]2? were found to have magnetic moments of 1.72–1.78 μB corresponding to an S=1/2 spin state owing to VIV electron spin. As a result, two latter salts show EPR signals with VIV hyperfine coupling. |
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| Keywords: | crystal structure dianionic salts of metal phthalocyanines Jahn– Teller distortion optical and magnetic properties titanyl and vanadyl phthalocyanines |
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