Zwitterionic {Fe(i)Pc(−2)−}·(TMP+) assemblies comprising anionic iron(i) phthalocyanines and coordinating N,N,N′-trimethylpiperazinium cations

Kuzmin

Faraonov

et al. 2014

Chemistry A European J

Self Cite

187

Radical anion salts of metal-containing and metal-free phthalocyanines [MPc(3-)](·-), where M = Cu(II), Ni(II), H2, Sn(II), Pb(II), Ti(IV)O, and V(IV)O (1-10) with tetraalkylammonium cations have been obtained as single crystals by phthalocyanine reduction with sodium fluorenone ketyl. Their formation is accompanied by the Pc ligand reduction and affects the molecular structure of metal phthalocyanine radical anions as well as their optical and magnetic properties. Radical anions are characterized by the alternation of short and long C-Nimine bonds in the Pc ligand owing to the disruption of its aromaticity. Salts 1-10 show new bands at 833-1041 nm in the NIR range, whereas the Q- and Soret bands are blue-shifted by 0.13-0.25 eV (38-92 nm) and 0.04-0.07 eV (4-13 nm), respectively. Radical anions with Ni(II), Sn(II), Pb(II), and Ti(IV)O have S = 1/2 spin state, whereas [Cu(II)Pc(3-)](·-) and [V(IV)OPc(3-)](·-) containing paramagnetic Cu(II) and V(IV)O have two S = 1/2 spins per radical anion. Central metal atoms strongly affect EPR spectra of phthalocyanine radical anions. Instead of narrow EPR signals characteristic of metal-free phthalocyanine radical anions [H2Pc(3-)](·-) (linewidth of 0.08-0.24 mT), broad EPR signals are manifested (linewidth of 2-70 mT) with g-factors and linewidths that are strongly temperature-dependent. Salt 11 containing the [Na(I)Pc(2-)](-) anions as well as previously studied [Fe(I)Pc(2-)](-) and [Co(I)Pc(2-)](-) anions that are formed without reduction of the Pc ligand do not show changes in molecular structure or optical and magnetic properties characteristic of [MPc(3-)](·-) in 1-10.

Section: Discussionmentioning

confidence: 63%

Synthesis, Structures, and Properties of Crystalline Salts with Radical Anions of Metal‐Containing and Metal‐Free Phthalocyanines

Kuzmin

Faraonov

et al. 2014

Chemistry A European J

Self Cite

187

“…The transition energy of this NIR absorption band is slightly affected by the central metal atom and shifts from λ =920 (for Cu II ) to 1040 nm (for Sn II ) . The [Fe I (Pc 2− )] − and [Co I (Pc 2− )] − anions with reduced central metals do not show such bands . Reduction of the Pc macrocycle in 1 results in a strong blueshift in the Q and Soret bands of the phthalocyanine, which manifests as a split band at λ =590 and 629 nm in the visible region and a single band at λ =334 nm in the UV region.…”

Section: Resultsmentioning

confidence: 98%

“…Am etal phthalocyanine (MPc) in the radical cation or radical anion state can show promising magnetic andc onducting properties. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] For example, the electrochemical or chemical oxidation of neutralM II Pcs or the electrochemical oxidation of {M III (CN) 2 Pc} À anions allows the preparation of compounds with metallic conductivity,w hich,i ns ome cases,i ss table down to liquid-heliumt emperatures. [1][2][3] The oxidation of unsubstituted and substituted manganese(II) phthalocyanines by the organic p-acceptor tetracyanoethyleney ields coordination chain compounds with ferrimagnetic ordering of the spins.…”

Section: Introductionmentioning

confidence: 99%

“…[4,5] The reduction of MPcsh as also been intensively studied. [6][7][8][9][10][11][12][13][14][15][16][17][18] Interest in this field is evoked by the prediction of metallicconductivityo rs uperconductivity in electron-dopedM Pcs [21] and the observation of ferrimagnetico rdering of spins in (Cp* 2 Cr + )[Fe I (Pc 2À )] À ·4C 6 H 4 Cl 2 (Cp* = pentamethylcyclopentadienyl) with chains of alternating iron(I) phthalocyanine anions (Fe I , S = 1/2) and decamethylchromocenium cations (Cr III , S = 3/ 2). [22] Up to now,s everal types of anionic metal phthalocyanines have been obtained as crystalsa nd have been structurally characterized.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Tetrabutylammonium Salts of Aluminum(III) and Gallium(III) Phthalocyanine Radical Anions Bonded with Fluoren‐9‐olato⁻ Anions and Indium(III) Phthalocyanine Bromide Radical Anions

Chemistry An Asian Journal

Khasanov

Ishikawa

et al. 2017

Self Cite

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 (Bu N ) [M (HFl-O )(Pc )] (Br )⋅1.5 C H Cl [M=Al (1), Ga (2); HFl-O =fluoren-9-olato anion; Pc=phthalocyanine] and (Bu N ) [In Br(Pc )] ⋅0.875 C H Cl ⋅0.125 C H (3). The salts were found to contain Pc radical anions with negatively charged phthalocyanine macrocycles, as evidenced by the presence of intense bands of Pc 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 μ at 300 K, respectively, owing to the presence of unpaired S=1/2 spins on Pc . 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/k =-0.9 and -1.1 K, respectively, and in the π-stacking {[In Br(Pc )] } dimers of 3 with an exchange interaction of J/k =-10.8 K. The salts show intense electron paramagnetic resonance (EPR) signals attributed to Pc . It was found that increasing the size of the central metal atom strongly broadened these EPR signals.

“…[12] Now the salts with negatively charged cobalt(I), iron(I) and metal free phthalocyanines and porphyrazines have been obtained. [13][14][15][16][17][18][19] However, anionic phthalocyanines with tetra-coordinated metal atoms are not deeply investigated so far because of weak acceptor properties of metal phthalocyanine and as a result high air sensitivity of their anions. Metal-free phthalocyanines are reduced with potential more negative than -0.6 V, whereas zinc(II), copper(II), nickel(II) and manganese(II) phthalocyanines are reduced with potential -0.8 ÷ -0.9 V. [20] To increase the acceptor ability of metal macroheterocycles electron-withdrawing substituents such as Cl, F or CN can be attached to the phthalocyanine macrocycle or the number of nitrogen atoms in the macrocycle should be increased.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Iron(II) Octachlorotetrapyrazinoporphyrazine, Molecular Structure and Optical Properties of the (X−)2FeTPyzPACl8 Dianions with Two Axial Anionic Ligands (X− = CN−, Cl−)

Ustimenko¹,

Khasanov³

et al. 2013

MHC

Self Cite