SnPhPc phthalocyanines with dianion Pc(2-) and radical trianion Pc˙(3-) macrocycles: syntheses, structures, and properties

Coordination-induced metal-to-macrocycle charge transfer and effect of cations on reorientation of the CN ligand in the {SnL2Mac}2− dianions (L = CN−, OCN−, Im−; Mac = phthalo- or naphthalocyanine)

Anionic coordination {crypt(M⁺)}₂{SnL₂Mac}²⁻ complexes of tin(ii) phthalo- (Pc) and naphthalocyanines (Nc) were obtained and discussed.

{CpFeII(CO)2SnII(Macrocycle•3-)} Radicals with Intrinsic Charge Transfer from CpFe(CO)2 to Macrocycles (Cp: Cp or Cp*); Effective Magnetic Coupling between Radical Trianionic Macrocycles•3

Neutral {CpFe^II(CO)₂[Sn^II(Pc^•3-)]} {Cp is cyclopentadienyl (1, 2) or Cp* is pentamethylcyclopentadienyl (3); Pc: phthalocyanine}, {Cp*Fe^II(CO)₂[Sn^II(Nc^•3-)]} (4, Nc: naphthalocyanine), and {CpFe^II(CO)₂[Sn^II(TPP^•3-)]} (5, TPP: tetraphenylporphyrin) complexes in which CpFe^II(CO)₂ fragments (Cp: Cp or Cp*) are coordinated to Sn^II(macrocycle^•3-) have been obtained. The product complexes were obtained at the reaction of charge transfer from CpFe^I(CO)₂ (Cp: Cp or Cp*) to [Sn^II(macrocycle^2-)] to form the diamagnetic Fe^II and paramagnetic radical trianionic macrocycles. As a result, these formally neutral complexes contain S = 1/2 spins delocalized over the macrocycles. This provides alternation of the C-N_imine or C-C_meso bonds in the macrocycles, the appearance of new bands in the near-infrared spectra of the complexes, and blue shift of both Soret and Q-bands. The {CpFe^II(CO)₂Sn^II(macrocycle^•3-)} units (Cp: Cp or Cp*, macrocycle: Pc or Nc) form closely packed π-stacking dimers in 1 and 3 or one-dimensional chains in 2 and 4 with effective π-π interaction between the macrocycles. Such packing allows strong antiferromagnetic coupling between S = 1/2 spins. Magnetic interaction can be described well by the Heisenberg model for the isolated dimers in 1 and 3 with exchange interaction J/k _B = -78 and -85 K, respectively. Magnetic behavior of 2 and 4 is described well by the model that includes contributions from an antiferromagnetically coupled S = 1/2 dimer (J _intra) and a Heisenberg S = 1/2 chain with alternating antiferromagnetic spin exchange between the neighbors (J _inter). Compound 2 demonstrates large intradimer interaction of J _intra/k _B = -54 K and essentially weaker interdimer exchange interactions of J _inter/k _B = -6 K, whereas compound 4 shows strong magnetic coupling of spins within the dimers (J _intra/k _B = -170 K) as well as between the dimers (J _inter/k _B = -40 K). Compound {CpFe^II(CO)₂[Sn^II(TPP^•3-)]} (5) shows no π-π interactions between the porphyrin macrocycles, and magnetic coupling is weak in this case (Weiss temperature is -5 K). Preparation of a similar complex with indium(III) chloride phthalocyanine yields {CpFe(CO)₂[In(Pc^2-)]} (6). In this complex, indium(III) atoms are reduced instead of the phthalocyanine macrocycles that explains electron paramagnetic resonance silence of 6 in the 4-295 K range.

Ring-Oxidized Zinc(II) Phthalocyanine Cations: Structure, Spectroscopy, and Decomposition Behavior

A bromonium oxidizing agent was used to produce a ring-oxidized zinc phthalocyanine (PcZn), [PcZn(solvent)]^•₂[BAr^F₄]₂ (1·solvent), in good yield. This material is dimeric in the solid state with one axially coordinated solvent [tetrahydrofuran (THF) or 1,2-dimethoxyethane (DME)] and close intradimer ring-ring distances of 3.18 and 3.136 Å (THF and DME respectively); this proximity facilitates strong antiferromagnetic coupling to yield diamagnetic dimers. 1·THF is present in solution as a monomer and a dimer. In CH₂Cl₂, the dimer is favored above 0.1 mM, and it is almost exclusively present in solvents with a high dielectric constant such as acetonitrile. The material 1·THF/DME decomposes in DME to a meso-nitrogen-protonated species, [HPcZn(DME)₂][BAr^F₄] (2), which was isolated and represents the first example of such a structurally characterized, protonated, unsubstituted PcM complex. A partially oxidized dimer or "pimer" [(PcZn(DME))₂]^•[BAr^F₄] (3) was also structurally characterized and has a intradimer ring-ring distance of 3.192 Å, similar to 1·THF/DME. Dimer 3 also represents the first isolated PcM-based pimer. Electron paramagnetic resonance analysis of a 1.0 mM solution of 1·DME in DME showed the production of 3 over hours by the combination of 1·DME and 2 in solution.

Dianionic Titanyl and Vanadyl (Cation+ )2 [MIV O(Pc4- )]2- Phthalocyanine Salts Containing Pc4- Macrocycles

In this study, the titanyl and vanadyl phthalocyanine (Pc) salts (Bu₄ N⁺ )₂ [M^IV O(Pc^4- )]^2- (M=Ti, V) and (Bu₃ MeP⁺ )₂ [M^IV O(Pc^4- )]^2- (M=Ti, V) with [M^IV O(Pc^4- )]^2- dianions were synthesized and characterized. Reduction of M^IV O(Pc^2- ) carried out with an excess of sodium fluorenone ketyl in the presence of Bu₄ N⁺ or Bu₃ MeP⁺ is exclusive to the phthalocyanine centers, forming Pc^4- 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 M^IV O(Pc^2- ) was reduced to [M^IV O(Pc^.3- )]^.- and [M^IV O(Pc^4- )]^2- . From magnetic measurements, [Ti^IV O(Pc^4- )]^2- was found to be diamagnetic and (Bu₄ N⁺ )₂ [V^IV O(Pc^4- )]^2- and (Bu₃ MeP⁺ )₂ [V^IV O(Pc^4- )]^2- were found to have magnetic moments of 1.72-1.78 μ_B corresponding to an S=1/2 spin state owing to V^IV electron spin. As a result, two latter salts show EPR signals with V^IV hyperfine coupling.

Reaction of tin(iv) phthalocyanine dichloride with decamethylmetallocenes (M = CrII and CoII). Strong magnetic coupling of spins in (Cp*2Co+){SnIVCl2(Pc˙3-)}˙-·2C6H4Cl2

The reaction of tin(iv) phthalocyanine dichloride {Sn^IVCl₂(Pc^2-)} with decamethylmetallocenes (Cp*₂M, M = Co, Cr) has been studied. Decamethylcobaltocene reduces Sn^IVCl₂(Pc^2-) to form the (Cp*₂Co⁺){Sn^IVCl₂(Pc˙^3-)}˙^-·2C₆H₄Cl₂ (1) complex. The negative charge of {Sn^IVCl₂(Pc˙^3-)}˙^- is delocalized over the Pc macrocycle providing the alternation of the C-N(imine) bonds, the appearance of new bands in the NIR range and a strong blue shift of both the Soret and Q-bands in the spectrum of 1. The magnetic moment of 1 is equal to 1.68μ_B at 300 K, indicating the contribution of one S = 1/2 spin of the Pc˙^3- macrocycles. These macrocycles form closely packed double stacks in 1 with effective π-π interactions providing strong antiferromagnetic coupling of spins at a Weiss temperature of -80 K. Decamethylchromocene initially also reduces Sn^IVCl₂(Pc^2-) to form the [(Cp*₂Cr⁺){Sn^VICl₂(Pc˙^3-)}˙^- complex but further reaction between the ions is observed. This reaction is accompanied by the substitution of one Cp* ligand of Cp*₂Cr by chloride anions originating from {Sn^IVCl₂(Pc˙^3-)}˙^- to form the complex {(Cp*CrCl₂)(Sn^IV(μ-Cl)(Pc^2-))}·C₆H₄Cl₂ (2) in which the (Cp*CrCl₂) and {Sn^IV(Pc^2-)} species are bonded through the μ-bridged Cl^- anion. According to the DFT calculations, this reaction proceeds via an intermediate [(Cp*₂CrCl)(SnClPc)] complex.

Synthesis and properties of N-methylimidazole solvates of vanadium(ii), chromium(ii) and iron(ii) phthalocyanines. Strong NIR absorption in VII(MeIm)2(Pc2−)

Crystal structures and optical and magnetic properties of N-methylimidazole (MeIm) solvates of vanadium(ii), chromium(ii) and iron(ii) phthalocyanines have been studied.

Salts with titanyl and vanadyl phthalocyanine radical anions. Molecular design and effect of cations on the structure and magnetic and optical properties

Our recent data on radical anion salts of titanyl (Ti^IVOPc) and vanadyl (V^IVOPc) phthalocyanines as well as additional new data are summarized.

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

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 [M^III (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⁺ ) [In^III 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 μ_B 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/k_B =-0.9 and -1.1 K, respectively, and in the π-stacking {[In^III Br(Pc^.3- )]^.- }₂ dimers of 3 with an exchange interaction of J/k_B =-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.