Bimetallic neutral and anionic complexes of transition metal (Co, Mn) carbonyls with indium(III) phthalocyanine

Heterobimetallic {[Co(CO)4]-[InIII(Pc2-)]} (1) and (Cp*2Cr+){[Mn(CO)5]-[InIII(Pc˙3-)]}·2C6H4Cl2 (2) complexes based on indium(III) phthalocyanine (Pc) were obtained as crystals. The complexes were synthesized by single (1) and double (2) reduction of indium(III) phthalocyanine chloride in the presence of transition metal carbonyls. Complex 1 contains dianionic Pc2- macrocycles. Thus, the coordinated Co(CO)4 carbonyl accepts an electron in the one-electron reduction forming a diamagnetic [Co(CO)4]- anion. Complex 2 contains a heterobimetallic {[Mn(CO)5]-[InIII(Pc˙3-)]}- anion and paramagnetic Cp*2Cr+ counter cations. Therefore, in the double reduction, electrons are transferred to Mn(CO)5 forming a diamagnetic [Mn(CO)5]- anion and to the Pc2- macrocycle forming a paramagnetic radical Pc˙3- trianion. Such assignments for 1 and 2 are in line with optical spectra, crystal structures and the data of magnetic measurements. The spectrum of 1 in the UV-visible range is similar to that of the starting InIIIClPc. The formation of 2 is accompanied by an essential blue-shift of the Q-band of Pc as well as by the appearance of an intense NIR band at 1005 nm characteristic of Pc˙3-. Compound 1 is EPR silent and diamagnetic, whereas the value of the effective magnetic moment of 2 is 4.24μB at 300 K, which corresponds to the contribution of S = 1/2 (Pc˙3-) and S = 3/2 (Cp*2Cr+) spins. Both weakly coupled paramagnetic centers (J = -0.41 cm-1) are observed in the EPR spectra.

Trinuclear coordination assemblies of low-spin dicyano manganese(II) (S = 1/2) and iron(II) (S = 0) phthalocyanines with manganese(II) acetylacetonate, tris(cyclopentadienyl)gadolinium(III) and neodymium(III)

The reaction of Mn^IIPc, Fe^IIPc or Fe^IIPcCl₁₆ with KCN in the presence of cryptand[2.2.2] yielded dicyano-complexes {cryptand(K⁺)}₂{M^II(CN)₂(macrocycle^2-)}^2-·XC₆H₄Cl₂ (M = Mn and Fe, X = 1 and 2) that were used for the preparation of trinuclear assemblies of the general formula {cryptand(K⁺)}₂{M^II(CN)₂Pc·(ML)₂}^2-·nC₆H₄Cl₂ (M^II = Mn^II and Fe^II; n = 1, 4 and 5). These assemblies were formed via coordination of two manganese(II) acetylacetonate (ML = Mn^II(acac)₂, S = 5/2), tris(cyclopentadienyl)gadolinium (ML = Cp₃Gd^III, S = 7/2) or tris(cyclopentadienyl)neodymium (ML = Cp₃Nd^III, S = 3/2) units to the nitrogen atoms of bidentate cyano ligands. The N(CN)-Mn{Mn^II(acac)₂} bond is 2.129(3) Å long but the bonds are elongated to 2.43-2.49 Å for tris(cyclopentadienyl)lanthanides. {Cryptand(K⁺)}₂{Mn^II(CN)₂Pc·(Mn^II(acac)₂)₂}^2-·5C₆H₄Cl₂ (2) contains three Mn(II) ions in different spin states (S = 5/2 and 1/2). Strong antiferromagnetic coupling of spins observed between them with the exchange interaction (J) of -17.6 cm^-1 enables the formation of a high S = 9/2 spin state for {Mn^II(CN)₂Pc·(Mn^II(acac)₂)₂}^2- dianions at 2 K. The estimated exchange interaction between Mn^II (S = 1/2) and Gd^III (S = 7/2) spins in {Mn^II(CN)₂Pc·(Cp₃Gd^III)₂}^2- is only -1.1 cm^-1, and in contrast to 2, nearly independent Gd^III and Mn^II centers are formed. As a result, no transition to the high-spin state is observed in {Mn^II(CN)₂Pc·(Cp₃Gd^III)₂}^2-. The {Mn^II(CN)₂Pc·(Cp₃Nd^III)₂}^2- and{Fe^II(CN)₂Pc·(Cp₃Nd^III)₂}^2- dianions with Cp₃Nd^III show a decrease of χ_MT values in the whole studied temperature range (300-1.9 K). A similar behaviour was found previously for pristine Cp₃Nd^III and Cp₃Nd^III·L complexes (L = alkylisocyanide ligand).

Interaction of InIIIClPc and TlIIIClPc phthalocyanines with deprotonated porphyrin HTPP− anions. Metal-centred reduction of TlIIIClPc

Reactions of In[Formula: see text]ClPc or Tl[Formula: see text]ClPc phthalocyanines with monodeprotonated tetraphenylporphyrin HTPP[Formula: see text] anions have been studied under reduction or in the presence of [Formula: see text]-methylimidazole ([Formula: see text]-MeIm). Formation of salt {In[Formula: see text]-MeIm)2(TPP[Formula: see text]}[Formula: see text]{In[Formula: see text](Pc[Formula: see text]}[Formula: see text] ⋅ 4C6H4Cl2 (1) justifies partial abstraction of indium(III) atoms from In[Formula: see text]ClPc to form cationic {In[Formula: see text](TPP[Formula: see text]}[Formula: see text] porphyrins[Formula: see text]solvated by [Formula: see text]-MeIm and double-decker {In[Formula: see text](Pc[Formula: see text]}[Formula: see text] anions. Crystals of Tl[Formula: see text](HTPP[Formula: see text] (2) have been only obtained at the interaction of HTPP[Formula: see text] with Tl[Formula: see text]ClPc under reduction indicating that Tl[Formula: see text] is reduced to Tl[Formula: see text] and is abstracted by HTPP[Formula: see text]. To confirm the possibility of Tl[Formula: see text] formation under reduction we have studied reduction of Tl[Formula: see text]ClPc by sodium fluorenone in the presence of cryptand[2.2.2]. Crystals of {Cryptand(Na[Formula: see text]}(Tl[Formula: see text](Pc[Formula: see text]}[Formula: see text] ⋅ C6H4Cl2(3) have been isolated indicating metal-centered reduction of Tl[Formula: see text]ClPc to form Tl[Formula: see text] and preserving dianionic Pc[Formula: see text] macrocycles. Optical spectra and structures of the obtained compounds are discussed and compared with those of pristine M[Formula: see text]ClPc. It is shown that 1–3 are EPR silent due to the formation of diamagnetic components.

Dianionic States of Trithiadodecaazahexaphyrin Complexes with Homotrinuclear MII3O Clusters (M = Ni and Cu): Crystal Structures, Metal- Or Macrocycle-Centered Reduction, and Doublet-Quartet Transitions in the Dianions

Metal complexes of trithiadodecaazahexaphyrin (Hhp) that contain M^II₃O clusters inside a π-extended trianionic (Hhp^3-) macrocycle have been prepared. Studies of the magnetic properties of Ni^II₃O(Hhp) and Cu^II₃O(Hhp) reveal a diamagnetic and EPR-silent trianionic (Hhp^3-) macrocycle and diamagnetic Ni^II₃(O^2-) or paramagnetic Cu^II₃(O^2-) tetracations. The positive charge of M^II₃O(Hhp) is compensated by one acetate anion {M^II₃O(Hhp)}⁺(CH₃CO₂^-). The three-electron reduction of {M^II₃O(Hhp)}⁺ yields {cryptand(Cs⁺)}₂{Ni^II₂Ni^IO(Hhp^5-)}^2-·2C₇H₈ (1) and {cryptand(Cs⁺)}₂{Cu^II₃O(Hhp^•6-)}^2-·C₇H₈ (2) crystalline salts. The magnetic properties of 1 reveal the formation of Hhp^5- and the reduction of nickel(II) to the paramagnetic Ni^I ion (S = 1/2), which is accompanied by the formation of the {Ni^II₂Ni^IO(Hhp^5-)}^2- dianion. As a result, the magnetic moment of 1 is 1.68 μ_B in the 20-220 K range, and a broad EPR signal of Ni^I was observed. The Hhp^5- macrocycle has a singlet ground state, but the increase in the magnitude of the magnetic moment of 1 above 220 K is attributed to the population of the triplet excited state in Hhp^5-. The {Ni^II₂Ni^IO(Hhp^5-)}^2- dianion is transferred from the doublet excited state to the quartet excited state with an energy gap of 1420 ± 50 K. Salt 1 also shows an unusually strong low-energy NIR absorption, which was observed at 1000-2200 nm. In 2, a highly reduced Hhp^•6- radical hexaanion (S = 1/2) coexists with a Cu^II₃(O^2-) cluster (S = 1/2) in the {Cu^II₃O(Hhp^•6-)}^2- dianions. The dianions have a triplet ground state with antiferromagnetic exchange between two S = 1/2 spins with J = -6.4 cm^-1. The reduction of Hhp in both salts equalizes the initially alternated C-N bonds, supporting the increase in the Hhp macrocycle electron delocalization.

{P2V3W15}-Polyoxometalates Functionalized with Phthalocyaninato Y and Yb Moieties

A tris(alkoxo)pyridine-augmented Wells-Dawson polyoxometalate (nBu₄N)₆[WD-Py] (WD = P₂V₃W₁₅O₅₉(OCH₂)₃C, Py = C₅H₄N) was functionalized with phthalocyaninato metal moieties (MPc where M = Y or Yb and Pc = C₃₂H₁₆N₈) to afford (nBu₄N)₄[HWD-Py(MPc)] compounds. High-resolution mass spectrometry was used to detect and identify the hybrid assembly. The magnetism studies reveal substantial differences between M = Yb (monomeric, single-ion paramagnetism) and M = Y (containing dimers, radical character). The results of electronic paramagnetic resonance spectroscopy, SQUID magnetometry, and magnetochemical calculations indicate the presence of intramolecular charge transfer from the MPc moiety to the polyoxometalate and of intermolecular charge transfer from the MPc moiety of one molecule to the polyoxometalate unit of another molecule. These compounds with identified V^IV ions represent unique examples of transition-metal/lanthanide complex-POM hybrid compounds with nonphotoinduced charge transfer between electron donor and acceptor centers.

Structure and properties of radical anion and dianion salts of organic dye trans-perinone and its mixed salt with gallium(iii) phthalocyanine

Reduction of organic dye trans-perinone in different experimental conditions was studied. New crystallite salts containing reduced species of trans-perinone together with mixed salt with Ga^IIIClPc radical anions were obtained and characterized.

Solid-State Properties of Hexaazatriphenylenehexacarbonitrile HAT(CN)6 .- Radical Anions in Crystalline Salts Containing Cryptand(M+ ) and Crystal Violet Cations

Crystalline {Cryptand[2.2.2](Na⁺ )}{HAT(CN)₆ ^.- }⋅0.5C₆ H₄ Cl₂ (1), {Cryptand[2.2.2](K⁺ )}{HAT(CN)₆ ^.- } (2), (CV⁺ ){HAT(CN)₆ ^.- } (3), and (CV⁺ ){HAT(CN)₆ ^.- }⋅2C₆ H₄ Cl₂ (4) salts (where CV⁺ is the crystal violet cation) containing hexaazatriphenylenehexacarbonitrile radical anions have been obtained. The solid-state molecular structure as well as the optical and magnetic properties of HAT(CN)₆ ^.- are studied. The formation of HAT(CN)₆ ^.- in 1-4 leads to the appearance of new bands in the visible range, at 694 and 740 nm. The HAT(CN)₆ ^.- radical anions have spin state S=1/2 and are packed in one-dimensional stacks containing the {HAT(CN)₆ ^.- }₂ dimers alternated with weaker interacting pairs of HAT(CN)₆ ^.- in 1 and nearly isolated {HAT(CN)₆ ^.- }₂ dimers in 2. The {HAT(CN)₆ ^.- }₂ dimers are diamagnetic in 1 but they effectively mediate one-dimensional antiferromagnetic coupling of spins within the stacks with moderate exchange interaction of J/k_B = -80 K. The behaviour of salt 2 is described by a singlet-triplet model for the {HAT(CN)₆ ^.- }₂ dimers with an energy gap of 434(±7) K. Magnetic behaviour of both salts agree well with the data of extended Hückel calculations. Salts 3 and 4 contain isolated stacks of alternated HAT(CN)₆ ^.- and CV⁺ ions, and in this case, nearly paramagnetic behaviour is observed with Weiss temperatures of -1 and -7 K, respectively. Narrow Lorentzian EPR signals with g = 2.0033-2.0039 were found for the HAT(CN)₆ ^.- radical anions in 1 and 4 but in solution g-factor shifts to 1.9964. The electronic structure of HAT(CN)₆ ^.- is analysed based on X-ray diffraction data for 2, showing a Jahn-Teller distortion of the radical anion that reduces the symmetry from D_3h to C_s and splits the initially degenerated LUMOs.

Reaction of GaIIIClPc, SnIVCl2TPP and BIIIClSubPc with cyanide anions: reduction of macrocycles vs. formation of cyano-containing macrocyclic anions

The reaction of GaIIIClPc, SnIVCl2TPP and BIIIClSubPc containing phthalocyanine (Pc), tetraphenylporphyrin (TPP) and subphthalocyanine (SubPc) macrocycles with cyanide in the presence of cryptand[2.2.2] under anaerobic conditions yields crystalline salts in which cyano anions substitute chloride anions at GaIII, SnIV or BIII, as well as reducing the macrocycles or adding one or two CN- to them. The reaction of GaIIICl(Pc2-) with CN- yields {crypt(K+)}{GaIIICN(Pc˙3-)}˙-·0.5C6H4Cl2 (1) in which the Pc2- macrocycle is reduced to Pc˙3-. Such reduction could probably occur through the addition of CN- to Pc2- forming {GaIII(CN)[Pc(CN)]3-}- which can decompose further interacting with an excess of CN-. As a result, Pc˙3- and cyanogene anions are formed. The interaction of SnIVCl2(TPP2-) with CN- is accompanied by the addition of CN- to the meso-carbon atom of porphyrin forming diamagnetic TPP(CN)3- macrocycles in {crypt(K+)}{SnIV(CN)2[TPP(CN)]3-}- (2). Salt 2 shows a strong NIR absorption band with the maximum at 854 nm whose intensity is comparable with that of the Soret band. The interaction of BIIICl(SubPc2-) with three equivalents of CN- is accompanied by the addition of two CN- to carbon atoms of SubPc2- closest to meso-nitrogen atoms forming {BIII(CN)[SubPc(CN)2]4-}2-. Most probably these dianions transfer electrons to C6H4Cl2 producing the {BIII(CN)[SubPc(CN)2]˙3-}˙- radical anions which form σ-bonded diamagnetic dianions in {crypt(K+)}2{BIII(CN)[SubPc(CN)2]}22-·3C6H4Cl2 (3). The remaining carbon atom closest to the meso-nitrogen atom is involved in this dimerization. According to the calculations, the energy of the C-CN bond is minimal for {GaIII(CN)[Pc(CN)]3-}- enabling further transformation of these anions to {GaIIICN(Pc˙3-)}˙- in 1, whereas cyano-containing anions in 2 and 3 with higher energy of this bond are stable towards the elimination of CN. Optical and magnetic properties of 1-3 together with their crystal and molecular structures are presented. The possible ways of the formation of 1-3 are discussed based on DFT calculations.

The borderline: exploring the structural landscape of triptycene in cocrystallization with ferrocene

When the effective packing of triptycene (TripH)–ferrocene chain oligomers in their cocrystal could not be achieved, we reached a borderline at the structural landscape of TripH, where the packing of TripH molecules reproduces the pattern in the native TripH crystal.

Effect of reduction on the molecular structure and optical and magnetic properties of fluorinated copper(ii) phthalocyanines

New salts based on reduced fluorinated copper(ii) phthalocyanines were obtained. The effect of reduction on the molecular structure and properties of the  [Cu^II(F_xPc)]ⁿ⁻ (x = 8 and 16) species in reduced states (n = 1 and 2) was studied.

Molecular structures, and optical and magnetic properties of free-base tetrapyrazinoporphyrazine in various reduction states

The synthesis, and spectral and structural characterization of the novel radical anion and dianion salts of free-base tetrapyrazinoporphyrazine (H₂TPyzPz) as well as studies of their magnetic properties have been described.

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.

Coordination Complexes of Titanium(IV) and Indium(III) Phthalocyanines with Carbonyl-Containing Dyes: The Formation of Singly Bonded Anionic Squarylium Dimers

Reduction methods for the preparation of coordination complexes of titanium(IV) and indium(III) phthalocyanines (Pc) with organic dyes such as indigo, thioindigo, and squarylium dye III (SQ) have been developed, which allow one to obtain crystalline {cryptand(K⁺ )}{(cis-indigo-O,O)^2- Ti^IV (Pc^2- )}(Cl^- )⋅C₆ H₄ Cl₂ (1), {cryptand(K⁺ )}{(cis-thioindigo-O,O)^2- In^III (Pc^2- )}^- ⋅C₆ H₄ Cl₂ (2), and {cryptand(K⁺ )}{[(SQ)₂ -O,O]^2- In^III (Pc^2- )}^- ⋅3.5 C₆ H₄ Cl₂ (3) complexes. The formation of these complexes is accompanied by the reduction of the starting dyes to the anionic state. Transition of trans-indigo or trans-thioindigo to the cis conformation in 1 and 2 provides coordination of both carbonyl oxygen atoms of the dye to Ti^IV Pc or In^III Pc. SQ is reduced to the radical anion state and forms unusual diamagnetic singly bonded (SQ^- )₂ dimers in 3. These dimers have two closely positioned carbonyl oxygen atoms coordinated to In^III Pc. Dianionic Pc^2- macrocycles have been found in 1-3. The complexes contain two chromophore molecules at one metal center. However, their optical spectra are defined mainly by absorption bands of the metal phthalocyanines.

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.

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.