Preparation and Structure of (Cu(pc))₃(ReO₄)₂ and Theoretical Investigation of Cu(pc)(ReO₄), Cu(pc)(ReO₄)₂, and (Cu(pc))₃(ReO₄)₂

Abstract

The compound (Cu(pc))(3)(ReO(4))(2) (pc = phthalocyaninato) has been prepared by electrocrystallization from a p-dichlorobenzene solution of Cu(pc) and [N(n-Bu)(4)][ReO(4)]. (Cu(pc))(3)(ReO(4))(2) crystallizes with one formula unit in the triclinic space group P1 with cell constants at T = 153 K of a = 12.6202(6) A, b = 13.7596(7) A, c = 14.0294(7) A, alpha = 64.6376(9) degrees, beta = 64.2570(9) degrees, and gamma = 66.0549(9) degrees. The molecular structure comprises a stack of three Cu(pc) rings; the Cu center in each peripheral ring has an attached ReO(4) ligand, the Cu-O distance being 2.374(5) A. The inter-ring distance is 3.1595(11) A. Density functional theory calculations for Cu(pc)(ReO(4)) and Cu(pc)(ReO(4))(2) suggest that the ring-pi states are the source of the electron donation to the ligands. Calculations for (Cu(pc))(3)(ReO(4))(2) suggest that the charges on the central and peripheral rings are nearly equal. For all three compounds the basic spin distributions are similar to each other and to those of other Cu(pc) systems. For (Cu(pc))(3)(ReO(4))(2) a localized, rather than an itinerant, description of the magnetism is indicated.

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

“…Compound 1 ·DME has an inter-Pc ligand rotation angle of 44.7°, which is similar to that of other dimeric [(PcM) • ] 2 2+ species ,, and partially oxidized [PcM] n (•+) complexes and aggregates. − ,, As with other [PcM] •+ species, the complete overlap of the two Pc ligands prevents any dihedral ring distortion, and thus each ring maintains planarity. ,,, The five-coordinate Zn II centers sit 0.4 Å out of the Pc cavity; this disposition is perhaps induced by the axial DME coordination, which was observed for the [(PcCu II (ReO 4 )) • ] 2 and [(PcZnCl) • ] 2 complexes. , As with [(PcCu II (ReO 4 )) • ] 2 and [(PcZnCl) • ] 2 , the axial substitution of 1 ·DME prevented further aggregation. , …”

“…[54][55][56][57][58][59][60][61][62][63][64][65][66]71,74 As with other [PcM] •+ species, the complete overlap of the two Pc ligands prevents any dihedral ring distortion, and thus each ring maintains planarity. 50,51,72,73 The five-coordinate Zn II centers sit 0.4 Å out of the Pc cavity; this disposition is perhaps induced by the axial DME coordination, which was observed for the [(PcCu II (ReO 4 )) • ] 2 and [(PcZnCl) • ] 2 complexes. 48,51 As with [(PcCu II (ReO 4 )) • ] 2 and [(PcZnCl) • ] 2 , the axial substitution of 1•DME prevented further aggregation.…”

“…This charge balance in 3 indicates that only one radical is present in the dimer. As with the partially oxidized Pc complexes and the porphyrin pimers mentioned above, ,,− the bond lengths in the inner N 8 C 8 ring of 3 show no evidence of localization of the radical on either (formally) [PcZn] 0.5(•+) molecule in the dimer, suggesting that it is delocalized across both.…”

“…67−72 One structure of a [PcCu II PcCu II PcCu II ] 2+ triple-decker complex with axial ReO 4 − anions also displayed a delocalization of the radicals across the three Pc rings. 73 Very few fully ring-oxidized PcM compounds ([PcM] •+ ) have been isolated and structurally characterized in part because of the high oxidation potentials often required to produce these species. 48−53 For example, the ring-unsubstituted PcZn and PcCu II complexes have high oxidation potentials of 0.78 and 0.98 V, respectively, versus saturated calomel electrode in dimethylacetamide.…”

“…The majority of structurally characterized [PcM] n (•+) compounds form stacks that are investigated for their conductivity properties, based on the opening of a conduction band between the ligands in the stack. There are far fewer examples of [PcM] n (•+) complexes that are not aggregated in this fashion, with one class of Pc 2 Ln III -based species standing out: the partial oxidation of double-decker [cation] + [Pc 2 Ln] − compounds to neutral [Pc 2 Ln III ] • systems has been targeted for its impact on the single-ion magnet and the near-IR absorption properties of these materials. − One structure of a [PcCu II PcCu II PcCu II ] 2+ triple-decker complex with axial ReO 4 – anions also displayed a delocalization of the radicals across the three Pc rings …”