Synthesis, structures and reduction chemistry of monophthalocyanine scandium hydroxides

Abstract

The preparation and structural characterization of a pair of scandium(III) phthalocyanine hydroxide complexes were achieved by reaction of PcScCl with alkali metal alkoxides, likely via hydrolysis of soluble PcSc-alkoxide intermediates. A Sc[Formula: see text]Li[Formula: see text]-OH)[Formula: see text] cubane supported by two distorted Pc rings of the form (PcSc)[Formula: see text]-OH)[Formula: see text]Li[Formula: see text](THF)(DME) was isolated from the reaction of PcScCl with LiO[Formula: see text]Pr, while a simpler alkali-metal-free [Pc[Formula: see text]Sc[Formula: see text]-OH)[Formula: see text](THF)] was obtained from addition of NaO[Formula: see text]Bu; both structures are reminiscent of bent metallocenes, with dihedral angles between the two Pc rings of 50.8 and 37.7[Formula: see text]respectively. A soluble PcScOH material can also be obtained directly via hydrolysis of insoluble PcScCl in approximately 95:5 THF:water. Reduction of the Pc ring of PcScCl using KC[Formula: see text] is reversible and generates Pc[Formula: see text] and Pc[Formula: see text]-containing materials that were characterized via UV-vis spectroscopy and, where appropriate EPR and [Formula: see text]H NMR spectroscopy; analogous reductions of the PcScOH-based species were irreversible. Exposure of the air-sensitive, reduced PcScCl-based species to ambient atmosphere generated PcScOH materials analogous to the direct hydrolysis route.

Preferential Formation of Side‐Pocket‐Substituted Zinc Phthalocyanines Emitting Beyond 800 nm

“…The increased elevation of Zn(II) from the Pc‐core, in addition to the shorter M−Cl bond length of 2HCl , compared to 1,4,8,11,15,18,22,25‐octabutoxyphthalocyanine)manganese(III) chloride, suggests that Zn(II) strongly favours a 5‐coordinate coordination sphere. This is surprisingly similar to phthalocyanine complexes of early transition metals and lanthanides, which were shown to be too large to fit within the Pc‐core and thus become displaced from the ligand‐plane, especially when additional axial ligands are present [43–45] …”