Sandwich Double‐Decker Lanthanide(III) “Intracavity” Complexes Based on Clamshell‐Type Phthalocyanine Ligands: Synthesis, Spectral, Electrochemical, and Spectroelectrochemical Investigations

Abstract

Phthalocyanine compounds of novel type based on a bridged bis-ligand, denoted "intracavity" complexes, have been prepared. Complexation of clamshell ligand 1,1'-[benzene-1,2-diylbis(methanediyloxy)]bis[9(10),16(17),23(24)-tri-tert-butylphthalocyanine] ((clam,tBu)Pc(2)H(4), 1) with lanthanide(III) salts [Ln(acac)(3)]⋅n H(2)O (Ln = Eu, Dy, Lu; acetylacetonate) led to formation of double-deckers (clam,tBu)Pc(2)Ln (2 a-c). Formation of high molecular weight oligophthalocyanine complexes was demonstrated as well. The presence of an intramolecular covalent bridge affecting the relative arrangement of macrocycles was shown to result in specific physicochemical properties. A combination of UV/Vis/NIR and NMR spectroscopy, MALDI-TOF mass-spectrometry, cyclic voltammetry, and spectroelectrochemistry provided unambiguous characterization of the freshly prepared bis-phthalocyanines, and also revealed intrinsic peculiarities in the structure-property relationship, which were supported by theoretical calculations. Unexpected NMR activity of the paramagnetic dysprosium complex 2 b in the neutral π-radical form was observed and examined as well.

Sandwich-Type Lanthanide(III) Dinaphthalocyanine Complexes Possessing an Intensive Absorption in the Near IR Region: Synthesis and Investigation of Properties

“…IV band occupies wide region and possesses multiple peak nature, which is refered to equilibrium processes in sandwich molecule [17] and corresponding splitting of energy levels. [18,19] In contrast to diphthalocyanines [16] of lanthanide the shape of this band doesn't exhibit dramatic changes for different central ions.…”

“…There are three bands referring to singleoccupied molecular orbital (SOMO): [16] blue valence (BV), red valence (RV) and intervalence (IV). IV band occupies wide region and possesses multiple peak nature, which is refered to equilibrium processes in sandwich molecule [17] and corresponding splitting of energy levels.…”

Novel peripherally and non-peripherally 6-oxyflavone substituted metal-free, zinc(II) and cobalt(II) phthalocyanines: Electrochemical and in situ spectroelectrochemical properties

“…In this study, the redox properties of the newly-synthesized metal free, zinc(II) and cobalt(II) Pcs bearing flavones substituents at peripheral and non-peripheral positions of the macrocycle (Scheme1) have been investigated by evaluation of the data from electrochemical and in situ spectroelectrochemical measurements. It is well known that solubility, aggregation and redox activity of Pc compounds can be modified by careful selection of the types and the binding positions of substituents [22][23][24]. Thus, the main purpose of this study is to investigate the effect of tetra 6-hydroxyflavonoxy substituents on these properties.…”

Synthesis, characterization and electrochemical properties of novel pyridine phthalocyanine derivatives

“…Furthermore, this delocalization, including the basic electrochemistry, can be modified by a careful selection of the redox activity of the central metal ions, and by changing the number, position and types of substituents on the Pc ring [23][24][25]. Among Pc derivatives, the syntheses of lanthanide(III) Pcs, especially double-decker lanthanide Pcs, have attracted a great deal of interest due to their unique electrochemical, and electrochromic behavior and the p-p interaction of the Pc rings in the double-decker complexes [26][27][28][29].…”