New Sandwich‐Type Phthalocyaninato–Metal Quintuple‐Decker Complexes

Abstract

Linked and fused arrays, as well as stacked multidecker complexes, with basic tetrapyrrole units as important p-conjugated systems, are of significant interests for advanced molecular materials with potential applications in the field of organic field transistors (OFETs), [1] nonlinear optics (NLO), [2] and solar cells. [3] Efforts towards extended tetrapyrrole motifs have led to new synthetic methodologies that have resulted in new tetrapyrrole systems with one-, [4] two-, [5] and even three-dimensional conjugated structures. [6, 7] Threedimensional, conjugated, sandwich-type, tetrapyrrole-metal, double-and triple-decker complexes, which have been fabricated by incorporating large metal centers into stacked tetrapyrrole (with two-dimensional conjugation) multidecker systems, [7] have been intensively studied due to the intriguing spectroscopic, [7b,c, 8] electrochemical, [9] and magnetic properties, [10] as well as potential applications in molecular mechanical devices.[11] However, stacked tetrapyrrole-metal complexes with sandwich-type structures have not exceeded three tetrapyrroles until the very recent reports on the tetrakis(tetrapyrrole)-rare-earth-cadmium compounds with a quadruple-decker molecular configuration. [10e, 12] The lack of these type of structures is associated with the limitations in the selection of an appropriate metal ion with suitable coordination number, geometry, charge, and hard/soft-acid/base behavior to match the coordination algorithm of tetrapyrroles. Herein we describe the facile synthesis, spectroscopic characterization, and electrochemical properties of new, sandwich-type, homoleptic, pentakis(phthalocyaninato), quintuple-decker complexes composed of two bis(phthalocyaninato)-lanthanideA C H T U N G T R E N N U N G (III) subunits bridged by two cadmium(II) ions and one phthalocyanine ligand (Scheme 1).A simple one-pot synthetic pathway, which starts from neutral unprotonated bis(2,3,9,10,16,17,23,24-octa- The sandwich-type nature of the quintuple-decker molecular structure of 1-3 was clearly revealed by MALDI-TOF MS and NMR spectroscopy. The MALDI-TOF mass spectra of these three compounds showed intense signals for the protonated molecular ion [M + H] + ( Figure S1 and Table S1 in the Supporting Information), which indicated the composition of two trivalent lanthanide cations, two divalent cadmium cations, and five divalent phthalocyanine anions. Satisfactory NMR spectra were obtained for the three sandwichtype, pentakis(phthalocyaninato), heterometal, quintupledecker complexes 1-3. A C H T U N G T R E N N U N G (butyloxy)phthalocyaninato) (H 2 PcA C H T U N G T R E N N U N G (OC

Historic overview and new developments in synthetic methods for preparation of the rare-earth tetrapyrrolic complexes

“…Both EPR and electrochemical data were suggestive of a reversible dissociation of these triple-decker systems in solution [261,262]. Work done by Cook and coworkers stimulated an additional interest toward the preparation of heteronuclear rareearth/cadmium complexes with four or more tetrapyrrolic ligands [34][35][36][37][38][39][40][41][42].…”

“…During the next 50 years, it was confirmed that rare-earth ions are capable of the formation of phthalocyanine single-, double, and triple-decker complexes and their analogues [22][23][24][25][26][27][28][29][30][31][32][33]. One of the interesting recent discoveries was the preparation and characterization of heteronuclear (rareearth / cadmium) multiple-decker complexes, which contain up to six Pc ligands [34][35][36][37][38][39][40][41][42].…”

Detailed Analysis of the Crystal Structures and Magnetic Properties of a Dysprosium(III) Phthalocyaninato Sextuple‐Decker Complex: Weak f–f Interactions Suppress Magnetic Relaxation

“…[46] This method was extendedb yW ang et al,a nd their researchg roup has reported the synthesis of multiple-decker complexes with five (quintuple-decker:L n 2 Cd 2 )a nd six (sextuple-decker:L n 2 Cd 3 )l igands, as shown in Figure 1. [47][48][49] These multiple-decker complexes have different intramolecular LnÀLn distances. By changingt he Ln III ion to amagnetically anisotropic ion such as Tb III dipole-dipole (MD) interactions.…”

Reactivity of Rare Earth Metal Porphyrins/Phthalocyanines in Acid Media

“…[30][31][32][33][34] Researches of both the first sandwich-type rare earth metal double-decker complexes with N-confused porphyrinato and phthalocyaninato ligands [35] and (phthalocyaninato)/(phthalocyaninato)(porphyrinato) rare earth(III)-cadmium(II) quadruple/quintuple/sextuple-decker complexes have been started. [36][37][38][39][40] Spectral and applied properties of the complexes are studied as a rule. Porphyrin and phthalocyanine double-and triple-decker complexes exhibit promising properties such as high stability of neutral and oxidized forms, solubility in organic solvents and ability to self-organization in solid layers.…”