Selective one-step synthesis of triple-decker (porphyrinato)(phthalocyaninato) early lanthanides: the balance of concurrent processes

Abstract

An effective one-step approach for the preparation of (porphyrinato)(phthalocyaninato) early lanthanides of type [Br₄TPP]Ln[(15C5)₄Pc]Ln[Br₄TPP], where Br₄TPP = 5,10,15,20-tetrakis-(4-bromophenyl)-porphyrinato-ligand, (15C5)₄Pc = tetrakis-(15-crown-5)-phthalocyaninato-ligand and Ln = La, Pr, Nd or Eu, is developed. The influence of various factors on the reaction pathway and yields of the complexes is investigated in detail. The developed protocol is found to be general for the early lanthanide subgroup. Variation of the synthetic conditions allowed the determination and isolation of possible side-products, namely heteroleptic double-deckers [Br₄TPP]Ln[(15C5)₄Pc] (Ln = Nd, Eu) and triple-decker [Br₄TPP]Nd[(15C5)₄Pc]Nd[(15C5)₄Pc]. The peculiarities of the NMR lanthanide-induced shifts (LIS) of resonances of the synthesized triple-decker complexes are precisely investigated. The isostructurality of the synthesized complexes within the series as well as isostructurality with previously synthesized compounds is demonstrated in terms of two-nuclei analysis of LIS.