1H NMR spectral analysis of structural features in a series of paramagnetic homoleptic binuclear triple-decker phthalocyaninato lanthanide complexes

Analysis of the lanthanide-induced shifts and relaxation rates in 1 H NMR spectra of a series of tetra-15-crown-5-phthalocyanine complexes with Nd 3+ , Tb 3+ , Dy 3+ , Ho 3+ , Er 3+ and Tm 3+ showed the isostructurality of the whole series of complexes despite f-compression and this result was confirmed by DFT calculations. The search for efficient methods of comparative structural investigations of coordination compounds in solid state and solutions is a very relevant task. In this study, structural assignments in a series of Ln 2 [(15C5) 4 Pc] 3 complexes (where [(15C5) 4 Pc] 2- is 2,3,9,10,16,17,24,25-tetrakis(15-crown-5)phthalocyaninato-dianion, Ln = Nd 3+ , Tb 3+ , Dy 3+ , Ho 3+ , Er 3+ and Tm 3+ ) was performed using NMR relaxation and paramagnetic lanthanide-induced shifts (LIS) data. Analysis of the paramagnetic chemical shifts and relaxation rates evidenced of isostructurality of the complete series of the investigated triple-decker complexes in the solutions. The performed systematic DFT calculations for a series of model complexes with methoxy-substituted ligands Ln 2 [(MeO) 8 Pc] 3 demonstrate that the calculated geometrical factors are in agreement with characteristics extracted from experimental NMR data.