Kristallchemische Analyse der Stereochemie des Kations und Anions in Bis(triphenylphosphin)iminium-di(phthalocyaninato)metallaten der Selenen Erden, (PNP)[Ln(Pc2-)2]•xH2O (Ln = La, Gd, Tm; x ≤ 0,5) / Crystalchemical analysis of the stereochemistry of the cations and anions in bis(triphenylphosphine)iminium di(phthalocyaninato)metalates of the rare earth elements, (PNP)[Ln(Pc2-)2]•xH2O (Ln = La, Gd, Tm; x ≤ 0,5)
Of the isostructural series of monoclinic (PNP)[Ln(Pc)2]• xH2O compounds (Ln = La ••• Tm) the crystal structures of the complex salts of tervalent La (1), Gd (2) and Tm (3) have been determined by single crystal X-ray diffraction analysis. Unit cell data for 2: space group P21/c; a = 15.172(8), b = 20.826(2), c = 25.876(3) Å, β = 95.19(3)°, V - 8143(4) Å3, Z = 4; 1 and 3 are isostructural with 2. The lanthanide ion occupies the center of a nearly ideal square antiprism, although the two staggered phthalocyanine rings are severely distorted in an unsymmetrical funnel-shaped fashion due to electronic, steric, and packing influences in the crystal lattice. Steric effects dictate also the geometry of the PNP cation, which adopts a hybrid conformation whose structural characteristics are between the common linear and bent conformers with medium short P-N distances (1.562 Å) and large P-N-P angles in the range 165.6° (1) > 158.3° (2) > 156.1° (3). The strong IR bands at ca. 1375 cm-1 assigned to the asym. (P-N) stretch are diagnostic for this hybrid conformation. The presence of water of crystallization in the periphery of the diphthalocyanine anion is confirmed. The shortest contact distance is observed to one of the bridging nitrogen atoms of the Pc2- ligand (3.02 Å) indicating a weak (HO-H•••N) hydrogen bond