Structural Systematics of Rare Earth Complexes. V. The Hydrated 1 : 1 Adducts of 2,2′:6′,2″-Terpyridine With the Lanthanoid(III) Chlorides

Abstract

Detailed examination of the strucures of the title salts, (tpy)LnCl3.xH2O, across the totality of the rare earth series shows a remarkable interplay of structural type and detail. The predominant phase is the previously studied monoclinic Cm array, a ˜ 7.5, b ˜ 16.6, c ˜ 9.8 ?, ß = 90.2°, V ˜ 2200 ?3, Z = 2 formula units. For the initial members of the series (La ? Nd ), x is 8; for Dy ? Er and Lu, x = 7 is accommodated within the same lattice, as are intermediate degrees of hydration for Sm ? Gd . A second monoclinic phase, P 21/c, a ˜ 11.6, b ˜ 13.9, c ˜ 13.8 ?, ß ˜ 92.3°, V ˜ 2200 ?3, Z = 4 formula units, is found for Yb and Lu (x = 7); the same phase but with ß acute (a ˜ 11.3, b ˜ 14.5, c ˜ 13.3 ?, ß ˜ 82.2°, V ˜ 2140 ?3, Z = 4 formula units) is found for Tm (and Y) (x = 6). A less hydrated binuclear phase, x=1, has also been observed for Sm , a 10.179(3), b 9.928(4), c 9.748(4) ?a 112.61(3), ß 109.85(3), ? 94.72(3)°, V 829.3 ?3, Z = 1 dimer.