Syntheses, X-ray structures, and properties of complexes of macrocyclic hexaimines with lanthanide nitrates

Abstract

Complexes [M (NO₃)₃L¹]{M = La or Ce, L¹= 2,7,13,18-tetramethyl-3,6,14,17,23,24-hexa-azatricyclo[17.3.1.1^8,12]tetracosa-1 (23),2,6,8,10,12(24),13,17,19,21-decaene}, [M(NO₃)₂L¹(H₂O)]NO₃·H₂O (M = La, Ce, or Pr), and [{M(NO₃)L¹(H₂O)₂}₂]NO₃[ClO₄]₃·4H₂O (M = Nd, Sm, Eu, Gd, Tb, Dy, Ho, or Er) have been synthesised by a template condensation or by ligand exchange. The X-ray crystal structures of a member of each series, [La(NO₃)₃L¹], [Ce(NO₃)₂L¹(H₂O)]NO₃·H₂O, and [{Nd(NO₃)L¹(H₂O)₂}₂]NO₃[ClO₄]₃·4H₂O have been determined; the complexes contain the hexadentate macrocycle L¹ co-ordinated to the lanthanide ion and are respectively 12-, 11-, and 10-co-ordinate. Properties including n.m.r. paramagnetic shifts are described.