Synthesis and physico-chemical studies on neodymium(III) and samarium(III) complexes with tetraaza macrocyclic ligands

Reactions of neodymium trichloride and samarium trichloride with 6, 7, 13, 14-R₄-3, 10-X₂-[14]- 5, 7, 12, 14-tetraene-l, 5, 8, l2-N₄-[2, 4, 9, l1-N₄] (R = CH₃, X = 0 (L₁ ⁽¹⁾); R = C₆H₅, X = O (L₁ ⁽²⁾); R = CH₃, X = S (L₂ ⁽¹⁾)) and R = C₆H₅, X = S (L₂ ⁽²⁾)) have been studied in ethanol and complexes of the type [M(L₁ ⁽¹⁾ or L₁⁽²⁾)]C1₃ and [M(L₂ ⁽¹⁾ or L₂ ⁽²⁾)(H₂O)₂]C1₃ (M = Nd(III) and Sm(III)) have been isolated. In addition, macrocyclic complexes of Nd(III) and Sm(III) with another series of tetraaza ligands, viz, 5, 6, 1 l, 12-R₄-3, 8-X₂-[12]-4, 6, 10, 12-tetraene-1, 4, 7, 10-N₄-[2, 9-N₂] (R = CH₃, X = O (L₃ ⁽¹⁾); R = C₆H₅, X = O (L₃ ⁽²⁾); R = CH₃, X = S (L₄ ⁽¹⁾); R = C₆H₅, X = S (L₃ ⁽²⁾)), formulated as [M(L₃ ⁽¹⁾, L₃ ⁽²⁾, L₄ ⁽¹⁾ or L₄ ⁽²⁾)(H₂O)₂]C1₃ (M = Nd(III) and Sm(III)) have been prepared by template condensation of Nd(III) and Sm(III) complexes of diacetylbis(semicarbazone/thiosemicarbazone) or benzilbis(semicarbazone/thiosemicarbazone) with diacetyl or benzil. The complexes have been identified by elemental analysis, electrical conductance, spectral and thermal measurements.