957014-12-9Relevant academic research and scientific papers
Synthesis and characterisation of dinuclear nickel(II) and cadmium(II) complexes of N-alkylated derivatives of hexaazadithiophenolate macrocycles
Gressenbuch, Mathias,Kersting, Berthold
, p. 90 - 102 (2007)
The effect of N-alkylation on the ligating properties of the Robson-type 24-membered hexaazadithiophenolate macrocycle H2L1 [13,27-bis(tert-butyl)-3,6,9,17,20,23-hexaazatricyclo[23.3.111,15] triaconta-1(28),11,13,15(30),25,26-hexaene-29,30-dithiol] has been examined. Two new derivatives (H2L3 and H2L4) of H2L1 have been prepared. H2L3 is a dimethylated derivative of H2L1 and H2L 4 is a tetraethylated derivative of H2L3. A series of complexes of the type [(LR)MII 2(μ-Cl)]+ [R = 1, M = Cd (10), R = 3, M = Ni (8), M = Cd (12), R = 4, M = Ni (9), M = Cd (13)] have been prepared and structurally characterised. The X-ray crystal structure determination of these dioctahedral complexes with an N3M(S)2(μ-Cl)MN3 core structure has revealed two conformations of the supporting ligands. In 8, 9, 10 and 12 the ligands adopt a folded Cs-symmetric conformation of type A whereas in the cadmium complex 13 the alternative C2v-symmetric bowl-shaped conformation (type B) is present. A structural comparison has allowed us to determine the factors that determine the ligand conformations. It has been established that the ligand conformations adopted depend not only on the co-ligand but also on the metal ion radius and the N-alkylation grade. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
