Nickel(II) Macrocyclic Complexes with Long Alkyl Pendant Chain: Synthesis, X-ray Structure, and Anion Exchange Property in the Solid State

Publisher Website
Google Scholar
Abstract
A nickel(II) pentaaza macrocyclic complex containing a 1-hexadecyl pendant chain, [Ni(C25H55N5)](ClO4)2·H2O (1), was synthesized by a one-pot metal-template condensation reaction. Crystal data for 1: triclinic, P1̄, a = 8.333(4) Å, b = 8.356(3) Å, c = 28.374(9) Å, α = 81.865(19)°, β = 86.242(18)°, γ = 63.871(17)°, Z = 2. Solid 1 forms hydrophobic layers that are constructed by the long alkyl chains of the macrocycles. Solid 1 exchanges ClO4- with NCS-, PF6-, C2O42-, NO3-, and CF3SO3- that are dissolved in water. From the reaction of [Ni(C25H55N5)Cl2] with Et3NH(TCNQ)2 in EtOH/DMF/acetone solution, [Ni(C25H55N5)(TCNQ)2](TCNQ)·(CH3COCH3) (2) (TCNQ = 7,7,8,8-tetracyano-p-quinodimethane) was prepared. Crystal data for 2: triclinic, P1̄, a = 8.459(0) Å, b = 13.945 (1) Å, c = 26.833(2) Å, α = 88.744(2)°, β = 84.536(2)°, γ = 80.089(4) °, Z = 2. In 2, TCNQ anions coordinate nickel(II) at the axial sites, which form π-stacked TCNQ- dimers to give rise to 1-D chains. The neutral TCNQ molecules are included between the dimerized TCNQ- species, which construct a π-stacked group of six TCNQ units as blocked by the long alkyl chains. Compound 2 is an electric insulator. It shows a weak signal in the EPR spectrum. The magnetic susceptibility data of 2 measured at 5−300 K exhibit a simple paramagnetism at low temperatures (22-.