Löffler Marta, Gregoliński Janusz, Korabik Maria, Lis Tadeusz, Lisowski Jerzy
Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie, 50-383 Wrocław, Poland.
Dalton Trans. 2016 Oct 4;45(39):15586-15594. doi: 10.1039/c6dt02504h.
The chiral macrocyclic amines R-L and S-L derived from the 3 + 3 condensation of 2,6-diformylpyridine and (1R,2R)-1,2-diaminocyclohexane or (1S,2S)-1,2-diaminocyclohexane form enantiopure trinuclear Ni(ii) and Cu(ii) complexes [Ni(L)(HO)Cl]Cl and [Cu(L)Cl]Cl and form the dinuclear complex Zn(L)Cl with Zn(ii). The X-ray crystal structures of these complexes indicate remarkably different conformations of the ligand and different binding modes of the chloride anions. The structure of the copper(ii) derivative [Cu(R-L)Cl]Cl·CHCN·7.5(HO) indicates unsymmetrical conformation of the macrocycle with three dissimilar pentacoordinate copper(ii) ions bridged by chloride; the structure of [Ni(R-L)(HO)Cl]Cl·0.4CHCN·4.2HO is somewhat more symmetrical, with three Ni(ii) ions of distorted octahedral geometry, also bridged by a common chloride anion. On the other hand, the macrocycle is highly folded in Zn(R-L)Cl·CHCl·0.8CHOH·3.7HO, forming a cleft where the third Zn(ii) ion is held via electrostatic interactions as the ZnCl anion. The magnetic data for [Cu(R-L)Cl]Cl indicate the coexistence of antiferromagnetic and ferromagnetic interactions within the quasi isosceles tricopper(ii) core (J = -85.6 cm, j = 77.1 cm). Compound [Ni(R-L)(HO)Cl]Cl shows the presence of weak antiferromagnetic coupling (J = -2.56 cm, j = -1.54 cm) between the three Ni(ii) ions.
由2,6 - 二甲基吡啶与(1R,2R)-1,2 - 二氨基环己烷或(1S,2S)-1,2 - 二氨基环己烷通过3 + 3缩合反应得到的手性大环胺R - L和S - L形成了对映体纯的三核Ni(ii)和Cu(ii)配合物[Ni(L)(HO)Cl]Cl和[Cu(L)Cl]Cl，并与Zn(ii)形成了双核配合物Zn(L)Cl。这些配合物的X射线晶体结构表明配体具有明显不同的构象以及氯离子的不同配位模式。铜(ii)衍生物[Cu(R - L)Cl]Cl·CHCN·7.5(HO)的结构表明大环具有不对称构象，三个不同的五配位铜(ii)离子由氯离子桥联；[Ni(R - L)(HO)Cl]Cl·0.4CHCN·4.2HO的结构则更具对称性，三个八面体几何构型畸变的Ni(ii)离子也由一个共同的氯离子阴离子桥联。另一方面，在Zn(R - L)Cl·CHCl·0.8CHOH·3.7HO中，大环高度折叠，形成一个裂缝，第三个Zn(ii)离子通过静电相互作用以ZnCl阴离子的形式存在于其中。[Cu(R - L)Cl]Cl的磁性数据表明在准等腰三铜(ii)核内存在反铁磁和铁磁相互作用的共存(J = -85.6 cm，j = 77.1 cm)。化合物[Ni(R - L)(HO)Cl]Cl表明三个Ni(ii)离子之间存在弱反铁磁耦合(J = -2.56 cm，j = -1.54 cm)。
