The reaction of NiCl2 with excess potassium pivalate (KPiv) in ethanol affords the chainpolymeric compound KNi4(Piv)7(OH)2(EtOH)6. In the solid compound, the tetranuclear nickel fragments alternate with potassium atoms. The use of KNi4(Piv)7(OH)2(EtOH)6 in the reaction with Ni(hfac)2 (hfac is the hexafluoroacetylacetonate anion) gave the first polynuclear mixed-ligand complexes [K2Ni6(Piv)7(hfac)3(OH)4(HPiv)2(Me2CO)2]·1.5C7H16, [Ni6(Piv)4(hfac)4(OH)4(Me2CO)4], [K2Ni8(Piv)8(hfac)4(OH)6(H2O)2(Me2CO)6], [Ni8(Piv)10(hfac)2(OH)2(MeO)2(MeOH)2(HPiv)2]·C6H14, and [Ni16(Piv)10(hfac)6(OH)10(MeO)6(MeOH)8(H2O)6]·C6H14 containing both Piv and hfac as the anionic ligands. The molecular and crystal structures of all these compounds were established, and their magnetic properties were studied. All solids containing simultaneously Piv and hfac ligands tend to undergo ferromagnetic ordering with decreasing temperature. The solid [Ni8(Piv)10(hfac)2(OH)2(MeO)2(MeOH)2(HPiv)2]·C6H14 undergoes cooperative magnetic ordering below T c (2.5 K).
在
乙醇中,NiCl2 与过量的特
戊酸钾(KPiv)反应生成链状聚合化合物 KNi4(Piv)7(OH)2(EtOH)6。在固体化合物中,四核
镍片段与
钾原子交替出现。利用 KNi4(Piv)7(OH)2(EtOH)6 与 Ni(hfac)2(hfac 是
六氟乙酰丙酮阴离子)反应,得到了第一个多核混合
配体复合物 [K2Ni6(Piv)7(hfac)3(OH)4(HPiv)2(Me2CO)2]-1。5C7H16、[Ni6(Piv)4(hfac)4(OH)4(Me2CO)4]、[K2Ni8(Piv)8(hfac)4(OH)6(
H2O)2(Me2CO)6]、[Ni8(Piv)10(hfac)2(OH)2(MeO)2(MeOH)2(HPiv)2]-
C6H14、以及同时含有 Piv 和 hfac 作为阴离子
配体的 [Ni16(Piv)10(hfac)6(OH)10(MeO)6(MeOH)8( )6]- 。我们建立了所有这些化合物的分子和晶体结构,并研究了它们的磁性能。所有同时含有 Piv 和 hfac
配体的固体都倾向于随着温度的降低而发生
铁磁有序化。固体[Ni8(Piv)10(hfac)2(OH)2(MeO)2(MeOH)2(HPiv)2]- 在低于 T c (2.5 K) 时会发生协同磁有序。