layers. Only compounds with n =2, 4 and 8 show a net magnetic moment within copper(II) layers. For the short chain anions, an antiferromagnetic order occurs at low temperature, with a metamagnetic transition in low field, except for the unsaturated dicarboxylate Cu 2 (OH) 1.92 (C 4 H 6 C 2 O 4 ) 1.04 ·0.22H 2 O which exhibits a long-range ferromagnetic order at T C =13 K. For the long-chain anion, X=C
摘要我们报道了一系列多层羟基二
羧酸铜(II)的制备,结构和磁性。这些是通过阴离子交换从
羟基乙酸铜(II)Cu 2(OH)3(OAc)·H 2 O制备的。
乙酸根离子用X取代正亚甲基二
羧酸盐O 2 CXCO 2 2-。 =(CH 2)n且n = 1至8。用不饱和二
羧酸根阴离子(X =(CH)n,n = 2、4和X = C 4 H 6)进行类似的交换反应。通式为Cu 2(OH)4-(xC 2 O 4)x / 2的化合物。·z H 2 O表现出一种层状结构,根据n个奇偶性,其基础间距呈阶梯状变化。红外光谱表明,
羧酸盐官能团与
金属离子相连,每个脂族链桥接相邻的氢氧化物层。只有n = 2的化合物,图4和图8示出了
铜(II)层内的净磁矩。对于短链阴离子,除不饱和二
羧酸铜2(OH)1.92(C 4 H 6 C 2 O 4)1.04·0.22H 2 O其中,在TC = 13 K时表现出远距离
铁磁序。对于长链阴离子X