New Magnetic Copper(II) Coordination Polymers with the Polynitrile Ligand (C[C(CN)2]3)2- and N-Donor Co-ligands
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- 作者：Smaï ; l Triki ; Franck Thé ; tiot ; Fanny Vandevelde ; Jean Sala-Pala ; and Carlos J. Gó ; mez-Garcí ; a
- 刊名：Inorganic Chemistry
- 出版年：2005
- 出版时间：May 30, 2005
- 年：2005
- 卷：44
- 期：11
- 页码：4086 - 4093
- 全文大小：292K
- 年卷期：v.44,no.11(May 30, 2005)
- ISSN：1520-510X
文摘
Reactions between CuCl2 and K2tcpd (tcpd2- = [C10N6]2- = (C[C(CN)2]3)2-) in the presence of neutral co-ligands(bpym = 2,2'-bipyrimidine, and tn = 1,3-diaminopropane) in aqueous solution yield the new compounds [Cu2(bpym)(tcpd)2(H2O)4]·2H2O (1), [Cu(tn)(tcpd)] (2), and [Cu(tn)2(tcpd)]·H2O (3), which are characterized by X-raycrystallography and magnetic measurements. Compound 1 displays a one-dimensional structure in which the bpymligand, acting with a bis-chelating coordination mode, leads to [Cu2(bpym)]4+ dinuclear units which are connectedby two 
2-tcpd2- bridging ligands. Compound 2 consists of a three-dimensional structure generated by [Cu(tn)]2+units connected by a 4-tcpd2- ligand. The structure of 3 is made up of centrosymmetric planar [Cu(tn)]2+ unitsconnected by a 2-tcpd2- ligand leading to infinite zigzag chains. In compounds 1 and 3, the bridging coordinationmode of the tcpd2- unit involves only two nitrogen atoms of one C(CN)2 wing, while in 2, this ligand acts via fournitrogen atoms of two C(CN)2 wings. Despite this difference, the structural features of the tcpd2- units in 1-3 areessentially similar. Magnetic measurements for compound 1 exhibit a maximum in the 
m vs T plot (at ~150 K)which is characteristic of strong antiferromagnetic exchange interactions between the Cu(II) metal ions dominatedby the magnetic exchange through the bis-chelating bpym. The fit of the magnetic data to a dimer model gives Jand g values of -90.0 cm-1 and 2.12, respectively. For compounds 2 and 3 the thermal variations of the magneticsusceptibility show weak antiferromagnetic interactions between the Cu(II) metal ions that can be well reproducedwith an antiferromagnetic regular S = 1/2 chain model that gives J values of -0.07(2) and -0.18(1) cm-1 with gvalues of 2.12(1) and 2.13(1) for compounds 2 and 3, respectively (the Hamiltonian is written in all the cases asH = -2JSaSb).
2-tcpd2- bridging ligands. Compound 2 consists of a three-dimensional structure generated by [Cu(tn)]2+units connected by a 4-tcpd2- ligand. The structure of 3 is made up of centrosymmetric planar [Cu(tn)]2+ unitsconnected by a 2-tcpd2- ligand leading to infinite zigzag chains. In compounds 1 and 3, the bridging coordinationmode of the tcpd2- unit involves only two nitrogen atoms of one C(CN)2 wing, while in 2, this ligand acts via fournitrogen atoms of two C(CN)2 wings. Despite this difference, the structural features of the tcpd2- units in 1-3 areessentially similar. Magnetic measurements for compound 1 exhibit a maximum in the m vs T plot (at ~150 K)which is characteristic of strong antiferromagnetic exchange interactions between the Cu(II) metal ions dominatedby the magnetic exchange through the bis-chelating bpym. The fit of the magnetic data to a dimer model gives Jand g values of -90.0 cm-1 and 2.12, respectively. For compounds 2 and 3 the thermal variations of the magneticsusceptibility show weak antiferromagnetic interactions between the Cu(II) metal ions that can be well reproducedwith an antiferromagnetic regular S = 1/2 chain model that gives J values of -0.07(2) and -0.18(1) cm-1 with gvalues of 2.12(1) and 2.13(1) for compounds 2 and 3, respectively (the Hamiltonian is written in all the cases asH = -2JSaSb).