Synthesis, Structure, Magnetic Properties, and 1H NMR Studies of a Moderately Antiferromagnetically Coupled Binuclear Copper(II) Complex
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- 作者：Anbanandam Asokan ; Babu Varghese ; and Periakaruppan T. Manoharan
- 刊名：Inorganic Chemistry
- 出版年：1999
- 出版时间：October 4, 1999
- 年：1999
- 卷：38
- 期：20
- 页码：4393 - 4399
- 全文大小：91K
- 年卷期：v.38,no.20(October 4, 1999)
- ISSN：1520-510X
文摘
A binuclear Cu(II) complex of [(Cu2(HAP)2IPA)(OH)(H2O)](ClO4)2·H2O (HAP = 3-amino-1-propanol; IPA =2-hydroxy-5-methylisophthalaldehyde) has been synthesized and characterized by X-ray crystallography, by solidstate magnetic susceptibility, and in solution by 1H NMR studies. The binuclear copper(II) complex crystallizesin the orthorhombic system, space group Pbcn, a = 27.9972(9) Å, b = 8.8713(3) Å, c = 19.5939(6) Å, and Z =8. The two copper(II) atoms in this binuclear Cu(II) complex are bridged by the oxygen atoms of the phenolateand hydroxy groups. The axial position at one Cu atom is occupied by a water molecule while another Cu hasweak interaction with a perchlorate group. The coordination geometries around the two Cu atoms are distortedsquare pyramid and square planar. The solid state magnetic susceptibility measurement reveals a moderateantiferromagnetic exchange interaction between the two Cu atoms with a -2J value of 113 ± 9 cm-1. The variable-temperature 1H NMR studies in CD3CN solution show that the observed relatively sharp hyperfine shifted signalsfollow a Curie behavior. The exchange coupling constant (-2J) obtained in solution by using chemical shift asa function of temperature also reveals a moderate antiferromagnetic exchange interaction between two Cu(II)ions. An analysis of the relaxation data shows that the reorientational correlation time (
tau.gif" BORDER=0 >c) is dominated probablyby a combination of electronic relaxation time tau.gif" BORDER=0 >s and rotational correlation time (tau.gif" BORDER=0 >r) due to an exchange-modulateddipolar mechanism for this moderately antiferromagnetically coupled binuclear copper(II) system.
tau.gif" BORDER=0 >c) is dominated probablyby a combination of electronic relaxation time tau.gif" BORDER=0 >s and rotational correlation time (tau.gif" BORDER=0 >r) due to an exchange-modulateddipolar mechanism for this moderately antiferromagnetically coupled binuclear copper(II) system.