铜 (II) - 加多 (III) 复合体中铁磁合的机制
Jozef Paulovic1, Fanica Cimpoesu, Marilena Ferbinteanu
1Department of Applied Chemistry, School of Engineering University of Tokyo, Tokyo, Japan.
Journal of the American Chemical Society
|March 12, 2004
概括
最先进的量子化学计算揭示了铜-加多复合体中铁磁合背后的机制. 铁磁合通常是由于特定的电子相互作用和伪C2对称性而观察到的.
科学领域:
- 量子化学 是一个量子化学.
- 材料科学 材料科学 材料科学
- 磁电化学 磁电化学 磁电化学
背景情况:
- 众所周知,铜-加多复合体具有铁磁合.
- 了解底层电子机制对于设计新的磁性材料至关重要.
研究的目的:
- 通过先进的量子化学计算,研究铜-加多复合体中近乎一般的铁磁合.
- 阐明负责铁磁相互作用的电子通路.
主要方法:
- 最先进的量子化学计算包括完整的活性空间自相一致场 (CASSCF),CAS支持的扰动理论到第二阶段 (CASPT2) 和多状态CASPT2 (MS-CASPT2).
- 分析模型和几何优化到C(2)(v) 对称.
- 非标准的计算程序,以解决非aufbau地面配置.
主要成果:
- 计算的磁性合常量准确地复制了CASSCF级别的实验值.
- 卡恩机制涉及从Cu(II) 3d到Gd(III) 5d轨道的电子转移,当使用CASPT2分子轨道时,有效地解释了铁磁合.
- 旋转对联体的极化效应,涉及Gd(III) 5d型原子轨道,放大铁磁合,支持和完善Gatteschi机制.
- 铁磁合在C(2)(v) 对称性中受到轨道正交的青,而分子不对称性则导致反铁磁的例外.
结论:
- 铁磁合Cu (II) -Gd (III) 的普遍性归因于近似伪C (II) -Gd (III) 几何学的普遍性.
- 卡恩和加特斯基机制都对铁磁合有助,并且可以相互转换.
- 分子对称性在确定磁性合的类型和强度方面发挥着关键作用.
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