Electronic structures of highly symmetrical compounds of f elements.: 37 [1] spectroscopic and structural characterization of Tris(2,6-di-t- butyl-phenolato)lanthanide(III) (Ln(OAr′)3; Ln = Pr, Nd), and parametric analysis of the crystal field splitting pattern of Nd(OAr′)3
Electronic structures of highly symmetrical compounds of f elements.: 37 [1] spectroscopic and structural characterization of Tris(2,6-di-t- butyl-phenolato)lanthanide(III) (Ln(OAr′)3; Ln = Pr, Nd), and parametric analysis of the crystal field splitting pattern of Nd(OAr′)3
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DOI：
10.1002/zaac.200300110
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发表时间：
2003-08-01
影响因子：
1.4
通讯作者：
Kanellakopulos, B
中科院分区：
文献类型：
--
作者：
Amberger, HD;Reddmann, H;Kanellakopulos, B
Pr(OAr')(3) 和 Nd(OAr')(3) 在单斜空间群 P2(1) 中结晶（分别在大约 150 K 和 200 K 下），晶胞中有四个分子。如果仅考虑直接配位的氧原子，则有效晶场具有C-3v对称性。即使使用溶液或固体，Pr(OAr')(3) 光谱中的信号也很宽，即使在大约 100°C 的情况下也是如此。 80-90 K，因此它们不适合解释目的。然而，Nd(OAr')(3) 在室温和低温下表现出尖锐的吸收带，这些吸收带类似于先前基于光学偏振测量确定的 Nd[N(SiMe3)(2)](3) 的吸收跃迁。通过拟合唯象哈密顿量的自由参数来模拟由此得出的晶体场分裂模式，从而实现了降低的均方根值。 64 次分配的偏差为 26.4 cm(-1)。使用的参数允许估计与 (OAr')(-) 配体相关的配体场强，将该配体插入经验霞石和相对论霞石系列中，以及在 f 范围内建立基于实验的非相对论和相对论分子轨道方案。
Pr(OAr')(3) and Nd(OAr')(3) crystallize (at approximately 150 K and 200 K, respectively) in the monoclinic space group P2(1) with four molecules in the unit cell. If one considers only the directly coordinating oxygen atoms, the effective crystal field is of C-3v-symmetry. The signals in the optical spectra of Pr(OAr')(3) are broad using either solutions or solids, even at ca. 80-90 K, thus they are not suitable for interpretation purposes. Nd(OAr')(3), however, exhibits sharp absorption bands at room and low temperatures, which are assigned in analogy to the previously identified absorption transitions of Nd[N(SiMe3)(2)](3) based on optical polarization measurements. The thus derived crystal field splitting pattern is simulated by fitting the free parameters of a phenomenological Hamiltonian, achieving a reduced r.m.s. deviation of 26.4 cm(-1) for 64 assignments. The parameters used allow the estimation of the ligand field strength associated with the (OAr')(-) ligand, the insertion of this ligand into empirical nephelauxetic and relativistic nephelauxetic series, and the setup of experimentally-based non-relativistic and relativistic molecular orbital schemes in the f range.