<sup>5</sup>T<sub>2</sub>⇌<sup>1</sup>A<sub>1</sub>and<sup>6</sup>A<sub>1</sub>⇌<sup>2</sup>T<sub>2</sub>spin transitions in iron(<scp>II</scp>) and iron(<scp>III</scp>) complexes of 2,2′-bi-2-imidazoline and related ligands
作者:Michael G. Burnett、Vickie McKee、S. Martin Nelson
DOI:10.1039/dt9810001492
日期:——
and L6 are fully high-spin (S= 2) over the temperature range 90–360 K, while for complexes of L3(X = ClO4 but not BPh4) and L4(X = ClO4 and BPh4) a 5T2⇌1A1 spin transition is observed in this temperature range. Electronic spectra of the corresponding nickel(II) complexes indicate a correlation between Dq(Ni) and the spin ground state of the iron(II) complexes. The iron(III) complex [FeIIIL33][ClO4]3
二齿配体2,2'-bi-2-咪唑啉(L 3),2的一系列六配位铁(II)配合物[Fe II L 3 ] X 2(X = ClO 4或BPh 4),2'-bi-1,4,5,6-四氢嘧啶(L 4),2,2'-bi-2-恶唑啉(L 5)和5,5'-二甲基-2,2'-bi-已经制备了2-恶唑啉(L 6),并通过其物理性质对其进行了表征。在所有情况下,均通过α-二亚胺基进行配位。磁化率和Mössbauer效应随温度的变化表明L 5和L 6的配合物是完全自旋的(小号= 2)的温度范围内90-360 K,而对于L的配合物3(X = CLO 4但不BPH 4)和L 4(X = CLO 4和BPH 4)一个5 Ť 2 ⇌ 1阿1旋在此温度范围内观察到转变。相应的镍(II)配合物的电子光谱表明Dq(Ni)与铁(II)配合物的自旋基态之间存在相关性。铁(III)络合物[Fe III L 3 3 ] [ClO 4