Berard Joel J, Schreckenbach Georg, Arnold Polly L, Patel Dipti, Love Jason B
Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada.
Inorg Chem. 2008 Dec 15;47(24):11583-92. doi: 10.1021/ic8010772.
Density functional theoretical methods are used to study heterobimetallic compounds of a new form of binucleating Schiff-base polypyrrolic macrocycle, denoted [An(VI)O(2)(1)H(2)L], An(V)O(2)(1)H(2)L, [An(VI)O(2)(TM)L] and An(V)O(2)(TM)L, and containing actinyl ions AnO(2)(n+) (An = U, Np, Pu; n = 1, 2) and 3d transition metals (TM): no TM = 1, Mn = 2, Fe = 3, Co = 4, and Zn = 5. Calculated bond orders (TM-O2 = 0.36 to 0.81) provide evidence for partial bond formation between the transition metal (TM) and the actinyl-endo-oxygen for all 24 cases studied. Redox potentials for [An(VI)O(2)(1)H(2)L]/An(V)O(2)(1)H(2)L couples were found to have the same Np(VI/V) > Pu(VI/V) > U(VI/V) trend as previously studied for the AnO(2)(H(2)O)(5) couples, where Np(VI) is the most easily reduced to Np(V). Extrapolation from the earlier penta-aqua actinyl results is used to predict [An(VI)O(2)(1)H(2)L]/An(V)O(2)(1)H(2)L redox couples of U = -1.10 eV, Np = 0.25 eV, and Pu = 0.01 eV. The calculated redox potential for [U(VI)O(2)(1)H(2)L]/U(V)O(2)(1)H(2)L is within 0.08 eV of the value found by cyclic voltammetry (-1.18 eV, in THF/NBu(n)(4)BF(4) solvent).
密度泛函理论方法用于研究一种新型双核席夫碱聚吡咯大环的异双金属化合物，分别表示为[An(VI)O₂(1)H₂L]、[An(V)O₂(1)H₂L]⁻、[An(VI)O₂(TM)L]和[An(V)O₂(TM)L]⁻，其中包含酰基离子AnO₂ⁿ⁺（An = U、Np、Pu；n = 1、2）和3d过渡金属（TM）：无TM = 1、Mn = 2、Fe = 3、Co = 4、Zn = 5。计算得到的键级（TM - O₂ = 0.36至0.81）为所研究的所有24种情况中过渡金属（TM）与酰基内氧之间的部分键形成提供了证据。发现[An(VI)O₂(1)H₂L]/[An(V)O₂(1)H₂L]⁻电对的氧化还原电位具有与先前研究的[AnO₂(H₂O)₅]²⁺/¹⁺电对相同的Np(VI/V) > Pu(VI/V) > U(VI/V)趋势，其中Np(VI)最容易还原为Np(V)。根据早期五水酰基的结果进行外推，预测[An(VI)O₂(1)H₂L]/[An(V)O₂(1)H₂L]⁻氧化还原电对的U = -1.10 eV、Np = 0.25 eV和Pu = 0.01 eV。[U(VI)O₂(1)H₂L]/[U(V)O₂(1)H₂L]⁻的计算氧化还原电位与循环伏安法测得的值（在THF/NBu₄BF₄溶剂中为-1.18 eV）相差0.08 eV以内。
