Marchetti Fabio, Pettinari Claudio, Pettinari Riccardo, Cerquetella Adele, Di Nicola Corrado, Macchioni Alceo, Zuccaccia Daniele, Monari Magda, Piccinelli Fabio
Dipartimento di Scienze Chimiche, Università degli Studi di Camerino, Via S. Agostino 1, I-62032 Camerino, MC, Italy.
Inorg Chem. 2008 Dec 15;47(24):11593-603. doi: 10.1021/ic801150c.
Arene ruthenium(II) complexes containing bis(pyrazolyl)methane ligands have been prepared by reacting the ligands L' (L' in general; specifically L(1) = H(2)C(pz)(2), L(2) = H(2)C(pz(Me2))(2), L(3) = H(2)C(pz(4Me))(2), L(4) = Me(2)C(pz)(2) and L(5) = Et(2)C(pz)(2) where pz = pyrazole) with (arene)RuCl(mu-Cl) dimers (arene = p-cymene or benzene). When the reaction was carried out in methanol solution, complexes of the type [(arene)Ru(L')Cl]Cl were obtained. When L(1), L(2), L(3), and L(5) ligands reacted with excess (arene)RuCl(mu-Cl), [(arene)Ru(L')Cl][(arene)RuCl(3)] species have been obtained, whereas by using the L(4) ligand under the same reaction conditions the unexpected [(p-cymene)Ru(pzH)(2)Cl]Cl complex was recovered. The reaction of 1 equiv of [(p-cymene)Ru(L')Cl]Cl and of [(p-cymene)Ru(pzH)(2)Cl]Cl with 1 equiv of AgX (X = O(3)SCF(3) or BF(4)) in methanol afforded the complexes (p-cymene)Ru(L')Cl (L' = L(1) or L(2)) and [(p-cymene)Ru(pzH)(2)Cl]BF(4), respectively. [(p-cymene)Ru(L(1))(H(2)O)]PF(6) formed when [(p-cymene)Ru(L(1))Cl]Cl reacts with an excess of AgPF(6). The solid-state structures of the three complexes, [(p-cymene)Ru{H(2)C(pz)(2)}Cl]Cl, [(p-cymene)Ru{H(2)Cpz(4Me))(2)}Cl]Cl, and (p-cymene)Ru{H(2)C(pz)(2)}Cl, were determined by X-ray crystallographic studies. The interionic structure of (p-cymene)Ru(L(1))Cl and [(p-cymene)Ru(L')Cl][(p-cymene)RuCl(3)] (L' = L(1) or L(2)) was investigated through an integrated experimental approach based on NOE and pulsed field gradient spin-echo (PGSE) NMR experiments in CD(2)Cl(2) as a function of the concentration. PGSE NMR measurements indicate the predominance of ion pairs in solution. NOE measurements suggest that (O(3)SCF(3))(-) approaches the cation orienting itself toward the CH(2) moiety of the L(1) (H(2)C(pz)(2)) ligand as found in the solid state. Selected Ru species have been preliminarily investigated as catalysts toward styrene oxidation by dihydrogen peroxide, [(p-cymene)Ru(L(1))(H(2)O)]PF(6) being the most active species.
通过使配体L'（一般情况下的L'；具体而言，L(1) = H₂C(pz)₂，L(2) = H₂C(pz(Me₂))₂，L(3) = H₂C(pz(4Me))₂，L(4) = Me₂C(pz)₂ 以及L(5) = Et₂C(pz)₂，其中pz = 吡唑）与[(芳烃)RuCl(μ-Cl)]₂二聚体（芳烃 = 对异丙基苯或苯）反应，制备了含有双(吡唑基)甲烷配体的芳烃钌(II)配合物。当反应在甲醇溶液中进行时，得到了[(芳烃)Ru(L')Cl]Cl类型的配合物。当L(1)、L(2)、L(3)和L(5)配体与过量的[(芳烃)RuCl(μ-Cl)]₂反应时，得到了[(芳烃)Ru(L')Cl][(芳烃)RuCl₃]物种，而在相同反应条件下使用L(4)配体时，回收得到了意想不到的[(对异丙基苯)Ru(pzH)₂Cl]Cl配合物。1当量的[(对异丙基苯)Ru(L')Cl]Cl和[(对异丙基苯)Ru(pzH)₂Cl]Cl与1当量的AgX（X = O₃SCF₃或BF₄）在甲醇中反应，分别得到了配合物(对异丙基苯)Ru(L')Cl（L' = L(1)或L(2)）和[(对异丙基苯)Ru(pzH)₂Cl]BF₄。当[(对异丙基苯)Ru(L(1))Cl]Cl与过量的AgPF₆反应时，形成了[(对异丙基苯)Ru(L(1))(H₂O)][PF₆]₂。通过X射线晶体学研究确定了三种配合物[(对异丙基苯)Ru{H₂C(pz)₂}Cl]Cl、[(对异丙基苯)Ru{H₂Cpz(4Me))₂}Cl]Cl和(对异丙基苯)Ru{H₂C(pz)₂}Cl的固态结构。通过基于NOE和脉冲场梯度自旋回波（PGSE）NMR实验的综合实验方法，在CD₂Cl₂中作为浓度的函数，研究了(对异丙基苯)Ru(L(1))Cl和[(对异丙基苯)Ru(L')Cl][(对异丙基苯)RuCl₃]（L' = L(1)或L(2)）的离子间结构。PGSE NMR测量表明溶液中离子对占主导。NOE测量表明，(O₃SCF₃)⁻接近阳离子，其自身朝向L(1)（H₂C(pz)₂）配体的CH₂部分定向，如同在固态中所发现的那样。已对选定的Ru物种作为过氧化氢氧化苯乙烯的催化剂进行了初步研究，[(对异丙基苯)Ru(L(1))(H₂O)][PF₆]₂是最具活性的物种。
