Substitution reactions in dinuclear Ru-Hbpp complexes: an evaluation of through-space interactions.
Substitution reactions in dinuclear Ru-Hbpp complexes: an evaluation of through-space interactions.
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双核 Ru-Hbpp 复合物中的取代反应：对空间相互作用的评估。
DOI：
10.1021/ic202225g
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发表时间：
2012
影响因子：
4.6
通讯作者：
A. Llobet
中科院分区：
文献类型：
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作者：
Nora Planas;G. Christian;Stephan Roeser;Elena Mas;M. Kollipara;J. Benet‐Buchholz;F. Maseras;A. Llobet
通式为：in-{[Ru(II)(trpy)(L)](μ-bpp)[Ru(II)(trpy)(L‘)]}(3+)[bpp(-)为双(2-吡啶)-3，5-吡唑酸阴离子配体；trpy为2，2’：6‘，2“-三联吡啶中性子午配体，L和L’为单齿配体；L=L‘=MeCN，3a(3+)；L=L’=3，5-lutidine(Me(2)-py)，3c(3+)；合成了L=MeCN，L‘=吡啶(Py)，4(3+)]，并对其进行了表征。此外，还合成和分离了通式为In-{[Ru(II)(Trpy)](2)(μ-bpp)(μ-L-L)}(3+)[μ-L-L=1，4-二氰基丁烷(己二腈，脂肪)，6a(3+)；1，3-二氰基丙烷(戊二腈，GUT)，6b(3+)；1，2-二氰基乙烷(丁二腈，Succ)，6c(3+)]的二腈桥联配体的双核配合物。此外，为了比较的目的，还制备了一些前述的含有阴离子双(吡啶基)吲哚(BID(-))三齿子午线配体代替trpy的同源双核配合物。在固态下，用X-射线单晶衍射法对六个配合物进行了表征，在溶液中，用核磁共振和紫外可见光谱对它们进行了表征。此外，还用循环伏安法和差示脉冲伏安法研究了它们的氧化还原性质，结果表明它们存在两个单电子波，分别与II、III和III、III物种的形成有关。二腈配合物6a(3+)、6b(3+)和6c(3+)表现出涉及其对映体相互转化的动态行为。这种相互转化的能垒可以由二腈配体之间的亚甲基单元的数量来控制。另一方面，In-{[Ru(II)(T)(Py)](2)(μ-bpp)}(n+)(T=trpy，n=3，3b(3+)；T=Bid(-)，n=1，3b‘(+))和3c(3+)中的吡啶配合物发生了两次连续的单齿取代反应。对于3b(3+)离子，其一级速率常数k(1)=(2.9±0.3)×10(-5)S(-1)，而对于第二取代物，k(2)=(1.7±0.7)×10(-6)S(-1)，二者在313K下的活化能分别为114.7和144.3 kJmol(-1)。对两个连续的取代反应进行了密度泛函理论(DFT)计算，揭示了中间体的性质。此外，对两个连续的取代反应进行密度泛函理论计算得到的能量与实验值基本一致。两个连续的取代反应的动力学性质在空间拥挤和空间相互作用方面是合理的。
The synthesis of new dinuclear complexes of the general formula in,in-{[Ru(II)(trpy)(L)](μ-bpp)[Ru(II)(trpy)(L')]}(3+) [bpp(-) is the bis(2-pyridyl)-3,5-pyrazolate anionic ligand; trpy is the 2,2':6',2″-terpyridine neutral meridional ligand, and L and L' are monodentate ligands; L = L' = MeCN, 3a(3+); L = L' = 3,5-lutidine (Me(2)-py), 3c(3+); L = MeCN, L' = pyridine (py), 4(3+)], have been prepared and thoroughly characterized. Further, the preparation and isolation of dinuclear complexes containing dinitrile bridging ligands of the general formula in,in-{[Ru(II)(trpy)](2)(μ-bpp)(μ-L-L)}(3+) [μ-L-L = 1,4-dicyanobutane (adiponitrile, adip), 6a(3+); 1,3-dicyanopropane (glutaronitrile, glut), 6b(3+); 1,2-dicyanoethane (succinonitrile; succ), 6c(3+)] have also been carried out. In addition, a number of homologous dinuclear complexes previously described, containing the anionic bis(pyridyl)indazolate (bid(-)) tridentate meridional ligand in lieu of trpy, have also been prepared for comparative purposes. In the solid state, six complexes have been characterized by X-ray crystallography, and in solution, all of them have been spectroscopically characterized by NMR and UV-vis spectroscopy. In addition, their redox properties have also been investigated by means of cyclic voltammetry and differential pulse voltammetry and show the existence of two one-electron waves assigned to the formation of the II,III and III,III species. Dinitrile complexes 6a(3+), 6b(3+), and 6c(3+) display a dynamic behavior involving their enantiomeric interconversion. The energy barrier for this interconversion can be controlled by the number of methylenic units between the dinitrile ligand. On the other hand, pyridyl complexes in,in-{[Ru(II)(T)(py)](2)(μ-bpp)}(n+) (T = trpy, n = 3, 3b(3+); T = bid(-), n = 1, 3b'(+)) and 3c(3+) undergo two consecutive substitution reactions of their monodentate ligands by MeCN.The substitution kinetics have been monitored by (1)H NMR and UV-vis spectroscopy and follow first-order behavior with regard to the initial ruthenium complex. For the case of 3b(3+), the first-order rate constant k(1) = (2.9 ± 0.3) × 10(-5) s(-1), whereas for the second substitution, the k obtained is k(2) = (1.7 ± 0.7) × 10(-6) s(-1), both measured at 313 K. Their energies of activation at 298 K are 114.7 and 144.3 kJ mol(-1), respectively. Density functional theory (DFT) calculations have been performed for two consecutive substitution reactions, giving insight into the nature of the intermediates. Furthermore, the energetics obtained by DFT calculations of the two consecutive substitution reactions agree with the experimental values obtained. The kinetic properties of the two consecutive substitution reactions are rationalized in terms of steric crowding and also in terms of through-space interactions.
影响因子：
56.9
作者：
Kelley, SO;Barton, JK
通讯作者：
Barton, JK
DOI：
10.1107/s0108767394005726
发表时间：
1995-01-01
期刊：
ACTA CRYSTALLOGRAPHICA SECTION A
影响因子：
--
作者：
BLESSING, RH
通讯作者：
BLESSING, RH