School of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083, People's Republic of China.
Inorg Chem. 2012 Oct 15;51(20):10529-35. doi: 10.1021/ic300638r. Epub 2012 Sep 21.
Dinuclear ruthenium nitrido complexes supported by the Kläui's tripodal ligand CpCo{P(O)(OEt)(2)}(3) (L(OEt)(-)) have been synthesized starting from the ruthenium(VI) nitrido precursor [L(OEt)Ru(VI)(N)Cl(2)] (1). Heating a solution of 1 in CCl(4) at reflux, followed by recrystallization from hexane under nitrogen, afforded the mixed-valence ruthenium(V)-ruthenium(IV) μ-nitrido complex [L(OEt)Cl(2)Ru(V)(μ-N)Ru(IV)Cl(2)L(OEt)] (2). The cyclic voltammogram of 2 exhibited reversible couples at 0.19 and 1.13 V versus Cp(2)Fe(+/0), which are assigned as the Ru(V)-Ru(IV)/Ru(IV)-Ru(IV) and Ru(V)-Ru(V)/Ru(V)-Ru(IV) couples, respectively. Recrystallization of 2 from Et(2)O/heptane in air yielded the diamagnetic Ru(IV)-Ru(IV) complex [H(13)O(6)][{L(OEt)Ru(IV)Cl(2)}(2)(μ-N)] ([H(13)O(6)][2]), which underwent cation exchange with n-Bu(4)NOH to give [n-Bu(4)N][2]. X-ray diffraction revealed that the complex anions in [H(13)O(6)][2] and [n-Bu(4)N][2] contain linear, symmetric Ru-N-Ru bridges. Treatment of 1 with (η(6)-p-cymene)Ru(II)Cl(2) in benzene afforded the tetranuclear ruthenium(IV) complex L(OEt)Cl(2)Ru(IV)(μ-N)Ru(IV)(H(2)O)Cl(2) (3) containing symmetric Ru(IV)-N-Ru(IV) bridges. The reaction of 1 with [Ru(II)(H)(Cl)(CO)(PCy(3))(2)] (Cy = cyclohexyl) gave the ruthenium(VI)-ruthenium(II) nitrido complex [L(OEt)Cl(2)Ru(VI)(μ-N)Ru(II)(H)Cl(CO)(PCy(3))(2)] (4). The observed short Ru(II)-N bond distance [1.915(5) Å] and high C-O stretching frequency (1985 cm(-1)) in 4 are suggestive of π interaction between Ru(II) and the nitride.
双核钌亚硝化物配合物由 Kläui 的三脚架配体 CpCo{P(O)(OEt)(2)}(3)（L(OEt)(-)) 支撑，它是由钌(VI)亚硝化物前体 [L(OEt)Ru(VI)(N)Cl(2)]（1）合成的。在回流的 CCl(4)中加热 1 的溶液，然后在氮气下从己烷中重结晶，得到混合价态的钌(V)-钌(IV)μ-亚硝化物配合物 [L(OEt)Cl(2)Ru(V)(μ-N)Ru(IV)Cl(2)L(OEt)]（2）。2 的循环伏安图在相对于 Cp(2)Fe(+/0) 为 0.19 和 1.13 V 处显示可逆偶，它们分别被分配为 Ru(V)-Ru(IV)/Ru(IV)-Ru(IV)和 Ru(V)-Ru(V)/Ru(V)-Ru(IV)偶。2 在空气中从 Et(2)O/庚烷中重结晶得到顺磁性 Ru(IV)-Ru(IV)配合物 [H(13)O(6)]{L(OEt)Ru(IV)Cl(2)}(2)(μ-N)，它与 n-Bu(4)NOH 进行阳离子交换得到[n-Bu(4)N][2]。X 射线衍射表明，[H(13)O(6)][2]和[n-Bu(4)N][2]中的配合物阴离子含有线性对称的 Ru-N-Ru 桥。用 (η(6)-p-cymene)Ru(II)Cl(2) 在苯中处理 1 得到包含对称 Ru(IV)-N-Ru(IV)桥的四核钌(IV)配合物 L(OEt)Cl(2)Ru(IV)(μ-N)Ru(IV)(H(2)O)Cl(2)（3）。1 与 [Ru(II)(H)(Cl)(CO)(PCy(3))(2)]（Cy = 环己基）的反应得到钌(VI)-钌(II)亚硝化物配合物 [L(OEt)Cl(2)Ru(VI)(μ-N)Ru(II)(H)Cl(CO)(PCy(3))(2)]（4）。在 4 中观察到的短 Ru(II)-N 键距离[1.915(5)Å]和高 C-O 伸缩频率（1985 cm(-1))表明 Ru(II)和亚硝化物之间存在π相互作用。
