Sellmann Dieter, Hille A, Rösler A, Heinemann F W, Moll M, Brehm G, Schneider S, Reiher M, Hess B A, Bauer W
Institut für Anorganische Chemie, der Universität Erlangen-Nürnberg, Egerlandstrasse 1, 91058 Erlangen, Germany.
Chemistry. 2004 Feb 20;10(4):819-30. doi: 10.1002/chem.200305499.
In the quest for low-molecular-weight metal sulfur complexes that bind nitrogenase-relevant small molecules and can serve as model complexes for nitrogenase, compounds with the [Ru(PiPr(3))('N(2)Me(2)S(2)')] fragment were found ('N(2)Me(2)S(2)'(2-)=1,2-ethanediamine-N,N'-dimethyl-N,N'-bis(2-benzenethiolate)(2-)). This fragment enabled the synthesis of a first series of chiral metal sulfur complexes, [Ru(L)(PiPr(3))('N(2)Me(2)S(2)')] with L=N(2), N(2)H(2), N(2)H(4), and NH(3), that meet the biological constraint of forming under mild conditions. The reaction of [Ru(NCCH(3))(PiPr(3))('N(2)Me(2)S(2)')] (1) with NH(3) gave the ammonia complex [Ru(NH(3))(PiPr(3))('N(2)Me(2)S(2)')] (4), which readily exchanged NH(3) for N(2) to yield the mononuclear dinitrogen complex [Ru(N(2))(PiPr(3))('N(2)Me(2)S(2)')] (2) in almost quantitative yield. Complex 2, obtained by this new efficient synthesis, was the starting material for the synthesis of dinuclear (R,R)- and (S,S)-[micro-N(2)Ru(PiPr(3))('N(2)Me(2)S(2)')] ((R,R)-/(S,S)-3). (Both 2 and 3 have been reported previously.) The as-yet inexplicable behavior of complex 3 to form also the R,S isomer in solution has been revealed by DFT calculations and (2)D NMR spectroscopy studies. The reaction of 1 or 2 with anhydrous hydrazine yielded the hydrazine complex [Ru(N(2)H(4))(PiPr(3))('N(2)Me(2)S(2)')] (6), which is a highly reactive intermediate. Disproportionation of 6 resulted in the formation of mononuclear diazene complexes, the ammonia complex 4, and finally the dinuclear diazene complex [micro-N(2)H(2)Ru(PiPr(3))('N(2)Me(2)S(2)')] (5). Dinuclear complex 5 could also be obtained directly in an independent synthesis from 1 and N(2)H(2), which was generated in situ by acidolysis of K(2)N(2)(CO(2))(2). Treatment of 6 with CH(2)Cl(2), however, formed a chloromethylated diazene species [[Ru(PiPr(3))('N(2)Me(2)S(2)')]-micro-N(2)H(2)[Ru(Cl)('N(2)Me(2)S(2)CH(2)Cl')]] (9) ('N(2)Me(2)S(2)CH(2)Cl'(2-) =1,2-ethanediamine-N,N'-dimethyl-N-(2-benzenethiolate)(1-)-N'-(2-benzenechloromethylthioether)(1-)]. The molecular structures of 4, 5, and 9 were determined by X-ray crystal structure analysis, and the labile N(2)H(4) complex 6 was characterized by NMR spectroscopy.
在寻找能结合与固氮酶相关的小分子并可作为固氮酶模型配合物的低分子量金属硫配合物的过程中，发现了具有[Ru(PiPr(3))('N(2)Me(2)S(2)')]片段的化合物（'N(2)Me(2)S(2)'(2 - ) = 1,2 - 乙二胺 - N,N' - 二甲基 - N,N' - 双(2 - 苯硫醇盐)(2 - )）。该片段使得能够合成第一系列手性金属硫配合物[Ru(L)(PiPr(3))('N(2)Me(2)S(2)')]，其中L = N(2)、N(2)H(2)、N(2)H(4)和NH(3)，这些配合物满足在温和条件下形成的生物学限制。[Ru(NCCH(3))(PiPr(3))('N(2)Me(2)S(2)')]（1）与NH(3)反应生成氨配合物[Ru(NH(3))(PiPr(3))('N(2)Me(2)S(2)')]（4），其能轻易地将NH(3)交换为N(2)，以几乎定量的产率生成单核二氮配合物[Ru(N(2))(PiPr(3))('N(2)Me(2)S(2)')]（2）。通过这种新的高效合成方法得到的配合物2，是合成双核(R,R)-和(S,S)-[μ - N(2)Ru(PiPr(3))('N(2)Me(2)S(2)')]（(R,R)-/(S,S)-3）的起始原料。（2和3之前均已报道。）密度泛函理论（DFT）计算和二维核磁共振（(2)D NMR）光谱研究揭示了配合物3在溶液中还会形成R,S异构体这一尚未得到合理解释的行为。1或2与无水肼反应生成肼配合物[Ru(N(2)H(4))(PiPr(3))('N(2)Me(2)S(2)')]（6），它是一种高活性中间体。6的歧化反应导致形成单核二氮烯配合物、氨配合物4，最终生成双核二氮烯配合物[μ - N(2)H(2)Ru(PiPr(3))('N(2)Me(2)S(2)')]（5）。双核配合物5也可通过1与N(2)H(2)的独立合成直接得到，N(2)H(2)由K(2)N(2)(CO(2))(2)的酸解原位生成。然而，用CH(2)Cl(2)处理6时，形成了一种氯甲基化的二氮烯物种[[Ru(PiPr(3))('N(2)Me(2)S(2)')]-μ - N(2)H(2)[Ru(Cl)('N(2)Me(2)S(2)CH(2)Cl')]]（9）（'N(2)Me(2)S(2)CH(2)Cl'(2 - ) = 1,2 - 乙二胺 - N,N' - 二甲基 - N - (2 - 苯硫醇盐)(1 - ) - N' - (2 - 苯氯甲硫醚)(1 - )]。通过X射线晶体结构分析确定了4、5和9的分子结构，不稳定的N(2)H(4)配合物6通过核磁共振光谱进行了表征。
