Silylation of Dinitrogen Coordinated to Transition Metals and its Application to Catalytic Nitrogen Fixation

1.双氮配合物cis-[W（N_2）_2（PMe_2Ph）_4]（1a）与R_3SiCl/NaI混合物反应，得到各种硅基二氮烯配合物trans-[WI（NNSiR_3）（PMe_2Ph）_4]，而1a或其Mo类似物1b与ClSiMe_2CH_2CH_2SiMe_2Cl/NaI反应，则得到硅基肼基（2-）配合物cis，mer-[WI_2（NNSiMe_2CH_2CH_2SiMe_2）（PMe_2Ph）_3]（2）.配合物1a还与R_3GeCl/NaI反应，得到锗基二氮烯配合物trans-[WI（NNGeR_3）（PMe_2Ph）_4]。用R_3SiCl和Na在催化量的1b存在下处理，在室温下，分子氮被转化为硅胺。通过这些新的催化反应生成的硅烷胺的产率在很大程度上取决于连接到Si原子上的取代基的性质。2中的一个PMe_2Ph配体在室温下很容易被一系列π受体配体取代，得到了各种二硅酰肼（2-）配合物cis，transs-[WI_2（NNSiMe_2CH_2CH_2SiMe_2）（PMe_2Ph）_2（L）]（L = CO，CH_2=CH_2，RCN）.相反，从2与'BuNC的反应混合物中分离出阳离子络合物mer-[WI（NNSiMe_2CH_2CH_2SiMe_2）（PMe_2Ph）_3]I作为主要产物。2与CH_2X_2（X = I，Cl）反应生成顺磁性的W（V）配合物mer，trans-[WX_3（NNSiMe_2CH_2CH_2SiMe_2）（PMe_2Ph）_2]。该W（V）配合物（X = I）水解后与酮发生缩合反应，分别得到新的W（V）配合物[WI_3（NNH_2）（PMe_2Ph）_2]和mer，trans-W（V）配合物[WI_3（NN= CRR '）（PMe_2Ph）_2]。

1. Treatment of a dinitrogen complex cis-[W(N_2)_2(PMe_2Ph)_4](1a) with R_3SiCl/NaI mixtures afforded a variety of silyldiazenido complexed trans-[WI(NNSiR_3)(PMe_2Ph)_4], while the reactions of 1a or its Mo analogue 1b with ClSiMe_2CH_2CH_2SiMe_2Cl/NaI resulted in the formation of silylhydrazido(2-) complexes cis, mer-[WI_2(NNSiMe_2CH_2CH_2SiMe_2)(PMe_2Ph)_3](2). Complex 1a also reacted with R_3GeCl/NaI to give germyldiazenido complexes trans-[WI(NNGeR_3)(PMe_2Ph)_4].2. By treatment with R_3SiCl and Na in the presence of a catalytic amount of 1b, molecular nitrogen has been converted into silylamines under ambient conditions. The yields of silylamines produced by these novel catalytic reactions considerably depended upon the nature of the substituents attached to the Si atom.3. One PMe_2Ph ligand in 2 was replaced readily by a series of pi-acceptor ligands at room temperature, affording various disilylhydrazido(2-) complexes cis, trans-[WI_2(NNSiMe_2CH_2CH_2SiMe_2)(PMe_2Ph)_2(L)](L = CO, CH_2=CH_2, RCN). In contrast, from the reaction mixture of 2 with 'BuNC a cationic complex mer-[WI(NNSiMe_2CH_2CH_2SiMe_2)(PMe_2Ph)_3]I has been isolated as the major product. Furthermore, 2 reacted with CH_2X_2 (X = I, Cl) to give paramagnetic W(V) complexes mer, trans-[WX_3(NNSiMe_2CH_2CH_2SiMe_2)(PMe_2Ph)_2]. Hydrolysis of this W(V) complex (X = I) and the subsequent condensation reaction with ketones afforded new W(V) complexes [WI_3(NNH_2)(PMe_2Ph)_2] and mer, trans-[WI_3(NN=CRR')(PMe_2Ph)_2], respectively.