Fawcett John, Harding Duncan A J, Hope Eric G, Singh Kuldip, Solan Gregory A
Department of Chemistry, University of Leicester, University Road, Leicester, UKLE1 7RH.
Dalton Trans. 2009 Sep 14(34):6861-70. doi: 10.1039/b906321h. Epub 2009 Jul 31.
Treatment of tetranuclear [RuF(-F)(CO)3]4 (1) with the free N-heterocyclic carbenes (NHCs), IMes (1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene) and IPr (1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene), followed by work-up in carbon tetrachloride leads to fluoride-bridge cleavage in 1 and the formation of the mononuclear octahedral complexes cis,cis,trans-[RuF2(CO)2(NHC)2] [NHC = IMes (2a), IPr (2b)], respectively. Complexes 2a and 2b can also be obtained by interaction of 1 with the corresponding imidazolium chloride, [-N(Ar)CHN(Ar)CHCH-]Cl (Ar = 2,4,6-Me3C6H2, 2,6-i-Pr2C6H3), in the presence of KOtBu. However, extension of this latter base-assisted approach to [-N(Ar)CHN(Ar)CHCH-]Cl (Ar = 2,6-Me2C6H3, 2,4,6-i-Pr3C6H2) results in halide exchange with the work-up solvent (CCl4) to generate cis,cis,trans-[RuCl2(CO)2(IMe)2] (3) and dinuclear [RuCl(mu-Cl)(CO)2(ITPr)]2 (4), respectively. Reaction of 2a with gaseous BF3 in dichloromethane and subsequent carbonylation affords in high yield monocationic Ru(FBF3)(CO)3(IMes)2 (5), while with 2b, BF3 addition alone results in solvent exchange to yield dinuclear monocationic Ru2(mu-Cl)3(CO)4(IPr)2/(F) (6). Conversely, interaction of 2a and 2b with BF3.OEt2 in acetonitrile furnishes dicationic cis,cis,trans-Ru(CO)2(NCMe)2(NHC)22 [NHC = IMes (7a), IPr (7b)]; in the case of 7a carbonylation gives Ru(CO)4(IMes)22 (8). Single crystal X-ray structures are presented for 3, 4, 5, 6 and 8.
用游离的氮杂环卡宾（NHCs），即1,3 - 双（2,4,6 - 三甲基苯基）咪唑 - 2 - 亚基（IMes）和1,3 - 双（2,6 - 二异丙基苯基）咪唑 - 2 - 亚基（IPr）处理四核的[RuF(-F)(CO)₃]₄（1），随后在四氯化碳中后处理，导致1中的氟桥断裂，并分别形成单核八面体配合物顺式，顺式，反式 - [RuF₂(CO)₂(NHC)₂] [NHC = IMes（2a），IPr（2b）]。配合物2a和2b也可以通过1与相应的咪唑鎓氯化物[-N(Ar)CHN(Ar)CHCH-]Cl（Ar = 2,4,6 - Me₃C₆H₂，2,6 - i - Pr₂C₆H₃）在叔丁醇钾存在下相互作用得到。然而，将后一种碱辅助方法扩展到[-N(Ar)CHN(Ar)CHCH-]Cl（Ar = 2,6 - Me₂C₆H₃，2,4,6 - i - Pr₃C₆H₂）会导致与后处理溶剂（CCl₄）进行卤化物交换，分别生成顺式，顺式，反式 - [RuCl₂(CO)₂(IMe)₂]（3）和双核的[RuCl(μ - Cl)(CO)₂(ITPr)]₂（4）。2a在二氯甲烷中与气态BF₃反应并随后进行羰基化反应，以高产率得到单核阳离子Ru(FBF₃)(CO)₃(IMes)₂（5），而对于2b，仅添加BF₃会导致溶剂交换，生成双核单核阳离子Ru₂(μ - Cl)₃(CO)₄(IPr)₂/(F)（6）。相反，2a和2b与乙腈中的BF₃·OEt₂相互作用得到双核阳离子顺式，顺式，反式 - Ru(CO)₂(NCMe)₂(NHC)₂₂ [NHC = IMes（7a），IPr（7b）]；对于7a，羰基化反应得到Ru(CO)₄(IMes)₂₂（8）。给出了3、4、5、6和8的单晶X射线结构。
