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• 870539-78-9 [Mo2(η5-cyclopentadienyl)2(μ-SMe)3(2,6-xylyl isocyanide)2] 

Relevant academic research and scientific papers

Formation of C-C, C-N, and C-O links between isonitrile, cyclopentadienyl, and hydroxide ligands bound to molybdenum(III): Syntheses and crystal structures of μ-aminocarbyne and μ-amino-oxycarbene dimolybdenum complexes

Reaction of the bis-isonitrile complex [Mo2Cp 2(μ-SMe)3(xylNC)2](BF4) (2b) with NaOH (suspension) under reflux in tetrahydrofuran produced, in quantitative yields, the μ-alkylidyne species [Mo2Cp(μ-SMe) 3{μ-(η5-C5H4)(xylN)CN(xyl)C}] (4), in which a deprotonated Cp and both isonitrile ligands of 2b are now linked by new C-C and C-N bonds. Under prolonged reflux (72 h) in tetrahydrofuran 2b with either NaOH (suspension) or (Me4N)OH (in MeOH) in the presence of excess isonitrile RNC (R = xyl, But) was converted in high yields into the mixed (μ-alkylidyne)(μ-amino-oxycarbene) derivatives [Mo2Cp(μ-SMe)2{μ-(η5- C5H4)(xylN)CN(xyl)C}{μ-η1(O), η1(C)-OCNHR}] (R = xyl (5a1), R = But (5b2)) and [Mo2Cp(μ-SMe)2{μ-(η5C 5H4) (xylN)CN(xyl)C}{μ-η1(O), η1(C)-OCNMeR}] (R = xyl (6a)). All these products result from hydroxide-isonitrile coupling reactions. When the mixture of 2b, (Me 4N)OH (excess), and ButNC (excess) in tetrahydrofuran was heated under reflux for a short time (2 h), complex 5b1 was formed in good yields. Compounds 5b1 and 5b2 are linkage isomers, which differ only in the mode of coordination of the μ-amino-oxycarbene ligand to the Mo1-Mo2 unit; 5b1 converts into 5b2 on prolonged heating. Reaction of the secondary amino-oxycarbene derivative 5a1 with a base (NaOH) and an alkylating agent R″4NBr (R″ = Et, Bun) afforded the corresponding tertiary(amino)-oxycarbene complexes [Mo2Cp(μ-SMe) 2{μ-(η5-C5H4)(xylN)CN(xyl)C} {μ-η1(O),η1(C)-OCNxylR″}] [R″ = Et (6b), Bun (6c)]. On heating a tetrahydrofuran solution of the μ-alkylidyne compound 4 with NaOH (suspension) and an excess of either xylNC or ButNC, the mixed μ-alkylidyne and μ-amino-oxycarbene species 5a1 and 5b2 were obtained, demonstrating that 4 is an intermediate in the formation of 5a1 and 5b2 from 2b. Treatment of the mixed isonitrile-nitrile species [Mo2Cp2(μ-SMe)3(MeCN)(xylNC)] (BF4) (3), containing a labile MeCN group, under reflux in tetrahydrofuran with NaOH (suspension) afforded quantitatively the μ-amino-oxycarbene compound [Mo2Cp2(μ-SMe) 3{μ-η1(O),η1(C)-OCNHxyl}] (7). All new complexes have been characterized by elemental analyses and spectroscopic methods, supplemented for 5a1, 5b1, 5b2, 6a, 6b, and 7 by X-ray diffraction studies.