136686-83-4

Upstream product

• 68088-96-0 bis(η6-1,3,5-trimethylbenzene)niobium(0) 

Downstream Products

• 144181-16-8 {Nb(C₆H₃(CH₃)3)2(CH₃CCCH₃)}⁽¹⁺⁾*B(C₆H₅)4^(1-) = {Nb(C₆H₃(CH₃)3)2(CH₃CCCH₃)}B(C₆H₅)4 

Relevant academic research and scientific papers

Synthesis, reactivity, and crystal and molecular structures of Nb(L) (η6-C6H5-nXn) 2B(C6H5-n,Xn)2, a class of mononuclear metal compounds containing the 12-electron-donor tetraarylborato ligand

The one-electron oxidation of Nb(mes)2 (mes = 1,3,5-trimethylbenzene) with ferrocenium tetraarylborate, produces the 16-electron [Nb(mes)2]+ cation, which adds disubstituted symmetrical alkynes to give the ionic compounds [Nb(mes)2)(alkyne)][Y] (alkyne = MeC2Me, Y = BPh4 (1a), Y = B(p-FC6H4)4 (1b), Y = B[3,5-(CF3)2C6H3]4 (1c); alkyne = PhC2Ph, Y = BPh4 (2a) Y = B(p-FC6H4)4 (2b)). 2b crystallizes in space group C2/c (No. 15) with four formula units in cells of dimensions a = 17.640(3) ?, b = 16.8386(8) ?, c = 19.616(2) ?, and β = 97.230(9)°; the [Nb(mes)2(PhC2Ph)]+ cation contains bent η6-mesitylene ligands, a coordination position being occupied by PhC2Ph as a formal two-electron donor. The alkyne in 1a-c is displaced by CO at room temperature and at atmospheric pressure to give the carbonyl derivatives [Nb-(mes)2CO] [Y] (3a-c). Thermal treatment of 1a,b and 2a in toluene gave mesitylene displacement and formation of the neutral covalent compounds containing the uninegative tetraarylborato ligand of formula [Nb(RC2R)(η6-C6H4X) 2B(C6H4X)2] (R = Me, X = H (4a), X = p-F (4b); R = Ph, X = H (5a)). 4a crystallizes in space group P421m (No. 113), with two formula units in cells of dimensions a = 9.734(1) ? and c = 11.6333(9) ?; 4b crystallizes in space group P212121 (No. 19) with eight formula units in cells of dimensions a = 11.776(3) ?, b = 15.666(3) ?, and c = 28.042(5) ?. 4a,b both contain the novel bonding arrangement of the tetraarylborato ligand with two interannularly niobium-bridged aryl rings. This new type of bonding is not restricted to the methyl-substituted (4a) or phenyl-substituted (4b) acetylenic derivatives: CO is also compatible with the new bonding arrangement. Alkyne displacement by CO gives the neutral covalent complex [Nb(CO)(η6-C6H4X)2B(C 6H4X)2] (X = H (6a), p-F (6b)). An X-ray diffractometric experiment on 6a has confirmed the novel bonding arrangement of the tetraarylborato ligand for this compound, which crystallizes in space group P212121 (No. 19) with four formula units in cells of dimensions a = 10.495(2) ?, b = 14.586(1) ?, and c = 17.174(3) ?.

Synthesis and reactivity of η6-arene derivatives of niobium(II), niobium(I), and niobium(0)

The primary reduction products in the Al/AlX3/NbX5/arene system, namely Nb(η6-arene)(AlX4)2, X = Cl, arene = benzene, hexamethylbenzene; X = Br, arene = hexamethylbenzene, have been isolated.Tetrahydrofuran at room temperature reacts with Nb(η6-hexamethylbenzene)(AlBr4)2, to give the aluminium-free complex Nb2(η6-hexamethylbenzene)2Br4, whose crystal structure was determined by X-ray diffraction methods.In the presence of tetrahydrofuran or dimethoxyethane, the η6-mesitylenetetrahaloaluminato complexes are further reduced by aluminium to bis-mesityleneniobium(0), Nb(mes)2, which undergoes: a) disproportionation with CO to +-, b) oxidation by V(CO)6 or (4,4'-dimethyl-2,2'-dipyridyl)(BPh4)2 under carbon monoxide to X, X = - or BPh4-.The structure of BPh4 has been determined by X-ray diffration methods.In the presence of CO, Nb(mes)2 is reduced by CoCp2* * = η5-C5(CH3)5> to -, which was isolated as its CoCp2*+ derivative; it efficiently deoxygenates CO2 to CO in the presence of carbon monoxide acceptors such as the + cation.