Tris(1-4-η4-anthracene)niobate(1–), the first polyaromatic hydrocarbon complex of niobium

Abstract

The first tris(arene)niobium complex, [Nb(1-4-eta 4-anthracene)3]-, has been obtained by the sodium or potassium anthracene reduction of NbCl4(THF)2, structurally characterized by X-ray analysis and shown to undergo facile anthracene displacement reactions in the presence of excess CO, PF3, 1,3,5,7-cyclooctatetraene and P(OMe)3.

From Storable Sources of Atomic Nb− and Ta− Ions to Isolable Anionic Tris(1,3‐butadiene)metal Complexes: [M(η4‐C4H6)3]−, M=Nb, Ta

“…From this reaction mixture, the satisfactorily pure anion [Nb(h 4 -C 10 2 ] À , and is a precursor to an unprecedented niobium-butadiene complex (see below). It is also the first niobium-naphthalene complex to be described, which is surprising because numerous other niobium arenes have been reported [12] and several vanadium- [3,13] and tantalum-naphthalene [5,14] complexes are well-established. However, none of these prior complexes are analogous to 3.…”

Structurally Distinct Homoleptic Anthracene Complexes, [M(C14H10)3]2−, M=Titanium, Zirconium, Hafnium: Tris(arene) Complexes for a Triad of Transition Metals

“…[23,24] Steric crowding around the titanium centers in 2 and 5 is also indicated by the presence of a welldeveloped long-short-short-long pattern in the TiÀC bond lengths of the h 4 -diene units. [25] This [9] [Nb(CO) 6 [5], respectively, because the coordination environments of titanium are nearly identical, despite the different crystal systems (triclinic versus monoclinic, respectively) of the salts and packing arrangements of cations and anions. [28] Based on a prior study, [29] there has been concern that the structure of anion 5 could be cation-dependent.…”

“…[ [5] and preparation of 2-7 and the structures of anions 3, 4, 5, and 6 are described in the Supporting Information. …”

“…[3] The first well-characterized homoleptic polyarenemetalate, tris(naphthalene)zirconate(2À) (1), [4] was reported nearly 15 years ago, and related complexes are now documented for Nb, [5] Ta, [6] Fe, [3] and Co. [7] However, little or nothing is known about the analogous metalates of other d-block elements. [2,8] We report herein the synthesis, isolation, and structural characterization of the first set of homoleptic polyarenemetalates for a triad of transition metals: the tris(anthracene)metalates(2À), [M-(C 14 H 10 ) 3 ] 2À , M = Ti (2), Zr (3), and Hf (4).…”

Catalysis and Organometallic Chemistry of Monometallic Species

“…It is suggested that these complexes could be used as convenient starting materials for entry into low valent niobium and tantalum chemistry. 98, 99 The first structural characterisation of a metalloceneol is represented by the vanadium() complex [V(η 5Ϫ C 5 H 4 OH)(η 7 -C 7 H 7 )] 100 and a theoretical study into Jahn-Teller effects in singlet and low energy triplet states of [Nb(η-…”