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

Abstract

Hat trick: Homoleptic butadienemetalates of 4d and 5d metals have for the first time been structurally characterized. The niobium–naphthalene species [Nb(η4‐C10H8)2(PMe3)2]− functions as a useful source of “naked” Nb− ions in its reaction with 1,3‐butadiene to afford an unprecedented homoleptic niobium–butadiene complex [Nb(η4‐C4H6)3]− (see structure). The tantalum analogue [Ta(η4‐C4H6)3]− was obtained by a similar route.

Synthesis and characterization of titanium tetraisocyanide complexes, [CpTi(CNXyl)4E], E=I, SnPh3, and SnMe3

“…A similar bifurcation of the IR m(CN) band envelope in THF solution was recently reported for trans-[Fe(CNXyl) 4 (SnPh 3 ) 2 ], which contains a Fe(CN) 4 Sn 2 core structure of nearly D 4h symmetry in the solid state [26]. 1 H and 13 C NMR spectra of diamagnetic 1, 3, and 4 are summarized in Section 2 under the respective compounds and show normal resonances and positions for the Cp and aliphatic/aromatic portions of the coordinated CNXyl ligands. In addition, unexceptional 1 H, 13 C and 119 Sn NMR spectra for the Ph 3 Sn and Me 3 Sn ligands in 3 and 4, respectively, were observed.…”

Modern applications of low-valent early transition metals in synthesis and catalysis

“…An improved synthesis and full electronic characterization of py 4 TiCl 2 ( 5 ) 57 , a rare example of a Ti II coordination complex, have recently been reported, building upon earlier studies by several groups 58,59 . The chemistry of low-valent early transition metal isocyanide 60–62 and arene complexes 63,64 has also continued to expand, including the recent synthesis of the formally Ta 0 complex 6 (REF 60 ).…”

A total loss of innocence: double ortho-metallation of bis(triphenylphosphano)iminium cation, [N(PPh3)2]+, by tris(η-naphthalene)tantalate(1−)

“…[1][2][3] Although [PPN] + reacts with hydroxide/methoxide, 4 undergoes reversible charge-transfer interactions with several carbonylmetallates, 5 and decomposes as the [PPN][Rh(CO) 4 ] salt at 200 1C under CO pressure in acetone-water, 6,7 no irreversible reactions with transition metal compounds, under ambient conditions, have been previously noted, even with anions that are good reducing agents, such as [Ta(CO) 6 ] À8 or [Ta(Z-C 4 H 6 ) 3 ] À . 9 We now report on a remarkable reaction of [PPN] + at 20 1C with the highly reactive and strongly reducing metallate ion, [Ta(Z-C 10 H 8 ) 3 ] À , 1 (C 10 H 8 = naphthalene). 10 Addition of a solution/slurry of bright yellow [Na(thf) 2 ][1], thf = tetrahydrofuran, to one equivalent of [PPN]Cl in thf showed no observable change at 0 1C, perhaps owing to the poor solubility of [PPN]Cl.…”