Novel poly(methimazolyl)borate complexes of niobium(v) and tantalum(v)

Abstract

The reactions of [MCl4(eta-C5H5)](M = Nb, Ta) with Ph3Sn{HB(mt)3} (mt = methimazolyl) provide structurally characterised complexes of the new chlorobis(methimazolyl)borate ligand, [MCl3(eta-C5H5){kappa2-S,S'-HClB(mt)2}].

Coordination and Hydroboration of Ru(II)‐Borate Complexes: Dihydridoborate vs. Bis(dihydridoborate)

“…The growth of this chemistry featuring these complexes was aided primarily by the introduction of Trofimenko's scorpionate ligands [14] . Reglinski, [15] Parkin, [16] Hill, [6a,17] Peters, [6b] Owen [6c,18] and others [19] have further investigated the role of the scorpionate ligands in stabilization of TM σ ‐borate complexes and in this regard, the heterocyclic borate ligands bearing both hard (N) and soft (S) donor atoms were observed to be quite dynamic [18]…”

Soft Scorpionate Ligands Based on Imidazole‐2‐thione Donors

“…The reaction of R 3 SnCl (R = Me, n Bu, Cy, Ph)81 with NaTm Me results in a complex with formula [Sn(Tm Me )R 3 ]. The tricyclohexyl81 and triphenyl82,83 tin complexes have been structurally characterised. Here the tin(IV) centre is tetracoordinate and the Tm ligand exhibits a κ 1 ‐S coordination mode.…”

“…Use of an organotin complex, Ph 3 SnTm Me , as a ligand transfer agent was similarly problematic with M 2 Cl 10 , but with [MCpCl 4 ] (M = Nb, Ta) orange compounds were obtained. These proved not to be simple Tm Me complexes, but rather complexes of ClBm Me (Figure 17), in which a single methimazole has been cleaved and replaced by a chloride abstracted either from the Ph 3 SnCl precursor, or more likely, from an intermediate in the reaction of [MCpCl 4 ] 83…”

Technetium Complexes and Radiopharmaceuticals with Scorpionate Ligands

“…A far richer chemistry was found after the introduction of thioimidazolyl scorpionates ( Figure 1 ) [ 6 , 32 , 33 ]. Usually, these ligands are obtained by reacting an alkali metal salt of the borohydride anion [BH 4 ] − with the appropriate mercaptoimidazole derivative.…”