Preparation and crystal structure of the [bis{hydrotris(methimazolyl)borato}thallium(III)] cation: modulated chemistry resulting from the use of soft and hard tripodal ligands

Abstract

The synthesis and crystal structure of the [bis{hydrotris(methimazolyl)borato}thallium(III)] cation is reported, in which the thallium ion is co-ordinated by six sulfur thione donors in a regular octahedral environment

The Preparation and Structures of Group 12 (Zn, Cd, Hg) Complexes of the Soft Tripodal Ligand Hydrotris(methimazolyl)borate (Tm)

“…Because of the formation of eightmembered chelates in its metal complexes the ligand is able to show flexibility, adapting to the environment, with SϪMϪS angles able to vary from less than 90°in octahedral complexes such as [Tl(Tm) 2 ] ϩ [7] and [Bi(Tm) 2 ] ϩ [5] through to normal tetrahedral angles in the complexes reported here. While this results in versatility in terms of their ability to coordinate a range of metals, it also renders the ligands susceptible to interaction of the borohydride moiety with the metal and opens a potential route of decomposition, as observed in the reaction with Hg 2 Cl 2 .…”

“…[6] Likewise, iodine oxidation of [Tl I (Tm)] results in the formation of the [Tl III (Tm) 2 ] ϩ cation, while [Tl(Tp)] is not oxidised by iodine, but undergoes ligand decomposition. [7] A further difference in reactivity has been noted by Hill, [8] who in an attempt to prepare the Tm analogue of [Ru(R)-(CO)(PPh 3 )(Tp)] observed intramolecular activation of the bridgehead BϪH bond with formation of a metalloboratrane. In the latter example the reactivity apparently arises from the greater flexibility afforded by the eight-membered chelate rings formed by Tm in its metal complexes.…”

Chemistry of the p-block elements with anionic scorpionate ligands

“…Reaction of LiTm Ph with TlOAc yielded the expected thallium(I) salt [121]. X-ray crystallography showed this to be a dimeric species, [Tl(Tm Ph )]2 centred on a Tl2S2 rectangular core (Figure 30).…”

“…The structure of [Tl(Bm Me )]2 ( Figure 30) shows a dimeric unit based on a rectangular Tl2S2 core [121]. One sulphur atom from each ligand bridges between the two thallium atoms and the other forms a primary coordination with a thallium atom in the core, but also a weaker interaction with an adjacent Tl2S2 unit to form an extended polymeric array.…”

“…The synthesis of a compound analysing as [Pb(Tm Me )2] has been reported, but the structure has not been determined [121]. LiTm Ph reacts with Pb (ClO4) Pb -S distances are 2.8482(6) Å for the strongly bound ligand and substantially longer, at 3.1718(8) Å, for the weakly bound ligand.…”