Titanocene dichloride route to a tetranuclear oxo-bridged monocyclopentadienyl titanium(iv) calix[4]arene complex

Abstract

Lithiation of p-tBu-calix[4]arene followed by reaction with titanocene dichloride affords a novel tetranuclear titanium(IV) monocyclopentadienyl complex, wherein a single calix[4]arene in a cone conformation provides O-phenoxy coordination to four titanium atoms, with additional mu-oxo bridging between titanium centres in an eight membered ring.

Calixarenes as platforms for the construction of multimetallic complexes

“…15. Interestingly, although there are numerous structurally characterised examples of two or more calix [4]arenes binding several transition metal ions simultaneously, this is a remarkable complex in having four transition metal atoms attached to one calix [4]arene, in a way which effectively locks the calixarene in a cone conformation [40].…”

A facile route to hetero-bimetallic Ti(iv)-alkali metal calix[4]arene complexes

“…16 Alternatively calixarene complexes devoid of bridging phenolate moieties can be formed by employing the steric buttressing effect of bulky ligands on the metal precursor reagents. [17][18][19] In this paper we report on the influence of alkali metal identity on the formation of novel monomeric and dimeric titanium() complexes arising from reactions of R-L[OH] 4 (R = t Bu or H), in concert with titanium() precursors having controlled reactivity. Our synthetic strategy involves partial deprotonation of the calix [4]arene with alkali metal, which disrupts the strong H-bonded array of the calix [4]arene phenolic groups and solubilises the resulting calix [4]arene anion.…”

Structural Investigation of Pyridinecarboxylato Titanium(IV) Complexes: An Uncommon Monomeric Octacoordinated Complex vs. a Hexaprismatic Architecture

“…Due to the recurrence in the literature of reports of square tetrameric titanium containing four bridging oxygen ligands [37][38][39][40][41][42] and, assuming the same coordination mode as in Ti(pic) 4 , it could be proposed that the structure of the Ti 4 O 4 (pic) 8 complex is analogous to the one indicated in Figure 4. Having identified the second complex that composes the crystalline solid recovered at the end of the synthesis, an estimation of the composition of this solid can be made according to the residual TiO 2 percentage determined by TGA.…”