Synthesis, structural and physicochemical characterization of a new type Ti-oxo cluster protected by a cyclic imide dioxime ligand

• Published in: Dalton transactions : an international journal of inorganic chemistry 2019-04, Vol.48 (17), p.5551-5559
• Main Authors: Passadis, Stamatis S, Hadjithoma, Sofia, Kalampounias, Angelos G, Tsipis, Athanassios C, Sproules, Stephen, Miras, Haralampos N, Keramidas, Anastasios D, Kabanos, Themistoklis A
• Format: Article
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c9dt00658c

Reaction of the cyclic ligand (2 Z ,6 Z )-piperidine-2,6-dione dioxime with TiCl 4 and KOH yielded the hexanuclear cluster K 6 [Ti IV 6 (μ 3 -O) 2 (μ 2 -O) 3 (CH 3 O) 6 (μ 2 -η 1 ,η 1 ,η 2 -Hpidiox- O , N , O ′) 4 (μ 2 -η 1 ,η 1 ,η 2 -pidiox- O , N , O ′) 2 ]·7.5CH 3 OH possessing a new {Ti 6 O 5 } structural motif. The cluster core {Ti 6 O 5 } is wrapped by external tripodal imide dioxime ligands, showing good solubility and stability and thus, allowing its solution to be studied by means of electrospray ionization mass spectrometry, electrochemistry and 2D NMR, c. w. EPR and UV-vis spectroscopies. Density Functional Theory (DFT) calculations reveal that the cyclo -Ti 3 metallic cores exhibit metallaromaticity which is expected to contribute to the stabilization of this system. A new type of Ti 6 -oxo cluster with a structural motif Ti IV 6 O 5 was synthesized of which the cyclo -Ti 3 metallic cores exhibit metallaromaticity.