Titanium‐Oxo Clusters with Bi‐ and Tridentate Organic Ligands: Gradual Evolution of the Structures from Small to Big

Abstract

Homometallic titanium oxo clusters are one of the most important groups of metal oxo clusters, with more than 300 examples characterized by X‐ray structure analyses. Most of them are uncharged and are obtained by partial hydrolysis and condensation of titanium alkoxo derivatives. The cluster cores, ranging from 3 to >50 titanium atoms, are stabilized by organic ligands. Apart from residual OR groups, carboxylato and phosphonato ligands are most frequent. The article critically reviews and categorizes the known structures and works out basic construction principles by comparing the different cluster types.

Titanium(IV) Oxo-Complex with Acetylsalicylic Acid Ligand and Its Polymer Composites: Synthesis, Structure, Spectroscopic Characterization, and Photocatalytic Activity

“…The research carried out reveals that the molecular structure of (1) consist {Ti4O2} cores stabilized by two carboxylate (asp), four isobutoxide bridges, and terminal isobutoxide groups (Figure 1). Analysis of bond lengths and angles prese in Table S1 reveals that the isolated oxo complex forms a similar type of tetranu cluster as found in previously described systems [Ti4O2(O i Bu)10(O2CR′)2] (R′ = C PhCl, PhNO2, PhNH2) [14,19,21]. The appearance of water molecules in the crystal la of ( 1) is an interesting issue from the structural point of view.…”

“…The important issue of works carried out are studies on oxo clusters consisting of {Ti a O b } cores containing a = 3 or 4 Ti atoms. These types of clusters are crucial in the synthesis of TOCs because the base units in the next stages of their synthesis can lead to the {Ti a O b } core enlargement (a > 4) [17][18][19][20][21]. On the other hand, studies on their electronic structure and photocatalytical applications are also exciting.…”

Synthesis, Structure, and Light Absorption Behaviors of Prismatic Titanium-Oxo Clusters Containing Lacunary Lindqvist-like Species

“…According to a concept recently proposed by Schubert, the d c values of PTC-238 and PTC-239 are 1.17 and 1.22 and the d s values of PTC-238 and PTC-239 are 1.17 and 0.44, respectively. 41 It is worth noting that the Ti−O connectivity and accumulation in the prepared prismatic titanium-oxo clusters can be related to the famous Lindqvist structure in the field of polyoxometalates. In the structure of PTC-237, two [TiO] 2+ groups are missing to give a lacunary Lindqvist-like Ti 4 unit, which is also an important building block in many PTCs (Figure 3a).…”

A Cyclic Titanium-Oxo Cluster with a Tetrathiafulvalene Connector as a Precursor for Highly Efficient Adsorbent of Cationic Dyes

“…When the crystals were isolated from the reactor and exposed to air, they gradually turned black and tarnished under ambient conditions. The process includes the condensation of TOCs by removing the alkoxyl groups (2RO → ROR) and hydroxylation (OR + H 2 O → OH + HOR) under moisture. , Figure S3 shows SEM images of the crystals, showing crystal bending and cracking. Freshly isolated red compound 1 is soluble in solvents such as dichloromethane and THF, but the condensation black sample, denoted as B- 1 , is insoluble in all solvents due to the polymeric structure of B- 1 .…”

“…Titanium-oxo clusters (TOCs) with different nuclearities, structures, and functional ligands have attracted great attention because of their applications not only as theoretical and experimental models of nano TiO 2 but also as molecular TiO materials. − In recent years, a booming development has occurred in the preparation of TiO nanoparticles and films using TOCs as molecular precursors or as single-source precursors through a convenient strategy. − TOCs with the formula of [Ti x O y (OR) z ] are generally moisture-sensitive and unstable under ambient conditions because they can self-condense or -hydroxylate in moisture by removal of the alkoxyl groups (−R 2 O or ROH). , …”