A review of phosphorus(V)-substituted titanium-oxo clusters

Phosphorus(V)-substituted titanium-oxo clusters are composed of titanoxane (Ti–O–Ti), phosphatitanoxane (Ti–O–P), and organic/inorganic groups, such as pentamethylcyclopentadienyl, alkoxyl, carboxylate, acetylacetonate, hydroxyl, and chloride. The first phosphorus(V)-substituted titanium-oxo cluster was reported in 1992. To date, many studies have been published on the syntheses, properties, and applications of these clusters. However, no review has been reported yet. In this study, these clusters are divided into four categories: (i) the syntheses, properties, and proposed formation mechanism of titanium phosphonate clusters, (ii) the syntheses of carboxylate-substituted titanium phosphonate clusters, (iii) the syntheses and properties of titanium phosphinate- and phosphate-clusters, and (iv) the advanced investigation of phosphorus(V)-substituted titanium-oxo clusters. Highlights Synthesis and properties of phosphorus(V)-substituted titanium-oxo clusters. Simple synthetic process for many clusters. Report on clusters more than 50-types. The influence of molar ratio and structure of titanium and phosphorus reagents on their structure. Application of alkoxy clusters in sol–gel method.