New Vistas for Functionalized Polyoxometalates

Maatta, Eric A.

Kansas State University, Manhattan, KS

关键词: Modifications;    Transformations Polyoxometalates;    Electrochromism;    Medicine;    Absorption;   

DOI  :  10.2172/881336
RP-ID  :  DOE/ER/14866-3
RP-ID  :  FG02-98ER14866
RP-ID  :  881336

美国|英语

来源: UNT Digital Library

【 摘 要 】

Polyoxometalates (POMs) - the multimetallic oxoanions [MxOyXz]n? formed by Mo, W, and, to a lesser extent, V, Nb and Ta ? have been described as "a class of inorganic compounds that is unmatched in terms of molecular and electronic structural versatility, reactivity, and relevance". The remarkable breadth of POM chemistry, which extends to areas as diverse as catalysis, medicine, imaging, photo- and electrochromism, and magnetic materials, derives from the confluence of the species' attractive intrinsic characteristics and their extraordinary compositional range. While many of these systems are easy to prepare, it is often difficult to modify POMs in a rational manner. Our goal is to provide for the intrinsic modifcation of POM systems so as to enable their further utility: our approach has provided many examples of fundamentally new types of polyoxometalates in which their ubiquitous oxo [O]2? ligands have been replaced by other isoelectronic entities including organoimido [N-R]2? and diazoalkane [NNCR2]2?ligands. These nitrogenous POM derivatives retain the attractive attributes typical of the class but with altered and tunable characteristics including their redox behavior and electronic absorption patterns. The organoimido and diazoalkane species provide the ability to couple remote and useful functionality via the appended substituents R. We also are now engaged in the preparation and study of nitrido-POM systems: these unprecedented inorganic complexes offer the possibility of effecting various types of nitrido-based transformations (such as nitrogen transfer) which could benefit from the superior oxidative and thermal stability of the POM ligation environment.