Coordination complexes future applications

As noted in the introduction, in contrast to attack by nucleophiles, attack of electrophiles on saturated alkene-, polyene- or polyenyl-metal complexes creates special problems in that normally unstable 16-electron, unsaturated species are formed. To be isolated, these species must be stabilized by intramolecular coordination or via intermolecular addition of a ligand. Nevertheless, as illustrated in this chapter, reactions of significant synthetic utility can be developed with attention to these points. It is likely that this area will see considerable development in the future. In addition to refinement of electrophilic reactions of metal-diene complexes, synthetic applications may evolve from the coupling of carbon electrophiles with electron-rich transition metal complexes of alkenes, alkynes and polyenes, as well as allyl- and dienyl-metal complexes. Sequential addition of electrophiles followed by nucleophiles is also viable to rapidly assemble complex structures. 

Coordination chemistry offers many examples of applications in industry beyond those addressed above. Recent developments in chemistry promise greater applications in the future. Here, a limited number of examples from two fields are presented to give a sense of opportunities for coordination complexes in commercial roles. 

In this paper, we present the metastable a-polymorph of strontium carbodiimide as a novel pseudochalkogenide host lattice for divalent europium ions. Because of the high thermal inertness and cationic nitrogen coordination of this compound looks like a promising candidate for future applications. Furthermore, Sr-based compounds are ideal host lattices for divalent rare-earth-ions, simply because Sr " " is spectroscopically inactive, and Sr and Eu have comparable ionic rachi and identical charge. As a synthetic challenge, however, the preparation of phase-pure samples is required. Inspired by the reaction of EuN, BN, and NaN3 to form Eu3(NBN)2, and the synthesis of In2.24(NCN)3 from InBr and NaCN, we developed a new flux route based on the metal halide, alkaline cyanide, and alkaline azide, which act as precursors for the synthesis of structurally rather complex rare-earth and alkaline-earth cyanamides and... 

The interfacial aqueous coordination chemistry of natural particles, in particular their surface complexation reactions, owes much of its development to the research of Werner Stumm. Beginning with the tentative interpretation of specific adsorption processes in terms of chemical reactions to form inner-sphere surface complexes, his seminal questions spawned a generation of research on the detection and quantitation of these surface species. The application of noninvasive spectroscopy in this research is exemplified by electron spin resonance and extended X-ray absorption fine structure studies. These studies, in turn, indicate the existence of a rich variety of surface species that transcend the isolated surface complex in both structure and reactivity, thereby stimulating future research in molecular conceptualizations of the particle-water interface. 

---