Research

The Verani Group is working on several research topics that encompass distinct aspects of modern coordination chemistry, including ligand design, inorganic synthesis, temperature and field dependent magnetic susceptibility, UV-visible, and EPR spectroscopy, electrochemistry, crystallography, computational calculations, Langmuir-Blodgett and self-assembly surface techniques, polarized microscopy, among others.

We use these tools to understand, design, and develop molecule-based materials with potential relevance to the broadly defined fields of metal-containing soft materials, supramolecular chemistry, and molecular electronics. The major fields of current interest are as follows:

1. The understanding of coordination modes in metal-containing soft materials




The understanding of coordination modes in metal complexes that act as precursors for responsive materials is important because many of the targeted species are soft materials and therefore are difficult to characterize using traditional methods. Smaller compounds retaining key attributes of the soft materials are studied instead. The design of soft materials based on these systems leads to unique physical properties associated with dissimilar donor sets such as phenolates and pyridines.

Rajendra Shakya, Camille Imbert, and currently Frank Lesh and Sarmad Hindo are involved with projects that use prototypical modeling. For details, please check papers 1, 3 and 10 in our publication list.





2. The development of surfactant and mesogenic metal-containing soft materials.




One of the main challenges of modern coordination chemistry is to find ways of translating the considerable amount of information learned from small molecules into useful systems that foster the development of new materials. A main step in this process is the need for small molecules to be organized in highly ordered assemblies, and usually the need for transfer onto surfaces. The rich chemistry of transition metal complexes is profuse in systems with well understood, controllable, and tunable properties and the incorporation of these motifs into soft materials-thus allowing for interface and surface organization- is highly desirable. The development of surfactant and mesogenic metal-containing soft materials and the study of their properties and surface chemistry is at the very core of our research.

Rajendra Shakya, and currently Jeff Driscoll, Sarmad Hindo, Frank Lesh, and Rama Shanmugam, are involved with projects that use prototypical modeling. For details, please check papers 3, 5, 9, and 10 in our publication list.



3. The development of weakly coupled redox-driven molecular switches.




The understanding and development of weakly coupled redox-driven molecular switches. Several current advances in nanoscience depend upon the development of molecular materials with controlled properties, and synthetic chemistry plays a unique role in delivering such systems. Molecules that act as switches are expected to have significant potential for information technology when the requirements of response to an external stimulus and bistability are fulfilled. Transition metal complexes with electroactive ligands able to support the generation and stabilization of organic radicals are of special interest. Among the well characterized redox-active systems, phenoxyl radicals resulting from phenolate oxidation can be generated in pseudo-octahedral complexes, but the remarkable redox reversibility seen in biological systems cannot be matched. Four decades of research in the bioinorganic field have given substantial answers about how enzymes operate, and suggest that in nature the phenolate/phenoxyl couple is bound to five-coordinate ions. This environment might be responsible for the observed redox versatility. Thus, the Verani Group has used ligand design to foster unusual geometries in trivalent metal centers and to enhance stable switching mechanisms.

Mauricio Lanznaster, Camille Imbert, and currently Marco Allard and Frank Lesh, are involved with projects that use prototypical modeling. For details, please check papers 2, and 6 in our publication list.




Other front involves the use of metal complexes in medicine:

4. The development of anti-tumor metallodrugs.




The approval of cisplatin as a chemotherapeutic agent nearly thirty years ago triggered an increased interest in the action of metallodrugs. Current efforts aim at broadening the spectrum of activity, improve clinical efficacy, and to reduce overall toxicity. This last topic concentrates on the development of gallium- and other metal-based drugs and prodrugs that are capable of inhibiting tumor growth.

Rajendra Shakya, and currently Sarmad Hindo, Rama Shanmugam, and Dajena Tomco are involved with projects that use prototypical modeling. For details, please check papers 4, 7, and 8 in our publication list.