SPEAKERS

Bryan

Koivisto

RESEARCH INTERESTS

The dye is the powerhouse of the cell. The focus for our group at Ryeron is to develop novel organic dye show improved efficiency and long-term device performance. We see molecules as very small building blocks. A DSSC dye is comprised of a redox-active donor (D), a pi-spacer, and an acceptor anchor (A) capable of binding to TiO2 (example below).

In addition to incorporating non-innocent pi-spacers into our dye motifs, we are interested in exploring metal-free organic dyes that can be interfaced with polymer hole transport materials. this hybridization of DSSC and bulk heterojunction solar cell technology represents a paradigm shift that will yield more efficient device architectures.

Matteo

Leoni

Leoni's group research is mainly focus in crystallography, ceramics and mechanical engineering areas.

Slavi

Sevov

The heavier members of Groups 14 and 15, both metals and semimetals, are known for their chemistry in various positive oxidation states. What we are interested in is how they behave when forced to accept electrons and become negatively charged, i.e. when in negative oxidation states. It turns out that such atoms tend to cluster together and form: nine-atom deltahedral clusters E94- for Si, Ge, Sn, and Pb; seven-atom species E73- for P, As, and Sb; etc. We have studied extensively the reactivity of Ge94- towards various reagents and have found, to our and many other people’s surprise, that they can be readily functionalized with various groups and form [R-Ge9-R]2- and [Ge9-R]3- for R=alkyl, alkenyl, main-group and transition-metal organometallic fragments, etc. Furthermore, they can oligo- and poly-merize to form dimers trimers, tetramers, and infinite chains, for example [Ge9-Ge9]6-, [Ge9=Ge9=Ge9]6-, and [-(Ge92-)-], and they can be centered by transition-metal atoms. The bismuth fragments, on the other hand, can react with various organometallic compounds and form mixed main-group/transition-metal clusters such as [Bi3Mo2(CO)6]3-, [Bi3Ni4(CO)6]3-, [Bi4Ni4(CO)6]2-, [Bi3Ni6(CO)9]3-, and the Ni-centered [Ni@{Bi6Ni6(CO)8}]4-.

Meyer's research concerns experimental investigations of the excited states of transition metal compounds that can drive subsequent electron or energy transfer reactions in fluid solution and at semiconductor interfaces. The excited states are based on transition metal compounds, particularly those based on Ru, Cu, or Co, and the semiconducting materials are typically wide band gap metal oxides such as anatase TiO2. Practical applications include light-to-electrical energy conversion, chemical sensing, and photo-catalysis. The principle tools of this research are synthetic chemistry, spectroscopy, and electrochemistry.

Transition metal compounds often possess low-lying excited states that can be populated with visible light. The nature of these excited states is of fundamental interest in their own right as is there subsequent reactivity. Particular emphasis on the excited states has focused on:

Quantification of light driven inner-sphere reorganization that is novel to copper phenanthroline compounds by photoluminescence and, more directly, by x-ray spectroscopies. The x-ray characterization represents an ongoing collaboration with Lin Chen and her coworkers at the Advanced Photon Source, Argonne National Laboratory.
Identifying the molecular origin(s) of the activational barriers for internal conversion of charge-transfer and ligand-field excited states in Ru polypyridyl compounds in fluid solution and at semiconductor interfaces.
Prevention of the rapid light induced excited state spin trapping by the 5T state of spin-crossover Fe(II) benzimidazole compounds that occurs at TiO2 interfaces.
Characterization of Co(I) compounds with low-lying metal-to-ligand charge transfer excited states.
Dissociative excited states that release CO will be exploited to measure dioxygen activation by copper on short time scales. This research represents an ongoing collaboration with Ken Karlin and his coworkers at Johns Hopkins.

Gerald

Meyer

The main focus of the Hinestroza Research Group is to explore the interface between the technologically established and mature field of textile science with the emerging and revolutionary field of nanoscale science. The field of textiles was the first beneficiary of the scientific developments from the 18th century's industrial revolution while the nanotechnology revolution emerged the end of the 20th century. Our research group aims at merging two hundred years of innovation history.
We believe that this unusual combination, between an established and an emerging scientific field, can provide unique scientific platforms that take advantage of the ability of nanoscale science of controlling the synthesis of materials and probing unusual phenomena at the nanoscale with the time-tested capabilities of textile and fiber manufacturing.
In order to explore and understand nanoscale phenomena of relevance to fiber science we decided to pursue a three-pronged approach as follows: The first branch is aimed at modifying the properties of existing textile products, specifically natural fibers, using nanomaterials. The second approach is aimed at creating novel nanofiber based materials by taking advantage of unique self and directed assembly phenomena. The third effort is aimed at developing metrology and computer simulation tools to better understand traditional issues in textile processing such as friction and electrostatic charging whose influence is magnified at the nanoscale.

Juan

Hinestroza

BECOME A SPONSOR

CONNECT

WITH US:

Karine Costuas is specialized in the rationalization of the relationship between structural arrangement, electronic structure and physical properties through quantum chemical calculations (mainly DFT).

Her research is mainly focused on coordination compounds of transition metals and/or lanthanides, either radical mono-metallic or poly-metallic complexes that show (i) redox activity (mixed-valency, electronic communication) (ii) magnetic behavior (magnetic coupling) (iii) optical properties (electronic excitation, emission). She is also interested in the theoretical design of new multifunctional compounds for molecular spintronics application, for which specific physical properties are required. Recently, she has been working on the study of modified surfaces featuring adsorbed molecules

Karine

Costuas

Stéphane Cordier is actually in charge of the development of metal atom cluster chemistry in the ‘Institut Sciences Chimiques de Rennes’ (ISCR) in particular in the group ‘Solid State Chemistry and Materials’. Cluster chemistry is an historic field of research in Rennes since the discovery of Chevrel-Sergent’s phases with their remarkable superconducting properties. This chemistry has yielded a wide library of compounds (synthesized and characterized by R. Chevrel, A. Perrin, M. Sergent, M. Potel,…) with fascinating crystal structures and properties such as Thermoelectricity, intercalation/de-intercalation processes, Mott insulator. Besides their numerous physical properties in the solid state, many solid-state compounds afford discrete soluble building blocks that are relevant for nanoarchitectonics and to build supramolecular frameworks. These versatile building blocks exhibit a well-defined organization of a precise number of atoms leading to a monodispersed size; giving rise to specific luminescence, sensitization, catalytic and photo-catalytic properties. Cluster functionalization improves their incorporation either in inorganic silica matrix or in organic copolymers and enables self-assembling in clustomesogens. Researches developed in ISCR encompass solid-state chemistry, nanocomposites, functionalization of surfaces, integration in functional devices (N. Audebrand, V. Bouquet, F. Grasset, Y. Molard, P. Gall, P. Gougeon, M. Guilloux-Viry, P. Lemoine,…). A special attempt is paid on multiscale characterizations (V. Demange, L. Le Pollès,…) and quantum chemical calculations in order to understand, for instance, the origin of the luminescence properties in cluster-based molecular assemblies or the thermoelectric properties in extended polymeric frameworks (K. Costuas, B. Fontaine, R. Gautier, J. F. Halet, L. Le Pollès,…). Cluster chemistry in Rennes is a multidisciplinary field of research ranging from fundamental approaches to applications purposes. It involves a lot of collaborations at the national at international level in particular with the Nikolaev Institute for Inorganic Chemistry of Novosibirsk and the National Institute for Materials Science at Tsukuba, and industrial companies as well, such as Saint Gobain.

Stéphane

Cordier

The development, characterization, and exploitation of novel materials based on the assembly of molecular components is an exceptionally active and rapidly expanding field. The research traverses the boundaries of chemistry, physics, biology, and medicine. A significant challenge in this context is the design, synthesis, and characterization of desired molecular components and their assembly into novel molecular architectures aimed at specific functions. Pursuant to this endeavor is our research program that has evolved from exploratory synthetic, structural, and reactivity studies on both molecular and nanoscale clusters.

Our general approach for undertaking this challenge has been to develop novel synthetic routes to the formation of metal clusters and their organization into nanoscopic assemblies. Using coordination chemistry-based synthetic approaches, my group has succeeded in producing new classes of polynuclear lanthanide clusters, cluster-supported metallodendrimers, and dendrimer-passivated gold nanoclusters. It has been possible to demonstrate not only the novel chemistry involved, but also the interesting electronic and optical properties of these materials. The ultimate goal of our research is to translate molecular properties of the metal clusters into the designed supramolecular assemblies for their applications in catalysis, separations, sensor technology, and information storage and processing.

Zhiping

Zheng

He is one of the three research liders of NANOCOSMOS Project, which try to resolve some of the misteries relatives to how nanoparticles of interestellar dust grains are formed, and which are the fundamental processess that can form the earth and space chemical complexity. To achieve these objectives, we work with a multidisciplinary group with expertise in Astronomy, Astrophysics, Molecular Physics, Surface Science, Physics of Plasma, Quantum and Engineering Chemistry.

NANOCOSMOS design and build a machinery capable of produce interestellar grain dust analogous by replicating the physical and chemical conditions of the external coat of evolved stars. The properties of these samples are analized through simulation chambers and advanced techniques of materials science and spectroscopy. Also, we carry out radioastronomic observation employing the ALMA (Atacama Large Millimeter/submillimeter Array) telescopes, in order to study the molecular composition and chemical processess associated to the zone where the grain dust are formed.

José

Cernicharo

The Bio-nanomaterials Chemistry and Engineering Laboratory (BnCE), under the direction of Dr. Emilio I. Alarcon, is located in the Research Centre of University of Ottawa Heart Institute. It is affiliated with the Biomaterials and Regenerative Research Program in the Division of Cardiac Surgery. BnCE’s main focus is the development and characterization of bio-inspired hybrid nanomaterials. 3D scaffolds are being fabricated with improved contractile properties and antibacterial properties for the reconstruction of tissues with poor regenerative capabilities like infarcted heart muscle and skin in patients with reduced vascularization (e.g., diabetic foot patients).

Emilio

Alarcón

My research task is centered on what the microscopic structure of materials means about its macroscopic behavior. This general objective rules along three research lines: i) Crystallographic studies by X-ray diffraction: obtaining precise electron densities and analysis of their topology, crystal structure, polymorph analysis, chemical bonding. ii) Studies on iron-containing materials by Mössbauer spectroscopy: magnetism of small particles and polynuclear complexes, instrumentation. iii) Studies on aerogels and related porous materials: preparation, characterization, properties and applications. For instance, we have established links between the topology of the electron density and the chemical bond energetics and we are preparing materials useful as catalysts in liquid (for synthetic purposes) and gas phases (materials for energy).

Elies

Molins

The realization of materials at the nanometer scale creates new challenges for quantitative characterization and modeling as many physical and chemical properties at the nanoscale are highly size and shape-dependent. In a modern transmission electron microscope a number of advanced electron microscopy techniques and electron energy-loss spectroscopy (EELS) are available which allows to achieve a local correlation between microstructure, chemical information and electronic properties with subnanometer spatial resolution.

My research is focused in the study, at the nanometer scale, of nanostructured materials by means of microscopy and spectroscopy with electrons. My field of expertise is in the development and application of advanced electron microscopy and spectroscopy techniques and in particular as applied to the study of novel oxide systems, for example for heterogeneous catalysis, carbonaceous materials like graphene oxide and materials for electrodes (cathode and anode) in Li-ion batteries. The different techniques used allow us to determine near-atomic structure, the oxidation state of active species and the 2D spatial distribution of the elemental constituents. In addition, to complement the experimental EELS data, theoretical real space multiple scattering calculations are used to understand the details of the energy loss spectra.

Sergio

Moreno

My group work on different theoretical and experimental areas, such as:

-Organic photovoltaics have received considerable attention because of their high power conversion efficiencies in thin films. They possess interesting physical properties such as, flexibility, transparency and lightweight. The potential of tuning the cell’s overall efficiency by incorporating organic molecules as the photoactive layer provides an infinite number of possible cell configurations.

-Synthesis of Endohedral Fullerenes, which are carbon cages containing incarcerated atoms, metals or clusters. The interaction between the cage and the incarcerated moiety can provide interesting electronic properties. Our research group has contributed extensively in the discovery of new endohedral fullerenes. Currently, we are focusing on the synthesis and discovery of new endohedral fullerenes that encapsulate new atom clusters. These fullerenes could potentially possess new and interesting optoelectronic properties and have interesting applications, mainly in organic photovoltaic technologies.

- Functionalization of Fullerenes cages has expanded their potential application in several fields, from biology to materials science. Our research group currently works in the regioselective addition to fullerene cages to obtain pure bis-adducts. These regioselectively prepared pure bis-adducts are being used as electron acceptors in OPV devices due to their high lying LUMO compared to those of their mono-adduct counterparts.

- Extended Fullerene Networks, due to they possess interesting physical and electronic properties that have allowed them to be used in numerous applications. Our interest is focused on the design and synthesis of regioisomerically pure fullerene derivatives that could potentially be incorporated as linkers in extended network structures, mainly in metal organic frameworks (MOFs) and metallopolymers.

Luis

Echegoyen

My actual research interests are mainly centered in the use of DFT-based methods to study the electronic structure of inorganic solids and its relation to electrical transport and magnetic properties as well as in the development and application of continuous symmetry measures to problems in structural chemistry.

Pere

Alemany

Excitation energy transfer is besides charge transfer a key issue in organic photovoltaics and organic electronics in general. When light is absorbed by an assembly of chromophores, excitation energy may be transferred from one dye molecule to the other within the aggregate. What is the speed at which this exchange takes place? What are the mechanisms behind? And how is energy transfer affected by the chemical composition of the aggregate?

In this context, we develop software for the calculation of electronic excitonic coupling strengths in covalently linked chromophore aggregates. Another focus lies in the implementation of suitable method for determining rate constants from these couplings. Applications focus up to now on quantum chemical studies of various organic homo- and hetero-dimers.

Jörg

Tatchen

Our group has a broad theoretical and observational background in the field of star formation, young stars and their initial mass function, cover a vast spectrum in both high-mass and low-mass star formation, including binaries, disks, jets, and exoplanets.

As SOFIA Mission Operations Deputy Director, Zinnecker co-directs SOFIA's overall scientific mission and is responsible for the Observatory's productivity. He also represents the German interests in both SOFIA's science and management, and is responsible for the US-based staff of the Deutsches SOFIA Institute. Amongst his various challenges is his hope to convert Herschel users to SOFIA users.

Hans

Zinnecker

The power of the unconscious, the chemical key to taking full brain potential. The focus of the work of Felipe is to explore and demonstrate how science is the gateway to the modification of chemical and hormonal processes in our body. Therefore to find happiness and measure it properly.

Based on studies of the most respected universities in the world, the challenge is to translate the use of science of the unconscious processes and how this changes the human behavior. We believe that emotions do not exist, they are just reactions to our thoughts.

By consciously we can modify the unconscious in our favor. This is the key to the processes of creativity, innovation, happiness and success. Felipe has written his latest book which has been validated and approved by PhD in the area of neurology and prominent businessmen.

Felipe

Montenegro

Gabriel Merino has focused his research on the prediction of new molecular systems that fully violate the traditional chemistry concepts and bring to the limit basic concepts such as structure, chemical bond and aromaticity. One of his first contributions was to show that under certain conditions it is possible to stabilize tetracoordinated hydrocarbons, but all the surrounding atoms of the central carbon atom remain in the same plane, which means, plane tetracoordinated carbon atom. The rules that emerged from this work were extended to other atoms in the periodic table of elements, such as Boron and other atoms that belong to group 14.