Emeriti

Micha Asscher

Prof. Micha Asscher

Professor of Chemistry
02 6585 742
Micha.Asscher@mail.huji.ac.il
Los Angeles 31 Fax: 02 6525 037

Read More

Research Focus: 
1. Model heterogeneous catalysis is studied under ultra-high vacuum (UHV) conditions on top of alloy bimetallic nano-clusters (e.g. Au-Cu and Cu-Pd) grown via buffer layer assisted growth method in UHV. In situ Auger and thermal desorption methods are used to follow reactivity and selectivity. High pressure-low pressure apparatus is uniquely used to study the thermal and photo-excited catalysis.

Cu-Au relative composition affecting yield and selectivity of C2H2 100% conversion to thylene (No benzene formation)
Cu-Au relative composition affecting yield and selectivity of C2H2 100% conversion to thylene (No benzene formation)

 

 

2. Local (transient) electric field effect on photo-induced and electron-induced reactivity of caged molecules on surfaces is studied near sharp edges and by growing model

in-vacuum nano-capacitors by trapping electrons in ice.

3. The role of plasmonic giant field enhancement near metallic (Ag) nano-particles on photo-reactivity vs. the effect of hot excited electrons on surface photochemistry has

been investigated. Its potential  enhancement in photo-catalysis when embedded within TiO2 films has been investigated. 

Ag nanoparticles SEM image (right) and their effect in enhancing photo-dissociation of ethyl chloride (left), red signal is the resulting product in the presence of Ag particles
Ag nanoparticles SEM image (right) and their effect in enhancing photo-dissociation of ethyl chloride (left), red signal is the resulting product in the presence of Ag particles

 

Selected Publications:

1.      Photoinduced desorption of Xe from porous silicon: Evidence for selective and highly effective optical activity, Toker, G., Asscher, M., Phys. Rev. Lett., 107, 167402-16406 (2011).
2.      Reduced Oxide Sites and Surface Corrugation Affecting the Reactivity, Thermal stability, and Selectivity of Supported Au–Pd Bimetallic Clusters on SiO2/Si(100) ; Gross, E., Sorek, E., Murugadoss,  A., Asscher, M., Langmuir , 29 (20), 6025–6031 (2013).
3.      Electron-induced chemistry of methyl chloride caged within amorphous solid water Horowitz, Y. and Asscher, M., J. Chem. Phys., 139, 154707 (2013).
4.      Structure and Composition of Au-Cu and Pd-Cu Bimetallic Catalysts ffecting Acetylene Reactivity, Murugadoss, A., Sorek, E., and Asscher, M., Topics in Catalysis57 (10), 1007-1014 (2014).
5.      Enhanced Photo Chemistry of Ethyl Chloride on Ag Nanoparticles,Toker, G., Bespaly A., Zilberberg, L., Asscher, M. Nano Letters, 15(2), 936-42 (2015);  
6.      Buffer Layer Assisted Growth of Ag Nanoparticles in Titania Thin Films  Zilberberg, L., Mitlin, S., Shankar, H., Asscher, M., J. Phys. Chem. C, 119(52), 28979-28991 (20155).

Read Less
Avi Bino

Prof. Avi Bino

Professor of chemistry
02 6585 722
bino@mail.huji.ac.il
 Los Angeles 204

Read More

 

• Ph.D., 1978, Hebrew University of Jerusalem

• B.Sc., 1973, Hebrew University of Jerusalem

 

 

Research Focus:

1. We study the formation and chemistry of free carbyne and carbene radicals in aqueous solution. These species are produced by degradation of metal complexes that contain triple or double metal-carbon bonds in water. An alternative route to obtain these extremely reactive species is by reacting tri- or di-halo alkanes with  chromium(II) ions according to:

      R-CX3 + 3Cr+2 = R-C  + 3[XCr]2+  or R-CHX2 + 2Cr+2 = RHC + 2[XCr]2+

Both carbynes and carbenes undergo coupling reactions and produce alkynes and alkenes respectively. In addition, they react with solvent molecules and produce a large variety of products.

2. We study the mechanism by which organo-metallic cluster complexes that contain alkylidyne ligands are formed. We believe that the origin of the alkylidyne group is a free carbyne that reacts with the tri-nuclear framework. We apply ion-exchange chromatography , GC-MS and X-ray crystallography techniques to elucidate the exact mechanism.

3. Ferric citrate complexes play an important role in the biological mobilization of iron in living cells. Ferric citrate preparations are used in medicine as iron supplements and for imaging purposes. Our goal has been the structural characterization of several ferric citrate complexes and the understanding of the role of each species in biological systems.

 

 

Selected Publications: 

1.      Bino, A.; Ardon, M.; Shirman, E. Formation of a Carbon-Carbon Triple Bond by  Coupling Reactions in Aqueous Solution Science 2005,308, 234-235.

2.      Kefalas, E. T.; Dakanali, M.; Panagiotidis, P.; Raptopoulou, C. P.; Terzis, A.;      Mavromoustakos, T.; Kyrikou, I.; Karligiano, N.; Bino, A.; Salifoglou, A. pH- Specific Aqueous Synthetic Chemistry in the Binary Cadmium(II)-Citrate System. Gaining Insight into Cadmium(II)-Citrate Speciation with Relevance to Cadmium Toxicity  Inorg. Chem. 2005, 44, 4818-4828.

3.      van Slageren, J.; Rosa, P.; Caneschi, A.; Sessoli, R.; Casellas, H.; Rakitin, Y.V.;  Cianchi, L.; Giallo, F.D.; Spina, G.; Bino, A.; Barra, A.L.; Guidi, T.; Carretta, S.;  Caciuffo, R.  Static and dynamic magnetic properties of an [Fe-13] cluster Phys. Rev. B, 2006 , 73,  014422.

4.    Bogoslavsky, B.; Levy, O.; Kotlyar, A.; Salem, M.; Gelman, F.; Bino, A. Do carbyne radicals really exist in Aqueous solution? Angew. Chem. Int. Ed.   2012,  51,90-94.

5.    Levy, O; Bogoslavsky, B.; Bino, A. Anhydrous Chromous Acetate Revisited –  a Very Simple Synthetic Route Inorg. Chim. Acta, 2012, 391,179-181.

6.    Levy, O; Bino, A. Metal Ions Do Not Play a Direct Role in the Formation of  Carbon- Carbon Triple Bonds During Reduction of Trihaloalkyls by Cr(II) or V(II) Chem. Eur. J. 2012, 18, 15944- 15947.

7.   Danovich, D.; Bino, A. ; Shaik, S. The formation of carbon-carbon triply  bonded molecules from two free carbyne radicals via a conical intersection J. Phys. Chem. Lett., 2013, 4, 58-64.

8.      Levy, O; Musa, S.; Bino, A. Formation of an Alkyne During Degradation of  Metal-Alkylidyne Complexes Dalton Trans., 2013, 42, 12248 – 12251.

9.      Halevi, O.; Bogoslavsky, B.; Grinstein, D.; Tibika-Apfelbaum, F.; Bino, A. Synthesis and Characterization of Nitrogen Rich Ruthenium Complexes Inorg. Chim. Acta, 2014, 421 , 228–232.

10.   Avisar Levy, M.; Levy, O.; Ascarelli, O.; Popov, I.;  Bino, A. Fractal  Structures of Highly-Porous Metals and Alloys at the Nanoscale J. Alloys Compd. 2015, 635, 48-54.

Read Less