Established in 1959 New Chemistry of Gold T. Pradeep Department of Chemistry Indian Institute of Technology Madras Chennai 600 036 pradeep@iitm.ac.in Quantum clusters: Au 25, Au 23, Au 22, Au 8, Ag 8, Ag 9, Ag 25 Anna University, March 7, 2011
Hardcover: 274 pages Publisher: Elsevier Science Ltd (June 1978) Language: English ISBN-10: 0444416242 ISBN-13: 978-0444416247 Gold Chemistry ISBN: 978-0-471-97369-0 Hardcover 908 pages March 1999
Gold catalysis Number of papers published per year after the discovery of gold catalysis.
5000 Numbe rof publication in gold nanoparticle 4000 3000 2000 1000 0 Publications per year as on December 31, 2010 With the key words, gold and nanoparticle* 5483 6054 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 Year
Monolayer Protected Metal Nanoparticles Monolayer Protected Clusters (MPCs) N. Sandhyarani and T. Pradeep, Int. Rev. Phys. Chem. 2003
A B 1 nm 1 nm 4.8 nm 7.8 nm 0.1 µm 20 nm E. S. Shibu et al. Adv. Mater. 2008; Nano Res. 2009; Chem. Mater. 2009
Fluorescent superlattices E. S. Shibu et al, Adv. Mater. 2008; Nano Res. 2008, Chem. Mater.; 2009
Manometer Rotary pump to gas source Power supply A 1.5 0.00 B C Keithley multimeter 0.00026 ma D c b a 1 cm 10 µm E. S. Shibu et al. Nanoscale (2011). 12
Current (ma) 3.5x10-6 A 1. 5 volt 100 torr 3.0x10-6 2.5x10-6 -----O 2 -----Ar -----N 2 -----CO 2 Current (ma) -----O 2 1.5 volt 500 torr 3.6x10-6 -----Ar -----N 2 -----CO 2 3.0x10-6 2.4x10-6 B 1.8x10-6 2.0x10-6 1000 1500 2000 Time (sec) 1.2x10-6 500 1000 1500 2000 Time (sec) Current (ma) 2.4x10-6 1.8x10-6 1.2x10-6 Current Raman Intensity C 500 400 300 200 100 Raman Intensity a d l a= particle diameter d= gas molecule diameter l= thickness of monolayer z D 0 200 400 600 800 Time (sec) 23 March 2011 E. S. Shibu, IIT M 13
P. R. Sajanlalal and T. Pradeep Nano Res. 2009; JPC C 2009; 2010
A B Intensity 4 3 2 1 Au Ag 1 µm 1 µm AuAg C D 0 0 200 400 600 800 Distance (nm) 500 nm 500 nm AuAg
Region-specific SERS activity ecreasing or er of SERS ac vity u g s u s u Pt s 1 µm 5 µm AuAg 600 1200 1800 EDAX image of Au/Ag MF Raman shift (cm -1 ) 0.8 µm Raman image of Au/Ag MF SERS intensity is higher at the tip compared to the body of the stem. Au/Ag mesoflowers show high SERS activity than Au mesoflowers. show ten-fold increase in the SERS enhancement factor than Au mesoflowers. capable of detecting biomolecules and explosives at very low concentrations. P. R. Sajanlal and T. Pradeep, Langmuir, 26 (2010) 8901 8907.
50 nm Faraday s gold preserved in Royal Institution. From the site, http://www.rigb.org/rimain/heritage/faradaypage.jsp
they are simply cases of pure gold in a divided state; yet I have come to that conclusion, and believe that the differentlycoloured fluids and particles are quite analogous. Experimental Relations of Gold (and Other Metals) to Light, M. Faraday, Philos. Trans. R. Soc. London, 1857, 147, 145
Gustav Mie (1868-1957) Surface plasmons 1905 By changing size 1940 Mie G. Beiträge zur Optik trüber Medien speziell kolloidaler Goldlösungen (contributions to the optics of diffuse media, especially colloid metal solutions). Ann Phys 1908;25:377 445. This paper, including an English translation, as well as other historic papers on light scattering and absorption can be found at www.iwt-bremen.de/vt/laser/wriedt/index_ns.html.
Gas phase cluster spectroscopy Mass spectra of positively charged Ar, Kr, Xe clusters, W. Miehle, O. Kandler, T. Leisner, and O. Echt. (1989) J. Chem. Phys., 91, 5940.
Laser desorption mass spectrometry Smalley et al. Nature 1985
Supported gold clusters in catalysis Schematic representation for CO oxidation pathways over Au/TiO2. M. Haruta. When Gold Is Not Noble: Catalysis by Nanoparticles. Chem. Rec. 2003, 3, 75.
Magic clusters From Gunter Schmidt, Chem. Soc. Rev. 2008, 37, 1909 1930
Gold clusters Au 13 Au 55 [Au 13 (PPhMe 2 ) 10 C1 2 ] 3+ Au 55 [P(C 6 H 5 ) 3 ] 12 Cl 6 - a gold cluster of unusual size, Schmid, G.; Pfeil, R.; Boese, R.; Brandermann, F.; Meyer, S.; Calis, G. H. M.; Van der Velden.; Jan W. A. Chemische Berichte 1981, 114, 3634. Synthesis and x-ray structural characterization of the centered icosahedral gold cluster compound [ Au 13 (PMe 2 Ph) 10 Cl 2 ](PF 6 ) 3 ; the realization of a theoretical prediction, Briant, C. E.; Theobald, B. R. C.; White, J. W.; Bell, L. K.; Mingos, D. M. P.; Welch, A. J. Chem. Commun. 1981, 5, 201. Synthesis of water-soluble undecagold cluster compounds of potential importance in electron microscopic and other studies in biological systems, Bartlett, P. A.; Bauer, B.; Singer, S. J. Am. Chem. Soc. 1978, 100, 5085.
Molecular Clusters 28 kda Alkanethiolate-Protected Au Clusters Give Analogous Solution Electrochemistry and STM Coulomb Staircases, Ingram, R. S.; Hostetler, M. J.; Murray, R. W.; Schaaff, T. G.; Khoury, J.; Whetten, R. L.; Bigioni, T. P.; Guthrie, D. K.; First, P. N. J. Am. Chem. Soc. 1997, 119, 9279. Isolation of Smaller Nanocrystal Au Molecules: Robust Quantum Effects in Optical Spectra, Schaaff, T. G.; Shafigullin, M. N.; Khoury, J. T.; Vezmar, I.; Whetten, R. L.; Cullen, W. G.; First, P. N.; Gutierrez-Wing, C.; Ascensio, J.; Jose-Yacaman, M. J. J. Phys. Chem. B 1997, 101, 7885. Optical Absorption Spectra of Nanocrystal Gold Molecules, Alvarez, M. M.; Khoury, J. T.; Schaaff, T. G.; Shafigullin, M. N.; Vezmar, I.; Whetten, R. L. J. Phys. Chem. B 1997, 101, 3706.
How to make them?