ChemInform Abstract: ORGANOMETALLIC CHALCOGEN COMPLEXES PART 27, STRUCTURE AND BONDING OF A METAL CARBONYL TETRAMER, CO4(CO)4(MU(2)-SC2H5)8, CONTAINING A PLANAR TETRAMETAL CLUSTER SYSTEM, A DIRECT STEREOCHEMICAL APPRAISEMENT OF STRONG METAL-METAL-INTERACT

1973 ◽  
Vol 4 (40) ◽  
pp. no-no
Author(s):  
CHIN HSUAN WEI ◽  
LASLO MARKO ◽  
GYOERGY BOR ◽  
LAWRENCE F. DAHL
Keyword(s):  
Metal Carbonyl ◽  
Cluster System ◽  
System A ◽  
Metal Metal ◽  
Structure And Bonding

scholarly journals Deep Wide-Field Photometry of the NGC 5128 Globular Cluster System: A Progress Report

2002 ◽  
Vol 207 ◽  
pp. 309-311
Author(s):  
G. L. H. Harris ◽  
D. Geisler ◽  
W. E. Harris ◽  
J. E. Hesser
Keyword(s):  
Globular Cluster ◽  
Luminosity Function ◽  
Progress Report ◽  
Cluster System ◽  
Wide Field ◽  
Preliminary Results ◽  
System A ◽  
Globular Cluster System

We have obtained CMR photometry for a roughly 1° square region centered on NGC 5128. Preliminary results indicate that the limiting magnitude of the images is ≳ 1 magnitude fainter than the peak of the globular cluster luminosity function (GCLF) at R ⋍ 21.

Universal aqueous synthesis of ultra-small polymer-templated nanoparticles: synthesis optimization methodology for counterion-collapsed poly(acrylic acid)

2018 ◽  
Vol 96 (1) ◽  
pp. 44-50 ◽  
Author(s):  
Nari Kim ◽  
Calvin C.H. Cheng ◽  
M. Cynthia Goh
Keyword(s):  
Acrylic Acid ◽  
Metal Ion ◽  
Rapid Development ◽  
Ion Concentration ◽  
Universal Method ◽  
Aqueous Synthesis ◽  
System A ◽  
Metal Metal ◽  
Optimization Methodology ◽  
Poly Acrylic Acid

A long polyelectrolyte chain collapses into a nano-sized particle upon the addition of counterions under appropriate solution conditions. This phenomenon forms the basis for a simple universal method for aqueous synthesis of ultra-small (<10 nm) metal, metal oxide, and other types of nanoparticles in the following manner: the counterion-collapsed polyelectrolyte chains are made stable by crosslinking, effectively trapping the counterions, which are subsequently chemically modified, to form metal nanoparticles via reduction or metal oxides nanoparticles via oxidation, within the collapsed polymer nanoparticle. This highly versatile platform methodology can be applied to almost any polyelectrolyte–counterion pair, making possible the rapid development of syntheses of different nanoparticles within the same chemical environment. Using poly(acrylic acid) as a model system, a methodology for the optimization of conditions for the polyelectrolyte collapse by various mono- and multi-valent metal cations is developed. The optimal counterion concentration did not correlate with ionic strength and metal ion valency and was highly variable from system to system. By monitoring the polyelectrolyte conformation using viscosity and turbidity measurements, the appropriate metal ion concentration for each nanoparticle system was determined.

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