Cluster of clusters. Structure of a novel gold-silver cluster [(Ph3P)10Au13Ag12Br8](SbF6) containing an exact staggered-eclipsed-staggered metal configuration. Evidence of icosahedral units as building blocks

1991 ◽  
Vol 113 (11) ◽  
pp. 4329-4331 ◽  
Author(s):  
Boon K. Teo ◽  
Xiaobo Shi ◽  
Hong Zhang
Keyword(s):  
Silver Cluster ◽  
Building Blocks ◽  
Gold Silver ◽  
Cluster Of Clusters

Crystal structure of a pentanuclear gold-silver cluster complex

1992 ◽  
Vol 22 (4) ◽  
pp. 421-425 ◽  
Author(s):  
Mazhar-Ul-Haque ◽  
William Horne ◽  
Omar M. Abu-Salah
Keyword(s):  
Crystal Structure ◽  
Silver Cluster ◽  
Cluster Complex ◽  
Gold Silver

Cosmic Chemistry

2017 ◽  
Author(s):  
John Chambers ◽  
Jacqueline Mitton
Keyword(s):  
Solar System ◽  
Chemical Elements ◽  
Building Blocks ◽  
Big Bang ◽  
Rich Variety ◽  
Gold Silver ◽  
The Rich ◽  
Rocky Planets ◽  
The Big Bang ◽  
The Universe

This chapter analyzes how humans owe their existence to the rich variety of chemical elements that exist in the universe. The solar system contains hydrogen to power the Sun; iron and silicon to build rocky planets; and carbon, nitrogen, and oxygen to form the building blocks of life. Almost 100 elements occur naturally in the solar system in varying amounts. Some, like hydrogen, oxygen, and iron, are abundant everywhere. Others, like gold, silver, and uranium, are much less common. The mixture of elements has remained almost constant since the solar system formed, apart from changes deep in the Sun's interior. The chapter shows how the composition of the solar system was shaped by events elsewhere in the universe dating back to the Big Bang itself.

Photochemical Evolution of Interstellar/Precometary Organic Material

1997 ◽  
Vol 161 ◽  
pp. 23-47 ◽  
Author(s):  
Louis J. Allamandola ◽  
Max P. Bernstein ◽  
Scott A. Sandford
Keyword(s):  
Origin Of Life ◽  
Building Blocks ◽  
Complex Species ◽  
Infrared Observations ◽  
Interstellar Ice ◽  
Polycyclic Aromatic ◽  
Ultraviolet Photolysis ◽  
The Origin Of Life ◽  
Simple Molecules ◽  
Complex Organic

AbstractInfrared observations, combined with realistic laboratory simulations, have revolutionized our understanding of interstellar ice and dust, the building blocks of comets. Since comets are thought to be a major source of the volatiles on the primative earth, their organic inventory is of central importance to questions concerning the origin of life. Ices in molecular clouds contain the very simple molecules H2O, CH3OH, CO, CO2, CH4, H2, and probably some NH3and H2CO, as well as more complex species including nitriles, ketones, and esters. The evidence for these, as well as carbonrich materials such as polycyclic aromatic hydrocarbons (PAHs), microdiamonds, and amorphous carbon is briefly reviewed. This is followed by a detailed summary of interstellar/precometary ice photochemical evolution based on laboratory studies of realistic polar ice analogs. Ultraviolet photolysis of these ices produces H2, H2CO, CO2, CO, CH4, HCO, and the moderately complex organic molecules: CH3CH2OH (ethanol), HC(= O)NH2(formamide), CH3C(= O)NH2(acetamide), R-CN (nitriles), and hexamethylenetetramine (HMT, C6H12N4), as well as more complex species including polyoxymethylene and related species (POMs), amides, and ketones. The ready formation of these organic species from simple starting mixtures, the ice chemistry that ensues when these ices are mildly warmed, plus the observation that the more complex refractory photoproducts show lipid-like behavior and readily self organize into droplets upon exposure to liquid water suggest that comets may have played an important role in the origin of life.

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