WIKIBOOKS
DISPONIBILI
?????????

ART
- Great Painters
BUSINESS&LAW
- Accounting
- Fundamentals of Law
- Marketing
- Shorthand
CARS
- Concept Cars
GAMES&SPORT
- Videogames
- The World of Sports

COMPUTER TECHNOLOGY
- Blogs
- Free Software
- Google
- My Computer

- PHP Language and Applications
- Wikipedia
- Windows Vista

EDUCATION
- Education
LITERATURE
- Masterpieces of English Literature
LINGUISTICS
- American English

- English Dictionaries
- The English Language

MEDICINE
- Medical Emergencies
- The Theory of Memory
MUSIC&DANCE
- The Beatles
- Dances
- Microphones
- Musical Notation
- Music Instruments
SCIENCE
- Batteries
- Nanotechnology
LIFESTYLE
- Cosmetics
- Diets
- Vegetarianism and Veganism
TRADITIONS
- Christmas Traditions
NATURE
- Animals

- Fruits And Vegetables



ARTICLES IN THE BOOK

  1. Atomic force microscope
  2. Atomic nanoscope
  3. Atom probe
  4. Ballistic conduction
  5. Bingel reaction
  6. Biomimetic
  7. Bio-nano generator
  8. Bionanotechnology
  9. Break junction
  10. Brownian motor
  11. Bulk micromachining
  12. Cantilever
  13. Carbon nanotube
  14. Carbyne
  15. CeNTech
  16. Chemical Compound Microarray
  17. Cluster
  18. Colloid
  19. Comb drive
  20. Computronium
  21. Coulomb blockade
  22. Diamondoids
  23. Dielectrophoresis
  24. Dip Pen Nanolithography
  25. DNA machine
  26. Ecophagy
  27. Electrochemical scanning tunneling microscope
  28. Electron beam lithography
  29. Electrospinning
  30. Engines of Creation
  31. Exponential assembly
  32. Femtotechnology
  33. Fermi point
  34. Fluctuation dissipation theorem
  35. Fluorescence interference contrast microscopy
  36. Fullerene
  37. Fungimol
  38. Gas cluster ion beam
  39. Grey goo
  40. Hacking Matter
  41. History of nanotechnology
  42. Hydrogen microsensor
  43. Inorganic nanotube
  44. Ion-beam sculpting
  45. Kelvin probe force microscope
  46. Lab-on-a-chip
  47. Langmuir-Blodgett film
  48. LifeChips
  49. List of nanoengineering topics
  50. List of nanotechnology applications
  51. List of nanotechnology topics
  52. Lotus effect
  53. Magnetic force microscope
  54. Magnetic resonance force microscopy
  55. Mechanochemistry
  56. Mechanosynthesis
  57. MEMS thermal actuator
  58. Mesotechnology
  59. Micro Contact Printing
  60. Microelectromechanical systems
  61. Microfluidics
  62. Micromachinery
  63. Molecular assembler
  64. Molecular engineering
  65. Molecular logic gate
  66. Molecular manufacturing
  67. Molecular motors
  68. Molecular recognition
  69. Molecule
  70. Nano-abacus
  71. Nanoart
  72. Nanobiotechnology
  73. Nanocar
  74. Nanochemistry
  75. Nanocomputer
  76. Nanocrystal
  77. Nanocrystalline silicon
  78. Nanocrystal solar cell
  79. Nanoelectrochemistry
  80. Nanoelectrode
  81. Nanoelectromechanical systems
  82. Nanoelectronics
  83. Nano-emissive display
  84. Nanoengineering
  85. Nanoethics
  86. Nanofactory
  87. Nanoimprint lithography
  88. Nanoionics
  89. Nanolithography
  90. Nanomanufacturing
  91. Nanomaterial based catalyst
  92. Nanomedicine
  93. Nanomorph
  94. Nanomotor
  95. Nano-optics
  96. Nanoparticle
  97. Nanoparticle tracking analysis
  98. Nanophotonics
  99. Nanopore
  100. Nanoprobe
  101. Nanoring
  102. Nanorobot
  103. Nanorod
  104. Nanoscale
  105. Nano-Science Center
  106. Nanosensor
  107. Nanoshell
  108. Nanosight
  109. Nanosocialism
  110. Nanostructure
  111. Nanotechnology
  112. Nanotechnology education
  113. Nanotechnology in fiction
  114. Nanotoxicity
  115. Nanotube
  116. Nanovid microscopy
  117. Nanowire
  118. National Nanotechnology Initiative
  119. Neowater
  120. Niemeyer-Dolan technique
  121. Ormosil
  122. Photolithography
  123. Picotechnology
  124. Programmable matter
  125. Quantum dot
  126. Quantum heterostructure
  127. Quantum point contact
  128. Quantum solvent
  129. Quantum well
  130. Quantum wire
  131. Richard Feynman
  132. Royal Society's nanotech report
  133. Scanning gate microscopy
  134. Scanning probe lithography
  135. Scanning probe microscopy
  136. Scanning tunneling microscope
  137. Scanning voltage microscopy
  138. Self-assembled monolayer
  139. Self-assembly
  140. Self reconfigurable
  141. Self-Reconfiguring Modular Robotics
  142. Self-replication
  143. Smart dust
  144. Smart material
  145. Soft lithography
  146. Spent nuclear fuel
  147. Spin polarized scanning tunneling microscopy
  148. Stone Wales defect
  149. Supramolecular assembly
  150. Supramolecular chemistry
  151. Supramolecular electronics
  152. Surface micromachining
  153. Surface plasmon resonance
  154. Synthetic molecular motors
  155. Synthetic setae
  156. Tapping AFM
  157. There's Plenty of Room at the Bottom
  158. Transfersome
  159. Utility fog

 



NANOTECHNOLOGY
This article is from:
http://en.wikipedia.org/wiki/Diamondoids

All text is available under the terms of the GNU Free Documentation License: http://en.wikipedia.org/wiki/Wikipedia:Text_of_the_GNU_Free_Documentation_License 

Diamondoid

From Wikipedia, the free encyclopedia

(Redirected from Diamondoids)

A diamondoid, in the context of building materials for nanotechnology components, most generally refers to structures that resemble diamond in a broad sense: namely, strong, stiff structures containing dense, 3-D networks of covalent bonds, formed chiefly from first and second row atoms with a valence of three or more. Examples of diamondoid structures would include crystalline diamond, sapphire, and other stiff structures similar to diamond but with various atom substitutions which might include N, O, Si, S, and so forth. Graphite consisting of carbon atoms arranged in planar sheets ("graphene" sheets), carbon nanotubes consisting of sheets of carbon atoms rolled into tubes, spherical buckyballs and other graphene structures are sometimes also included in the class of diamondoid materials for nanotechnology.

Chemistry

In the context of classical chemistry, "diamondoid" refers to variants of the carbon cage molecule known as adamantane (C10H16), the smallest unit cage structure of the diamond crystal lattice. Diamondoids also known as nanodiamonds or condensed adamantanes may include one or more cages (adamantane, diamantane, triamantane, and higher polymantanes) as well as numerous isomeric and structural variants of adamantanes and polymantanes. These diamondoids occur naturally in petroleum deposits and have been extracted and purified into large pure crystals of polymantane molecules having more than a dozen adamantane cages per molecule [1]. These species are of interest as molecular approximations of the cubic diamond framework, terminated with C-H bonds. Cyclohexamantane may be thought of as a nanometer-sized diamond of approximately 2.8 * 10-21 carats. [2]


 

Diamondoids, from left to right adamantane, diamantane, triamantane and one isomer of tetramantane

Examples include:

  • Adamantane (C10H16)
  • Iceane (C12H18)
  • BC-8 (C14H20)
  • Diamantane (C14H20) also diadamantane, two face-fused cages
  • Triamantane (C18H24), also triadamantane. Diamantane has 4 identical faces available for anchoring a new C4H4 unit.
  • Isotetramantane (C22H28). Triamantane has 8 faces on to which a new C4H4 unit can be added resulting in 4 isomers. One of these isomers displays a helical twist and is therefore prochiral. The P and M enantiomers have been separated.
  • Pentamantane has 9 isomers with chemical formula C26H32 and one more pentamantane exists with chemical formula C25H30
  • Cyclohexamantane (C26H30)
  • Super-adamantane (C35H36)
  • Basic beryllium acetate Be4O(O2CCH3)6

One tetramantane isomer is the largest ever diamondoid prepared by organic synthesis. The first ever isolation of a wide range of diamondoids from petroleum took place in the following steps [1]: a vacuum distillation above 345C, the equivalent atmospheric boiling point, then pyrolysis at 400 to 450C in order to remove all non-diamondoid compounds [3] and then a series of HPLC separation techniques.

In one study a tetramantane compound is fitted with thiol groups at the bridgehead positions [4]. This allows their anchorage to a gold surface and formation of self-assembled monolayers (diamond-on-gold).

Organic chemistry of diamondoids even extends to pentamantane [5]. The medial position (base) in this molecule is calculated to yield a more favorable carbocation than the apical position (top) and simple bromination of pentamane 1 with bromine exclusively gives the medial bromo derivative 2 which on hydrolysis in water / DMF forms the alcohol 3.

Pentamane chemistry

In contrast nitroxylation of 1 with nitric acid gives the apical nitrate 4 as an intermediate which is hydrolyzed to the apical alcohol 5 due to the higher steric demand of the active electrophilic NO2 - HNO3+ species. This alcohol can react with thionyl bromide to the bromide 6 and in a series of steps (not shown) to the corresponding thiol. Pentamantane can also react with tetrabromomethane and tetra-n-butylammonium Bromide (TBABr) in a free radical reaction to the bromide but without selectivity.

See also

  • Other diamond-like compounds: Boron nitride

External links

  • http://www.physik.tu-berlin.de/cluster/diamondoids.html
  • Molecular Diamond Technologies, Chevron Texaco

References

  1. ^ a b Isolation and Structure of Higher Diamondoids, Nanometer-Sized Diamond Molecules J. E. Dahl, S. G. Liu, and R. M. K. Carlson Science 3 January 2003 299: 96-99; published online 29 November 2002 Abstract
  2. ^ J. E. P. Dahl, J. M. Moldowan, T. M. Peakman, J. C. Clardy, E. Lobkovsky, M. M. Olmstead, P. W. May, T. J. Davis, J. W. Steeds, K. E. Peters, A. Pepper, A. Ekuan, R. M. K. Carlson (2003). "Isolation and Structural Proof of the Large Diamond Molecule, Cyclohexamantane (C26H30)". Angewandte Chemie International Edition 42: 2040-2044. DOI:10.1002/anie.200250794.
  3. ^ Diamondoids are thermodynamically very stable and will survive this pyrolysis
  4. ^ Functionalized Nanodiamonds Part 3: Thiolation of Tertiary/Bridgehead Alcohols Boryslav A. Tkachenko, Natalie A. Fokina, Lesya V. Chernish, Jeremy E. P. Dahl, Shenggao Liu, Robert M. K. Carlson, Andrey A. Fokin, and Peter R. Schreiner Org. Lett.; 2006; 8(9) pp 1767 - 1770; (Letter) Graphical abstract
  5. ^ Reactivity of [1(2,3)4]Pentamantane (Td-Pentamantane): A Nanoscale Model of Diamond Andrey A. Fokin, Peter R. Schreiner, Natalie A. Fokina, Boryslav A. Tkachenko, Heike Hausmann, Michael Serafin, Jeremy E. P. Dahl, Shenggao Liu, and Robert M. K. Carlson J. Org. Chem.; 2006; 71(22) pp 8532 - 8540; (Article) DOI:10.1021/jo061561x
Retrieved from "http://en.wikipedia.org/wiki/Diamondoid"