Chemistry of hydrocarbon compounds – Alicyclic compound synthesis – Adamantane or derivative
Reexamination Certificate
2001-12-12
2004-11-02
Wood, Elizabeth D. (Department: 1755)
Chemistry of hydrocarbon compounds
Alicyclic compound synthesis
Adamantane or derivative
C585S016000, C585S021000, C585S800000, C585S802000, C585S803000, C117S068000, C117S069000, C117S070000
Reexamination Certificate
active
06812370
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is directed to novel compositions comprising one or more hexamantanes. This invention is also directed to novel processes for the separation and isolation of hexamantane components into recoverable fractions from a feedstock containing at least a higher diamondoid component which contains one or more hexamantane components.
References
The following publications and patents are cited in this application as superscript numbers:
All of the above publications and patents are herein incorporated by reference in their entirety to the same extent as if each individual publication or patent was specifically and individually indicated to be incorporated by reference in its entirety.
2. State of the Art
Hexamantanes are bridged-ring cycloalkanes. They are the face-fused hexamers of adamantane (tricyclo[3.3.1.1
3,7
]decane) or C
10
H
16
. The compounds have a “diamondoid” topology, which means their carbon atom arrangement is superimposable on a fragment of the diamond lattice (FIG.
1
). Hexamantanes possess six of the “diamond crystal units” and therefore, it is postulated that there are thirty-nine possible hexamantane structure (FIG.
2
). Among them, twenty-eight of the thirty-nine have the molecular formula C
30
H
36
(molecular weight 396) and of these, six are symmetrical, having no enantiomers. Ten of the thirty-nine hexamantanes have the molecular formula C
29
H
34
(molecular weight 382), and the remaining hexamantane is fully condensed having the molecular formula C
26
H
30
(molecular weight 342), at times referred to as “cyclohexamantane.”
3
McKervey,
Synthetic Approaches to Large Diamondoid Hydrocarbons
, Tetrahedron, 36:971-992 (1980).
7
Balaban et al., Systematic
Classification and Nomenclature of Diamondoid Hydrocarbons
—I, Tetrahedron. 34, 3599-3606 (1978).
Very little published work is available for hexamantanes and higher molecular weight diamondoids. Hexamantanes have not been artificially synthesized and these compounds have been recently thought only to have a theoretical existence.
1,7
Academic chemists have primarily focused research on the interplay between physical and chemical properties in lower diamondoids such as adamantane, diamantane and triamantane. Adamantane and diamantane, for instance, have been studied to elucidate structure-activity relationships in carbocations and radicals.
3
Process engineers have directed efforts toward removing lower diamondoids from hydrocarbon gas streams.
2
These compounds cause problems during the production of natural gas by solidifying in pipes and other pieces of equipment.
The literature contains little information regarding the practical application of hexamantanes. This fact is probably due to extreme difficulties encountered in their isolation and due to failed synthesis attempts. Lin and Wilk, for example, discuss the possible presence of pentamantanes in a gas condensate and further postulate that hexamantane may also be present.
1
The researchers postulate the existence of the compounds based on a mass spectrometric fragmentation pattern. They did not, however, report the isolation of a single pentamantane or hexamantane. Nor were they able to separate non-ionized components during their spectral analysis. McKervey et al. discuss an extremely low-yielding synthesis of anti-tetramantane.
3
The procedure involves complex starting materials and employs drastic reaction conditions (e.g., gas phase on platinum at 360° C.). Although one isomer of tetramantane, i.e. anti-, has been synthesized through a double homologation route, these syntheses are quite complex reactions with large organic molecules in the gas phase and have not led to the successful synthesis of other tetramantanes. Similar attempts using preferred ring starting materials in accordance with the homologation route, have likewise failed in the synthesis of pentamantanes. Likewise, attempts using carbocation rearrangement route employing Lewis acid catalysts, useful in synthesizing triamantane and lower diamondoids have been unsuccessful to synthesize tetramantanes or pentamantane. Hexamantanes have also failed like synthesis attempts.
1
Lin, et al.,
Natural Occurrence of Tetramantane
(C
22
H
28
),
Pentamantane
(C
26
H
32
) and
Hexamantane
(C
30
H
36
) in a
Deep Petroleum Reservoir
, Fuel, 74(10):1512-1521 (1995)
2
Alexander, et al., Purfication of Hydrocarbonaceous Fractions, U.S. Pat. No. 4,952,748, issued Aug. 28, 1990
3
McKervey,
Synthetic Approaches to Large Diamondoid Hydrocarbons
, Tetrahedron, 36:971-992 (1980).
7
Balaban et al., Systematic
Classification and Nomenclature of Diamondoid Hydrocarbons
—I, Tetrahedron. 34, 3599-3606 (1978).
Among other properties, diamondoids have by far the most thermodynamically stable structures of all possible hydrocarbons that possess their molecular formulas due to the fact that diamondoids have the same internal “crystalline lattice” structure as diamonds. It is well established that diamonds exhibit extremely high tensile strength, extremely low chemical reactivity, electrical resistivity greater than aluminum trioxide (Al
2
O
3
) and excellent thermal conductivity.
In addition, based on theoretical considerations, the hexamantanes have sizes in the nanometer range and, in view of the properties noted above, the inventors contemplate that such compounds would have utility in micro- and molecular-electronics and nanotechnology applications. In particular, the rigidity, strength, stability, variety of structural forms and multiple attachment sites shown by these molecules makes possible accurate construction of robust, durable, precision devices with nanometer dimensions. The various hexamantanes are nanometer sized three-dimensional structures showing different spacial arrangements. This translates into a variety of rigid shapes and sizes for the thirty-nine hexamantanes. For example, [12121] hexamantane is rod shaped, [121(3)4] hexamantane is “T” shaped, while [12134] is “L” shaped and [1(2)3(1)2] is flat with four lobes. The two enantiomers of [12131] are left and right-handed screw like structures. A variety of other shapes exist among the hexamantanes which may serve in applications which depend upon specific geometries. It has been estimated that MicroElectroMechanical Systems (MEMs) constructed out of diamond should last 10,000 times longer then current polysilicon MEMs, and diamond is chemically benign and would not promote allergic reactions in biomedical applications.
6
Again, the inventors contemplate that hexamantanes would have similar attractive properties. Furthermore, some of the isomers of hexamantane (molecular weight 396 and 382) possess chirality, offering opportunities for making nanotechnology objects of great structural specificity and ones which have useful optical properties. Applications of these hexamantanes include molecular electronics, photonic devices, nanomechanical devices, nanostructured polymers and other materials.
6
Sandia National Laboratories (2000),
World's First Diamond Micromachines Created at Sandia
, Press Release, (Feb. 22, 2000) www.Sandia.gov.
Notwithstanding these advantages of hexamantanes, the art, as noted above, fails to provide for compositions comprising hexamantanes or for processes that would lead to these compositions. In view of the above, there is an ongoing need in the art to provide for compositions comprising one or more hexamantanes.
SUMMARY OF THE INVENTION
This invention is directed to novel compositions comprising one or more hexamantane components.
Accordingly, in one of its composition aspects, this invention is directed to a composition comprising one or more hexamantane components wherein said composition comprises at least about 25 weight percent hexamantane components based on the total weight of the diamondoids in the composition with the proviso that when only a single hexamantane is present than that hexamantane is not the fully condensed unsubstituted hexamantane compone
Carlson Robert M.
Dahl Jeremy E.
Burns Doane Swecker & Mathis L.L.P.
Chevron U.S.A. Inc.
Wood Elizabeth D.
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