chemia - Studia

DIAMOND D 5 , A NOVEL ALLOTROPE OF CARBON
Formulas enabling the calculation of net parameter (vertices v, edges e,
and the number of monomers m in a cubic domain), the ring polynomial
R(x), number of carbon atoms C(sp 2 ) and C(sp 3 ) and their ratios together
with the limits of these quantities (when k trends to infinity) are presented in
Table 2, function of k – the number of monomers along the edge of cubic
domain. The network in Figure 5 is related to the P-type crystal proposed by
Mackay for the Schwarzites [31].
Table 2. Topology of spongy diamond SD 5 (C 81 ) network
Formulas
v(SD 5) = 3 k [27 + 23( k− 1)] = 69k + 12k
;
3
3
e(SD 5) = 130k
; m(SD 5)
= k
R( x)
= ax + bx + cx
2
2
a = 6 k [9 + 11( k− 1)] ; b= 6 k [18 + 26( k− 1)] ; c= 2
k + k−
Csp ( ) = 53k − 12k
Csp ( %) = (53k − 12 k) / (69k + 12 k)
3
lim( C(
sp %)) = 53/ 69 ; 0.768116
1 2 3 2
2 5 9 10
3 3 3 2
4 3 3 2 3 2
k→∞
6 [27 44( 1)]
Notice that there exist other diamond structures, either as real (Lonsdaleite,
a rare stone of pure carbon discovered at Meteor Crater, Arizona, in 1967) or
hypothetical [2,33] ones.
The structure C 17 , has the skeleton of centrohexaquinane, and was
synthesized (so far) as centrohexaindane [34], or C-trioxa-s-hexaquinane [35]
CONCLUSIONS
A new, yet hypothetically, carbon allotrope, called diamond D 5 , was
designed by using the structure C 81 as the repeating unit (for the spongy
form SD 5 ). Diamond D 5 was theorized here for the first time in literature (even
the origins of this completely new idea were presented in two previous articles
[23,24]). The geometric and energetic arguments/proofs, summarily presented
here, as well as the dense D 5 diamond network will be completed in further
papers [36,37].
We expect the same mechanical, thermal, electrical, lubricating, catalyst
support, biological, etc. properties as those found for the nano-diamond D 6 .
ACKNOWLEDGMENTS
The work is supported by the Romanian CNCSIS-UEFISCSU project number
PN-II IDEI 129/2010. The author wish to thank to Dr. Csaba L. Nagy for quantum
chemical calculations.
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