Other planar lattices with -hybridized carbon

Other planar infinite lattices with sp -hybridized carbon 

Local defects in the molecular plane of graphite may involve fracture zones with 4- and 8-membered rings, as seen in Fig. 1, causing angle strain and lowering the aromaticity they may become annealed on heating (see above the Wigner effect). Other defects were enumerated by Dias (3.  

However, in the 4, 8 semiregular planar lattice (Fig. 2) both the angle strain and the antiaromaticity contribute to destabilization in the conjugated circuits model there are 10- and 14-membered circuits with small positive contributions R2, Rsas well as 4-, 8- and 12-membered rings with appreciable negative coefficients Qi, Q2, 03. 

Two other semiregular nets examined in 1968 [1] and 1994 [8 were [3, 9 and (4, 6, 12 with resonance energies per electron -0.007 and -0.0744 eV, respectively. Other 3-connected planar nets, but without regular polygons, were analyzed. From 

Burdett et al. [9,10] reported calculations by means of the moments method on the nets (3, 9, 4, 8 and 5, 7 ). Hoffmann, Eisenstein and Balaban (11] discussed a hypothetical strain-free oligoradical with 8-membered rings whose carbon atoms have sp2 -hybridization. 

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