Spherical Molecules: Structure
Two are the main spherical types of structures, as we see in the drawing: Hexa and tetra.
>>> Hexas are regular structures, which are formed by six atoms whose bonds are in the centre of the molecule.
Their bonds can be single, double, composed (or benzene type of) and triple.
--They are simple when a single bond (by mean of two hydrogen or electrons) is used for the whole molecule.
--They are double when a double bond is used for the whole molecule.
--They are composed (or benzene type) when a single bond is used for the whole molecule and another single connection for each one of the two triads of the molecule.
--Sometime, as in the fullerene structure, triple bonds can be produced. (triple bond for the whole molecule).
It can also happen that a triad is of double bond and the other one of single bond.
>>> Tetras are irregular molecules, which are formed by four atoms, one of which forms the vertex and taking the contrary position (cis or trans) to the other three atoms. Their bonds can be single, double or complementary.
--They are simple if the molecule is united by a single bond only.
--They are double if the molecule is united by a double bond.
--And they are complementary if the triad uses a double bond and the vertex atom is together to the molecule for a single bond.
The same as in the lineal molecules, the common bond for the hexa-molecules can also be used as covalent bond by other atoms or tetra-molecules that want to unite to this hexa-molecule. Example of these are naphthalene and anthracene.
In the following drawings we will see example of union between hexas and tetras molecules and of hexa-molecules with triads.
