When presented in the "linear" drawing style [need better term], acyclic chains are drawn exclusively with horizontal and vertical bonds. Accordingly, their use is limited to those structure that truly can be represented using only horizontal and vertical bonds. Extremely congested structures, for example, are not suitable to this drawing style.
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Additionally, atoms with more than four attached bonds cannot be represented in this style. Accordingly, this style should be used to represent only relatively simple structures. Some further points are discussed below, and unless otherwise indicated, all other issues relating to chains in general would apply to the linear drawing style as well.
Because there is no "bend" in the chain of bonds, all atoms should be labeled explicitly.
| RECOMMENDED |
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The standard bond length used when drawing the structure should be long enough that the bonds are not obscured by the atom labels. This is much more of a problem in this drawing style than in the "chain" style because it is much easier for a horizontally-oriented atom label to obscure a horizontal bond than a bond at an angle.
| RECOMMENDED | AVOID |
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A substituent on a non-terminal atom should preferentially be positioned above that atom, rather than below
| RECOMMENDED | AVOID |
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If the linear drawing style is used for part of a structure, it should be used for the entire structure. Similarly, a group of related structures should be consistent in the style that is used among them.
| RECOMMENDED | AVOID |
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There is no equivalent of the linear style for use with cyclic structures. Any ring system should be drawn as a ring system, even if the rest of the structure is drawn using the linear drawing style. However, any bonds connecting the ring to the linear portion of the structure should remain horizontal or vertical.
| RECOMMENDED | AVOID | AVOID |
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