Wedge-shaped bond solid

A note on good practice Dashed and solid wedge-shaped bonds are commonly used when displaying organic structures to convey a sense of the three-dimensional shapes. The dashed wedge-shaped bonds go into the page and the solid wedge-shaped bonds come toward us. The thin lines are in the plane of the paper. 

FIGURE 3-3 Stereoisomerism in n-amino acids, (a) The two stereoisomers of alanine, l- and o-alanine, are nonsuperimposable mirror images of each other (enantiomers), (b, c) Two different conventions for showing the configurations in space of stereoisomers. In perspective formulas (b) the solid wedge-shaped bonds project out of the plane of the paper, the dashed bonds behind it. In projection formulas (c) the horizontal bonds are assumed to project out of the plane of the paper, the vertical bonds behind. However, projection formulas are often used casually and are not always intended to portray a specific stereochemical configuration. 

FIGURE 7-2 Three ways to represent the two stereoisomers of glyc-eraldehyde. The stereoisomers are mirror images of each other. Ball-and-stick models show the actual configuration of molecules. By convention, in Fischer projection formulas, horizontal bonds project out of the plane of the paper, toward the reader vertical bonds project behind the plane of the paper, away from the reader. Recall (see Fig. 1-17) that in perspective formulas, solid wedge-shaped bonds point toward the reader, dashed wedges point away. 

A reminder solid wedge-shaped bonds are coming towards us out of the paper while cross-hatched bonds are going back into the page away from us. 

Shapes of formaldehyde, CHjO, and ethylene, CjH. Molecules shown from (a) top view and (b) side view Note that chemists commonly use solid wedges to represent bonds projecting toward the viewer and broken wedges for bonds projecting away from the viewer. 

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