Full structural formulas

Isoprene (2-methylbuta- 1,3-diene [Structures 7.1a and 7.1b]) is a C5 unit. Structure 7.1a shows the full structural formula where each line between the atoms represents two shared electrons in a covalent bond. In the case of more complex molecules, skeletal structures are used, as in Structure lb, where carbon atoms are normally represented by an intersection of bonds. Carbon-hydrogen bonds are not shown, although all other atoms (O, N, P and so on) are indicated. 

The structural formula of a compound not only shows the number of each kind of atom in the molecule, but also how the atoms are joined together. The simplest of these structural formulae is the full structural formula, in which all the bonds between the atoms are displayed. For example, the full structural formula of 2,3-dimethylpentan-3-ol is drawn on the left and alongside it are two abbreviated structural formulae. 

You must be able to draw full structural formulae, abbreviated structural formulae and skeletal structural formulae and be able to interconvert them. 

State the number of (a) cr bonds and (b) k bonds in a molecule of quinolone. (Hint drawing the full structural formula of quinoline will help.)... 

Furthermore, it has been shown that the three nitro and the three amino groups are in the para positions in the benzene rings. The full structural formula for the tri-amipo tri-phenyl methane is, therefore,... 

The molecular formula of a compound shows how many atoms of each dement are present in its molecule e.g. C2IU for ethane, but this tells you nothing about how the atoms are actually linked together. It is the structural fimnula of a compound which tdls you how the atoms are joined to each other. A full structural formula is often called a graphical formula because it shows the arran ment of the atoms in space. Sometimes it is useful to represent these as a linear formula as these can be written simpfy in text on one lin eg ethane CH3CH3. 

The full structural formula of methane is often written as though it was flat. Such formulae are called projection or displayed formulae, but by using a molecular modd kit and remembering that covalent bonds are directed in space, you can construct the more correct 3-D shapes for methane, ethane, propane and butane. 

The simple structure of ethene (C2H4) does not permit any variations, nor does the full structural formula of propene shown in Figure 6.4.22. 

Hint Draw a full structural formula, and include all the carbon and hydrogen atoms in your count.)... 

Draw full structural formulas for the following compounds. 

This type of unambiguous formula is allowed unless a full structural formula is asked for. 

It becomes a significant task to write a full structural formula for a polypeptide chain that contains any more than a few amino acid residues. In this situation, use of the one-letter abbreviations (Table 24.1) is the norm for showing the sequence of amino acids. Very short peptide sequences are sometimes still represented with the three-letter abbreviations (Table 24.1). 

Using full structural formulas, draw a typical portion of a Nylon-6,6 molecule that is, expand a portion of the formula given in Equation 22.15. Show at least two hexanedioic acid units and two 1,6-hexanediamine units. 

Structural formula See perspective formula, full structural formula, shortened structural formula. 

Drawing organic compounds using full structural formulae and other conventions is discussed in Section 2.5... 

Full structural formula (or Kekule structure) A line = 2 electrons... 

Key point. Organic compounds are classified by functional groups, which determine their chemistry. The names of organic compounds are derived from the functional group (or groups) and the main carbon chain. From the name, the structure of organic compounds can be drawn using full structural formulae,... 

In full structural formulae, every carbon atom and every C H bond are shown. 

Draw the full structural formula fhat is represented by each shorthand formula. 

In the discussion so far we have referred to two different ways of writing the formulas of the organic molecules that have been used as examples. Tables 10.2 and 10.4 show the molecular formulas of the alkanes and alcohols, while Figure 10.7 gives the full structural formulas of the first six straight-chain alkanes. These different types of formulas provide different levels of information and are each useful in their own distinctive way. Three different types of formulas are used for organic compounds empirical, molecular and structural formulas. 

However, looking at the condensed structural formula of butane, CH3CH2CH2CH3, there is an alternative way of arranging the atoms, which involves a branched chain. This alternative form is CH3CH(CH3)CH3, where there is a -CH3 group branching off the middle carbon atom. Figure 10.19 shows the full structural formulas of these two forms. 

From Figure 10.32 we can see how the structure of an ester is huilt up. However, it is more conventional to draw the condensed or full structural formulas of esters the other way round. Thus, ethyl ethanoate is usually written CH3COOC2H5 in chemical equations, for instance. Figure 10.33 shows the structures of some esters (propyl methanoate, methyl ethanoate and ethyl propanoate) written or drawn in this more usual format. 

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