Converting a chemical formula to its iupac name

Question

I have a periodic table which I coded in java and i'm working on creating simple compounds (only binary compounds) and returning information about them, but I'm having trouble with turning a chemical formula into the IUPAC name. I have it setup so that a person can click on an element on the periodic table and then click on another element, and then a window would pop up displaying possible compounds that could be created from those two elements. These compounds would be displayed as chemical formulas such as CO2 or CH4. I want to be able to convert the chemical formula of the compound that someone picked into the iupac name so it can be displayed with the other information.

I attempted to use the chemistry development kit, but I honestly don't have much of an idea of how to use it and even if it can be applicable in fixing my issue. It makes me put in the bond types manually, which seems like a ton more work than I should be bargaining for.

For example: CO2 would output Carbon Dioxide and CH4 would output Methane.

Answer 1

It makes me put in the bond types manually, which seems like a ton more work than I should be bargaining for.

This is unavoidable. IUPAC names are based on the structural properties of a compound, not its formula. Most nontrivial chemical formulae will have numerous possible structural isomers -- for instance, C₅H₁₂ is the formula for n-pentane, methylbutane, and 2,2-dimethylpropane. There's no way to pick one of these names without knowing the structure first.

As an alternative, you may want to consider writing a tool for converting from a structural formula (e.g, in the SMILES format) to IUPAC names. This isn't a trivial task either, but it's at least feasible to do algorithmically.

Answer 2

It really sounds like you need a database:

create table compound ( 
    first_chemical VARCHAR,
    first_amount INT,
    second_chemical VARCHAR,
    second_amount INT,
    name VARCHAR
)

and use it like

INSERT INTO compound VALUES('H', 2, 'O', 1, 'Water')

Then you can do something like

SELECT * FROM compound WHERE first_element = ? AND second_element = ?

Answer 3

It's gonna take a (really) long time to program an API that uses IUPAC nomenclature. There is, however, a way of obtaining the proper chemical name for a chemical formula that does not require you to spend a lifetime creating an API. This is a really dirty workaround, but it does work. You can use the JSoup library to perform a chemical name search through this website. It sends an HTTP post request, parses the results, and returns a string array with the search results. It's really messy, and probably considered sinful to most programmers, but it works.

public static String[] searchIUPACName(String chemicalFormula) throws IOException {
    org.jsoup.nodes.Document doc = org.jsoup.Jsoup.connect("http://www.endmemo.com/chem/chemsearch.php")
            .data("Search", "Search").data("name", chemicalFormula).data("sel", "f").post();
    org.jsoup.select.Elements elements = doc.getElementById("note").getElementsByClass("cmline");
    if (elements.isEmpty())
        return new String[] { "No results" };
    String[] names = new String[elements.size() - 1];
    for (int i = 1; i < elements.size(); i++) {
        names[i - 1] = elements.get(i).getElementsByClass("cmname").get(0).getElementsByTag("a").get(0).text();
    }
    return names;
}

However, like duskwuff said, IUPAC names are based on the structural properties of a compound, not its formula. So you can get a chemical name, but it's not necessarily the proper IUPAC name.