Animated Solution for Chemistry - Coordination Compounds: The IUPAC name of the complex $[Pt(N{H}_3{)}_{2}Cl(N{H}_{2}C{H}_3)]Cl$ is

Have you ever looked at a massive coordination compound and felt a wave of intimidation? You are not alone! These chemical formulas look like secret codes, but once you understand the rules of the IUPAC nomenclature, they become as easy to read as your favorite book. Today, we are going to decode the complex $[Pt(N{H}_3{)}_{2}Cl(N{H}_{2}C{H}_3)]Cl$. Let's dive in!

First things first, we need to identify the major players in our compound. Just like a simple salt such as sodium chloride ($NaCl$) is made of a positive cation and a negative anion, our coordination compound follows the same logic.

When we look at $[Pt(N{H}_3{)}_{2}Cl(N{H}_{2}C{H}_3)]Cl$, the square brackets act as a VIP room. Everything inside the brackets forms the complex cation, which is $[Pt(N{H}_3{)}_{2}Cl(N{H}_{2}C{H}_3){]}^{+}$. The species outside the bracket is our humble counter ion, the chloride ion ($C{l}^{-}$). In IUPAC naming, we always name the cation first, followed by a space, and then the anion. So, our final name will end with 'chloride'.

Before we can name the complex, we must figure out the oxidation state of our central metal atom, Platinum ($Pt$). This is a crucial step because the oxidation state must be included in the final name as a Roman numeral.

Let's set up a simple algebraic equation. Let the oxidation state of Platinum be $x$. We have two ammonia ($N{H}_3$) ligands and one methanamine ($N{H}_{2}C{H}_3$) ligand. Both of these are neutral molecules, meaning they contribute a charge of $0$. We also have one chloride ($C{l}^{-}$) ligand inside the coordination sphere, which carries a charge of $-1$.

Since the entire complex cation has a net charge of $+1$ (to balance the $-1$ of the counter chloride ion), we can write:

Solving for $x$, we get:

Brilliant! Our Platinum is in the $+2$ oxidation state. We will write this as $(II)$ in our final name.

Now comes the fun part: naming the ligands! Inside our VIP room, we have three types of guests attached to the Platinum atom.

1. Ammonia ($N{H}_3$): In the world of coordination chemistry, ammonia is called ammine (notice the double 'm'!). Since we have two of them, we add the prefix 'di', making it diammine. 2. Chloride ($C{l}^{-}$): As a ligand, chloride gets an 'o' at the end, becoming chlorido. 3. Methanamine ($N{H}_{2}C{H}_3$): This organic ligand is systematically named methanamine. Because it is a composite organic name, we will enclose it in parentheses to keep things neat and avoid confusion.

IUPAC rules dictate that ligands must be listed in strict alphabetical order based on their base names. We completely ignore prefixes like 'di' or 'tri' when alphabetizing.

So, let's line them up: - ammine comes first. - chlorido comes second. - methanamine comes third.

Our ligand sequence is: diamminechlorido(methanamine).

We have all our puzzle pieces; now it's time to put them together.

We start with the ligands in alphabetical order, followed immediately by the name of the central metal and its oxidation state in Roman numerals. Remember, the entire complex cation is written as one single word without any spaces!

Cation name: diamminechlorido(methanamine)platinum(II)

Finally, we add a space and write the name of our counter ion, which is chloride.

Putting it all together, the grand IUPAC name is:

And there you have it! By breaking the compound down into its cation and anion, finding the metal's charge, and carefully alphabetizing the ligands, we've successfully decoded the name. Keep practicing these rules, and soon you'll be naming coordination compounds in your sleep!