Naming Coordination Compounds - Video Tutorials & Practice Problems

Ligand Naming

Naming co-ordination compounds uses a systematic set of rules known as Iupac. And one important portion of this naming system is the naming of ligands. Now, here we're gonna say ligands themselves can either be anions or neutral molecules. Remember we've said before that there are such things as cic ligands, but we're not gonna cover those types of ligands within this general chemistry course. So for right now, ligands can either be negatively charged or neutral. Now, if we take a look here on our anionic or negatively charged ligand side, for example, here, bro my ion, it's li and name is bromo oxide is 02 minus in terms of its li N name, it's oxo hydroxide becomes hydroxy cyanide becomes cyano. So we can see a kind of theme being formed where we have this old ending of the negatively charged ligand azide ion is N three minus one. Here, it would be called Isoda and then nitro is nitrate, nitrite is nitro oxalate, an ion is oxalate and then carbonate is carbonado. For our neutral side. Here, we have the Lagan name already, we just have to determine what the formula will be for Lagan aqua is water. So h2o a meme is the ammonia molecule, carbonyl is co carbon monoxide. We have nitros which is no. And then finally, we have ethylene diamine here realize that we have this numerical prefix within it. We'll see how that plays a role in our naming of these different types of YN structures. Ethylene diamine is just en for short. So these are the most important and most commonly used negatively charged ligands and neutral ones.

Naming Coordination Compounds Example

In this example question, it says, right? Names of all ligands and complex ions. So here we have a silver connected to two of these ethylene diamine or bent ligands, then we have two chloride ions, right. So step one here is we name ligands in alphabetical order. If a liad is an anion, so negatively charged you change the ending to o. So here, if we take a look, who is our negatively charged Lyan here, it would be the chloride ion. So here, if we're saying chloride is this C minus, then its name would become chop. Next. If a Ln is neutral name is molecules with exceptions here are neutral Ln would be this uh basically this ethylene diamine the en so that'd be this portion right here that we're talking about in terms of our neutral Ln here. So here that would just be uh ethyl ethylene diamine as its name. And then when more than one identical lie again, we use the prefixes of die for two, try for three tetra for four, usually we won't see beyond that. So we don't worry about too much beyond that. Um But if it does happen, we'll we'll see that when it occurs. So here if a Ln has a prefix in the name, so Ethylene die, I mean die here is a numerical prefix, then you place the lyin in parentheses and use the prefixes of this. If there's two of them tris, if there's three of them and tetra kiss, if there's four, OK, again, we see this with ethylene diamine because it has the dye in its name, that numerical prefix with all information. Uh How would we name these two ligands? Well, there's two chlorine within the original complex ion, we name it first because we name Li Gans alphabetically. So it'd be die chloral since it's the same identical. And there's two of them. And then here Elene diamine has dye in its name and there's two of them in the formula. So this would be bis and in parentheses, the lia name bis ethylene diamine. So this is how we name the liga within this particular complex ion.

Complex Ion Naming

And continue our discussion of naming complex ions and eventually coordinations complexes. We are now ready to name the complex ion by adding the name of the transition metal. So here we have our transition metals and we have their metal names which are pretty standard for some. But then we have Latin based elements in the periodic table. So they're gonna have a Latin name. So here, if we're looking at just the regular way, we name them chromium, Cobalt, manganese molybdenum, you can see that the common theme is that the ending ends with eight. But then when we get to the ones with Latin based names. So iron here, it's simple as fe based on its Latin name. So here would be frate copper cu this would be crate silver. Here is Argentite 10 here sn this would be stan eight gold here A U. That would be all right. And then finally, we have a led which is uh PV, which would be plumb bait. So these are some commonly referenced transition metals. When it comes to naming these complex ions. On one side, we have their regular metal names. But then for the Latin based ones, they have New Latin names.

Naming Coordination Compounds Example

In this example, it says write the full name of the complex ion. So step one we've done before in earlier videos, it says name like ends in alphabetical order. So we have coal here and then we have ethylene diamine here, we'd say there's two chloral. So Dior, then we'd say that there are two di um ethylene diamine because of the presence of dye, the numerical prefix, we'd use bis bis and then ethylene diamine step two, we name the transition metal after the lances and you remove spaces from all names. So we'll fix that up once we write the whole name out. So here, if a complex ion is a cat ion which it's not, it has a negative charge, the metal's name is not modified. If the complex ion is an anion like it is in this case, then you change the ending of the transition metal to eight. Now this important note, some transition metals will use Latin names. Now, here you'd add a Roman numeral for oxidation number in parentheses after the metal name and then you have to get and then the overall charge of the complex ion is not named all right. So let's put all of this together. We say that let's see, our complex ion is negatively charged. So we have to change the ending of the metal, the transition metal to eight silver has a Latin based name, its name would be Ar Gate. That's the name of our medal. So now we'd also have to talk about what is its oxidation number? Well, here this is neutral. So it's zero silver. Here is X chloride ions. Each one is minus one. So X plus the two ethylene diamine, which are zero plus the two chloride ions which each one is minus one equals the overall charge of the species, which is minus one. So we're gonna have X minus two equals minus one, X equals oops X equals plus one. So here, this would be our silver one ion. So here, if we put it all together, we'd have Diora bi ethylene Diamine, Argen Tate and then the Roman numeral one again, remove all spaces from the name. So that's why it's all this one long string of letters and then a Roman numeral at the end. So this will be the name of this particular complex ion.

Provide name of complex ion [Fe(CN)₅NO]^3–

• A. pentacyanidenitrosylferrate(II)
• B. pentacyanidenitroferrate(III)
• C. pentacyanonitrosylferrate(II)
• D. pentacyanonitroferrate(III)

Coordination Compound Naming

At this point, we know how to name the lines within our complex ion and the complex ion itself. Now we have to go one step further and talk about the coordinations complex as a whole. So here we're gonna say similar to naming ionic compounds. We're gonna say that the name of the cion here is positive is written before the anion, which is negative. We're gonna say here that the cat ion can be either a counter ion or it could be a complex ion. So we have to pay very close attention if we take a look here at these two coordinations complex examples. Here we have potassium connected to what's in the brackets. Remember what's in the brackets is a clear giveaway that that is our complex ion, which would mean that what's in the red, this the potassium would be our counter ion. OK. So here this is our complex ion and then potassium here would be our counter ion for the other one it's reversed. What's in brackets is first that is our complex ion and it's the coin ion that's on the end, that is our counter ion. So just remember the art in terms of naming the co-ordination complex as a whole is to be able to identify which portion is the counter ion and which portion is the complex ion. In addition to this also recognizing which one is the Canion and anion is essential to properly naming these coordinations complexes.

Naming Coordination Compounds Example

Provide a systematic name for the following co-ordination complex in it. What we have is our complex ion and brackets here. And then we have our counter ion in the form of bromide ions. Portions of this we've covered before. Step one, we have to name the liens in alphabetical order. If the Ln is negatively charged, we change the ending to oxo. If the lien is neutral, you keep its name. Now remember we use numerical prefixes of di Trent tetra unless we're dealing with the lend like ethylene diamine where it has a numerical prefix in its name. So then we use the prefixes of bis tris and Tetris. Step two. You name the transition metals after your ligands, remove the spaces between the names. If the complex sign is a cion, the metal name stays the same. If the complex sign is an an ion, you change the ending to eight. Remember some transition metals have Latin based names. We add a Roman numeral depending on the charge of the transition metal. And then the overall charge of the complex line is not important in terms of naming it. Well, we don't include it in the name it does help us to determine the charge of the transition metal though. Now, here this is where it's new. We're talking about the counter ion. Finally. Now, if the counter ion, if it's a cat ion, the name is not changed. If it's an anion, you change the ending to ide poly atomic ions, their name is not changed. Finally, you write the full name of the Coronation Complex, you name the cat ion first before you name the anion. And then you add a space between the cat ion name and the anion name. So that's where space is allowed. So if you move up back up here and take a look at this. All right. So what do we have here? Well, we have here, bromide ion and then we have our complex ion. The two that's with the br on the outside here, it came from this complex ion. So the complex ion portion is chromium with five waters, one bromide Liang and an overall charge of two plus, right? So now let's name the live Gans that are inside the complex ion water. Here, it's aqua. And then Bromine here is Broma. We name them alphabetically. Here we have five water. So that'd be Penta for its numerical prefix name. So Penta aqua and here you can drop the A because that'd be Penta and then aqua, you could drop one of the A's because that would be two A's. So Penta aqua. And then where there's only one bromo. So, bromo, now, chromium here, uh we're gonna say if the complex ion is a cat ion, then the metal name is not modified. So we're looking at this portion here. So chromium is part of a positive complex science or keep its name, it's gonna still stay chromium, but we need to determine its charge. Well, here, we don't know it's charge, it's X water, here is neutral. So it's zero. Broman, here is minus one. We're gonna say X plus five water. Each one is zero plus one times negative one equals plus two, X minus one equals plus two X equals plus three. So this is chromium three ion. We've named our complex ion portion and remember if the counter ion is an an ion, you change its ending to. So this would re state the bromide ion. Remember there's a space between the ca the cion portion which is this complex ion and the anion portion, which is this counter ion. So that would be the full name Penta aqua bromo chromium three bromide.

Provide a systematic name for K₂[Mo(O)Cl₄].

• A. Potassium tetrachlorocarbonylmolybdate(VI)
• B. Dipotassium tetrachlorocarbonylmolybdate(IV)
• C. Potassium tetrachloroxomolybdate(IV)
• D. Dipotassium tetrachloroxomolybdate(VI)

Provide name for the following coordination compound: [Ag(H₂O)₂]NO₃.

• A. Diaquasilver(I) nitrate
• B. Dihydroxidesilver(I) nitrate
• C. Diaquasilver(II) nitrosyl
• D. Dihydroxidesilver(II) nitrosyl

What is the systematic name of [Co(en)₂(NH₃)CN]Cl₂.

• A. Amminocyanodiethylenediaminecobalt(II) chloride
• B. Amminecyanobisethylenediaminecobalt(II) chloride
• C. Amminocyanodi(ethylenediamine)cobalt(III) chloride
• D. Amminecyanobis(ethylenediamine)cobalt(III) chloride