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afrekcan
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NOMENCLATURE OF BRANCHED ALKANES
Carbon chains can also form more complicated structures with numerous branches. This section will (briefly) cover the systematic method for naming these types of compounds.
General Procedure:
Step 1 - Identify the longest consecutive chain (the one consisting of the most carbon atoms). This is referred to as the parent chain. Other branches that are attached to the parent chain are called substituents.
In cases where there appears to be more than 1 possible parent chain, we use the one with the greatest number of substituents. Below the correct parent chain is highlighted in red, and an incorrect choice is highlighted in blue.

Step 2 - Name the parent chain and the substituents. This is done according to the general rules previously described for simple alkanes.
Step 3 - Assign the position of each substituent. Now we need to number each carbon of the parent chain such that the substituents are placed at the lowest possible number.
Step 4 - Writing the name.
The basic formula for writing systematic names is as follows (X is a placeholder for substituent location):
X,X,X-(first substituent)-X,X,X-(second substituent)(parent name)
(there can be many more substituents but only 2 are shown above for simplicity)
Example walkthrough:
What is the systematic name of the compound below?

First identify the parent chain (highlighted in red below). In this case, it contains 9 carbons, so it is called nonane. Now identify the four substituents (circled in green) by counting the number of carbon atoms. Substituents are named using the same prefix as a typical alkane but are given the suffix -yl. When determining the name of a substituent, be careful not to count any of the carbon atoms that are part of the parent chain.

Now we number each carbon of the chain. Note where we begin counting in this case, it would be incorrect if we had began at the opposite end.

Correct numbering:
Ethyl at carbon #6
2x Methyl at carbon #3
Propyl at carbon #5
Incorrect:
Ethyl at #4
Methyl at #7
Propyl at #5
Now we can name the structure. Here are some important rules to note:
-Numbers are separated from one another by commas, while numbers and words are separated by hyphens.
-Substituents are listed in alphabetical order such that the earliest in the alphabet is the first listed. IE: an ethyl group is written before methyl, ect. If there is a prefix (di, tri, ect) it is irrelevant to the order.
-The number(s) associated with each susbstituent are located directly infront of that substituent.
-If there is more than one of the same substituent, a prefix is placed before it's name to indicate how many are present (di, tri, tetra, ect...). Additionally, a number will be listed for each if there are multiples. These can be on different carbon atoms, in such a case, the numbers are written in increasing order.
Thus, the name of our example compound is 6-ethyl-3,3-dimethyl-5-propylnonane
Practice:
What is the systematic name for the structure below?

Edited by afrekcan (11/25/14 10:46 PM)
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4HO-DMT


Registered: 01/11/11
Posts: 5,073
Loc: County Line Road
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Re: Organic Chemistry [Re: afrekcan]
#20892838 - 11/26/14 11:33 AM (9 years, 2 months ago) |
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thank you for your contributions. Many of us have been waiting for a update on this thread for a long time!
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kmetric


Registered: 08/23/14
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Re: Organic Chemistry [Re: 4HO-DMT]
#20894523 - 11/26/14 07:25 PM (9 years, 2 months ago) |
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I second that, thank you! I'm very happy this thread is alive.
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wolf8312
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Re: Organic Chemistry [Re: kmetric]
#20895864 - 11/27/14 06:08 AM (9 years, 2 months ago) |
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Is it 3,5 diethyl 2,6,8 trimethyl nonane?
-------------------- "I'm every nightmare you ever had. I am your worst dreams come true. I am everything you ever were afraid of." Pennywise the dancing clown
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afrekcan
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Re: Organic Chemistry [Re: wolf8312]
#20896211 - 11/27/14 09:03 AM (9 years, 2 months ago) |
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Quote:
wolf8312 said: Is it 3,5 diethyl 2,6,8 trimethyl nonane?
Indeed it is, however 3,5-diethyl-2,6,8-trimethylnonane is more proper.
Excellent choice of numbers! In a situation like this where there are two possibilities that yield the same set of numbers, the best name places the substituent that comes first in the alphabet at the lowest number.
I'm glad you all are interested. I should have more to post within the next few days.
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Razzldazzle

Registered: 05/27/13
Posts: 87
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Re: Organic Chemistry [Re: afrekcan]
#20898888 - 11/27/14 11:45 PM (9 years, 2 months ago) |
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You guys just lost me, how do you know which side to start from?
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wolf8312
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At first glance it seems that you have two identical parent chains but if you have two groups of equal importance (in this case 2 methyl on both possible parent chains both at position 2) appearing at the same point on both sides then you have to keep going and see which of the two possible chains has a substituent that appears sooner than on the other side.
If you and others really want to learn though best thing I would advise is to do what I myself am doing. Buy yourself a good O Chem book and then work through it chapter by chapter. If you come to something you don’t understand type it into YouTube and watch some videos. Then continue reading! In this day and age we have the best teachers money can buy teaching for free and right at our fingertips.
If you actually start getting into OC you will see why so many people dismiss organic chemistry as being a really difficult subject while others say in fact it is nowhere near as bad as it seems.
Some of the reaction mechanisms would be ridiculously difficult to understand if all you have is a book and a few classes with a professor a few times a week but really as with learning a language repetition is the key. With 'videos' you can stop, rewind, and replay them as many times as you like which is really vital for me -I think anyone really- as concentration needs to be utterly absolute and if you miss one sentence or even one word you can lose track of everything that the teacher is talking about.
Ive been learning for a few months and am just now getting to the exciting stuff- the reaction mechanisms. 
One question though...

In the Oxymercuration Demercuration reaction does anyone know why if mercury acetate :Hg(OAC)2 is an ionic bond and mercury only has two free valence electrons how is it then able to form an ionic bond with Oxygen(2) and yet still have a lone pair of electrons to then later use and form a bond with carbon?
I know that Oxygen is acting as a nucleophile and only sharing its own electrons but where then is mercury getting its positive charge from and why is it refered to as an ion if it has not lost any electrons?
Wouldnt the negative Oxygen ion's grab the electrons away from mercury and if not how then can mercury be a positively charged ion?
Hers a vid shes a great teacher first one explains the reaction I am talking about, the others are some links for noobs like me who just want to get started
(this one is not starting from the basic principles but the guy has videos on all different topics)
-------------------- "I'm every nightmare you ever had. I am your worst dreams come true. I am everything you ever were afraid of." Pennywise the dancing clown
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afrekcan
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Re: Organic Chemistry [Re: wolf8312]
#20899791 - 11/28/14 09:42 AM (9 years, 2 months ago) |
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@wolf8312: Let me know if this helps or if you have further questions.
The bonds in mercury acetate are not ionic. However, before mercury will react with a double bond, it's bond to one of the acetate groups is broken and the acetate takes both electrons with it (essentially an ionic mechanism). However, what i've just described is not terribly important to understanding the reaction. After the formation of HgAOc+, mercury still has a lone pair of electrons. These electrons then interact with a double bond (consists of two electrons). This results in the formation of a three membered ring intermediate, called a mercurinium ion.
Edited by afrekcan (11/28/14 03:31 PM)
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wolf8312
Pennywise


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Re: Organic Chemistry [Re: afrekcan]
#20900261 - 11/28/14 12:19 PM (9 years, 2 months ago) |
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Quote:
Let me know if this helps or if you have further questions.
Ah thanks dude I have plenty I'm sorry to say!
Quote:
The bonds in mercury acetate are not ionic.
Ah... 1.44! Shouldn’t have gone with the old metal + non-metal = ionic bond rule!
Quote:
However, before mercury will react with a double bond, it's bond to one of the acetate groups is broken and the acetate takes both electrons with it (essentially an ionic mechanism).
Yeah I should have been clearer I realized that one of the OAC groups withdraws from the bond, but as one mercury electron remains still bonded to the other OAC molecule from where do we then get the free lone pair (2 electrons) that goes onto attack the carbon?
Mercury has only 2 available valance electrons, and even loses one of these to a leaving OAC (negatively charged because of this) group and then while still being bonded to another OAC group (with its only remaining electron) it somehow and from somewhere still has a free lone pair -2 electrons- to attack the carbon with and form the mercurinium ion? So what am I missing?
I could only understand this if Hg(OAC)2 in fact has and started with 4 valance electrons -1 each for both Hg-OAC bonds and a free lone pair for the attack. If it indeed only has two valence electrons however, loses one and still has 2 free to attack the carbon with then I am totally stumped!
Sorry if I’m being dense and totally missing something obvious here dude! If it loses one electron to one OAC group and has one electron already involved in a Hg-0AC bond how can it have enough electrons left to attack the carbon with, as by my count it would have already lost one electron and have one still bonded to the Hg-OAC giving it no electrons left to attack with.
Quote:
One of these electrons initially "belongs" to mercury, so the net effect is that mercury loses an electron.
But is acetate (CH3COO-) not negative not because it gained a mercury electron but because it originally lost a hydrogen (when it was an acid CH3COOH and not a conjugate base CH3COO-) and was after this then bonded or reacted together with the mercury to form Hg(OAC)2?
Would this not explain why when the Hg and the one OAC group seperate that the Mercury is still left with one free lone pair and this is why we can then still have 2 valance electrons (not involved in the bond between itself and Oxygen) ready to then attack the carbon with?
I found some information online stating that Mercury acually very stubbornly refuses to share its valence electrons and also found this on answers.com
Quote:
Mercury was long believed not to use any other electrons in forming bonds and is called a post transition element.
Bit tired (3.15 in the morning here) so no time to delve too deep into post transition elements but Wiki mentioned something called mixed metallic bonding. Are we perhaps talking about a bond that operates in a manner of which I am not familliar? Is it perhaps a bond somehow apart from others which enables it to keep its own lone pair and yet still form covalent bonds somehow?
Or am I just missing something incredibly obvious?
This is driving me nuts lol!
I'm beat dude! Enough O chem for tonight been studying all day!
A drawing showing each and every electron involved in the bonds might really help me here dude!
Many thanks again!
-------------------- "I'm every nightmare you ever had. I am your worst dreams come true. I am everything you ever were afraid of." Pennywise the dancing clown
Edited by wolf8312 (11/28/14 12:28 PM)
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Razzldazzle

Registered: 05/27/13
Posts: 87
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Re: Organic Chemistry [Re: wolf8312]
#20900295 - 11/28/14 12:28 PM (9 years, 2 months ago) |
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I have a "The Great Courses" video lecture class on Organic Chem from an actual O-Chem professor that I would love to give anyone who wants it, or maybe even upload it on here. Its 36 lectures and comes with a PDF guide book, here is the link to the website of the course. Its 16 GB so its a pretty big file. If anyone knows a way to either upload it here or send it to them let me know!
Foundations of Organic Chemistry
Also, Here are some chemistry classes anyone can take for free online at any time from MIT
MIT Organic Chemistry 1
MIT Physical Chemistry 1
MIT Intro to Experimental Chemistry
Principles of Chemical Science
Here is an O-Chem Virtual Textbook
O-Chem Virtual Textbook
Edited by Razzldazzle (11/28/14 12:43 PM)
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Ice9
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In a deoxymercuration reaction, the first step is nucleophilic attack of mercury acetate by the pi electrons in the carbon-carbon double bond. This ejects an acetate group and is then followed by the lone pair of mercury attacking carbon to form the mercurinium ion.
Remember when doing mechainsms in organic chemistry, nothing ever just happens, you need to push electrons around.
-------------------- The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man. -- George Brenard Shaw
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wolf8312
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Re: Organic Chemistry [Re: Ice9]
#20903871 - 11/29/14 10:05 AM (9 years, 2 months ago) |
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Yeah thanks dude but if you closely read what is written above you will see we are not so much talking about the reaction mechanism itself as whole or working out how it proceeds step by step but specifically talking about how mercury and the acetate ion interact together when accounting for the fact that mercury only contains 2 valence electrons.
-------------------- "I'm every nightmare you ever had. I am your worst dreams come true. I am everything you ever were afraid of." Pennywise the dancing clown
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afrekcan
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Registered: 07/12/14
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Re: Organic Chemistry [Re: wolf8312]
#20904224 - 11/29/14 12:00 PM (9 years, 2 months ago) |
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To be honest I can't really answer your question wolf, however in my textbook mercury acetate is shown with 2 valence electrons in addition to the two bonds to acetate groups. I can post a picture later if you want, its more detailed than what I was able to find elsewhere.
However I think there may be a chance that what you found (mercury not wanting to share its 2 valence ect...) may be an explanation. I'm going to look into it over the next few days. If you find anything I'd be curious to know.
Edited by afrekcan (11/29/14 12:05 PM)
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wolf8312
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Re: Organic Chemistry [Re: afrekcan]
#20904373 - 11/29/14 12:41 PM (9 years, 1 month ago) |
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Quote:
To be honest I can't really answer your question wolf, however in my textbook mercury acetate is shown with 2 valence electrons in addition to the two bonds to acetate groups. I can post a picture later if you want, its more detailed than what I was able to find elsewhere.
Don’t worry my good buddy I honestly cannot find anywhere online that can answer it either! Ha ha its driving me fucking nuts!
I cant work out if the lack of information online means that it is such a ridiculously easy and obvious answer that nobody has ever bothered to ask the question or if it is one so difficult that no-one has ever been able to solve it!
Mercury is a transition metal and so perhaps is a real wild card and I do get the feeling that the acetate bonds to it somehow without Hg sharing any electrons whatsoever!
Please if you ever do crack this though do get back to me! I have even sent an email to my dear mother asking for clarification (shes pretty good at chemistry ha ha)!
I see it as somehow that the mercury lone pair is not involved at all in bonding with the acetate ions and perhaps because mercury only has two valence electrons it is somehow naturally an unhappy and ready-made unstable electrophile! It will not share any electrons until it has gained a few here and there! I think in the reaction mechanism it is indeed referred to as electrophilic!
Even at the beginning of the reaction -when it is bonded to two acetate groups- in many depictions the mercury is represented with a lone pair of electrons!
I can only presume that although the bond is 'covalent' that in actual fact somehow the OAC is attracted only to an overall charge of the unstable mercury atom. 
At least for the sake of my own sanity that is how I am for the moment choosing to understand it!
Thanks for your help dude! Good vibes!
-------------------- "I'm every nightmare you ever had. I am your worst dreams come true. I am everything you ever were afraid of." Pennywise the dancing clown
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afrekcan
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Re: Organic Chemistry [Re: wolf8312]
#20904528 - 11/29/14 01:32 PM (9 years, 1 month ago) |
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That explanation actually makes sense because the lone pair doesn't interact with anything until the formation of the carbocation (maybe it won't give them up except to a sufficiently positive charge..?).
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wolf8312
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Re: Organic Chemistry [Re: afrekcan]
#20904646 - 11/29/14 02:05 PM (9 years, 1 month ago) |
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Exactly! It seems to stubbornly do absolutely nothing with its lone pair until it is already 'electroned up' with 2 electrons from 2 other different bonds (carbon and Oxygen) and only then does it seem to decide to use its lone electron pair. I think somehow it needs to be bonded to other atoms before it will act.
-------------------- "I'm every nightmare you ever had. I am your worst dreams come true. I am everything you ever were afraid of." Pennywise the dancing clown
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Ice9
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Re: Organic Chemistry [Re: wolf8312]
#20906233 - 11/29/14 10:10 PM (9 years, 1 month ago) |
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The issue you are having here is that the electrons involved in the oxymercuration reaction are those from the 5d10 electron orbitals. Specifically, in mercury(II) acetate the 5dz^2 orbital is empty, and the "lone pair" electrons are those of the 5dxz orbital. The 6s2 electrons are not involved and as with many metals in the transition block filled s orbitals can be fairly inert.
-------------------- The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man. -- George Brenard Shaw
Edited by Ice9 (11/29/14 10:22 PM)
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wolf8312
Pennywise


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Re: Organic Chemistry [Re: Ice9]
#20906699 - 11/30/14 12:18 AM (9 years, 1 month ago) |
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Quote:
The issue you are having here is that the electrons involved in the oxymercuration reaction are those from the 5d10 electron orbitals. Specifically, in mercury(II) acetate the 5dz^2 orbital is empty, and the "lone pair" electrons are those of the 5dxz orbital. The 6s2 electrons are not involved and as with many metals in the transition block filled s orbitals can be fairly inert.
Ah thanks a lot dude a great help thank you!
Still a bit hazy and had to brush up on electron configurations for the inorganic elements! Really helped me actually cause it was something Id become rather rusty on!
I just spent 15 minutes drawing out the electron configeration diagram for mercury so we could all see what you are talking about only to find that the shroomerys disabled uploads (will post it later).
I can see clearly now that the 5f orbital is empty and that the 5d10 are the electrons that are involved in the bond.
Just to be clear the 'lone pair' are the inert 6 shell electrons, but the bond between the mercury and the acetate is coming from the electrons in the 5d10 5th shell right?
So the acetate forms a covalent bond with the orbitals in the 5th shell while leaving the lone pair in the sixth shell free?
None of these electrons are removed by the acetate when it withdraws right?
Most important thing now is that I know is we are dealing with an anomaly, so I can stop worrying!
-------------------- "I'm every nightmare you ever had. I am your worst dreams come true. I am everything you ever were afraid of." Pennywise the dancing clown
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Ice9
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Re: Organic Chemistry [Re: wolf8312]
#20907586 - 11/30/14 09:43 AM (9 years, 1 month ago) |
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Mercury acetate is an ionic compound, with mercury having a formal 2+ charge, when the acetate group leaves, it takes both its electrons with it (otherwise we would be making radical species). In this reaction the lone pair are actually the electrons in the 5dxz orbital, technically electrons in the 6s orbital are actually lower energy than electrons in the 5d orbitals (6s orbital fills with electrons before the 5d orbital). Also, because mercury is in the 2+ oxidation state the 5d orbital is 5d8--->5d10 from the electrons from the 2 acetate groups.
-------------------- The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man. -- George Brenard Shaw
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wolf8312
Pennywise


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Re: Organic Chemistry [Re: Ice9]
#20907886 - 11/30/14 11:18 AM (9 years, 1 month ago) |
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Quote:
Mercury acetate is an ionic compound, with mercury having a formal 2+ charge, when the acetate group leaves, it takes both its electrons with it (otherwise we would be making radical species).
Sorry when you say 'its' you mean acetate takes its own eletrons back or withdraws with two electrons from mercurys 5 shell?
Quote:
Also, because mercury is in the 2+ oxidation state the 5d orbital is 5d8--->5d10 from the electrons from the 2 acetate groups.
Sorry I dont really understand what you mean by this.
Are you sure its ionic?
I have read conflicting information about this and now don’t know what to believe!
Also the mercury acetate in the oxymercuration demercuration video I provided above only represents the acetate ion after having been detached during the first step with seven electrons and surely one of these must have come from the hydrogen bond what with the acetate originally being the conjugate base of vinegar CH3COOH no?
Ive found a guy online who also said this:
Quote:
From my experience, Mercury (II) Acetate is one of these – unfortunately many, many – examples which you find in many forms in different database – and it is very hard to normalize or correct them to a unique representation – probably because it isn’t clear whether the type of Hg-O bond is ionic or covalent, or the rules are complex, or change from metal to metal or ligand/ion to ligand/ion.
Mercury also has an electronegativity of 2, Oxygen, 3.44 with a difference of 1.44 which I thought was supposed to mean it is closer to covalent than ionic? 
Any chance you could provide a diagram or link to show what you mean so as to illustrate the movement of the acetate and oxygen electrons?
-------------------- "I'm every nightmare you ever had. I am your worst dreams come true. I am everything you ever were afraid of." Pennywise the dancing clown
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