; void 0;){kind=small}
27
10
2009
How would you draw Mercury (II) Acetate
Posted by: Antony Williams in ChemSpider ChemistryCopyright©2009 Antony Williams
What’s your favorite flavor of mercury acetate..on Wikipedia here? on CAS Common Chemistry here or on ChemSpider here?
How would you represent this structure if you were to draw it as a 2D diagram?
Stumble it!
Entries (RSS)
October 27th, 2009 at 3:25 pm
Assuming the bond angle at the mercury atom (-O-Hg-O-) is ~180°, I’d go with the Wikipedia version.
October 27th, 2009 at 3:54 pm
Top one if you like covalent mercury–oxygen bonds; bottom one if you prefer ionic. The middle one just seems a bit silly and has too many hydrogens…
October 27th, 2009 at 3:59 pm
My own personal preference would be for Wikipedia style structure (perhaps with the oxidation state of the metal shown), the ChemSpider representation is the next best. While I wouldn’t describe the CAS representation as unclear, I find it much less obvious at a glance.
October 27th, 2009 at 4:24 pm
Stuart….what do you prefer…covalent or ionic? yes, CAS’s common chemistry is just a couple of H’s heavy
October 27th, 2009 at 5:09 pm
That’s a good question… what do you get when you dissolve mercuric acetate in water? Do you get ions or do you get Hg(OAc)2 molecules? Mercury is a funny one, as far as I know it’s got a large soft squidgy electron cloud and does covalent bonding well – so if you’re going to make me come down off the fence, let’s go with covalent.
October 27th, 2009 at 8:28 pm
I also would say the Wikipedia version is the best for Mercury (II) Acetate.
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.
October 28th, 2009 at 12:37 pm
Chemical structures are not used to indicate the “true” actual state of being but emphasis of certain idea and concept. That’s why for instance carbon backbones are often drawn with explicit bond bars while carbon-hydrogen bonds are ignored. So there is no universal ‘best’ choice.
However, obscure or wrong valence is always not allowed. All the three diagrams clearly define the valence of all atoms so they are all okay for me.
November 3rd, 2009 at 10:11 am
From informatics point view, I would like have the first one as input, because it keeps more structure information for the machine to understand…
November 8th, 2009 at 7:14 pm
The top diagram is the correct one for crystalline mercury diacetate. The middle diagram is simply wrong coz it shows uncharged acetic acid. I am not sure if the bottom structure is correct for aqueous solution: mercury diacetate only partially dissociates into acetate anion and (acetyloxy)mercury(1+) (CHEBI:49727).