Questions tagged [structural-formula]

This tag should be applied to questions about structural diagrams - diagrams used to show the crude location of possible existent bonds and lone pairs of electrons in a chemical species. Do not use this tag if your question is about Lewis structures, use [lewis-structures] instead.

Filter by
Sorted by
Tagged with
28
votes
2answers
38k views

What are the meanings of dotted and wavy lines in structural formulas?

So I came across this diagram,the other day: As a chemistry student, I am well-versed with the dashed and wedged lines, but I was wondering what the wavy and the dotted line represent?
24
votes
1answer
277 views

How were old style stereographic structures produced?

Old papers on chemical structures often contained "3D" renderings of the molecule by using 2 2D images and requiring the reader to go cross-eyed to get the 3D image. A good example I recently found ...
22
votes
1answer
657 views

Interlocked cyclic compounds

Being new to chemistry, there may ought to be some properties I couldn't understand fully. One of them being cyclic compounds. One particular question about this is, whether these cyclic compounds, ...
21
votes
1answer
5k views

PBP vs TBP geometry?

Why are the axial bond lengths greater than those of the equatorial bonds in a trigonal bi-pyramid (TBP) geometry molecule; but the opposite is true for pentagonal bi-pyramid (PBP) geometry molecules? ...
20
votes
3answers
1k views

Why are arenes with conjoined benzene rings drawn as they are?

Whilst we are taught to represent benzene as below (A) due to its delocalised electrons, however when two benzene rings share carbons (e.g. naphtalene) it seems to be more commonly represented in ...
19
votes
1answer
1k views

Skeletal formula for carbon with two double bonds

How do I depict an sp-hybridised carbon with two double bonds? $$\ce{R=C=R}$$ If I just leave it out, like I would for a normal $\mathrm{sp^3}$ or $\mathrm{sp}$ carbon, it's difficult to see that it'...
18
votes
6answers
686 views

Organic Structure Challenge

Recently we had this challenge in our Organic Chemistry Department. I was not involved in it but I thought it might be interesting for the SE Chemistry site, so here it is. Propose a structure for ...
18
votes
4answers
8k views

Can ozone have a triangular structure?

The structure of ozone is traditionally depicted using two resonance forms: However, what I am wondering is instead of using such an idea to explain the structure why can't we show the structure of ...
17
votes
5answers
27k views

What is the chemical structure / hybridization of sulfuric acid?

I was looking at the chemical structure of $\ce{H2SO4}$. Intuitively, I would have expected this molecule to be square planar in accordance with $p^2d^2$ or $sp^2d$ hybridization, but instead it is ...
16
votes
2answers
1k views

What is the correct way to illustrate a bond to something irrelevant in a structural formula?

You can probably tell I'm not really a chemist (hi from physics!), but I've suddenly found myself having to draw some structural formulae, hence the stupid question. I've drawn a diagram of the four ...
15
votes
5answers
6k views

Are there notable organic compunds which look very similar but have very different properties?

I've seen people arguing for some questionable "miracle cure-all" alternative medicines not scientifically, but by their own logic. A common claim is, that if a compound looks very similar to an ...
15
votes
2answers
639 views

Structural representation of substituted benzene

Recently, I was watching a video about separating o-chlorotoluene and p-chlorotoluene from its solution. Following was a reaction demonstrated in the video: I was curious about the structure of ...
14
votes
3answers
1k views

Portable library to render 2D structural formulas as vector graphics from SMILES or InChI

For a web-based project, I am looking for a piece of software to create a 2D vector graphics structural formula from a textual structure encoding scheme such as SMILES or InChI, running on the server ...
12
votes
5answers
8k views

Is there a way to use free software to convert SMILES strings to structures?

So far I've been unsuccessful in finding an open source tool that will convert a large number (>100k) of SMILES strings to a chemical structure. Is this really only solved by commercial applications? ...
12
votes
2answers
1k views

Hydrocarbons with only 4 carbon atoms

How many different organic structures (from the pure theoretical viewpoint) can be drawed with only 4 (exact) carbon atoms and with/without hydrogen? Polycyclic compounds and bridged compounds are ...
12
votes
3answers
1k views

Structure of Ca2B6O11

What is its structure? I found an image of $\ce{B6O11}$ unit, but it looks incorrect: The top left corner one. The oxygen can make max 2 bonds but atom $\mathrm{O8}$ has three! There are ...
12
votes
1answer
2k views

Derivation of formula for the degree of unsaturation

Degree of Unsaturation (DU) of an organic compound tells us about the total number of $\pi$ bonds (both double bonds and triple bonds) and number of rings/cyclic chains in the compound. Degree of ...
12
votes
1answer
590 views

Why is the orbital angular momentum of a pi electron along the axis of two atoms' molecule one?

I'm reading quantum chemistry. The book says that the orbital angular momentum of a $\pi$ electron along the symmetry axis of a molecule made up of two atoms is $\pm 1$. I think this is a primary ...
11
votes
1answer
11k views

Why are X-rays used in crystallography?

Can any other wavelength of electromagnetic radiation be used? Why can't gamma radiation be used?
10
votes
1answer
5k views

Interpreting a formula tattoo

I saw on the Internet and I'm curious as to what compound is represented by it.
10
votes
1answer
279 views

Standards for drawing chemical molecules

I'll preface this by saying I haven't had a chemistry class in 10 years and molecular structures are not my thing. But I'm submitting a revision to a journal paper where I need to include figures of ...
10
votes
1answer
1k views

Double bond crossed lines representation

I have been studying organic chemistry for years, and I do not remember the spotting double bond represented with crossed lines, except maybe one ore two more times in addition to the following one ...
10
votes
2answers
555 views

What is the structural formula of alkali hypohalite: MOX or MXO?

Recently I came across this question and in the comment section, there was an argument regarding the formula of sodium hypoiodite which kept me wandering: what is the actual formula of alkali ...
10
votes
1answer
8k views

What is the structure of iodide of Millon's base?

In qualitative analysis, $\ce{NH4+}$ ions are confirmed using Nessler's reagent:- $$\ce{NH4+ + 2[HgI4]^{2−} + 4OH− → HgO·Hg(NH2)I ↓ + 7I^{−} + 3H2O}$$ The brown precipitate ...
9
votes
2answers
16k views

Is the valency of carbon satisfied in graphite?

Graphite has hexagonal parallel planes. In a hexagonal structure the carbon atom has three bonds. Since the valancy of carbon is 4 is the valency satisfied in graphite?
9
votes
3answers
1k views

Oxalic acid structure

What is the reason why oxalic acid has its second $\ce{-COOH}$ group flipped? I'm guessing it's something to do with steric repulsions between the $\ce{-COOH}$ groups but I'm not sure.
9
votes
1answer
583 views

Chemical diagram for cummingtonite?

Any suggestions on diagramming the chemical structure for cummingtonite? $$\ce{(Mg,Fe)_7 Si_8 O_{22} (OH)_2}$$ As I understand it, the $\ce{(Mg,Fe)_7}$ says the molecule has seven atoms that could be ...
9
votes
1answer
254 views

Why is it that the bigger the side-chain is, its hydrogen atoms tend to be more equatorial?

The most stable cyclohexane form is the chair conformation but on the other hand, the bigger the side-chain of the cyclohexane is, its hydrogen atoms become more equatorial rather than axial, which ...
8
votes
1answer
4k views

Doubts about IUPAC nomenclature of 4-ethyl-1-fluoro-2-nitrobenzene

Why is 4-ethyl-1-fluoro-2-nitrobenzene (structure is in the attached picture) called so ? Shouldn't it be called as 1-ethyl-4-fluoro-3-nitrobenzene since the precedence of ethyl is greater than ...
8
votes
1answer
999 views

What is the difference between an angular and linear skeletal formula?

When drawing a skeletal formula, what is the difference between an angular version and a linear version? I was asked to draw the Z isomer of Resveratrol: For which I drew: However the markscheme ...
7
votes
4answers
3k views

Is the order of orientation of electron box diagrams meaningful or arbitrary?

Here is my interpretation when asked to: By drawing arrows in the appropriate boxes, complete the outer electron structures for Cu and Cu2+ I had no problem in drawing out the electron structure, ...
7
votes
2answers
3k views

Why are there different chemical structures for epinephrine (adrenaline)?

The Wikipedia structure is: Note the empty bond at far-right. "Journals on the Web" has: CH3 added at far-right. And rxlist.com shows: There's an extra H going into the page! Is one of these ...
7
votes
1answer
1k views

Why doesn't EDTA have a double bond?

EDTA (Ethylenediaminetetraacetic acid) has a structure like this But why, as the name 'Ethylene' suggests, doesn't it should have a double bond between carbons?
7
votes
2answers
502 views

Why does this compound only have one pair of enantiomers?

I've been doing some reading about enantiomers, which are apparently chiral molecules that are non-superimposable mirror images of each other. An example I found of this in some problems that I've ...
7
votes
1answer
413 views

Can not find structural formula with compounds' IUPAC name

I currently need to read a paper. In that paper the following compound was mentioned: 1,2-benzo-6-(N-ethyl-N-isobutylamino)fluoran I tried to find the corresponding structural formula using the ...
7
votes
1answer
252 views

Solvation of uranyl formate/acetate

Uranyl formate has a structure something like: $\ce{UO2-(OCHO)2}$ So the structural formulae I've seen have two double-bonded oxygens directly attached to the U and each formate group is attached by ...
7
votes
1answer
1k views

What sort of molecules or polymers are used in OLED displays?

OLED displays have been emerging as competitors for LCD displays for some time and are now common in mobile phones (see comparison of a Google Nexus 1 and an iPhone here) The displays use small ...
6
votes
2answers
468 views

Identify two amines

I was reading a random text about the surface chemistry of YBaCuO superconductors. In the text, there was a table. The table had a list of several chemical compounds, including these two: Alkyl Amine:...
6
votes
3answers
2k views

Is there any way of representing a dative/coordinate covalent bond?

I was wondering if there was any way of representing a dative/coordinate covalent bond on a chemical diagram. A single bond can easily be represented as a single line, a double bond as a double line ...
6
votes
1answer
14k views

Structures for NO+ (Nitrosonium)

There are two possible structures for Nitrosonium : In the first structure, there is a +1 Formal charge on Oxygen, whereas, In the second structure, there is a +1 Formal charge on Nitrogen. Q. ...
5
votes
2answers
8k views

What is the meaning of parentheses in a condensed molecular formula?

In the formula $\ce{(CH3)3-C-CH(CH3)-CH2-CH3}$, what do the parenthesized portions represent? What is the molecular structure, and how do I name the compound?
5
votes
1answer
377 views

How to infer formula from diagram

Hello Folks I am not now nor have I ever been any kind of chemist. My question is, how is the formula for Cerin, C30H50O2, consistent with this diagram taken from Chemspider? I can count the 30 ...
5
votes
2answers
565 views

Shape Of Cetyl Alcohol

Why is cetyl alcohol bent at the 9th position?
5
votes
1answer
37k views

Lines on inside of hexagonal shapes of structure diagrams

just a simple question from me today... I was looking at the structure of Norepinephrine for a school project and was curious about the diagrams on the Wikipedia page for it. I was wondering why ...
5
votes
1answer
1k views

Existence of Deuterium peroxide

Does deuterium peroxide exist? Wikipedia has no reference. Also, the sites for delivery of chemicals like "Pubchem" or "Chemspider" have no reference. In my book, a preparation of $\ce{D2O2}$ is ...
5
votes
1answer
1k views

Why is this organic compound trans, and not cis? [duplicate]

I'm reading a high school chemistry course online, and I'm now reading about geometric isomers. They provide this example: And in terms of naming it, they say this: Begin by identifying the ...
5
votes
2answers
2k views

How can we rationalise the amount of crystal water in coordination complexes?

I was wondering why specific number of water molecules are attached to salts like $\ce{CuSO4.5H2O}$? Searching gave me a satisfying picture : I think $\ce{FeSO4.7H2O}$ should have a similar ...
5
votes
1answer
459 views

How to find chemical similarity between two compounds using Tanimoto method

I came across a paper named "Chemical Similarity Searching" by Peter Willett John M. Barnard and Geoffrey M. Downs, 1998. At one place, this paper talks of finding chemical structure similarity ...
5
votes
0answers
163 views

Pseudo 3D skeletal structure style which emphasizes geometry

If one searches and navigates to a wiki page for, say, dichlorodifluoromethane one sees the 2D skeletal structure of the compound as below This representation appears to be of a particular style that ...
5
votes
0answers
486 views

Getting structural formula of complex molecules? [closed]

How is it possible to precisely map huge molecules? Somehow, scientists easily know the structure of a compound of any complexity. What techniques are used to know the sturcture of molecules like ...