Here’s a molecule everybody must have heard about: testosterone (a).
(a) |
---|
|
Metals: facts, factoids and some not quite related stuff too
Here’s a molecule everybody must have heard about: testosterone (a).
(a) |
---|
|
In most organic chemistry textbooks, double bond cis/trans isomerism is exemplified by alkenes. It is also observed in cycloalkenes such as cyclooctene that can exist as either cis (a) or trans (b) isomer:
(a) | (b) |
---|
|
To the trans isomer, there is a twist — and the pun is fully intended. Have a look at the structures (c) and (d) (or at their 3-D models here, Fig. 2 and Fig. 3, respectively).
(c) | (d) |
---|
|
Have a look at the structures (a) and (b). They are the stereoisomers of laballenic acid, with (a) is naturally occurring in plants of the Lamiaceae family. What kind of stereoisomers are they?
(a) | (b) |
---|
|
If there was just one double bond in the middle of the molecule, we’ll be dealing with cis/trans isomerism. But we have two cumulative double bonds, which makes our molecules chiral, even though there are no chiral atoms. Why?
Have a look at the structures (a) and (b).
(a) | (b) |
---|
|
Although structural descriptors such as we’ve seen in the names of boron hydrides, for example catena or closo, provide information on atomic connectivity, they tell us little or nothing about the geometry of the molecule.
Have a look at the structures (a) and (b):
(a) | (b) |
---|
|
Both of them can be named additively pentaoxidotungstate(4−). Yet, as you can see, they have very different shapes.
Can we expand the parent hydride naming philosophy much beyond organic chemistry? Not going too far, let’s have a peek at carbon’s immediate neighbour in the periodic table, boron.
(a) |
---|
|
The mononuclear hydride (a) is systematically named ‘borane’ while neutral boron hydrides as a class are called boranes.