“The treetops, consistently towering
Through sunshine and April’s rain-showering;
Now, branches connecting
With blooms, intersecting:
The structures, once-skeletal, flowering.”
The 2 April 2023 Twitter limerick used a theme from organic chemistry to note the approach of spring weather. It is somewhat unusual in its structure for two reasons: first, that the organic chemistry term is not introduced until the very end, so there’s not the same benefit in a line-by-line explanation; second, that it had an accompanying photo (included here, as well). The title here alludes to both the change of seasons and the idea of “turning over a new leaf.”
“The treetops, consistently towering
Through sunshine and April’s rain-showering…”
I am fortunate to have a few hiking trails near my home, and it is reliably reassuring to watch the scenery change throughout the seasons. In particular, I enjoy watching the trees shift from summer to fall and winter to spring, each year: while the leaves fall and grow, the trees themselves are consistent.
“Now, branches connecting /
With blooms, intersecting: /
The structures, once-skeletal, flowering.”
In organic chemistry, skeletal structures are drawing conventions that simplify depictions of complicated molecules by focusing on the hydrocarbon connectivity patterns (the “carbon skeleton”). The only atoms shown in skeletal structures are heteroatoms: those that are NOT carbon or hydrogen.
For instance, the molecule ethane consists of two carbon atoms connected to one another, with each carbon atom further connected to three hydrogen atoms; in its skeletal structure depiction, it is simply a line. The molecule propane, in which three carbon atoms are connected to one another, looks like a V when written out in a skeletal structure. The utility of such a convention for efficient communication becomes much clearer with increasingly complex structures.
Tree branches in late winter, before the season turns and their new leaves and blossoms flourish, always remind me of this drawing convention. As spring arrives, “the structures, once-skeletal, [are] flowering.”
Chemphasis 