Posted on 11/01/2024 8:03:59 AM PDT by Red Badger
A way to link carbon rings thought impossible for a century has now been done, and could have medical applications.
For exactly 100 years, chemists have considered double bonds impossible – or nearly so – in organic chemistry under specific circumstances. Known as Bredt’s rule, this axiom was based not on theory, but decades of previous observations of molecules where such bonds were lacking. Confidence was high enough that it has widely been published in textbooks. New research shows it’s not true, and will encourage chemists to look for molecules they previously thought couldn’t exist.
Carbon is such an immensely versatile element that the vast majority of molecules we know of contain it. Since we ourselves are composed primarily of molecules built around a carbon structure, the study of what is and isn’t possible with carbon, i.e. organic chemistry, is particularly crucial for us.
Key to carbon’s molecule-making flexibility is that it forms four bonds, which can involve single, double, or triple bonds with other carbon molecules. However, Julius Bredt claimed to find a limitation on that capacity. Where a molecule contains two rings of carbon atoms, joined together by a bridge, Bredt claimed the bridgehead cannot involve a double bond. Now UCLA chemists have shown that it can.
Although Bredt reached this conclusion based on noticing an absence of such double bonds in relevant molecules, an explanation subsequently arose that double bonds in these circumstances would twist the molecule out of a plane. Since then, the rule has been modified twice. Double bonds between larger ring systems are now accepted as existing. Moreover, other chemists have claimed to make such molecules with smaller rings, but found them unstable, so the rule is now taken as precluding lasting molecules with smaller ring systems. In this form the rule is recognized by the International Union of Pure and Applied Chemistry.
However, Professor Neil Garg heads a team that has found molecules that violate the rule. These “anti-Bredt olefins” (ABOs) could be just the tip of the iceberg, since several kinds have been identified already.
The ABOs were made by applying fluoride to molecules whose names sound like they come from a sketch mocking chemists: silyl (pseudo)halides. The ABOs produced were initially unstable, showing the rule was not entirely wrong, but the team then used a variety of agents to trap them enough to analyze and potentially use. Maybe the pseudohalides are not so silyl after all.
Among scientists, as with other people, there are always those who most want to do the thing they are told is impossible. However, far more have accepted Bredt’s rule, at least in modified form, and not looked back.
“People aren’t exploring anti-Bredt olefins because they think they can’t,” Garg said in a statement. They haven’t been ignoring ABOs because they thought they would be useless, however.
“There’s a big push in the pharmaceutical industry to develop chemical reactions that give three-dimensional structures like ours because they can be used to discover new medicines,” Garg said. “What this study shows is that contrary to one hundred years of conventional wisdom, chemists can make and use anti-Bredt olefins to make value-added products.”
Discoveries like this raise questions about how often textbooks are wrong in other ways. Garg sees the problem as treating observational rules as if they were fundamental laws. “We shouldn’t have rules like this – or if we have them, they should only exist with the constant reminder that they’re guidelines, not rules. It destroys creativity when we have rules that supposedly can’t be overcome.”
The study is published in Science.
http://dx.doi.org/10.1126/science.adq3519
Nothing in science is possible until it’s observed and you can’t trust it even then.
Think outside the box.......
Everything is impossible until it’s not.
Heavier than air flight was ‘impossible’.
Speeds faster than 60 mph would kill people by suffocating them.
Iron boats will never float...................
“She’s tidied up, and now I can’t find anything!”
Really. A lot of people surround themselves with the trappings of science, but what they actually do is not science at all. Trimming the data to fit the conclusions is not science, and people who do it are not scientists. They’re frauds. Covidiots, creationists, and transgenderists are good examples of such frauds.
IDK
“Speeds faster than 60 mph would kill people by suffocating them.”
Driving @ 90-100 mph or more, even “alone” on a track, kinda takes my breath away.
YMMV.
100+ MPH on a motorcycle is definitely breathtaking...............
Really, the people you cite are not real scientists.
Naturally occurring anti-Bredt bonds have been known for a long time.
From a good 2014 review:
“ Lastly, we feel that Julius Bredt himself probably would never have imagined his legacy would continue into modernity, especially as he was already aware that violations of the rule were on the horizon. Nevertheless, the occurrence in nature of architecturally beautiful and biologically active candidates, unearthed by the isolation chemist, suggest that the field will continue to develop attracting the attention of biologists and chemists alike.”
Naturally Occurring Anti-Bredt and Bridgehead Olefinic Systems
Jeffrey Y. W. Mak, Rebecca H. Pouwer and Craig M. Williams*
Won’t need it in our new carbon free world the left is pushing.
Everything is made of carbon............
You’re now moving the goalposts.
We’re not talking about funding. We’re talking about whether a particular activity is science, or a fraud masquerading as science.
My observation of “origins” science is, so far, that both “creationists” and “evolutionists” are both doing science so badly that their activities border on fraud and sometimes cross the line.
Again, the creation scientists are basically self funding and trying to publish their own findings. They are not using government funding nor are they getting grants, and all of the current scientific publications, being run by evolutionists, are not allowing peer review or publication of these findings.
So I am curious how you have come to see their research as fraud? Have you been reviewing that research?
That’s my point. It was sarcasm. The Left is so stupid they don’t even realize it.
Again, we’re not talking about funding. Quit dragging a red herring into the discussion.
Fraud:the crime of getting money by deceiving people.
Maybe you should find a dictionary.
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