Saedius
Saedius t1_iv3umb1 wrote
Reply to Can we tell whether the bonds in a molecule are polar or nonpolar just by knowing the dipole moment of these molecules? by Hidden-Felon
Yes - because geometry matters. Carbon dioxide is non-polar because the individual bond dipole moments are equal in magnitude and opposite in direction, leading them cancelling each other out. So if we consider the bond polarity and the relative orientation then we can deduce the overall polarity.
Carbontetrachloride? Four polar bonds, but they are evenly spaced about a tetrahedron, so no net dipole moment. Chloroform, dichloromethane, and chloromethane, where the symmetry is broken? All polar to greater or lesser extent.
I recommend that in analyzing a molecule, you start with the Lewis structure in an approximately accurate orientation of the atoms. Doing so for ozone reveals two things. One that the molecule is bent and has no charge neutral octet Lewis structure. That's a big hint that (a) electron distribution in the molecule isn't just due to polarity and (b) the lack of symmetry means that it's unlikely that the uneven charge distribution will be canceled out.
There's also a fair number of polar molecules where all the atoms are roughly the same electronegativity but due to the nature of charge distribution in the ground state (which often can be approximated with Lewis structures) lead to a dipole. The best example might be azulene, which is a hydrocarbon with a large dipole moment due to the molecular orbital arrangement of the p-orbitals of the carbon atoms. https://en.wikipedia.org/wiki/Azulene
Saedius t1_iupn77z wrote
I'm betting it would still stick because of the high affinity of organosulfur compounds for gold surfaces (https://www.nature.com/articles/nchem.1352 and references therein). As long as the amino acid cysteine or things that contain it are present (and they are pretty much ubiquitous) I think the food would likely stick to the surface in some capacity.
Fun fact - this Au-S affinity underpins the many of the uses of the analytical technique Surface Plasmon Resonance, which is a fantastic binding assay they can tell you many things about protein interactions with other molecules. https://en.wikipedia.org/wiki/Surface_plasmon_resonance
Saedius t1_itxv3wy wrote
Reply to comment by Blakut in Ask Anything Wednesday - Biology, Chemistry, Neuroscience, Medicine, Psychology by AutoModerator
Also rimonabant was removed from the market due to suicidal ideation. It's a CB1 inverse agonist that acts on the cannabanoid receptor opposite to how marijuana does with the idea being that it would suppress appetite and aid weightloss. It worked (modestly) but it also made people think about killing themselves. That got it removed from the market pretty quickly.
Saedius t1_ix5bcy3 wrote
Reply to Could you turn any organic molecule into any other, given unlimited steps and reagents? by ZoofusCos
Yes - although you'd have to ask at some point in time what constitutes the same molecule. With enough energy we can burn all the carbon into carbon dioxide, reduce the CO2 to methane, and use that to make every carbon skeleton extant, but I shudder at the budget. There are others as well. You could heat the alkane in the absence of oxygen to pyrolyze it. From that, one should be able to get a variety of aromatic scaffolds that you can elaborate to most aromatic structures. You'd expect yields in the fraction of a percent, and a reagent/energy budget that rivals the GDP of a small country.