tag:blogger.com,1999:blog-9633767.post6522318847060393889..comments2024-03-25T09:11:17.877-07:00Comments on The Curious Wavefunction: Why would a molecule become more soluble at low temperature?Wavefunctionhttp://www.blogger.com/profile/14993805391653267639noreply@blogger.comBlogger8125tag:blogger.com,1999:blog-9633767.post-2568323853293064452011-06-09T12:57:05.665-07:002011-06-09T12:57:05.665-07:00LCST<a href="http://en.wikipedia.org/wiki/LCST" rel="nofollow">LCST</a>Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-9633767.post-19141544116090951932011-06-01T12:58:42.603-07:002011-06-01T12:58:42.603-07:00One does need to be careful when 'explaining&#...One does need to be careful when 'explaining' thermodynamic observations in terms of one of the states. There is a tendency to pick the state with which one is most comfortable. It's also worth remembering that changes in viscosity will affect kinetics and not thermodymanics.Peter Kennyhttps://www.blogger.com/profile/12180360326821860667noreply@blogger.comtag:blogger.com,1999:blog-9633767.post-24182644900477451872011-05-31T18:53:21.893-07:002011-05-31T18:53:21.893-07:00Thanks for your comments. It's intriguing to c...Thanks for your comments. It's intriguing to consider the conformational shift in lipids that was mentioned. It's also interesting to contemplate the change in the structure of water. I wonder if anyone has investigated the effect of viscosity on conformations. The hydrophobic effect might also contribute, being driven by enthalpy at high T and entropy at low TWavefunctionhttps://www.blogger.com/profile/14993805391653267639noreply@blogger.comtag:blogger.com,1999:blog-9633767.post-30855302030414684252011-05-31T13:09:11.969-07:002011-05-31T13:09:11.969-07:00Is the solid state conformation strained? Do the ...Is the solid state conformation strained? Do the polar groups in the compound make optimal interactions in the solid state? Are there ionisable groups in the molecule and, if so, is the aqueous medium buffered? How different are the solubilities and temperatures?Peter Kennyhttps://www.blogger.com/profile/12180360326821860667noreply@blogger.comtag:blogger.com,1999:blog-9633767.post-48810752036179192872011-05-31T08:47:52.285-07:002011-05-31T08:47:52.285-07:00Don't forget about the change in the solvent p...Don't forget about the change in the solvent properties... it seems just as likely that changing the properties of water with temperature could be responsible.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-9633767.post-18680512607612164772011-05-28T22:48:43.673-07:002011-05-28T22:48:43.673-07:00Inverse solubility is also seen for salts. It is ...Inverse solubility is also seen for salts. It is usually due to the dissolution being exothermic, so that added heat drives the reaction towards the undissolved state (Le Chatelier's principle)Jan Jensenhttps://www.blogger.com/profile/08595894308946022740noreply@blogger.comtag:blogger.com,1999:blog-9633767.post-59876219130994766852011-05-28T19:49:16.256-07:002011-05-28T19:49:16.256-07:00Isn't the hydrophobic effect driven primarily ...Isn't the hydrophobic effect driven primarily by entropy? So, if the hydrophobic effect is driving the formation of insoluble aggregates, then decreasing the temperature of the system would decrease the strength of this effect relative to enthalpic effects that might promote the dissolution of the substance.Yggdrasilnoreply@blogger.comtag:blogger.com,1999:blog-9633767.post-41681973059622706922011-05-28T09:53:03.645-07:002011-05-28T09:53:03.645-07:00It sounds vaguely analogous to what is believed to...It sounds vaguely analogous to what is believed to occur with micellar systems (formation of the small disc-like structures at low temperature to the formation of the "Swiss cheese" lamellar structures at higher temperature with increased viscosity).<br /><br />Combining the above and your suggestion - perhaps as the temperature decreases these flexible, complex organic molecules interact to form aggregates which primarily only expose the polar functional groups to solvent. <br /><br />An interesting question to be sure!MJhttps://www.blogger.com/profile/02796378432680640144noreply@blogger.com