Researchers have investigated for the first time how two different forms of vatn (ortho- and para-) behave differently when undergoing chemical reactions.
Vatn is a chemical entity, a molecule in which a single súrefni atom is linked to two hydrogen atoms (H2O). Vatn exists as liquid, solid (ice) and gas (vapours). It is among the few chemicals which do not contain kolefni and still can be liquid at room temperature (about 20 degrees). Vatn is ubiquitous and important for life. At the molecular level it is well known that everyday vatn exists in two different forms but this information is not of common knowledge. These two forms of vatn are called isomers and are referred to as ortho- or para- vatn. The main difference between these forms is very subtle and is simply the relative orientation of the nuclear spins of the two hydrogen atoms which are aligned in either same or opposite direction, hence their names. This spin of hydrogen atoms is due to atomic physics though this phenomenon is not yet fully understood. These two forms have identical physical properties and it has been believed so far that they should also then have identical chemical properties.
Í nýlegri rannsókn sem birt var í Nature Communications, researchers from the University of Basel, Hamburg have for the first time investigated the difference in chemical reactivity of these two forms of vatn and have proven that ortho- and para- forms react very differently. Chemical reactivity means the way or the ability by which a molecule undergoes a chemical reaction. The study involved separation of vatn into its two isomeric forms (ortho- and para-) using an electrostatic deflector by involving electric fields. Since both these isomers are practically the same and have identical physical properties, this separation process is complex and challenging. The separation was achieved by this group of researchers by using a method based of electric fields developed by them for Free-Electron Laser Science. The deflector introduces an electric field to a beam of atomized water. Since there is crucial difference in nuclear spin in the two isomers, this slightly impacts the way by which atoms interact with this electric field. Therefore, as the water travels through the deflector it starts separating into its two forms ortho- and para-.
Researchers have demonstrated that para- vatn reacts around 25 percent faster than ortho-water and its able to attract to a viðbrögð maka sterkari. Þetta skýrist örugglega af muninum á kjarnasnúningnum sem hefur áhrif á snúning vatnssameindanna. Einnig getur rafsvið para-vatns laðað jónirnar hraðar að. Hópurinn gerði ennfremur tölvuhermun á vatnssameindum til að staðfesta niðurstöður sínar. Allar tilraunir voru gerðar með sameindir í mjög lágum hitastillingum næstum -273 gráður á Celsíus. Þetta er mikilvægur þáttur eins og höfundar útskýrðu að aðeins við slíkar aðstæður er hægt að skilgreina einstök skammtaástand og orkuinnihald sameinda vel og stjórna betur. Sem þýðir að vatnssameind kemst á stöðugleika sem annað hvort tveggja form og munur þeirra verður augljós og skýr. Þannig getur rannsókn á efnahvörfum leitt í ljós undirliggjandi kerfi og gangverki sem leiðir til betri skilnings. Hins vegar gæti hagnýting þessarar rannsóknar ekki verið mjög mikil á þessum tíma.
***
{Þú getur lesið upprunalegu rannsóknarritgerðina með því að smella á DOI hlekkinn sem gefinn er upp hér að neðan á listanum yfir tilvitnaðar heimildir}
Heimildir)
Kilaj A et al 2018. Athugun á mismunandi hvarfgirni para og ortóvatns gagnvart föstum díazenýljónum. Nature Communications. 9 (1). https://doi.org/10.1038/s41467-018-04483-3
