Kvantnokemijski izračuni međudjelovanja diola i aldehida

undergraduate thesis

• Title (english): Quantum-chemical calculations of the interaction between diol and aldehyde
• Author: Dora Mendaš
• Mentor: Vladimir Dananić (mentor)
• Committee member: Vladimir Dananić (predsjednik povjerenstva)
• Committee member: Iva Movre Šapić (član povjerenstva)
• Committee member: Robert Vianello (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2023-09-08, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

Primjenom programskog paketa „GAUSSIAN 09“, kvantnokemijskim izračunima ispitana su fizikalna i kemijska svojstva odabranih molekula aldehida i diola te određena energija i najpovoljnija geometrija njihovog međudjelovanja. Uz to, određen je doprinos vodikovih veza njihovoj reaktivnosti za 20 reakcijskih kompleksa koristeći teoriju funkcionalne gustoće (DFT) B3LYP (engl. Becke, 3-parameter, Lee-Yang-Parr Hybrid Functionals) uz standardnu bazu funkcija 6-31+G(d). Ispitivanjem reaktanata u vodenoj otopini utvrđeno je da dioli formiraju strukturu s intramolekulskom vodikovom vezom između OH skupina, koja se održava i u kompleksima s aldehidima. Analizom različitih kompleksa utvrđeno je da su sustavi s jednom takvom vezom stabilniji od onih s dvije, što je povezano s povoljnijom vodikovom vezom između hidroksilnih skupina povoljnija od one između hidroksilne i karbonilne. Ispitivanje više molekula aldehida i diola ukazuje na optimalne vodikove veze s povoljnim udaljenostima i kutovima. Međutim, stvaranje reakcijskih kompleksa je endergoni proces, što znači da je potrebno dovesti energiju kako bi se ta interakcija uspostavila. Ova energija nije samo rezultat elektronskih svojstava, već i steričkih zahtjeva oba sudionika. Na kraju, razmotrena je veza između sposobnosti stvaranja vodikovih veza i uspješnosti konverzije aldehida i diola u cikličke acetale i molekulu vode.

Abstract (english)

Quantum chemical calculations within the "GAUSSIAN 09" program were employed to evaluate physical and chemical properties of selected aldehyde and diol molecules, and to elucidate the energy and the most stable geometry of their interaction. Through this, the contribution of hydrogen bonds to their reactivity was determined for 20 reaction complexes using the B3LYP (Becke, 3-parameter, Lee-Yang-Parr) Density Functional Theory (DFT) hybrid functional with the standard 6-31+G(d) basis set. Additionally, the contribution of hydrogen bonds to their reactivity was determined for 20 reaction complexes using Density Functional Theory (DFT) with the B3LYP (Becke, 3-parameter, Lee-Yang-Parr Hybrid Functionals) functional and the standard 6-31+G(d) basis set. By examining reactants in an aqueous solution, it was established that diols adopt a structure with an intramolecular hydrogen bond between the OH groups, which is also maintained in complexes with aldehydes. Analysis of various complexes revealed that systems with a single hydrogen bond are more stable than those with two, a phenomenon linked to the more favorable hydrogen bonding between hydroxyl groups compared to that between hydroxyl and carbonyl groups. Examination of multiple aldehyde and diol molecules indicated optimal hydrogen bonds with favorable distances and angles. However, the formation of reaction complexes is an endergonic process, requiring an input of energy to establish this interaction. This energy is influenced not only by electronic properties but also by the steric requirements of both reactants. Lastly, the connection between the capacity to form hydrogen bonds and the success of the conversion of aldehydes and diols into cyclic acetals and water molecules was considered.

• Keywords: aldehid; diol; kvantnokemijski izračuni; računalna kemija
• Keywords (english): aldehyde; diol; quantum chemical calculations; computional chemistry
• Language: croatian
• URN:NBN: urn:nbn:hr:149:683595
• Study programme: Title: Materials Science and Engineering - Undergraduate study; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2023-09-15
• Created on: 2023-09-12 13:25:32