"Estonian Science Foundation Research Grant" project ETF7374
ETF7374 "Superacidity and Superbasicity Scales in different Media (1.01.2008−31.12.2011)", Ivo Leito, University of Tartu, Faculty of Physics and Chemistry, University of Tartu, Faculty of Science and Technology (old), Institute of Chemistry, Tartu University, University of Tartu, Faculty of Science and Technology (old).
ETF7374
Superhappelisuse ja superaluselisuse skaalad erinevates keskkondades
Superacidity and Superbasicity Scales in different Media
1.01.2008
31.12.2011
R&D project
Estonian Science Foundation Research Grant
Field of researchSubfieldCERCS specialtyFrascati Manual specialtyPercent
4. Natural Sciences and Engineering4.11. Chemistry and Chemical TechnologyP400 Physical chemistry 1.3. Chemical sciences (chemistry, other allied subjects)100,0
InstitutionRolePeriod
University of Tartu, Faculty of Physics and Chemistrycoordinaator01.01.2008−31.12.2011
University of Tartu, Faculty of Science and Technology (old), Institute of Chemistry, Tartu Universitycoordinaator01.01.2008−31.12.2011
University of Tartu, Faculty of Science and Technology (old)coordinaator01.01.2008−31.12.2011
PeriodSum
01.01.2008−31.12.2008260 400,00 EEK (16 642,59 EUR)
01.01.2009−31.12.2009249 984,00 EEK (15 976,89 EUR)
01.01.2010−31.12.2010227 112,00 EEK (14 515,10 EUR)
01.01.2011−31.12.201114 515,20 EUR
61 649,78 EUR

Ülitugevad happed ja alused – superhapped ja superalused – ning nende derivaadid pälvivad üha kasvavat tähelepanu nii praktilisest kui ka teoreetilisest vaatepunktist. Superhapete ja superaluste uurimise eluliselt oluline osa on nende tugevuse mõõtmine. Käesoleva projekti raames luuakse selliste mõõtmiste jaoks usaldusväärsed tööriistad - superhappelisuse ja superaluselisuse skaalad erinevates keskkondades. Superhapped: superhappelisuse skaala ulatusega ca 10 suurusjärku luuakse 1,2-dikloroetaani keskkonnas. Loodav skaala seotakse meie poolt varem loodud keskmise tugevusega happelisuse skaalaga atsetonitriili keskkonnas, kasutades happeid, mille pKa väärtused on samaaegselt mõlemal skaalal. Sellisel moel on võimalik saada pKa väärtuste hinnangud atsetonitriilis hapetele, mis on liiga tugevad selleks, et neid vahetult atsetonitriilis mõõta, ja on võimalik olemasolevat atsetonitriili happelisuse skaalat pikendada superhappelisse piirkonda. Olemasolev gaasifaasiline happelisuse skaala saab tugevate hapete piirkonnas (alla 300 kcal/mol) verifitseeritud ja pikendatud superhappelisse piirkonda. Plaanis on luua ka täiesti uus keskkond superhapete uurimiseks, millel on kõrge polaarsus, kuid samal ajal väga madal aluselisus. Selle solvendi molekuli ehitus hakkab baseeruma sulfolaani skeletil, mille polaarsust tõstetakse ja aluselisust alandatakse) fluoro- ja CF3 rühmadega. Superalused: Tetrahüdrofuraani aluselisuse skaalat laiendadatakse lisades uusi aluseid erinevatest perekondadest. Sellisel moel saadud superaluselisuse andmetest tetrahüdrofuraani keskkonnas ennustatakse vastavate aluste aluselisused atsetonitriili keskkonnas neile alustele, mis on liiga tugevad, et neid atsetonitriilis vahetult mõõta. Gaasifaasilist aluselisuse skaalat laiendatakse kuni P4 fosfaseenide aluselisuse tasemeni (280-300 kcal/mol). Happelisuse ja aluselisuse andmed (pKa väärtused lahustes ja DeltaGacid ning GB väärtused gaasifaasis) mõõdetakse võimalikult paljudele erinevate superhapete ja superaluste perekondade esindajatele.
Acids and bases of very high strength – superacids and superbases – and their derivatives are receiving increasing attention from both practical and theoretical points of view. Measurements of acidity and basicity are a vital part of studies of superacids and superbases. Reliable tools – scales of superacidity and superbasicity in different media – will be created. Superacids: superacidity scale in 1,2-dichloroethane (DCE) spanning for ca ten orders of magnitude will be set up. The DCE acidity scale will be linked to our existing MeCN acidity scale via acids that are present on both scales. This way estimates of MeCN pKa values of the superacids, which cannot be directly measured in MeCN, can be obtained and the current MeCN acidity scale can be extended into the superacidic region. The gas-phase superacidity scale will be verified and extended in the region of superacidity (region below 300 kcal/mol). New solvent will be designed for studies of superstrong acids, based on sulfolane skeleton with inclusion of several –F and/or –CF3 substituents. Superbases: superbasicity scale in THF will be extended adding bases from different families of superbases. Based on the THF superbasicity scale pKa values of superbases that cannot be directly measured in acetonitrile will be calculated. The current gas-phase superbasicity scale will be extended up to the basicity level of P4 phosphazenes (280-300 kcal/mol). Acidity-basicity data (pKa values in solvents and DeltaGacid as well as GB values in the gas phase) will be measured for as many as possible representatives of different families of strong and superstrong acids and bases.