"1"^^ . . "P\u0159es velik\u00FD v\u00FDznam NMR spektroskopie k\u0159em\u00EDku-29 pro ur\u010Dov\u00E1n\u00ED struktury anorganick\u00FDch materi\u00E1l\u016F obsahuj\u00EDc\u00EDch k\u0159em\u00EDk, organok\u0159emi\u010Dit\u00FDch slou\u010Denin a t\u00E9\u017E i organick\u00FDch, zejm\u00E9na polyfunk\u010Dn\u00EDch, slou\u010Denin (prot\u0159ednictv\u00EDm tzv. Si-29 NMR tagging) jsou na\u0161e znalosti a ch\u00E1p\u00E1n\u00ED faktor\u016F, kter\u00E9 ovliv\u0148uj\u00ED pozorovan\u00E9 chemick\u00E9 posuny, st\u00E1le ve sv\u00FDch po\u010D\u00E1tc\u00EDch. Dob\u0159e pops\u00E1ny, by\u0165 ne zcela uspokojiv\u011B vysv\u011Btleny, jsou velk\u00E9 efekty substituent\u016F p\u0159\u00EDmo v\u00E1zan\u00FDch na k\u0159em\u00EDk. Vlivy vzd\u00E1len\u00FDch substituent\u016F, kter\u00E9 jsou p\u0159irozen\u011B men\u0161\u00ED, jsou dostate\u010Dn\u011B pops\u00E1ny jen pro omezen\u00FD po\u010Det typ\u016F slou\u010Denin. Systematicky zpracovan\u00E9 a m\u011B\u0159en\u00E9 za identick\u00FDch podm\u00EDnek jsou pouze chemick\u00E9 posuny v rozs\u00E1hl\u00E9 \u0159ad\u011B trimethylsilylderiv\u00E1t\u016F a n\u011Bkter\u00E9 \u0159ady terc.butyldimethylsilyl deriv\u00E1t\u016F. Na\u0161studie deriv\u00E1t\u016F obou posledn\u011B zm\u00EDn\u011Bn\u00FDch skupin mj. uk\u00E1zaly, \u017Ee chemick\u00E9 posuny jsou podstatn\u011B ovlivn\u011Bny sterick\u00FDmi faktory ze zbytku molekuly a \u017Ee rozm\u011Br silylsub-stituentu v\u00FDznamn\u011B m\u011Bn\u00ED tento sterick\u00FD efekt. Proto se v tomto projektu chceme soust\u0159edit n" . . . . . . . . "http://www.isvav.cz/projectDetail.do?rowId=GA203/99/0132"^^ . "0"^^ . . . "Chemick\u00E9 posuny k\u0159em\u00EDku-29" . "Despite the recognized importance of Si-29 NMR for the determination of the structure of inorganic silicon-containing materials, organosilicon compounds and organic polyfunctional compounds (through Si-29 NMR tagging), our understanding of factors contributing to the observed chemical shifts is still in the state of infancy. Well documented (though not well understood) are the gross effects of substituents directly attached to the silicon atom in question. Effects of remote substituents, which arenaturally smaller, are sufficiently described only for a limited number of series of compounds. Systematic data measured under comparable conditions are available especially for extensive series of trimethylsilyl- and some tert.-butyldimethysilyl derivatives. Our studies of the last two types mentioned revealed the importance of the size of the silyl-substituent on the extent to which steric factors from the rest of the molecule can contribute to the observed chemical shift. In the project we sha"@en . . "Byly studov\u00E1ny p\u0159enosy substitu\u010Dn\u00EDch vliv\u016F v silylovan\u00FDch fenolech a deriv\u00E1tech hydroxamov\u00E9 kyseliny, d\u00E1le konformace silylovan\u00FDch steroidn\u00EDch diol\u016F a cyklohexanolu. Byla vytvo\u0159ena a dopl\u0148ov\u00E1na datab\u00E1ze 29Si NMR spekter. Byla aplikov\u00E1na metoda DOSY do ob"@cs . . . "2003-04-01+02:00"^^ . "Neuvedeno."@en . . . "GA203/99/0132" . . . "Silicon-29 chemical shifts"@en . "0"^^ . "4"^^ . "4"^^ .