Yog tias koj saib cov keeb kwm ntawm kev tshawb fawb hauv chemical science ntawm lub peev xwm ntawm atoms ntawm ntau lub ntsiab lus sib cuam tshuam nrog ib leeg, peb tuaj yeem tawm hauv nruab nrab ntawm lub xyoo pua 19th. Thaum lub sijhawm ntawd, cov kws tshawb fawb tau xav txog qhov tseeb tias hydrogen compounds ntawm oxygen, fluorine, nitrogen yog cov yam ntxwv los ntawm ib pawg ntawm cov khoom uas tuaj yeem hu ua anomalous.
Cov no yog, ua ntej ntawm tag nrho cov, cov ntsiab lus melting siab heev thiab boiling, piv txwv li, rau cov dej los yog hydrogen fluoride, uas yog siab tshaj rau lwm yam sib xws. Tam sim no, nws twb paub lawm tias cov yam ntxwv ntawm cov tshuaj no yog txiav txim los ntawm cov cuab yeej ntawm hydrogen atoms los ua ib qho txawv txawv ntawm daim ntawv cog lus nrog cov atoms ntawm cov ntsiab lus uas muaj ib tug high electronegativity Performance index. Lawv hu ua hydrogen. Cov khoom ntawm daim ntawv cog lus, qhov tshwj xeeb ntawm nws qhov tsim, thiab cov piv txwv ntawm cov khoom sib txuas uas muaj nws yog cov ntsiab lus tseem ceeb uas peb yuav tsom mus rau hauv peb tsab xov xwm.
Vim kev sib txuas
Qhov kev txiav txim ntawm lub zog ntawm electrostatic attraction yoglub hauv paus ntawm lub cev rau cov tsos ntawm feem ntau hom tshuaj bonds. Cov hom tshuaj tiv thaiv uas tau tshwm sim los ntawm kev sib cuam tshuam ntawm kev sib cuam tshuam ntawm atomic nuclei ntawm ib lub caij thiab cov hluav taws xob ntawm lwm tus paub zoo. Cov no yog covalent non-polar thiab polar bonds, yam ntxwv ntawm cov yooj yim thiab complex compounds ntawm non-metallic ntsiab.
Piv txwv li, nruab nrab ntawm cov fluorine atom, uas muaj lub siab tshaj plaws electronegativity, thiab cov electroneutral particle ntawm hydrogen, ib-electron huab uas pib tsuas yog nyob rau hauv lub H atom, muaj kev hloov nyob rau hauv lub negatively charged ceev.. Tam sim no hydrogen atom nws tus kheej tuaj yeem raug hu ua proton. Yuav ua li cas ntxiv?
Electrostatic interaction
Cov huab cua hluav taws xob ntawm hydrogen atom yuav luag tag kis mus rau fluorine particle, thiab nws tau txais cov nqi tsis zoo. Ntawm qhov liab qab, uas yog, tsis muaj qhov tsis zoo, hydrogen atom - proton, thiab F -ion ntawm cov nyob sib ze hydrogen fluoride molecule, lub zog ntawm electrostatic attraction yog manifested. Nws ua rau cov tsos ntawm intermolecular hydrogen bonds. Vim nws qhov tshwm sim, ob peb HF molecules tuaj yeem tsim cov koom haum ruaj khov ib zaug.
Lub ntsiab lus tseem ceeb rau kev tsim cov ntawv cog lus hydrogen yog qhov muaj cov atom ntawm cov khoom siv tshuaj lom neeg nrog lub siab electronegativity thiab hydrogen proton cuam tshuam nrog nws. Hom kev sib cuam tshuam no tau tshaj tawm hauv cov pa oxygen thiab fluorine compounds (dej, hydrogen fluoride), tsawg dua nyob rau hauv nitrogen-muaj tshuaj, xws li ammonia, thiab txawm tsawg dua nyob rau hauv sulfur thiab chlorine tebchaw. Piv txwv ntawm hydrogen bonds tsim ntawm molecules kuj tuaj yeem pom hauv cov organic tshuaj.
Yog li, hauv cawv ntawm cov pa oxygen thiab hydrogen atoms ntawm pawg hydroxyl ua haujlwm, electrostatic attraction rog kuj tshwm sim. Yog li ntawd, twb yog thawj tus neeg sawv cev ntawm homologous series - methanol thiab ethyl cawv - yog kua, tsis gases, zoo li lwm yam khoom ntawm no muaj pes tsawg leeg thiab molecular hnyav.
Lub zog tus yam ntxwv ntawm kev sib txuas lus
Cia peb piv lub zog siv ntawm covalent (40–100 kcal / mol) thiab hydrogen bonds. Cov piv txwv hauv qab no lees paub cov lus hauv qab no: hom hydrogen tsuas muaj 2 kcal / mol (nruab nrab ntawm ammonia dimers) txog 10 kcal / mol zog hauv cov tshuaj fluorine. Tab sis nws hloov tawm los ua kom txaus rau cov khoom ntawm qee yam khoom uas tuaj yeem khi rau hauv cov koom haum: dimers, tetra - thiab polymers - pawg uas muaj ntau lub molecules.
Lawv tsis yog nyob rau hauv cov kua theem ntawm cov compound, tab sis tuaj yeem khaws cia yam tsis muaj kev tawg, thaum dhau mus rau hauv lub xeev roj. Yog li ntawd, hydrogen bonds, uas tuav cov molecules nyob rau hauv pawg, ua rau txawv txav siab kub thiab melting ntsiab lus ntawm ammonia, dej, los yog hydrogen fluoride.
Yuav ua li cas dej molecules associate
Ob qho tshuaj inorganic thiab organic muaj ntau hom tshuaj tiv thaiv. Cov tshuaj lom neeg daim ntawv cog lus uas tshwm sim nyob rau hauv cov txheej txheem ntawm kev koom ua ke ntawm polar hais nrog ib leeg, thiab hu ua intermolecular hydrogen, yuav radically hloov lub physicochemical.yam ntxwv kev sib txuas. Cia peb ua pov thawj cov lus no los ntawm kev xav txog cov khoom ntawm dej. Molecules H2O muaj daim ntawv ntawm dipoles - cov khoom uas nws cov ncej nqa cov nqi sib txawv.
Cov neeg nyob ib puag ncig cov molecules tau sib koom ua ke los ntawm qhov muaj txiaj ntsig zoo hydrogen protons thiab cov nqi tsis zoo ntawm oxygen atom. Raws li qhov tshwm sim ntawm cov txheej txheem no, molecular complexes yog tsim - cov neeg koom tes, ua rau cov tsos ntawm qhov txawv txav siab kub kub thiab melting cov ntsiab lus, siab kub muaj peev xwm thiab thermal conductivity ntawm lub compound.
Qhov tshwj xeeb ntawm dej
Lub xub ntiag ntawm hydrogen bonds ntawm H2O yog lub luag haujlwm rau ntau yam ntawm nws cov khoom tseem ceeb. Dej muab cov tshuaj tiv thaiv metabolic tseem ceeb tshaj plaws - hydrolysis ntawm carbohydrates, proteins thiab rog tshwm sim hauv cell - thiab yog cov kuab tshuaj. Xws li cov dej, uas yog ib feem ntawm cytoplasm los yog intercellular kua, hu ua dawb. Ua tsaug rau hydrogen bonds ntawm molecules, nws tsim hydration shells nyob ib ncig ntawm cov proteins thiab glycoproteins, uas tiv thaiv kom txhob lo ntawm polymer macromolecules.
Nyob rau hauv cov ntaub ntawv no, cov dej yog hu ua structured. Cov piv txwv peb tau muab los ntawm hydrogen daim ntawv cog lus uas tshwm sim ntawm cov khoom ntawm H 2 O ua pov thawj nws lub luag haujlwm tseem ceeb hauv kev tsim cov yam ntxwv ntawm lub cev thiab tshuaj lom neeg ntawm cov organic - proteins thiab polysaccharides, Nyob rau hauv cov txheej txheem ntawm assimilation thiab dissimilation tshwm sim nyob rau hauv cov kab mob nyob.
Intramolecular hydrogen daim ntawv cog lus
Salicylic acid yog ib qho ntawm cov tshuaj paub zoo thiab siv tau ntev nrog kev tiv thaiv kab mob, kho qhov txhab thiab tshuaj tua kab mob. Cov kua qaub nws tus kheej, bromo derivatives ntawm phenol, cov organic complex tebchaw muaj peev xwm tsim tau ib qho kev sib txuas ntawm intramolecular hydrogen. Cov piv txwv hauv qab no qhia txog cov txheej txheem ntawm nws txoj kev tsim. Yog li, nyob rau hauv lub spatial configuration ntawm salicylic acid molecule, mus kom ze ntawm cov pa atom ntawm carbonyl pawg thiab cov hydrogen proton ntawm hydroxyl radical yog ua tau.
Vim qhov ntau dua electronegativity ntawm oxygen atom, lub electron ntawm hydrogen particle yuav luag tag nrho poob rau hauv lub zog ntawm oxygen nucleus. Ib daim ntawv cog lus hydrogen tshwm sim hauv salicylic acid molecule, uas ua rau cov kua qaub ntau ntxiv vim qhov nce hauv cov concentration ntawm hydrogen ions hauv nws.
Summing, peb tuaj yeem hais tias hom kev sib cuam tshuam ntawm atoms tshwm sim nws tus kheej yog tias pawg neeg pub dawb (particle uas pub ib lub tshuab hluav taws xob) thiab cov atom txais uas lees txais nws yog ib feem ntawm tib lub molecule.
