Yintoni hydrogen bond? Iintlobo nempembelelo

Yintoni hydrogen bond? Yonke Umzekelo ezaziwayo oku ngamanzi zesiqhelo (H2O). Ngenxa yokuba i-atom oksijini (O) yeyona electronegative ngaphezu ezimbini atom hydrogen (H), oko isiginci njengazo ezi athom hydrogen ekwakheni electron. Ukusekwa onjalo bond polar covalent dipole kwakhiwa. Oxygen ingaphezulu izuza na intlawulo elikhulu kakhulu ezimbi kwaye athom hydrogen - ngentlawulo encinane entle, nto leyo ababetsaleleke electron (isibini elilolo kwabo) kwi-oxygen atom iimolekyuli H2O osecaleni (ngamanye amazwi, amanzi). Ngenxa yoko, sinokuthi ulwalamano hydrogen - indlela amandla umtsalane phakathi atom hydrogen kunye atom electronegative. Inkalo ebalulekileyo ye atom hydrogen kukuba nomphetho wayo kunye nokutsala electron uba ezingundoqo wayizalela (ngamanye amazwi, Proton, akukho ezinye electron amsindise). Nangona bond hydrogen ithambile covalent, ukuba ubangela yonke uthotho iipropati anomalous of H2O (amanzi).

Amaninzi, kulo mabophe kwenziwa kunye atom le miba ilandelayo: oksijini (O), nitrogen (N) kunye fluorine (F). Oku kwenzeka ngenxa yokuba atom zezi zinto ezincinane ngobukhulu yaye electronegativity eliphezulu. C atom ubungakanani obukhulu (S sulphur okanye ichlorine Cl) esakha ubuhlobo hydrogen ithambile, nangona ngo electronegativity yazo ezi zinto ayalingana N (ngamanye nitrogen).

Kukho iindidi ezimbini iibhondi hydrogen:

1. Iperoksayidi bond aphakathi - kwenzeka phakathi iimolekyuli ezimbini, umzekelo: methanol, ammonia, hydrogen fluoride.
2. intramolecular hydrogen bond - lwenzeka molecule elilodwa, ezifana-nitrophenol 2.

Kwakhona ngoku kukholelwa ukuba hydrogen bond yemichiza ubuthathaka kunye namandla. Baya kwahluka enye kwenye amandla ubude iqhina (umgama phakathi atom):

1. iibhondi hydrogen zibuthathaka. Amandla - 10-30 kJ / Mol, ubude iqhina - 30. Zonke izinto ezidweliswe ngasentla imizekelo eqhelekileyo okanye ababuthathaka hydrogen iqhina.
2. iibhondi hydrogen ninamandla. Amandla - 400 kJ / Mol, ubude - 23-24. Idatha ezifunyenwe abantu balinge, zibonisa ukuba obusenyongweni akhiwa kule ion zilandelayo: i ion-vodoroddiftorid [FHF] -, ion-hydrated hayidroksayidi [HO-H-OH] -, ion oxonium hydrated [H2O-H-OH2] + kwakunye nezinye iikhompawundi ezahlukeneyo eziphilayo nezingaphiliyo.

Impembelelo hydrogen-Ukuhlanganisa

Amaxabiso Anomalous abilayo amanqaku kunye ukunyibilika enthalpies ze vaporization kunye imeko umphezulu kwezinye khompawundi kunganxulunyaniswa ubukho imixokelelwane hydrogen. Amanzi unemilinganiselo anomalous zonke ezi zakhiwo, hydrogen fluoride kunye ammonia - lokubila nawokunyibilika. Amanzi kunye hydrogen fluoride kwi ithi eziqinileyo kwaye ulwelo ngenxa yobukho kuzo ndisezintanjeni aphakathi hydrogen zithathwa ukuba polymerized. Le ubudlelwane licacisa kuphela ubushushu yokunyibilika ophezulu kakhulu kwezi zinto, kodwa mninzi yabo. Enanikade phezu ukunyibilika hydrogen bond kancinci siyabutyaka, ngenxa apho molekyuli amanzi (H2O) afakwa ezingxobeni kakhulu ezinabantu.

Le dimerization kwezinto ezithile (carboxylic acid, umz, benzoic kunye acetic acid) nako sachaza bubukho hydrogen nimanyane. Dimer - molecule ezimbini ezinxibelelene kunye. Ngenxa yesi sizathu, ii-asidi carboxylic lokubila ngaphezu ukuba iikhompawundi ukuba malunga enye ubunzima eziphilayo. Umzekelo, acetic acid (CH3COOH) ubushushu abilayo ngu 391 K, lo gama acetone (CH3COCH3), kuba 329 K.

Impembelelo izibopho intramolecular hydrogen

Oku ubuhlobo kwakhona kuchaphazela ngesakhiwo neempawu iikhompawundi ezahlukeneyo, ezifana 2- no-4-nitrophenol. Kodwa umzekelo edume kakhulu nebalulekileyo iqhina hydrogen - a deoxyribonucleic acid (abbr: DNA.). Le molecule acid isongiwe ibe kweleli kabini, izigaba ezimbini apho amaqhina oqhagamshelwano phakathi ngeentambo hydrogen.