Waa maxay bond hydrogen? Noocyada saamaynta

Waa maxay bond hydrogen? All tusaale la garanayo oo la xidhiidha tani waa biyo caadi ah (H2O). Sababo la xaqiiqada ah in la eb oxygen ah (O) waa ka electronegative ka badan laba eb hydrogen (H), waxa uu jiidayo la mid ah atamka hydrogen ee lagala kulmo electrons. Samaynta sida a bond horjeeda covalent Dipole sameeyay. eb oksijiin ma keensataa lacag xun oo aad u ballaaran iyo atamka hydrogen - ka kharash yar wanaagsan, taas oo soo jiidatay inay electrons ah (Labada nin keliya oo ka mid ah) on eb oxygen ah u taagoo H2O ku xiga (i.e., biyo). Sidaas darteed, waxaan dhihi karaa in bond hydrogen ah - hab ciidan ee soo jiidashada ka dhexeeya eb hydrogen iyo eb electronegative. Muqaalka muhiimka ah ee la eb hydrogen waa in ay ku qabanaya la soo jiidashada of electrons ah waxa uu noqonayaa mid core dhashay (i.e., proton, ma electrons kale gaashaan). Inkasta oo bond hydrogen waa ka nugul yihiin covalent, in uu keeno taxane ah oo dhan guryaha anomalous of H2O (oo biyo ah).

Inta badan, xidhmaddaas waxaa la aasaasay la atamka ka mid ah arrimaha soo socda: oxygen (O), nitrogen (N) iyo fluorine (F). Tani waxay dhacdaa sabab ah in atamka victorious waa kuwan yaryar ee size iyo leedahay electronegativity sare. atamka C size weyn (S baaruud ama chlorine cl) foomamka bond hydrogen a tirana, inkastoo xaqiiqda ah in ay electronegativity waxyaabaha kuwanu waa u dhigma N (i.e. nitrogen).

Waxaa jira laba nooc oo dhaaraheedii ay hydrogen:

1. hydrogen bond intermolecular - dhacdaa inta u dhaxaysa laba taagoo, tusaale ahaan: methanol, ammonia, fluoride hydrogen.
2. bond hydrogen intramolecular - dhacaa hal Britain ah, sida 2-nitrophenol.

Sidoo kale hadda waxaa la rumeysan yahay in hydrogen ku bond kiimikada waa mid daciif ah oo xoog ah. Waxay ku kala duwan ka soo midba midka kale in tamar iyo dhererka bond (masaafada u dhaxaysa atamka):

1. bonds hydrogen kuwa itaalka daran. Energy - 10-30 KJ / mol, dhererka debaajiga - 30. walxaha kor ku xusan oo dhan waxaa ku qoran tusaalooyinka caadiga ah ama tabar bond hydrogen.
2. bonds hydrogen waa xoog badan yihiin. Energy - 400 KJ / mol, oo dhererkeedu wuxuu - 23-24. Data helay tijaabo, ayaa tilmaamaya in bonds xoog loo sameeyay in ka udhigo soo socda: ah ra'iyi-vodoroddiftorid [FHF] -, hydroxide ra'iyi-biyuhu uga [HO-H-OH] -, oxonium ra'iyi biyo cabaan [H2O-H-OH2] + iyo sidoo kale xarumaha kale ee kala duwan ee organic iyo imanba.

Influence ee hydrogen-xiriirinaya

qiimaha Anomalous ah karkaraya dhibcood iyo barafka enthalpies of vaporization iyo xiisadda dusha sare ee qaar ka mid ah xarumaha ay loo saarin karaa in joogitaanka bonds hydrogen. Biyaha ayaa qiimaha anomalous oo ka mid ah hantida oo dhan, fluoride hydrogen iyo ammonia - karkaraya dhibic iyo barafku. Biyaha iyo fluoride hydrogen in dalalka adag oo dareere ah ay sabab u tahay joogitaanka iyaga ka mid ah bonds intermolecular hydrogen ee waxaa loo arkaa in la polymerized. Xiriirka waxa uu sharaxayaa ma aha oo kaliya heerkulka barafku aad u sareeya ee qalabkan, laakiin sidoo kale ka mid ah cufnaanta u hooseeya. Sidee ku dul barafka bond hydrogen qayb ahaan burburo, ay sabab u tahay taas oo u taagoo biyo ah (H2O) waxaa lagu buuxiyey oo dheeraad ah oo ay dadku.

dimerization The walxaha qaarkood (carboxylic acid, tus, Benzosyrene iyo acetic acid) ayaa sidoo kale lagu macnayn karaa by joogitaanka lagala kulmo hydrogen. Dimer - laba taagoo in ay si wadajir ah loola xiriirinayay. Sababtan awgeed, acids carboxylic dhibic ka sareeyaa in xeryahooda isagoo ku dhowaad isku mid ah karkaraya miisaanka kelli. Tusaale ahaan, acetic acid (CH3COOH) heerkulka karaya waa 391 K, halka acetone (CH3COCH3), waa 329 K.

Influence iyo silsilado intramolecular hydrogen

Xiriirka Tani waxay sidoo kale saamayn ku dhismeedka iyo sifooyinka xeryahooda kala duwan, sida 2- iyo 4-nitrophenol. Laakiin tusaale ahaan ugu caansan oo muhiim ah oo bond hydrogen - ka acid ah deoxyribonucleic (abbr: DNA.). Britain Tani acid duubnaadaan galay galool a double, labada qaybood kuwaas oo isku xidhan by bonds hydrogen.