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The CCC HO OH Lactic acid Think and analyze which of the following pairs of objects are chiral or achiral: ears, shoes, two hammers, two shells. Have you noticed that there are chiral objects in pairs? And the molecules? One way to check if a molecule is chiral (but not only) is to observe if the molecule possesses at least one asymmetric carbon atom. Lactic acid (present in sour milk), the C carbon atom is bonded to four different groups with each other (H, H C-OH and HO C Therefore, it is asymmetric. After all, what is asymmetric carbon? And chiral molecule? Let's make "art" and learn more about chemistry? You will need modeling clay or Styrofoam balls of different sizes (remember the size of the atom is related to the atomic number), painted in various colors to represent different atoms and straws (soda) or toothpicks to make bonds between the atoms. ACTIVITY Construct two possible molecular models of lactic acid. Place a template on the other. What happened? The lactic acid molecule is chiral? Why? Now only one of the models set in front of a plane mirror. What happened to the image relative to the model? If the molecule is chiral lactic acid, it shows optical isomerism. As we noted the occurrence of optical isomerism? What is the relationship between carbon and asymmetric chiral molecule? Another way to check if a molecule is chiral if it has observed symmetry plane. All molecules that have no plane of symmetry are asymmetric, or chiral. An example of a chiral molecule that has no plane of symmetry (not have asymmetric carbon) are accumulated alkadienes (hydrocarbon with two double bonds joints) that exhibit different groups from each other, each connected pair of carbon.
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HGK HO OH Mliječna kiselina Razmislite i analizirati koje se od sljedećih parova objekata su ki ili achiral: uši, cipele, dva čekići, dvije granate. Jeste li primijetili da postoje kiralni objekti u parovima? I molekule? Jedan od načina da provjerite je li molekula je ki (ali ne samo) je promatrati ako molekula posjeduje barem jedan asimetričan ugljikov atom. Mliječna kiselina (prisutna u kiselo mlijeko), C ugljikov atom vezan na četiri različite skupine s drugim (H, H C-OH i HO C Dakle, to je asimetrična. Uostalom, ono što je asimetričan ugljikov? A ki molekule? Učinimo "umjetnost" i naučiti više o kemiji? Trebat će vam modeliranje gline ili stiropor kugle različitih veličina (sjetite se veličina atoma povezana s atomskim brojem), slikano u različitim bojama da predstavljaju različite atome i slamke (soda) ili čačkalice napraviti Veze između atoma. AKTIVNOST Izgraditi dva moguća molekularne modele mliječne kiseline. Postavite predložak na druge. Što se dogodilo? Mliječna kiselina molekule ki? Zašto? Sada je samo jedan od modela postavljena ispred ravnine zrcala. Ono što se dogodilo na slike u odnosu na modelu? Ako molekula je ki-mliječne kiseline, što pokazuje optički isomerism. Kao što smo već spomenuli pojavu optičkih isomerism? Koja je veza između ugljika i asimetrične kiralnog molekula? Još jedan način da provjerite je li molekula je ki ako je promatrati simetrija ravnine. Sve molekule koje nemaju ravninu simetrije su asimetrični, ili ki. Primjer kiralnih molekula koja nema ravninu simetrije (nema asimetrični ugljik) deponiraju alkadienes (ugljikovodika s dvije dvostruke veze spojeva) koji pokazuju različite skupine jedni od drugih, svaki spojen par ugljika.