Thupi katundu wa aldehydes

Ndi aldehydes monga mankhwala organic, amene yodziwika ndi mgwirizano awiri pakati pa mpweya ndi mpweya maatomu ndi awiri nsinga umodzi wa chomwecho mpweya atomu ndi hydrocarbon kwakukulu amaimira kalata R, ndi atomu wa hydrogen ndi. Gulu la atomu> C = O amatchedwa carbonyl gulu, ndi khalidwe la aldehydes onse. aldehydes ambiri ndi fungo lokoma. Iwo akhoza kukhala okonzekera ku alcohols ndi dehydrogenation (kuchotsa haidrojeni), ndipo kunali dzina wamba - aldehydes. Katundu ofunitsitsa ndi kukhalapo kwa aldehyde carbonyl gulu, malo ake mu molekyulu ndi, komanso kutalika okhudza malo ndi nthambi ya hydrocarbon kwakukulu. Ndiko kuti, kudziwa dzina la thunthu kuwalitsa ake chilinganizo structural, mungayembekezere zina mankhwala ndi thupi katundu wa aldehydes.

Pali njira ziwiri zikuluzikulu za anangotchula aldehydes. Yoyamba njira zachokera dongosolo ntchito ndi telefoni Union International (IUPAC), amangonena kuti nomenclature mwadongosolo. Bukuli lili ndi mfundo yakuti unyolo yaitali imene mpweya atomu Ufumuyo gulu carbonyl, ndipamene maziko a mutu aldehyde, ndiye, dzina lake likuchokera ku dzina la alkane okhudzana ndi kuchotsa suffix kutanthauza suffix pa -Al (dziko - matanal, ethane - ethanal propane - propanal, byuteni - butanal ndi zina zotero). njira ina amagwiritsa mapangidwe aldehydes mutu dzina lolingana asidi carboxylic womwe chifukwa cha makutidwe ndi okosijeni (methanal - formic aldehyde, ethanal - acetic aldehyde, propanal - aldehyde ndi propionaldehyde, butanal - mafuta aldehyde ndi zina zotero).

Waukulu structural kusiyana pakati alkanes ndi aldehydes, aldehydes kudziwa thupi katundu, ndi kukhalapo mu kumapeto kwa carbonyl gulu (> C = O). gulu ili udindo kusiyana mu thupi katundu ndi mankhwala a zinthu ndi anthu ngati omwewo maatomu mpweya kapena yemweyo kulemera maselo. kusiyana ndi chifukwa kugawanika kwa magulu carbonyl> = + Sδ Oδ-. Ndiko kuti, kachulukidwe elekitironi pa mpweya atomu ankatembenukira kwa mpweya atomu, kupanga mpweya tsankho electronegative ndi electropositive mpweya gawo. Kusonyeza polarity wa gulu carbonyl kawirikawiri amagwiritsidwa ntchito Greek kalata ankadziwana (δ), amenewa amasonyeza tsankho mlandu. Mapeto zoipa kam'bulu kamodzi kumalo ozizira umalakalaka mapeto abwino a molekyulu wina kumalo ozizira. molekyulu Izi zikhoza kukhala chimodzimodzi ngati chikhazikitso ena. Aldehydes, ketones mosiyana mu mpweya wotsiriza wa gulu carbonyl chikugwirizana ndi nsinga limodzi ankafuna kusintha zinthu mopitirira awiri hydrocarbon. Mu nkhani imeneyi chidwi kuyerekeza thupi katundu wa aldehydes ndi ketones.

Iwo polarity gulu> C = O amakhudza thupi katundu wa aldehyde kuti: kusungunukira mfundo kutentha kwa kuwira mfundo, solubility, dipole mphindi. Hydrocarbon mankhwala okhala okha hydrogen ndi mpweya maatomu, kusungunula ndi chithupsa pa otsika kutentha. Mu zipangizo ndi gulu carbonyl ndi apamwamba kwambiri. Mwachitsanzo, byuteni (CH3CH2CH2CH3), propanal (CH3CH2CHO) ndi kafungo kabwino (CH3SOSN3) ndi maselo misa chomwecho 58 ndi kuwira mfundo byuteni 0 ° C, pamene chifukwa propanal ndi 49 ° C, pamene acetone ndi 56 ° C. Chifukwa kusiyana lalikulu kwagona kuti mamolekyulu kumalo ozizira ndi mwayi kwambiri kuti azifunana kuposa mamolekyulu sanali kumalo ozizira Choncho wovulala awo amafuna mphamvu, choncho amafuna kutentha kwambiri kusungunula pawiri kapena yophika.

Ndi kukula kulemera maselo a kusintha thupi katundu wa aldehydes. Formaldehyde (HCHO) ndi gaseous mankhwala pa zinthu zachilendo, acetaldehyde (CH3CHO) zithupsa firiji. aldehydes Other (kupatula kwa kulemera mkulu maselo) m'mikhalidwe muyezo ndi madzi. mamolekyulu kumalo ozizira sizimayenderana mosavuta sanali kumalo ozizira chifukwa mamolekyulu kumalo ozizira amakopeka ndi mzake, sanali kumalo ozizira ndipo sangathe Finyani pakati pawo. Choncho chimasanduka si sungunuka m'madzi, kuyambira mamolekyulu madzi ndi kumalo ozizira. Aldehydes mamolekyulu limene chiwerengero cha maatomu mpweya poyerekeza 5, kotero mu madzi, koma ngati chiwerengero cha maatomu mpweya kuposa 5, yanyumba amapezeka. Good solubility aldehydes zolemetsa otsika maselo chifukwa mapangidwe kumangidwa wa hydrogen pakati pa atomu wa hydrogen wa madzi molekyulu ndi mpweya atomu a gulu carbonyl.

The polarity la tinthu anapanga ndi maatomu osiyanasiyana, akhoza quantitatively zowonetseredwa ndi chiwerengero, wotchedwa dipole mphindi. Molekyulu popangidwa ndi maatomu yomweyo si kumalo ozizira ndipo alibe mphindi dipole. Vekitala dipole mphindi mwachindunji kwa zinthu ataima tebulo zodziwitsa (nthawi imodzi) ku lamanja. Ngati molekyulu ndi wapangidwa ndi ma atomu a subgroup mmodzi, elekitironi kachulukidwe kudzasiya kwa zinthu ndi chiwerengero ang'onoang'ono zinayendera. Ambiri chimasanduka ali palibe mphindi dipole kapena ukulu wake ndi yaing'ono kwambiri, koma aldehydes n'chachikulu amene akufotokoza thupi katundu wa aldehydes.