Payvasthoi aromati (az yunoni aroma — khushbuy), p a y v a s t h oi mushkin, sinfi payvasthoi organikii siklie, ki hamai atomhoi onho dar hosil kardani sistemai yagonai bo hamdigar aloqamand ishtirok mekunand; l-elektronhoi chunin sistema qabati elektronii ustuvori sarbasta hosil mekunand. Ba Payvasthoi aromati benzol (I, I a), naftalin (II), aptrasen (III), fenantren (IV) va gayra mansuband:
Khosiyati acocii Payvasthoi aromati dar on ast, ki onho aslan bandhoi soddayu karatii bo navbat takrorshavanda (chunon ki dar formula nishon doda shudaast) nadorand. Darozin har yak banda karbon—karbon dar benzol (1,4 A) ba qimati miyonai darozii banddoi oddii (ordinarna) karbon — karbono (1,54 A) va karatii (duchandaa) karbon — karbon (1,34 A) barobar ast. Binobar in bo formulam I a ifoda- kardani sokhti benzolro afzaltar medonand. Payvasthoi aromati nisbat ba reaksiyai payvastshavi ba reaksiyai joyivaz- kuni beshtar mayl dorand. Onho dar zeri tasiri reagentnoy elektrofili atomhoi gidrogeni khudro ba osoni ivaz karda metavonand. Hamin tavr bo tasiri kislotai nitrat az benzol nitrobenzol hosil mekunand: SvNv +. to, — C,HaNO, + VD>
Payvasthoi aromati khele ustuvorand; binobar in hosil kardana onho az digar moddaho dushvor ast. Masalan, benzolro az asetilen dar 65(R S bo ishtiroki angishti jozib yo degidrogenonii siklogeksan (V) hosil kardan mumkin ast malumand, ki qafasaashon faqat az atomhoi karbon iborat ast; ba onho ion- hoi sobiti organiki, masalan, kationi tropiliy (VI), anioli siklopenta- dienil (VII), payvasthoi bipolyarii azulennuskha (VIII) misol meshavand:
SI
ns A \n I! + «I NS\ ‘SI
NS—SI
VI
sn-sn jch
Ch 4 –
VIII
Payvasthoi aromati ahamiyati kalon dorand. Onho dar sintezi rangubor, moddahoi doruvor va tarkanda, polimerho va gayra istifoda meshavand.