Duba wurin da ke ƙasa sannan ka amsa tambayar daga baya a cikin harshe ɗaya kamar yadda wurin yake:  Passage: A cikin 1856 Kekulé ya zama Privatdozent a Jami'ar Heidelberg. A shekara ta 1858 an dauke shi aiki a matsayin farfesa na yau da kullun a Jami'ar Ghent, sannan a shekara ta 1867 aka kira shi zuwa Bonn, inda ya kasance har zuwa ƙarshen aikinsa. Bisa ga ra'ayoyinsa na magabata kamar Williamson, Edward Frankland, William Odling, Auguste Laurent, Charles-Adolphe Wurtz da sauransu, Kekulé shine babban mai tsara ka'idar tsarin sunadarai (1857<unk>58). Wannan ka'idar ta samo asali ne daga ra'ayin atomic valence, musamman ma tetravalence na carbon (wanda Kekulé ya sanar a ƙarshen 1857) da kuma ikon carbon atoms don haɗuwa da juna (wanda aka sanar a cikin takarda da aka buga a watan Mayu 1858), don ƙayyade tsarin haɗin dukkan kwayoyin a cikin kwayar halitta. Archibald Scott Couper da kansa ya zo da ra'ayin haɗin kai na ƙwayoyin carbon (takardarsa ta bayyana a watan Yuni 1858), kuma ya ba da tsarin kwayoyin farko inda layuka ke nuna alamun haɗin da ke haɗa da atoms. Ga masana kimiyyar sunadarai, ka'idar tsari ta ba da sabon haske game da fahimta, da kuma ingantaccen jagora ga duka nazari da kuma musamman aikin haɗin kai. Sakamakon haka, filin ilimin sunadarai na halitta ya bunkasa fashewa daga wannan batu. Daga cikin waɗanda suka fi himma wajen bin binciken bincike na farko sun kasance, ban da Kekulé da Couper, Frankland, Wurtz, Alexander Crum Brown, Emil Erlenmeyer, da Alexander Butlerov. Tunanin Kekulé na sanya wasu atoms zuwa wasu wurare a cikin kwayar halitta, da kuma haɗa su ta hanyar amfani da abin da ya kira su "Verwandtschaftseinheiten" ("ƙungiyoyin haɗin kai", yanzu ana kiransu "valences" ko "bonds"), ya dogara ne akan shaidar daga halayen sunadarai, maimakon hanyoyin kayan aiki waɗanda zasu iya duba kai tsaye cikin kwayar, kamar su X-ray crystallography. Ba a riga an ƙirƙiro irin wannan hanyar ba, saboda haka, masana sunadarai na zamanin Kekulé sun dogara ne a kan ilimin sunadarai. Wasu masana kimiyyar sunadarai, musamman Hermann Kolbe, sun soki amfani da...  Tambaya: A wane fannin kimiyya ne ka'idar Kekulé take?
Tsarin sunadarai