Alkanes are notable for having no other groups, and therefore for the absence of other characteristic spectroscopic features of a functional group like –OH, –CHO, –COOH, etc.
ˈælkeɪnz ɑːɹ nˈoʊɾəbəl fɔːɹ hˌævɪŋ nˈoʊ ˈʌðɚ ɡɹˈuːps, ænd ðˈɛɹfoːɹ fɚðɪ ˈæbsəns ʌv ˈʌðɚ kˌæɹɪktɚɹˈɪstɪk spˌɛktɹəskˈɑːpɪk fˈiːtʃɚz əvə fˈʌŋkʃənəl ɡɹˈuːp lˈaɪk ˌoʊˈeɪtʃ, tʃˈoʊ, kˈuː, ɛtsˈɛtɹə.