Thermotropic liquid crystals based on ferrocenylbiphenyl and ferrocenylterphenyl

4′‐Ferrocenyl‐1,1′‐biphenyl‐4‐yl 4‐alkoxybenzoates Fc–(C6H4)2–OC(O)–C6H4–O–C n H2n+1 (n = 8, 10, 12) (3a–c), representing a new class of ferrocene‐containing thermotropic mesogens with nematogenic properties, were prepared. Two approaches were used for the construction of these mesogens: (i) reaction of 4′‐ferrocenyl‐1,1′‐biphenyl‐4‐ol with 4‐alkoxybenzoylchlorides, and (ii) crosscoupling of tris(4‐ferrocenylphenyl)boroxine with the corresponding halobenzenes. Crosscoupling was also applied for the synthesis of terphenyl‐containing mesogens Fc–(C6H4)3–OC(O)–C6H4–O–C n H2n+1 (n = 10, 12) (6a,b) and (RC5H4)Fe‐[C5H4–(C6H4)3–OC(O)–C6H4–O–C10H21] (11a, R = Et; 11b, R = n−Bu). The latter compounds also form nematic phases. Mesogens 6a,b form mesophases with wider temperature ranges than their biphenyl‐containing counterparts 3b,c. The most pronounced mesomorphism was displayed by compounds 11a and 11b, which have mesophases in the ranges 141–253°C and 120–238°C, respectively. The purity of compounds was established by 1H NMR spectra and elemental analysis. Mesophases were identified by polarizing optical microscopy and differential scanning calorimetry.