Synthesis of compounds containing 3-phenyl-3-hydroxypropanoic subunit with liquid crystal properties : diploma thesis

Pripravljeni su homolozi nesimetriĉnih dimera kako bi se ispitala njihova mezogena svojstva. Dimeri posjeduju 3-fenil-3-hidroksipropansku podjedinicu povezanu esterskom vezom preko neparne alkilne razmaknice s cijanobifenilnom podjedinicom. Pripravljeni dimeri se razlikuju po duljini terminalnih lanaca. Kljuĉna reakcija u sintezi je Reformatskyjeva reakcija kojom je pripravljen etil-3-(4-(benziloksi)fenil)-3- hidroksipropanoat (2) na kojeg je u slijedećim koracima esterskom vezom vezan 4'-(3-hidroksipropil)-[1,1'- bifenil]-4-karbonitril (1). Spoj 1 pripravljen je Suzuki-Miyaura reakcijom. Uz pomoć polarizacijskog optiĉkog mikroskopa i diferencijalne pretražne kalorimetrije ispitana su mezogena svojstva ciljnih molekula. Oba spoja pokazuju svojstva tekućih kristala. Temeljem optiĉke teksture utvrĊeno je da se spojevi samoorganiziraju u antiklinalnu smektiĉku C fazu (SmC A ).H omologues of asymmetric dimers were prepared to examine their mesogenic properties. The dimers possess a 3-phenyl-3-hydroxypropane subunit which is linked to the cyanobiphenyl subunit by an ester bond via an odd alkyl spacer. The prepared dimers differ in the length of the terminal chains. The key reaction in the synthesis is the Reformatsky reaction to prepare ethyl-3-(4-(benzyloxy)phenyl) -3-hydroxypropanoate (2) to which 4'-(3-hydroxypropyl)-[1,1'-biphenyl]-4-carbonitrile (1) is attached in the following steps by an ester bond. Compound 1 was prepared by Suzuki-Miyaura reaction. The mesogenic properties of the target molecules were examined with the help of a polarizing optical microscope and differential scanning calorimetry. Both compounds show the properties of liquid crystals. Based on the optical texture, the compounds were found to self-organize into the anticline smectic C phase (SmCA)