Cubic Phase Formation from New Hexacatenar Metallomesogens Based on Cobalt 3,4,5-Trialkoxybenzoate

• Published in: Journal of the Chinese Chemical Society (Taipei) 2015-01, Vol.62 (1), p.26-32
• Main Authors: Lin, Chien-Ho, Kao, Hsien-Chang, Sung, Wen-Te, Cheng, Yao-Wen, Wang, Wen-Jwu
• Format: Article
• Language: English
• Subjects: Cobalt carboxylates; Cubic mesophase; Metallomesogens; Room temperature liquid crystals
• ISSN: 0009-4536; 2192-6549
• DOI: 10.1002/jccs.201400214

Cobalt complexes of Co(3Cn)2(MeOH)4, derived from 3,4,5‐trialkyloxybenzoate ligand (noted as 3Cn) with n = 10, 12, 14 and 16, were synthesized and characterized. The crystal of Co(1C12)2(MeOH)4 were determined by means of x‐ray single crystal analysis. It crystallizes in the monoclinic P21/c space group with a = 24.3271(19) Å, b = 14.0058(11) Å, c = 6.4612(4) Å, α = γ = 90o, β = 94.368(4)o, and Z = 2. The phase texture and mesogenic properties were detected by polarized optical microscopic and powder x‐ray diffraction technique. It was found that these compounds display the cubic phases. Differential scanning calorimetric data indicated that these compounds were nearly room temperature liquid crystalline and with a very wide mesogenic phase range. Two 3,4,5‐trialkyloxybenzaotes were coordinated to a cobalt ion to form novel hexacatenar metallomesogens. The solid‐state structure confirmed that two monodentate carboxylate ligands and four methanol molecules coordinated to the cobalt ion to give a slight distorted octahedral geometry. The mesomorphic behavior are stable and exist over a wide temperature range, which is arranged in layers and exhibited enantiotropic cubic mesophase.