Synthesis and separation of asymmetrically octa-substituted phthalocyanines （Pcs） derivatives obtained by cyclotetramerization of two different phthalonitriles （Pns） precursors is described. The phthalonitriles we...Synthesis and separation of asymmetrically octa-substituted phthalocyanines （Pcs） derivatives obtained by cyclotetramerization of two different phthalonitriles （Pns） precursors is described. The phthalonitriles were designed to have different polarity to enable successful chromatographic isolation. The side-chains was designed to lie perpendicular to the plane of the macrocycle via ketal link. It was hoped that the obtained materials would exhibit enhanced solubility and less columnar aggregation both in solution and in the solid state. The preparation of the ketal compounds （2,2-didodecyl- 1,3-benzodioxoles ） with was performed according to Cole method in which catechol and the didodecyl ketone were refluxed in toluene solution in the presence of a catalytic amount of p-toluene sulphonic acid （PTSA）. The resultant water was removed by azeotropic distillation using a Dean-Stark trap. 2,2-didodecyl-l,3-benzodioxoles was brominated then cyanated as described in literature to give the desired phthalonitrile. The other phthalonitrile （4,5-bis（1＇,4＇,7＇,10＇-tetraoxaundecyl） phthalonitrile was obtained also as described in literature. The structures of the obtained isomers were confirmed by spectroscopic methods. Optical microscopy and differential scanning calorimetry （DSC） measurements revealed that two of the obtained derivatives display hexagonal and rectangular columnar liquid crystalline phases （Dhd＆Drd） over a wide temperature range.展开更多
文摘Synthesis and separation of asymmetrically octa-substituted phthalocyanines （Pcs） derivatives obtained by cyclotetramerization of two different phthalonitriles （Pns） precursors is described. The phthalonitriles were designed to have different polarity to enable successful chromatographic isolation. The side-chains was designed to lie perpendicular to the plane of the macrocycle via ketal link. It was hoped that the obtained materials would exhibit enhanced solubility and less columnar aggregation both in solution and in the solid state. The preparation of the ketal compounds （2,2-didodecyl- 1,3-benzodioxoles ） with was performed according to Cole method in which catechol and the didodecyl ketone were refluxed in toluene solution in the presence of a catalytic amount of p-toluene sulphonic acid （PTSA）. The resultant water was removed by azeotropic distillation using a Dean-Stark trap. 2,2-didodecyl-l,3-benzodioxoles was brominated then cyanated as described in literature to give the desired phthalonitrile. The other phthalonitrile （4,5-bis（1＇,4＇,7＇,10＇-tetraoxaundecyl） phthalonitrile was obtained also as described in literature. The structures of the obtained isomers were confirmed by spectroscopic methods. Optical microscopy and differential scanning calorimetry （DSC） measurements revealed that two of the obtained derivatives display hexagonal and rectangular columnar liquid crystalline phases （Dhd＆Drd） over a wide temperature range.
