TY - JOUR
T1 - Designing Eu-β-diketonate complexes as a support of ionic liquid crystals (ILCs) with additional luminescent properties
AU - Sánchez, Ignacio
AU - Cuerva, Cristián
AU - Marcelo, Gonçalo
AU - Oliveira, Elisabete
AU - Santos, Hugo M.
AU - Campo, José A.
AU - Lodeiro, Carlos
AU - Cano, Mercedes
N1 - Sem PDF conforme despacho.
info:eu-repo/grantAgreement/FCT/5876/147218/PT#
M.C. thanks the finantial support by the Spanish Ministerio de Economia y Competitividad (project CTQ2015-63858-P (MINECO/FEDER)). I.S. acknowledges the Ministerio de Educacion, Culture y Deporte for his FPU scholarship. C.C. is grateful to the Programa de Financiacion de Universidad Complutense de Madrid-Santander Universidades (Spain), for his predoctoral contract. C.L., H.M.S., E.O. and G.M. thank the financial support by the Associate Laboratory for Green Chemistry, LAQV which is financed by national funds from FCT/MEC (UID/QUI/50006/2013) and co-financed by the ERDF under the PT2020 Partnership Agreement (POCI-01-0145-FEDER - 007265). The PROTEOMASS Scientific Society (Portugal) is acknowledged for funding provided to the Laboratory for Biological Mass Spectrometry - Isabel Moura (General Funding Grant). E.O and G.M. thank Fundacao para a Ciencia e a Tecnologia (FCT - Portugal) for their post-doctoral and doctoral grants, SFRH/BPD/108660/2015 and SFRH/BD/1428652018, respectively. H.M.S. thanks FCT - Portugal for his research contract FCT-Investigator program.
PY - 2018/12/1
Y1 - 2018/12/1
N2 - Here we describe the preparation, characterisation, liquid crystal properties and photophysical studies of new potassium salts of tetrakis(β-diketonate)europium(III) complexes based on long-chained symmetrical and unsymmetrically substituted 1,3-dialkyloxyphenyl-β-diketones ligands, K[Eu(OOR(n)R(m))4] (R(n) = OC6H4OCnH2n+1; R(m) = OC6H4OCmH2m+1; n = m = 8, 10, 12, 14, 16; n = 4, 8, m = 12, 16; n = 12, m = 16). All compounds exhibit mesomorphic and luminescence behaviour, regardless the presence of symmetrical or unsymmetrical ligands. It has been shown that the shortest molecular lengths, established by the summation of the two alkyl chains at the substituents of the β-diketonate ligand, give rise to more effective mesophase transition temperatures, while the asymmetry favours higher clearing temperatures. Related to the ionic salts based on long-chained pirazolium cations [H2pzR(n)]+ (R(n) = OC6H4OCnH2n+1; n = 4, 6, 8, 10, 12, 14, 16, 18) and tetrakis(1,3-bis(methoxyphenyl)propane-1,3-dionate)europium(III) as anion, they have also been studied and proved to be luminescent materials. By contrast, none of them was found to be mesomorphic. Therefore, the strategically increased chain length at the cation did not show to be effective for achieving liquid crystal properties. Integration of one of these luminescent europium complexes onto a polymeric PMMA matrix was positively evaluated towards its use as a temperature sensor and fluoride or cyanide ion sensor.
AB - Here we describe the preparation, characterisation, liquid crystal properties and photophysical studies of new potassium salts of tetrakis(β-diketonate)europium(III) complexes based on long-chained symmetrical and unsymmetrically substituted 1,3-dialkyloxyphenyl-β-diketones ligands, K[Eu(OOR(n)R(m))4] (R(n) = OC6H4OCnH2n+1; R(m) = OC6H4OCmH2m+1; n = m = 8, 10, 12, 14, 16; n = 4, 8, m = 12, 16; n = 12, m = 16). All compounds exhibit mesomorphic and luminescence behaviour, regardless the presence of symmetrical or unsymmetrical ligands. It has been shown that the shortest molecular lengths, established by the summation of the two alkyl chains at the substituents of the β-diketonate ligand, give rise to more effective mesophase transition temperatures, while the asymmetry favours higher clearing temperatures. Related to the ionic salts based on long-chained pirazolium cations [H2pzR(n)]+ (R(n) = OC6H4OCnH2n+1; n = 4, 6, 8, 10, 12, 14, 16, 18) and tetrakis(1,3-bis(methoxyphenyl)propane-1,3-dionate)europium(III) as anion, they have also been studied and proved to be luminescent materials. By contrast, none of them was found to be mesomorphic. Therefore, the strategically increased chain length at the cation did not show to be effective for achieving liquid crystal properties. Integration of one of these luminescent europium complexes onto a polymeric PMMA matrix was positively evaluated towards its use as a temperature sensor and fluoride or cyanide ion sensor.
KW - Ionic liquids
KW - Liquid crystals
KW - Liquid crystalline
UR - http://www.scopus.com/inward/record.url?scp=85049337154&partnerID=8YFLogxK
U2 - 10.1016/j.dyepig.2018.06.030
DO - 10.1016/j.dyepig.2018.06.030
M3 - Article
AN - SCOPUS:85049337154
SN - 0143-7208
VL - 159
SP - 395
EP - 405
JO - Dyes and Pigments
JF - Dyes and Pigments
ER -