title: Silver and gold luminescent metallomesogens based on pyrazole ligands.
abstract: A series of ionic bis(pyrazole)-silver(I) and -gold(I) complexes [ML(2)][A] (M = Ag, Au; A = BF(4)(-), PF(6)(-), NO(3)(-)), prepared by coordination of the mesomorphic L = Hpz(2R(n)) or non-mesomorphic L = Hpz(R(n)) pyrazole ligands (Hpz(2R(n)) = 3,5-bis(4-alkyloxyphenyl)pyrazole; Hpz(R(n)) = 3-(4-alkyloxyphenyl)pyrazole), has been studied. The complexes exhibit enantiotropic behaviour, showing smectic A (SmA) mesophases. The choice of the ligands allows the achievement of 'H' or 'U' molecular shapes, which appear to be responsible for the attainment of liquid crystal mesophases, these not being dependent on the coordinating or non-coordinating nature of the A counteranions. The new complexes are photoluminescent both in the solid state and in solution at room temperature. In addition, the luminescent behaviour of selected compounds as a function of the temperature indicates that the luminescence is maintained in the mesophase.
authors.affiliation: Departamento de Química Inorgánica I, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain.
authors.forename: María José
authors.initials: MJ
authors.lastname: Mayoral
authors.forename: Paloma
authors.initials: P
authors.lastname: Ovejero
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Campo
authors.forename: José Vicente
authors.initials: JV
authors.lastname: Heras
authors.forename: Elena
authors.initials: E
authors.lastname: Pinilla
authors.forename: María Rosario
authors.initials: MR
authors.lastname: Torres
authors.forename: Carlos
authors.initials: C
authors.lastname: Lodeiro
authors.forename: Mercedes
authors.initials: M
authors.lastname: Cano
mesh_terms: D018360:Crystallography, X-Ray; D006046:Gold / Q000737:chemistry*; D008024:Ligands; D050866:Liquid Crystals / Q000737:chemistry*; D049449:Luminescence; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D011720:Pyrazoles / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013696:Temperature
chemical_list: D008024:Ligands; D009942:Organometallic Compounds; D011720:Pyrazoles; D012834:Silver; C031280:pyrazole; D006046:Gold