Silver and gold luminescent metallomesogens based on pyrazole ligands.
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.
Mayoral
María José
MJ
Departamento de Química Inorgánica I, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain.
Ovejero
Paloma
P
Campo
José Antonio
JA
Heras
José Vicente
JV
Pinilla
Elena
E
Torres
María Rosario
MR
Lodeiro
Carlos
C
Cano
Mercedes
M
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
D008024:Ligands; D009942:Organometallic Compounds; D011720:Pyrazoles; D012834:Silver; C031280:pyrazole; D006046:Gold