TY - JOUR
T1 - Structural and luminescence studies of trivalent europium complexes with pentaethylene glycol and 18-crown-6 ligands in the presence of picrate anion
AU - Saleh, Muhammad I.
AU - Kusrini, Eny
AU - Saad, Bahruddin
AU - Adnan, Rohana
AU - Mohamed, Abdussalam S.
AU - Yamin, Bohari M.
N1 - Funding Information:
We would like to thank Universiti Sains Malaysia and the Malaysian Government for granting research grants IRPA (305/PKIMIA/612906) and FRGS (304/PKIMIA/670006) that have made the work possible.
PY - 2007/10
Y1 - 2007/10
N2 - Two new isostructural complexes of europium picrate (Eu-Pic) with pentaethylene glycol (EO5) and 18-crown-6 (18C6) ligands formed complexes of molecular formula [Eu(Pic)2(18C6)]+(Pic)- I and [Eu(Pic)2(EO5)]+(Pic)- II have been isolated and characterised. Compound I showed 10-coordination number through six oxygen atoms from the 18C6 ligand and two bidentate picrate anions. Meanwhile, compound II exhibited 9-coordination number via six oxygen atoms from EO5 ligand, two oxygen atoms from a bidentate and one oxygen atom from monodentate picrate anions. Photoluminescence (PL) spectra of the solid-state europium complexes display sharp lines which are assigned to 5D0→7F0-4 and 5D1→7F1,2,4 transitions. No emission of polyether ligands is observed, indicating that the energy transfer from the polyether ligands to the Eu3+ ion is quite efficient. The PL spectra of [Eu(Pic)2(OH2)6]+(Pic)-·6H2O III, [Eu(NO3)3(OH2)3]·(18C6) IV, [Eu(NO3)3·6H2O] V and Eu2O3 VI are also observed. Compounds I-IV exhibited high Ω2 intensity parameter values, namely 16.93, 10.23, 17.10 and 12.35 (in units of 10-20 cm2), respectively. These relatively high values reflect the hypersensitive behaviour of the 5D0→7F2 transition and indicate that the Eu3+ ion is located in a highly polarisable chemical environment.
AB - Two new isostructural complexes of europium picrate (Eu-Pic) with pentaethylene glycol (EO5) and 18-crown-6 (18C6) ligands formed complexes of molecular formula [Eu(Pic)2(18C6)]+(Pic)- I and [Eu(Pic)2(EO5)]+(Pic)- II have been isolated and characterised. Compound I showed 10-coordination number through six oxygen atoms from the 18C6 ligand and two bidentate picrate anions. Meanwhile, compound II exhibited 9-coordination number via six oxygen atoms from EO5 ligand, two oxygen atoms from a bidentate and one oxygen atom from monodentate picrate anions. Photoluminescence (PL) spectra of the solid-state europium complexes display sharp lines which are assigned to 5D0→7F0-4 and 5D1→7F1,2,4 transitions. No emission of polyether ligands is observed, indicating that the energy transfer from the polyether ligands to the Eu3+ ion is quite efficient. The PL spectra of [Eu(Pic)2(OH2)6]+(Pic)-·6H2O III, [Eu(NO3)3(OH2)3]·(18C6) IV, [Eu(NO3)3·6H2O] V and Eu2O3 VI are also observed. Compounds I-IV exhibited high Ω2 intensity parameter values, namely 16.93, 10.23, 17.10 and 12.35 (in units of 10-20 cm2), respectively. These relatively high values reflect the hypersensitive behaviour of the 5D0→7F2 transition and indicate that the Eu3+ ion is located in a highly polarisable chemical environment.
KW - 18-Crown-6
KW - Europium
KW - Pentaethylene glycol
KW - Photoluminescence
KW - Picrate complex
UR - http://www.scopus.com/inward/record.url?scp=34248591178&partnerID=8YFLogxK
U2 - 10.1016/j.jlumin.2007.01.017
DO - 10.1016/j.jlumin.2007.01.017
M3 - Article
AN - SCOPUS:34248591178
SN - 0022-2313
VL - 126
SP - 871
EP - 880
JO - Journal of Luminescence
JF - Journal of Luminescence
IS - 2
ER -