TY - JOUR
T1 - Synthesis, spectroscopic, structural and complexation studies of a new tetra-naphthylmethylene pendant-armed macrocyclic ligand
AU - Nuñez, Cristina
AU - Oliveira, Elisabete
AU - Giestas, Leticia
AU - Valencia, Laura
AU - Macías, Alejandro
AU - Lima, João Carlos
AU - Bastida, Rufina
AU - Lodeiro, Carlos
N1 - We are indebted to Fundação para a Ciência e a Tecnologia/FEDER (Portugal/EU) (Project POCI/QUI/55519/2004 FCT-FEDER), Xunta de Galicia (Spain) (Project PGIDIT07PXIB209039PR) for financial support. C.N., A.M., R.B. and C.L. also thank the joint program “Joint Portuguese–Spanish Project 2007” for the bilateral agreement number 63/07 (Portugal)/HP2006-0119 (Spain). C.N. thanks Xunta de Galicia for her Maria Barbeito program pre-doctoral contract. E.O. and L.G. thank FCT-MCTES (Portugal) by their PhD Grants SFRH/BD/35905/2007 and POSI/SFRH/BD/13783/2003, respectively. Appendix A
PY - 2008/6/2
Y1 - 2008/6/2
N2 - A novel emissive tetra-naphthylmethylene pendant-armed macrocyclic ligand and a series of complexes with monovalent and divalent metal ions have been synthesized. Solid compounds have been isolated as mononuclear (Co(II), Cu(II) and Zn(II)) or dinuclear (Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Ag(I)), complexes, depending on the counterions used. The chemical and photophysical properties of the free ligand, the protonation behavior and its metal complexes have been investigated in solution. UV-Vis spectroscopy has revealed a 1:1 binding stoichiometry for Cu(II), Zn(II), Cd(II), Ni(II) and Co(II), and 2:1 molar ratio for Ag(I). In chloroform, the free ligand presents two emission bands related to the monomer naphthalene emission and a red-shifted band attibutable to an exciplex due to a charge transfer from the nitrogen lone electron pair to the excited chromophore. Upon protonation of the free amines or due to metal complexation, the exciplex band disappears. The crystal structure of [Ag2L(NO3)2] is also reported. The structure reveals that both metal ions are into the macrocyclic cavity in a distorted square plane {AgN3O} environment. Each Ag(I) atom interacts with two neighbouring amine nitrogen atoms, one pyridine nitrogen and one oxygen atom from a monodentate nitrate ion.
AB - A novel emissive tetra-naphthylmethylene pendant-armed macrocyclic ligand and a series of complexes with monovalent and divalent metal ions have been synthesized. Solid compounds have been isolated as mononuclear (Co(II), Cu(II) and Zn(II)) or dinuclear (Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Ag(I)), complexes, depending on the counterions used. The chemical and photophysical properties of the free ligand, the protonation behavior and its metal complexes have been investigated in solution. UV-Vis spectroscopy has revealed a 1:1 binding stoichiometry for Cu(II), Zn(II), Cd(II), Ni(II) and Co(II), and 2:1 molar ratio for Ag(I). In chloroform, the free ligand presents two emission bands related to the monomer naphthalene emission and a red-shifted band attibutable to an exciplex due to a charge transfer from the nitrogen lone electron pair to the excited chromophore. Upon protonation of the free amines or due to metal complexation, the exciplex band disappears. The crystal structure of [Ag2L(NO3)2] is also reported. The structure reveals that both metal ions are into the macrocyclic cavity in a distorted square plane {AgN3O} environment. Each Ag(I) atom interacts with two neighbouring amine nitrogen atoms, one pyridine nitrogen and one oxygen atom from a monodentate nitrate ion.
KW - Exciplex
KW - Fluorescence probes
KW - Macrocycles
KW - Metal complexes
KW - Naphthalene
KW - Silver(I)
UR - http://www.scopus.com/inward/record.url?scp=43949084035&partnerID=8YFLogxK
U2 - 10.1016/j.ica.2007.11.024
DO - 10.1016/j.ica.2007.11.024
M3 - Article
AN - SCOPUS:43949084035
SN - 0020-1693
VL - 361
SP - 2183
EP - 2194
JO - Inorganica Chimica Acta
JF - Inorganica Chimica Acta
IS - 8
ER -