title: Three-dimensional porous metal-radical frameworks based on triphenylmethyl radicals.
abstract: Lanthanide coordination polymers {[Ln(PTMTC)(EtOH)(2)H(2)O]·x H(2)O, y EtOH} [Ln=Tb (1), Gd (2), and Eu (3)] and {[Ln(αH-PTMTC)(EtOH)(2)H(2)O]·x H(2)O, y EtOH} [Ln=Tb (1'), Gd (2'), and Eu (3')] have been prepared by reacting Ln(III) ions with tricarboxylate-perchlorotriphenylmethyl/methane ligands that have a radical (PTMTC(3-)) or closed-shell (αH-PTMTC(3-)) character, respectively. X-ray diffraction analyses reveal 3D architectures that combine helical 1D channels and a fairly rare (6,3) connectivity described with the (4(2).8)·(4(4).6(2).8(5).10(4)) Schäfli symbol. Such 3D architectures make these polymers porous solids upon departure of the non-coordinated guest-solvent molecules as confirmed by the XRD structure of the guest-free [Tb(PTMTC)(EtOH)(2)H(2)O] and [Tb(αH-PTMTC)(EtOH)(2)H(2)O] materials. Accessible voids represent 40% of the cell volume. Metal-centered luminescence was observed in Tb(III) and Eu(III) coordination polymers 1' and 3', although the Ln(III)-ion luminescence was quenched when radical ligands were involved. The magnetic properties of all these compounds were investigated, and the nature of the {Ln-radical} (in 1 and 2) and the {radical-radical} exchange interactions (in 3) were assessed by comparing the behaviors for the radical-based coordination polymers 1-3 with those of the compounds with the diamagnetic ligand set. Whilst antiferromagnetic {radical-radical} interactions were found in 3, ferromagnetic {Ln-radical} interactions propagated in the 3D architectures of 1 and 2.
authors.affiliation: Departament de Nanociència Molecular i Materials Orgànics, Institut de Ciència de Materials de Barcelona, Campus de la UAB, 08193 Bellaterra, Spain.
authors.forename: Angela
authors.initials: A
authors.lastname: Datcu
authors.forename: Nans
authors.initials: N
authors.lastname: Roques
authors.forename: Véronique
authors.initials: V
authors.lastname: Jubera
authors.forename: Daniel
authors.initials: D
authors.lastname: Maspoch
authors.forename: Xavier
authors.initials: X
authors.lastname: Fontrodona
authors.forename: Klaus
authors.initials: K
authors.lastname: Wurst
authors.forename: Inhar
authors.initials: I
authors.lastname: Imaz
authors.forename: Georges
authors.initials: G
authors.lastname: Mouchaham
authors.forename: Jean-Pascal
authors.initials: JP
authors.lastname: Sutter
authors.forename: Concepció
authors.initials: C
authors.lastname: Rovira
authors.forename: Jaume
authors.initials: J
authors.lastname: Veciana
mesh_terms: D018360:Crystallography, X-Ray; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D008163:Luminescent Measurements / Q000295:instrumentation* / Q000379:methods; D008968:Molecular Conformation; D015394:Molecular Structure; D016062:Porosity; D014320:Triphenylmethyl Compounds / Q000737:chemistry*
chemical_list: D028581:Lanthanoid Series Elements; D014320:Triphenylmethyl Compounds