Heteronuclear lanthanide terephthalate coordination polymers with the general chemical formula [Ln2–2xLn′2x(bdc)3(H2O)4]∞, for which bdc2– symbolizes benzene‐1,4‐dicarboxylate (or terephthalate) and Ln and Ln′ represent trivalent rare earth ions, were synthesized and structurally characterized. Analysis of the Y/Lu compounds by 89Y and 13C solid‐state NMR spectroscopy was carried out, and the results support the hypothesis of randomly distributed lanthanide ions. The spectroscopic and colorimetric properties of this family of compounds were investigated in detail. The resulting data demonstrate that this series of compounds presents highly tunable luminescence properties and clearly indicate that intermetallic deactivation processes play an important role in the emission mechanism. Playing with intermetallic distances allows one to tune the color and the brightness of the lanthanide emission in these coordination polymers.

The luminescent properties of two families of heteronuclear lanthanide-containing coordination polymers are compared. These families have general chemical formulas [Ln2-2xLn'2x(ip)3(H2O)9·6H2O]∞ and [Ln2-2xLn'2x(aip)2(H2O)10·(aip)·4H2O]∞ where H2ip and H2aip stand for isophthalic acid and 5-amino-isophthalic acid, respectively, and where Ln and Ln' are one of the lanthanide ions between Sm(3+) and Dy(3+). Heteronuclear compounds that belong to each family are isostructural to the already reported homonuclear compounds [Gd2(ip)3(H2O)9·6H2O]∞ and [Eu2(aip)2(H2O)10·(aip)·4H2O]∞, respectively. These two crystal structures are very similar. However, despite similar chemical formulas, similar crystal structures, and similar hydration rates, these two families of compounds present very different luminescent properties that have thus been deeply investigated. This study demonstrates that these different optical behaviors can be attributed to the presence of a PET (photoinduced electron transfer) mechanism that is only present in the amino-isophthalate-containing coordination polymers.

International audienceReactions in water at room temperature between lanthanide ions and 5-hydroxy-1,3-benzene-dicarboxylic acid hereafter referred to as H2(hip) lead to a new family of lanthanide-based hetero-nuclear compounds with the general chemical formula [Ln2 2xLn2x 0(hip)2(H2O)10,(hip),4H2O]N where Ln and Ln0 ¼ Pr-Lu or Y and where 0 # x # 1. The physico-chemical properties of this family have been characterized by PXRD, TDXD, TG/TD, EDS, SEM, 89Y solid state NMR spectroscopy and optical spectroscopy. The luminescent properties of these compounds are studied in detail. This study reveals that the competition between intermetallic energy transfer and photo-induced electron transfer gives rise to complex multiple emission spectra. It is therefore possible, for some Ln/Ln0 compositions, to obtain green, yellow or red emission by tuning the excitation wavelength over a 50 nm range. From a global point of view, this study shows that this series of compounds could be of great interest as far as luminescent coordination polymers usable as taggants for the fight against counterfeiting are aimed

Reactions in water of 4,5-dichlorophthalate (dcpa) with the heaviest lanthanide ions lead to a family of compounds with the general chemical formula [Ln(dcpa)(HO)·3HO], where Ln = Tb-Lu, Y. The synthesis, crystal structure, thermal behavior, and luminescent properties of this series of homonuclear compounds are described. Additionally, this family can be extended to isostructural heteronuclear compounds that can contain some light lanthanide ions and therefore present some original photophysical properties. These compounds show potential interest as multiemissive materials (visible and infrared light between 450 and 1600 nm) and could find application as luminescent bar codes.

Reactions in water between the sodium salt of benzene-1,2,4,5-tetracarboxylic acid (H4btec) and lanthanide ions (Sm-Dy) led to a series of isostructural lanthanide-based coordination polymers with the general chemical formula [Ln4(btec)3(H2O)12·20H2O]∞ with Ln = Sm-Dy. The family has been structurally characterized. From a luminescent point of view, the heterodinuclear strategy has been successfully applied and allows significant brightness enhancement (+35%) and color tuning from green to yellow to orange to red.

Reactions in water between the sodium salt of 4-carboxyphenylboronic acid (Hcpb) and lanthanide ions (Pr-Nd, Sm-Lu, and Y) led to a family of lanthanide-based coordination polymers with general chemical formula {[Ln(cpbOH)(H2O)2](cpb)}∞. Structural characterizations were ensured by single-crystal X-ray diffraction and solid-state NMR spectroscopy ((11)B, (13)C, and (89)Y). This family of compounds constitutes the first example of lanthanide-based coordination polymers involving 4-carboxyphenylboronic acid as ligand. To evaluate their potential usefulness, luminescent and magnetic properties of some of the compounds that constitute this family were explored. From a magnetic point of view, the Yb(III) compound is the more promising. On the other hand, upon UV irradiation (λexc = 303 nm) ligand phosphorescence is quite intense and offers a sizable blue component to emission spectra. This is quite unusual and can constitute an asset as far as white emission is targeted. Moreover, luminescence properties of these compounds are highly temperature-dependent, and some of them seem promising as molecular thermometers.

International audienceReactions in water between lanthanide chlorides and the disodium salt of 5-methoxyisophthalic acid, Na2(mip)·7H2O, lead to the first three series of lanthanide-based coordination polymers based on this ligand. The first series contains only one compound with chemical formula [Ce(mip)3/2(H2O)5·2H2O]∞. The second series has general chemical formula [Ln(mip) (Hmip)(H2O)5·H2O]∞ with Ln = La–Ce. The last family is constituted by compounds with general chemical formula [Ln2(mip)3(H2O)8·4H2O]∞ with Ln = Sm–Er plus Y. Luminescent properties of the compounds that belong to this family have been studied. The Tb-based compound presents one of the brightest luminescences reported to date for a lanthanide-based coordination polymer. The weak intermetallic energy transfer evidenced on the third family of compounds allows easy and predictable color modulation of the heterobimetallic powders through additive colors strategy

Reactions in water of lanthanide chlorides with the sodium salt of 1,4-carboxyphenylboronic acid lead to two series of isostructural compounds with respective general chemical formulas [Ln­(cpb)3(H2O)2]∞ for Ln = La or Ce and [Ln­(cpbOH)­(H2O)2·(cpb)]∞ for Ln = Pr–Lu (except Pm) plus Y. Heterolanthanide coordination polymers that are isostructural to the second series have been synthesized, and their photophysical properties have been studied. This study evidences that it is possible to design multiemissive lanthanide-based coordination polymers that could find their application as multigauge luminescent thermometric probes.