Synthesis, Thermal, Structural Analyses, and Photoluminescent Properties of a New Family of Malonate-Containing Lanthanide(III) Coordination Polymers

Abstract

Five new Lanthanide(III) complexes of malonic acid (HOOC-CH 2 -COOH); {[Gd(C 3 H 2 O 4 )(H 2 O) 4 ]·NO 3 } n ( 1 ), {[Tb(C 3 H 2 O 4 )(H 2 O) 4 ]·NO 3 } n ( 2 ), {[Ho(C 3 H 2 O 4 )(H 2 O) 4 ]·NO 3 } n ( 3 ), [Er(C 3 H 2 O 4 )(C 3 H 3 O 4 )(H 2 O) 2 ] n ( 4 ), and {[Eu 2 (C 3 H 2 O 4 ) 2 (C 3 H 3 O 4 ) 2 (H 2 O) 6 ]·4H 2 O} n ( 5 ) were synthesized and characterized by elemental, infrared spectral, and thermal analyses. The structures of compounds 1 – 5 were determined by single crystal X-ray diffraction technique. The X-ray analysis reveals that compounds 1 , 2 , and 3 are isostructural and crystallized in the orthorhombic space group Pmn 2 1 . The lanthanide(III) ions are coordinated by four carboxylate and four water oxygen atoms adopting a distorted square antiprism geometry. The LnO 8 square antiprisms are linked into infinite layers by malonate (C 3 H 2 ) dianions sandwiching sheets of nitrate counter ions. Compound 4 contains ErO 8 square antiprisms linked into a two-dimensional network by hydrogen malonate (C 3 H 3 ) anions and malonate dianions. The europium complex, 5 is dinuclear having the two europium(III) ions (Eu1 and Eu2) bridged by carboxylate groups of hydrogen malonate ligands. The europium ions in 5 are nine-coordinate and exhibit a distorted monocapped square antiprism geometry. All the structures are consolidated by O–H⋯ O hydrogen bonds. The photoluminescence spectra of 1–5 exhibit characteristic emissions in the visible region. The IR spectra and thermal data are consi...

Synthesis, crystal structures and, magnetic and photoluminescence properties of lanthanide-based metal–organic frameworks constructed with 2,5-dihydroxybenzene-1,4-dicarboxylic acid

“…The mean Ln-O bond distances of 2.417, 2.408 and 2.389Å in 2, 3 and 4, respectively, are close to those reported in other Ln(III) complexes with carboxylic acids. [3][4][5]35,49,50,[69][70][71] This bond length order is consistent with the expected trend based on the lanthanide contraction effect, which describes that the ionic radii decrease as the atom number increases, that lead average Ln-O bond lengths decrease accordingly. 3,4,72 It may be noted that in each case, the Ln-O bonds for the chelating C12/O7/O8 carboxylate group are relatively longer due to formation of strained four-membered rings.…”

“…The carboxylate bending vibrations, d(O-C-O) are observed around 900 cm À1 . 49,50 The spectra also give characteristic n(C]C) modes of benzene ring near 1450 cm À1 . The weak bands appearing around 3000 cm À1 are assigned to the C-H stretching vibration of the ligand.…”

“…2,3,10,16,[33][34][35] Lanthanide(III) ions have high affinity towards hard bases, such as oxygen donors and in this respect multicarboxylate ligands, which possess hard base sites of high density, seem to be ideal ligands in the construction of MOFs. [3][4][5]8,11,15,16,[34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51] Among these ligands, the rigid carboxylates, benzene-1,4-dicarboxylic acid (Bdc-H 2 ) 4, [34][35][36][37][38] and its derivatives with a centrosymmetric structure 3,5,9,35,[38][39][40][41][42][43] have drawn considerable attention because they possess various coordination modes such as, monodentate, bis-monodentate, bidentate, tridentate and chelating bridging; which favor the bui...…”

Synthesis, Crystal Structures and Photoluminescent Properties of One-Dimensional Europium(III)- and Terbium(III)-Glutarate Coordination Polymers, and Their Applications for the Sensing of Fe3+ and Nitroaromatics

“…In this regard, aromatic carboxylic acids such as, terephthalic acid (Daiguebonne et al, 2008; Wang et al, 2012) benzene-carboxylic acids (Yan et al, 2005; Wang et al, 2010b, 2012; Zhuravlev et al, 2011; Gai et al, 2013), and pyridine-dicarboxylic acid (Reinhard and Güdel, 2002; Huang et al, 2008; Zhu et al, 2009; Song et al, 2016; Xiang et al, 2017; Kumar et al, 2018) have been particularly used to design luminescent lanthanide coordination polymers. A number of studies also exist on the complexes of aliphatic carboxylic acids such as, malonic acid (Hussain et al, 2019), succinic acid (Cui et al, 2005; De Oliveira et al, 2013), glutaric acid (Głowiak et al, 1987; Legendziewicz et al, 1999; Antic-Fidancev et al, 2002), and adipic acid (Wang et al, 2010b).…”

“…Among the luminescent lanthanide complexes, those of europium(III) and terbium(III) (emitting red and green light, respectively) have been especially widely studied because of their efficient luminescent properties (Cui et al, 2005; Bangaru et al, 2010; Tsaryuk et al, 2010; Zhuravlev et al, 2011; Hussain et al, 2019). To further explore the luminescent behavior of such complexes and as a part of our ongoing research on lanthanide complexes (Hussain et al, 2014, 2015a,b, 2018, 2019) herein, we report the structural characterization and photoluminescent properties of two one-dimensional Eu(III) and Tb(III) coordination polymers based on the glutarate ligand. In addition, the possible use of these complexes as sensors for detection of Fe 3+ and 4-nitrophenol was investigated.…”