Dysprosium Chlorocyanoanilate-Based 2D-Layered Coordination Polymers

Abstract

A series of two-dimensional (2D)-layered coordination polymers (CPs) based on the heterosubstituted anilate ligand ClCNAn 2− derived from 3-chloro-6-cyano-2,5-dihydroxybenzoquinone and Dy III are reported. By changes in the synthetic methods (layering technique, solvothermal or conventional one-pot reactions) and conditions (solvent, concentration, etc.), different types of 2D extended networks could be prepared and structurally characterized. Compounds 1 a n d 1 ′ , t w o p o l y m o r p h s w i t h t h e f o r m u l a [Dy 2 (ClCNAn) 3 (DMSO) 6 ] n •(H 2 O) x [x = 7 (1), 0 (1′)], were prepared by a conventional one-pot reaction and recrystallized at different concentrations. Compound 2, formulated as [Dy 2 (ClCNAn) 3 (DMF) 6 ] n , was prepared by a layering technique, while compound 3, formulated aswas obtained by a solvothermal method. Compounds 1 and 2 are neutral 2D CPs of the ClCNAn 2− ligand and Dy III ions, while 3 presents 2D anionic layers of [Dy 2 (ClCNAn) 4 (H 2 O) 2 ] 2− alternating with cationic layers of Me 2 NH 2 + ions. These compounds show very diverse networks, with compound 1 forming 2D (8,3) and (4,3) topology with eight-and four-membered rings with square cavities, 1′ and 2, respectively, a 2D (6,3) topology with six-membered rings (a rectangular cavity for 1′ and a regular hexagonal cavity for 2), and 3 a 2D (4,4) topology with distorted square cavities. In this respect, 1 and 1′ represent the first examples of polymorphism in the family of anilate-based CPs. Thermal analysis measurements (differential scanning calorimetry and thermogravimetry) show an exothermic polymorphic transformation from the kinetically stable 1′ phase to the thermodynamically stable phase 1. The magnetic behavior of 1−3 very likely indicates depopulation of the m J levels, while the presence of weak antiferromagnetic coupling between the Dy III centers mediated by the anilate bridge cannot be excluded.

Heteroleptic NIR-Emitting YbIII/Anilate-Based Neutral Coordination Polymer Nanosheets for Solvent Sensing

“…Very recently we and other groups have reported on the ability of 3,6-disubstituted-2,5-dihydroxy-1,4-benzoquinone derivatives,− known as anilates, to construct 2D layered architectures− with lanthanides.− The light-harvesting capability of the heterosubstituted 3-chloro-6-cyano-2,5-dihydroxybenzoquinone ClCNAn− toward NIR emissive Er III , Yb III and Nd III ions, was highlighted yielding 2D [Ln 2 (ClCNAn) 3 (DMF) 6 ]·(DCM) x } n (Ln III = Yb ( x = 0), Nd, and Er ( x = 2)) CPs. Interestingly these 2D CPs have been delaminated to produce ultrathin nanosheets with lateral sizes and thicknesses in the micrometer and nanometer range, respectively and bulk/nanosheets photophysical properties have been investigated.…”

Redox-active benzoquinones as challenging “non-innocent” linkers to construct 2D frameworks and nanostructures with tunable physical properties

“…1). 55–62 The first example of a semiquinoid-bridged 1D single-chain magnet, containing the chloranilate linker, Cl 2 An, formulated as (NMe 4 ) 2 [(Cl 2 An)FeCl 2 ], is generated via temperature-induced metal-to-ligand electron transfer (valence tautomerism) from high spin Fe II units (L 2− ) to low spin Fe III (L˙ 3− ) upon decreasing temperature, with a transition temperature of T 1/2 = 213 K and conductivity value of σ = 5.7 × 10 −8 S cm −1 . 63…”

Combined Experimental/Theoretical Study on the Luminescent Properties of Homoleptic/Heteroleptic Erbium(III) Anilate-Based 2D Coordination Polymers

“…14,15 On the other hand, CPs based on 3,5-disubstituted-2,6-dihydroxy-1,4-benzoquinone, commonly called anilates, have been widely studied over the past decade. [16][17][18][19] Anilates are excellent building blocks for constructing layered mono/multifunctional materials showing magnetic, [20][21][22][23][24][25] conducting, [26][27][28][29] and luminescent properties. [30][31][32] Among them, the first example of heterosubstituted anilate, the chlorocyananilate ligand (3-chloro-6-cyano-2,5-dihydroxybenzoquinone-ClCNAn 2-), is an interesting antenna linker for constructing Ln-CPs, due to the absence of IR quenchers in its molecular structure.…”