scholarly journals Two-dimensional square-grid iron(ii) coordination polymers showing anion-dependent spin crossover behavior

RSC Advances ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 5040-5049 ◽  
Author(s):  
Jong Won Shin ◽  
Ah Rim Jeong ◽  
Jong Hwa Jeong ◽  
Hikaru Zenno ◽  
Shinya Hayami ◽  
...  

Two-dimensional Fe-based coordination polymers with square-grid shapes were prepared by self-assembly and exhibited an interesting spin crossover behavior depending on the coordinated counter ions.

2009 ◽  
Vol 65 (3) ◽  
pp. m139-m142 ◽  
Author(s):  
Rajesh Koner ◽  
Israel Goldberg

The title compound, (5,10,15,20-tetra-4-pyridylporphyrinato)zinc(II) 1,2-dichlorobenzene disolvate, [Zn(C40H24N8)]·2C6H4Cl2, contains a clathrate-type structure. It is composed of two-dimensional square-grid coordination networks of the self-assembled porphyrin moiety, which are stacked one on top of the other in a parallel manner. The interporphyrin cavities of the overlapping networks combine into channel voids accommodated by the dichlorobenzene solvent. Molecules of the porphyrin complex are located on crystallographic inversion centres. The observed two-dimensional assembly mode of the porphyrin units represents a supramolecular isomer of the unique three-dimensional coordination frameworks of the same porphyrin building block observed earlier. The significance of this study lies in the discovery of an additional supramolecular isomer of the rarely observed structures of metalloporphyrins self-assembled directly into extended coordination polymers without the use of external ligand or metal ion auxiliaries.


2018 ◽  
Vol 74 (11) ◽  
pp. 1434-1439
Author(s):  
Hong-Tao Zhang ◽  
Xiao-Long Wang

In recent years, much initial interest and enthusiasm has focused on the self-assembly of coordination polymers due to the aesthetics of their crystalline architectures and their potential applications as new functional materials. As part of an exploration of chiral coordination polymers, a new twofold interpenetrated two-dimensional (2D) coordination polymer, namely, poly[[tetraaquabis[μ3-(2R,2′R)-2,2′-(benzene-1,4-dicarboxamido)dipropionato-κ5 O,O′:O′′,O′′′:O′′]dicadmium(II)] trihydrate], {[Cd2(C14H14N2O6)2(H2O)4]·3H2O} n , has been synthesized by the reaction of Cd(CH3COO)2·2H2O with the designed ligand (2R,2′R)-2,2′-(benzene-1,4-dicarboxamido)dipropionic acid (H2 L). The compound has been structurally characterized by elemental analysis, IR spectroscopy, powder X-ray diffraction and single-crystal X-ray diffraction analysis. In the crystal structure, each CdII cation binds to three carboxylate groups from two crystallographically independent L 2− dianions. Four carboxylate groups link two crystallographically independent cadmium cations into a 4,4-connected secondary building unit (SBU). The resulting SBUs are extended into a two-dimensional folding sheet via the terephthalamide moiety of the ligand as a spacer, which can be simplified as a (4,4)-connected 4,4L15 net with the point symbol (3.53.62)(32.52.62). In the lattice, two independent folding sheets interpenetrate each other to yield a double-sheet layer. The resulting 2D layers pack in parallel arrays through intermolecular hydrogen bonds and interlayer π–π interactions. The thermal stability and photoluminescence properties of the title compound have been investigated and it exhibits an enhanced fluorescence emission and a longer lifetime compared with free H2 L.


2020 ◽  
Vol 8 (5) ◽  
pp. 1623-1633 ◽  
Author(s):  
Manuel Meneses-Sánchez ◽  
Lucía Piñeiro-López ◽  
Teresa Delgado ◽  
Carlos Bartual-Murgui ◽  
M. Carmen Muñoz ◽  
...  

Two series of coordination polymers have been synthesized to exhibit extrinsic or intrinsic luminescence modulated by spin crossover behavior. This study provides further insight into the features governing the synergy between both properties.


2018 ◽  
Vol 74 (8) ◽  
pp. 894-900 ◽  
Author(s):  
Lin Wang ◽  
Qian-Kun Zhou ◽  
Yun Xu ◽  
Ni-Ya Li

In recent years, the design and construction of crystalline coordination complexes by the assembly of metal ions with multitopic ligands have attracted considerable attention because of the unique architectures and potential applications of these compounds. Two new coordination polymers, namely poly[[μ-trans-1-(2-aminopyridin-3-yl)-2-(pyridin-4-yl)ethene-κ2 N:N′](μ3-5-methylisophthalato-κ4 O 1,O 1′:O 3:O 3′)cadmium(II)], [Cd(C9H6O4)(C12H11N3)] n or [Cd(5-Me-ip)(2-NH2-3,4-bpe)] n , (I), and poly[[μ-trans-1-(2-aminopyridin-3-yl)-2-(pyridin-4-yl)ethene-κ2 N:N′](μ2-5-hydroxyisophthalato-κ4 O 1,O 1′:O 3:O 5)cadmium(II)], [Cd(C8H4O5)(C12H11N3)] n or [Cd(5-HO-ip)(2-NH2-3,4-bpe)] n , (II), have been prepared hydrothermally by the self-assembly of Cd(NO3)2·4H2O and trans-1-(2-aminopyridin-3-yl)-2-(pyridin-4-yl)ethene (2-NH2-3,4-bpe) with two similar dicarboxylic acids, i.e. 5-methylisophthalic acid (5-Me-H2ip) and 5-hydroxyisophthalic acid (5-HO-H2ip). The coordination network of (I) is a two-dimensional sql net parallel to (101). Adjacent sql nets are further linked to form a three-dimensional supramolecular framework via hydrogen-bonding interactions. Compound (II) is a two-dimensional (3,5)-connected coordination network parallel to (010) with the point symbol (63)(55647). As the other reactants and reaction conditions are the same, the structural differences between (I) and (II) are undoubtedly determined by the different substituent groups in the 5-position of isophthalic acid. Both (I) and (II) exhibit good thermal stabilities and photoluminescence properties.


Author(s):  
Kostiantyn V. Domasevitch ◽  
Vira V. Ponomarova

In the structures of the title salts, poly[[μ4-4-(3,5-dinitropyrazol-4-yl)-3,5-dinitropyrazol-1-ido]rubidium], [Rb(C6HN8O8)] n , (1), and its isostructural caesium analogue [Cs(C6HN8O8) n , (2), two independent cations M1 and M2 (M = Rb, Cs) are situated on a crystallographic twofold axis and on a center of inversion, respectively. Mutual intermolecular hydrogen bonding between the conjugate 3,5-dinitopyrazole NH-donor and 3,5-dinitropyrazole N-acceptor sites of the anions [N...N = 2.785 (2) Å for (1) and 2.832 (3) Å for (2)] governs the self-assembly of the translation-related anions in a predictable fashion. Such one-component modular construction of the organic subtopology supports the utility of the crystal-engineering approach towards designing the structures of polynitro energetic materials. The anionic chains are further linked by multiple ion–dipole interactions involving the 12-coordinate cations bonded to two pyrazole N-atoms [Rb—N = 3.1285 (16), 3.2261 (16) Å; Cs—N = 3.369 (2), 3.401 (2) Å] and all of the eight nitro O-atoms [Rb—O = 2.8543 (15)–3.6985 (16) Å; Cs—O = 3.071 (2)–3.811 (2) Å]. The resulting ionic networks follow the CsCl topological archetype, with either metal or organic ions residing in an environment of eight counter-ions. Weak lone pair–π-hole interactions [pyrazole-N atoms to NO2 groups; N...N = 2.990 (3)–3.198 (3) Å] are also relevant to the packing. The Hirshfeld surfaces and percentage two-dimensional fingerprint plots for (1) and (2) are described.


Nanoscale ◽  
2020 ◽  
Vol 12 (15) ◽  
pp. 8180-8187 ◽  
Author(s):  
Suhail Usmani ◽  
Mirko Mikolasek ◽  
Angélique Gillet ◽  
José Sanchez Costa ◽  
Mathilde Rigoulet ◽  
...  

Spin crossover is unambiguously demonstrated by magnetic and electrical measurements in ordered self-assemblies of ultra-small platinum nanoparticles with coordination polymers.


2019 ◽  
Vol 2019 (5) ◽  
pp. 543-543
Author(s):  
Nayarassery N. Adarsh ◽  
Marinela M. Dîrtu ◽  
Philippe Guionneau ◽  
Eamonn Devlin ◽  
Yiannis Sanakis ◽  
...  

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