A Three-Dimensional Dynamic Supramolecular "Sticky Fingers" Organic Framework.

Engineering high-recognition host-guest materials is a burgeoning area in basic and applied research. The challenge of exploring novel porous materials with advanced functionalities prompted us to develop dynamic crystalline structures promoted by soft interactions. The first example of a pure molecular dynamic crystalline framework is demonstrated, which is held together by means of weak "sticky fingers" van der Waals interactions. The presented organic-fullerene-based material exhibits a non-porous dynamic crystalline structure capable of undergoing single-crystal-to-single-crystal reactions. Exposure to hydrazine vapors induces structural and chemical changes that manifest as toposelective hydrogenation of alternating rings on the surface of the [60]fullerene. Control experiments confirm that the same reaction does not occur when performed in solution. Easy-to-detect changes in the macroscopic properties of the sample suggest utility as molecular sensors or energy-storage materials

Construction of coordination polymers with a bifurcating ligand: synthesis, structure, photoluminescence, and magnetic studies

A new ligand, 3,5-di(1H-imidazol-1-yl)benzonitrile (DICN), has been synthesized by reacting 3,5-difluorobenzonitrile with imidazole in good yields. The cyanide group hydrolyzes to carboxylic acid under solvothermal conditions in the presence of different metal salts giving rise to carboxylate and imidazole bonded coordination polymers. Seven such polymers, {[Cd(DIBA)I]·H<SUB>2</SUB>O}<SUB>n</SUB> (1), {[Zn(DIBA)(MeCOO)]·H<SUB>2</SUB>O}<SUB>n</SUB> (2·H<SUB>2</SUB>O), {[Zn(DIBA)(NO<SUB>3</SUB>)]}<SUB>n</SUB> (3), {[Cu(DIBA)]·H<SUB>2</SUB>O}<SUB>n</SUB> (4), {[Ni(DIBA)<SUB>2</SUB>(H<SUB>2</SUB>O)<SUB>2</SUB>]·3H<SUB>2</SUB>O}<SUB>n</SUB> (5), {[Co(DIBA)(OH)]·H<SUB>2</SUB>O}<SUB>n</SUB> (6), and {[Pb<SUB>2</SUB>(DIBA)(OH)(NO<SUB>3</SUB>)]}<SUB>n</SUB> (7) (DIBA<SUP>−</SUP> = 3,5-di(1H-imidazol-1-yl)benzoate)), have been isolated. These polymers have been structurally characterized by single crystal X-ray diffraction, thermogravimetric (TGA), and elemental analysis. Both 1 and 2·H<SUB>2</SUB>O form honeycomb two-dimensional (2D) layer structures that stack on top of one another to form three-dimensional (3D) networks. 3 and 6 have the same (2,4,6) connected net, while 4 is a rare 3-connected net with a 3D network. Compounds 5 and 7 have one-dimensional (1D) and zigzag 2D polymeric structures, respectively. 2·H<SUB>2</SUB>O exhibits dynamic behavior through sliding of the 2D layers upon removal of solvent molecules in a single-crystal to single-crystal (SC-SC) fashion. The Zn<SUP>2+</SUP> and Cd<SUP>2+</SUP> coordination polymers exhibit solid-state luminescence at RT. Variable temperature (2-300 K) magnetic susceptibility data on 5 are consistent with a weak ferromagnetically coupled 1D chain of Ni<SUP>2+</SUP> ions. For 6, a spin-glass behavior with slow relaxation and frustration is inferred from the susceptibility data

A dicarboxylate with asymmetric coordination ability: characterization of a two dimensional coordination polymer of copper(II) exhibiting spin canting

A copper(II) coordination polymer {[Cu2(cpa)2]}n (1) (cpaH2 = 4-carboxyphenoxyacetic acid) has been synthesized by hydrothermal technique. The X-ray structure of the compound shows that it is a 2D coordination polymer where Cu(II) ions are pentacoordinated in a square pyramidal fashion. The magnetic measurement of 1 in different magnetic fields suggest a weak ferromagnetic ordering taking place below 20 K, arising from spin canting phenomenon due to the non-coplanar basal planes of copper ions

Comparative Magnetic Studies in the Solid State and Solution of Two Isostructural 1D Coordination Polymers Containing CoII/NiII-Curcuminoid Moieties

Two novel 1D coordination chains containing the curcuminoid (CCMoid) ligand 9Accm have been characterized: [CoII(9Accm)2(4,4´-bpy)]n (1) and [NiII(9Accm)2(4,4´-bpy)]n (2). The two compounds were synthesized by solvothermal and microwave (MW) assisted techniques, respectively, and crystals of both systems were directly obtained from the mother solutions. Crystal structures of 1 and 2 prove that both systems are isostructural, with the ligands in a trans configuration. The two chains have been magnetically characterized in solution by paramagnetic 1H NMR, where 1 displayed typical features from CoII systems, with spread out signals; meanwhile, 2 showed diamagnetic behaviour. The dissociation of the latest in solution and the stability of the “[Ni(9Accm)2]” unit were proved by further experiments in C5D5N. Additional UV-Vis absorption and fluorescence studies in solution were performed using exclusively 1. In the solid state χMT vs. T and M/NµB vs. H/T data were collected and fitted for 1 and 2; both systems display Ising plane anisotropy, with significant D values. System 1 presented slow relaxation of the magnetization, displaying frequency dependence in the in-phase/out-phase ac magnetic susceptibility data, when an external dc field of 0.2 T was applied. Finally, 1 was deposited on a HOPG (highly oriented pyrolytic graphite) substrate by spin-coating and analysed by AFM.The authors thank N. Clos from the Serveis Científicotècnics de la UB for her great assistance regarding the magnetic data and are grateful to O. Roubeau (ICMA, CSIC and Universidad de Zaragoza) for his help in the data acquisition and refinement of the structure of compound 1. This work was supported by the MINECO (Spain) (Projects CTQ2012-32247, and MAT2013-47869-C4-2-P) and from the FONDECYT REGULAR grant 1110206. N.A.-A. acknowledges support of the Spanish MINECO through the Severo Ochoa Centers of Excellence Program under Grant SEV-2015-0496. The Advanced Light Source (S.J.T.) is supported by the Director, Office of Science, Office of Basic Energy Sciences of the U.S. Department of Energy under Contract DE-AC0205CH11231.Peer reviewe

Microwave assisted synthesis: A Mn/Ni reaction system affording Mn5Ni4, Mn2Ni2 and Mn7 complexes

Following our interest in microwave assisted synthesis in coordination chemistry; we report here the results of the study of a mixed metal Mn/Ni system under common bench-top conditions and using the microwave reactor. Using bench-top, the mixed metal Mn/Ni complex Mn5Ni4(OH)4(C5H12NO)4(SALOH)6(SALO)4] (complex 1) is obtained while the microwave reactor affords a Mn7 complex, [Mn7(OH)3(C5H12NO)2(C5H13NO)(SALO)6(SALOH)3] complex 2, where the Ni(II) has not been incorporated or a Mn2Ni2 cubane, [Pr2NH2][Mn2Ni2(OH)2(C5H12NO)2(SALO)3(SALOH)2] complex 3. Graphical abstract Following our interest in microwave assisted synthesis in coordination chemistry; we report here the results of the study of a mixed metal Mn/Ni system under common bench-top conditions and using the microwave reactor. Using bench-top, the mixed metal Mn/Ni complex [Mn5Ni4(OH)4(C5H12NO)4(SALOH)6(SALO)4] (complex 1) is obtained while the microwave reactor affords a Mn7 complex, [Mn7(OH)3(C5H12NO)2(C5H13NO)(SALO)6(SALOH)3] complex 2, where the Ni(II) has not been incorporated or a Mn2Ni2 cubane, [Pr2NH2][Mn2Ni2(OH)2(C5H12NO)2(SALO)3(SALOH)2] complex 3.Universidad de Costa Rica/[115-B1-168]/UCR/Costa RicaGobierno español/[CTQ2009-06959]//EspañaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Electroquímica y Energía Química (CELEQ)UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Químic

Coordination polymers of various architectures built with mixed imidazole/benzimidazole and carboxylate donor ligands and different metal ions: syntheses, structural features and magnetic properties

Ten coordination polymers {[Cd(L1)2]}n (1), {[Cu(L1)2]}n (2), {[Cd2(L1)2(HCOO)2(H2O)]}n (3), {[Cd2(L1)4]·3H2O}n (4), {[Cd(L1)(CH3COO)]}n (5), {[Cd(L1)2(C5H5N)]·2.5H2O}n (6), {[Zn(L2)2]}n (7), {[Cd2(L2)4]·H2O}n (8), {[Cd3(L2)6(H2O)]·2EtOH·H2O}n (9) and {[Cd(L3)2]·2DMF·4H2O}n (10), where HL1 = 4-imidazole-1-yl-benzoic acid, HL2 = 3-imidazole-1-yl-benzoic acid and HL3 = 4-benzmidazole-1-yl-benzoic acid, have been synthesized under different experimental conditions. Their structures are determined by single-crystal X-ray diffraction analyses and further characterized by IR spectra, thermogravimetric (TG) and elemental analyses. The structure of 1 is a 2D → 2D (2D = two dimensional) interpenetrating network with (4,4) grid topology while 2 has an interesting Kagome structure. Compounds 4 and 6 crystallize in 4- and 3-fold interpenetrating diamondoid frameworks respectively. Compound 7 is a layered non-interpenetrating (4,4) grid network whereas 8 has an unprecedented self-penetrating structure with 2D framework. Compound 9 is a self-penetrating 3D structure while 10 crystallizes in a non-interpenetrating (4,4) square-grid with one-dimensional (1D) channels. From these results, it is demonstrated that the structures of the coordination polymers are strongly dependent on the geometry of L1, L2 and reaction conditions. Variable temperature magnetic susceptibility study of 2 has also been performed

Three lanthanide complexes with mixed salicylate and 1,10-phenanthroline: syntheses, crystal structures, and luminescent/magnetic properties

<p>Three new lanthanide complexes incorporating salicylate (H<b>SA</b> or <b>SA</b>) and 1,10-phenanthroline (phen), Ln₃(H<b>SA</b>)₅(<b>SA</b>)₂(phen)₃ [Ln = Ho (<b>1</b>) and Er (<b>2</b>)], and Sm₂(H<b>SA</b>)₂(<b>SA</b>)₂(phen)₃ (<b>3</b>), have been synthesized. X-ray structural analysis reveals that <b>1</b> and <b>2</b> are isostructural with a trinuclear pattern, and <b>3</b> exhibits a binuclear structure. Comparison of the structural differences between <b>1</b>/<b>2</b> and <b>3</b> suggests that the identity of metal plays an important role in construction of such complexes. The magnetic properties of <b>1</b> are discussed. Moreover, <b>2</b> and <b>3</b> are both photoluminescent materials, and their emission properties are closely related to their corresponding Ln^III centers.</p