Redetermination of diaqua­tetra­kis­(dimethyl­formamide-κO)magnesium dichloride

The crystal structure of the title compound, [Mg(C3H7NO)4(H2O)2]Cl2, in which the Mg ion lies on a crystallographic inversion centre, confirms that of the previous room-temperature study [Pavanello et al. (1995 ▶). Main Group Met. Chem. 18, 9–19]. This redetermination at 113 K has improved geometry precision by almost an order of magnitude [e.g. Mg—O(w) (w = water) distances = 2.094 (4) and 2.0899 (7) Å in the old and new structures, respectively] and allowed the water H atoms to be located and their positions refined. In the crystal, O—H⋯Cl hydrogen bonds between the two aqua ligands of the complex mol­ecule and neighboring chloride counter-anions generate supra­molecular chains propagating along [010]. The dicationic [Mg(DMF)4(H2O)2] unit (DMF is dimethyl­formamide) adopts a slightly distorted octa­hedral geometry in which the Mg atom is coordinated by four DMF O atoms in a pseudo-tetra­gonal arrangement and two trans aqua ligands

1,3,5,7-Tetrakis(tetrazol-5-yl)-adamantane: the smallest tetrahedral tetrazole-functionalized ligand and its complexes formed by reaction with anhydrous M(II)Cl-2 (M = Mn, Cu, Zn, Cd)

1,3,5,7-Tetrakis(tetrazol-5-yl)-adamantane (H4L) was probed as a building block for the synthesis of tetrazolato/halido coordination polymers with open-network structures. MCl2 (M = Cu, Cd, Zn, Mn) was reacted with H4L in DMF at 70 degrees C to yield Cu4Cl4L(DMF)(5)]center dot DMF, 1; Cd4Cl4L(DMF)(7)]center dot DMF, 2; Zn3Cl2L(DMF)(4)]center dot 2DMF, 3 and Mn2L(DMF)(2)(MeOH)(4)]center dot DMF center dot 2MeOH center dot 2H(2)O, 4.1 and 2 (Fddd) are nearly isostructural and have zeolitic structures with a {4(3).6(2).8}, gis or gismondine underlying net, where the rote of the tetrahedral nodes is served by the coordination bonded clusters and the adamantane moiety. 3 (P2(1)/n) has a porous structure composed of coordination bonded layers with a (4.8(2)) fes topology joined via trans-{Zn(tetrazolate)(2)(DMF)(4)) pillars with an overall topology of {4.6(2)}{4.6(6).8(3)}, fsc-3,5-Cmce-2. 4 (Pca2(1)) is composed of stacked (Mn2L) hexagonal networks. In 1 and 2 the ligand fulfills a symmetric role of a tetrahedral building block, while in 3 and 4 it fulfills rather a role of an effective trigonal unit. Methanol-exchanged and activated 1 displayed an unusual type IV isotherm with H2 type hysteresis for N-2 sorption with an expected uptake at high P/P-0, but with a smaller S-BET = 505.5 m(2) g(-1) compared to the calculated 1789 m(2) g(-1), which is a possible result of the framework's flexibility. For H-2 sorption 0.79 wt% (1 bar, 77 K) and 0.06 wt% (1 bar, RT) uptake and Q(st) = -7.2 kJ mol(-1) heat of adsorption (77 K) were recorded. Weak antiferromagnetic interactions were found in 1 and 4 with J(1) = -9.60(1), J(2) = -17.2(2), J(3) = -2.28(10) cm(-1) and J = -0.76 cm(-1) respectively. The formation of zeolitic structures in 1 and 2, the concept of structural `imprinting' of rigid building blocks, and design opportunities suggested 4 as a potential hexafunctionalized biadamantane building block

Novel coordination frameworks incorporating the 4,4’-bipyrazolyl ditopic ligand

The reaction of the rigid spacer 4,4′-bipyrazole (H2BPZ) with late transition metals, either following conventional routes or under solvothermal conditions, afforded the coordination polymers [M(BPZ)]·Solv (M = Zn,1; Co, 2; Cd, 3; Hg, 4; Cu,5; Ni, 6; Pd, 7; Solv = DMF, 3; MeCN, 5 and 6; H2O, 7), [Cu(H2BPZ)2(NO3)2 ](8), and [Cd(H2BPZ)(CH3COO)2] (9). State-of-the-art laboratory powder diffraction methods allowed to disclose the isomorphous character of 1 and 2 , as well as of 5 and 6, which feature 3D porous networks containing 1D channels of square and rhombic shape, respectively. 3, crystallizing in the relatively rare P6122 space group, consists of homochiral helices of octahedral Cd(II) ions, packing in bundles mutually linked by “radial”, nonplanar BPZ(2-) ligands. Finally, the dense species 8 and 9 contain parallel 2D layers of square and rectangular meshes, respectively. Thermogravimetric analyses witnessed the relevant thermal robustness of all the [M(BPZ)] materials [except the mercury(II) derivative], which are stable in air at least up to 300°C, with the zinc(II) derivative decomposing only around 450 °C. Variable-temperature powder diffraction experiments highlighted the permanent porosity of 1−3, 5, and 6, retained along consecutive temperature cycles in all cases but3. When probed with N2 at 77 K,1−3 and 5−7 showed Brunauer−Emmett− Teller and Langmuir specific surface areas in the ranges 314(2)−993(11) and 509(16)−1105(1) m2/g, respectively

10-Vertex closo-carborane: a unique ligand platform for porous coordination polymers

1,10-Dicarboxy-1,10-dicarba-closo-decaborane, a classical dicarboxylate spacer ligand type similar to the prototypical terephthalic acid, proved to be different not only from the latter, but also from its closest relative compound, 1,12-dicarboxy-closo-1,12-dicarbadecaborane, with regard to the topology of its derived PCPs. Highly porous and robust compounds of zinc (rob net) and cobalt (‘quasi’ pcu) as well as a topologically unexpected copper compound (lvt) define the individuality of the 10-vertex carborane cage as a new fundamental spacer type in PCP chemistry. A combination of a lower steric demand compared to the 12-vertex analogue, a preferred orientation angle of 45° between the carboxylate planes and a moderately low rotation barrier are held responsible for the uniqueness of the 10-vertex analogue.crosscheck: This document is CrossCheck deposited related_data: Supplementary Information related_data: Crystal Structure Data copyright_licence: The Royal Society of Chemistry has an exclusive publication licence for this journal history: Received 20 December 2015; Accepted 15 February 2016; Accepted Manuscript published 16 February 2016; Advance Article published 1 March 2016; Version of Record published 14 March 2016status: publishe

Pd(/Fe3O4)-on-ZIFs: nanoparticle deposition on (nano-)MOFs from ionic liquids

Well-defined spherical Pd-NPs (similar to 6-12 nm size, 4-17% wt content) were efficiently deposited on nano- or micro- (similar to 100-2500 nm) crystals of zeolite imidazolate frameworks (ZIFs) from different ionic liquids (ILs, typically 1-butyl-3-methylimidazolium bistriflimidate, [BMIm]NTf2) at 180-230 degrees C under microwave (MW) heating for 1-10 min. The firm, nearly exclusive on-surface deposition, proven by systematic analysis of TEM micrographs, is achieved via size-exclusion of the IL-solvated PdCl2 precursor. The one-pot high-quality NP deposition from partially stabilizing IL media leads to particularly well-defined metal nanoparticles-on-metal-organic frameworks, MNP-on-MOF(NP)s. They are contraposed to MNP@MOFs or non-specified MNP/MOFs, and are viewed as an extension of MNPs from ionic liquids, securing MNP-agglomeration protection after removal of the IL and reversible redispersion, and offering the functionality of the porous support. Pd-on-ZIF-8-NP (R = Me substituent of the azole ligand) demonstrated the highest stability and morphological quality, while the ZIF-90 analogues with the same sod topology (R = COOH, CHO, CH2CH2NH2) or the triazolate MAF-66 (R = NH2) with dia topology showed lesser stability (particularly for R = COOH and CHO). Ferromagnetic Pd/Fe3O4- and Fe3O4/Pd-on-ZIF-8-NP, ZIF-90-NH2(-NP), and MAF-66 composites with nanoparticulated Fe3O4 (5-13 nm size, 5-22%(wt) content) demonstrate the feasibility of sequential NP deposition of varied nature. The Pd-on-ZIF composites demonstrated high catalytic activity in the reduction of 4-nitrophenol to 4-aminophenol by NaBH4 in water (TOF 0.38-4.10 vs. 0.088 s(-1) for 10%(wt) Pd/C; amino-functionalization and the presence of Fe3O4 are a major and a minor factor, respectively). The reduction of the same substrate with H-2 in apolar media was much slower for the composite catalysts compared to Pd/C (10%(wt)) due to possible poisoning by the residual IL

Novel Coordination Frameworks Incorporating the 4,4′-Bipyrazolyl Ditopic Ligand

The reaction of the rigid spacer 4,4′-bipyrazole (H₂BPZ) with late transition metals, either following conventional routes or under solvothermal conditions, afforded the coordination polymers [M­(BPZ)]·Solv (M = Zn, <b>1</b>; Co, <b>2</b>; Cd, <b>3</b>; Hg, <b>4</b>; Cu, <b>5</b>; Ni, <b>6</b>; Pd, <b>7</b>; Solv = DMF, <b>3</b>; MeCN, <b>5</b> and <b>6</b>; H₂O, <b>7</b>), [Cu­(H₂BPZ)₂(NO₃)₂] (<b>8</b>), and [Cd­(H₂BPZ)­(CH₃COO)₂] (<b>9</b>). State-of-the-art laboratory powder diffraction methods allowed to disclose the isomorphous character of <b>1</b> and <b>2</b>, as well as of <b>5</b> and <b>6</b>, which feature 3D porous networks containing 1D channels of square and rhombic shape, respectively. <b>3</b>, crystallizing in the relatively rare <i>P</i>6₁22 space group, consists of homochiral helices of octahedral Cd^II ions, packing in bundles mutually linked by “radial”, nonplanar BPZ ligands. Finally, the dense species <b>8</b> and <b>9</b> contain parallel 2D layers of square and rectangular meshes, respectively. Thermogravimetric analyses witnessed the relevant thermal robustness of all the [M­(BPZ)] materials [except the mercury­(II) derivative], which are stable in air at least up to 300 °C, with the zinc­(II) derivative decomposing only around 450 °C. Variable-temperature powder diffraction experiments highlighted the permanent porosity of <b>1</b>–<b>3</b>, <b>5</b>, and <b>6</b>, retained along consecutive temperature cycles in all cases but <b>3</b>. When probed with N₂ at 77 K, <b>1</b>–<b>3</b> and <b>5</b>–<b>7</b> showed Brunauer–Emmett–Teller and Langmuir specific surface areas in the ranges 314(2)–993(11) and 509(16)–1105(1) m²/g, respectively

Novel Coordination Frameworks Incorporating the 4,4′-Bipyrazolyl Ditopic Ligand

The reaction of the rigid spacer 4,4′-bipyrazole (H₂BPZ) with late transition metals, either following conventional routes or under solvothermal conditions, afforded the coordination polymers [M­(BPZ)]·Solv (M = Zn, <b>1</b>; Co, <b>2</b>; Cd, <b>3</b>; Hg, <b>4</b>; Cu, <b>5</b>; Ni, <b>6</b>; Pd, <b>7</b>; Solv = DMF, <b>3</b>; MeCN, <b>5</b> and <b>6</b>; H₂O, <b>7</b>), [Cu­(H₂BPZ)₂(NO₃)₂] (<b>8</b>), and [Cd­(H₂BPZ)­(CH₃COO)₂] (<b>9</b>). State-of-the-art laboratory powder diffraction methods allowed to disclose the isomorphous character of <b>1</b> and <b>2</b>, as well as of <b>5</b> and <b>6</b>, which feature 3D porous networks containing 1D channels of square and rhombic shape, respectively. <b>3</b>, crystallizing in the relatively rare <i>P</i>6₁22 space group, consists of homochiral helices of octahedral Cd^II ions, packing in bundles mutually linked by “radial”, nonplanar BPZ ligands. Finally, the dense species <b>8</b> and <b>9</b> contain parallel 2D layers of square and rectangular meshes, respectively. Thermogravimetric analyses witnessed the relevant thermal robustness of all the [M­(BPZ)] materials [except the mercury­(II) derivative], which are stable in air at least up to 300 °C, with the zinc­(II) derivative decomposing only around 450 °C. Variable-temperature powder diffraction experiments highlighted the permanent porosity of <b>1</b>–<b>3</b>, <b>5</b>, and <b>6</b>, retained along consecutive temperature cycles in all cases but <b>3</b>. When probed with N₂ at 77 K, <b>1</b>–<b>3</b> and <b>5</b>–<b>7</b> showed Brunauer–Emmett–Teller and Langmuir specific surface areas in the ranges 314(2)–993(11) and 509(16)–1105(1) m²/g, respectively

Novel Coordination Frameworks Incorporating the 4,4′-Bipyrazolyl Ditopic Ligand

The reaction of the rigid spacer 4,4′-bipyrazole (H₂BPZ) with late transition metals, either following conventional routes or under solvothermal conditions, afforded the coordination polymers [M­(BPZ)]·Solv (M = Zn, <b>1</b>; Co, <b>2</b>; Cd, <b>3</b>; Hg, <b>4</b>; Cu, <b>5</b>; Ni, <b>6</b>; Pd, <b>7</b>; Solv = DMF, <b>3</b>; MeCN, <b>5</b> and <b>6</b>; H₂O, <b>7</b>), [Cu­(H₂BPZ)₂(NO₃)₂] (<b>8</b>), and [Cd­(H₂BPZ)­(CH₃COO)₂] (<b>9</b>). State-of-the-art laboratory powder diffraction methods allowed to disclose the isomorphous character of <b>1</b> and <b>2</b>, as well as of <b>5</b> and <b>6</b>, which feature 3D porous networks containing 1D channels of square and rhombic shape, respectively. <b>3</b>, crystallizing in the relatively rare <i>P</i>6₁22 space group, consists of homochiral helices of octahedral Cd^II ions, packing in bundles mutually linked by “radial”, nonplanar BPZ ligands. Finally, the dense species <b>8</b> and <b>9</b> contain parallel 2D layers of square and rectangular meshes, respectively. Thermogravimetric analyses witnessed the relevant thermal robustness of all the [M­(BPZ)] materials [except the mercury­(II) derivative], which are stable in air at least up to 300 °C, with the zinc­(II) derivative decomposing only around 450 °C. Variable-temperature powder diffraction experiments highlighted the permanent porosity of <b>1</b>–<b>3</b>, <b>5</b>, and <b>6</b>, retained along consecutive temperature cycles in all cases but <b>3</b>. When probed with N₂ at 77 K, <b>1</b>–<b>3</b> and <b>5</b>–<b>7</b> showed Brunauer–Emmett–Teller and Langmuir specific surface areas in the ranges 314(2)–993(11) and 509(16)–1105(1) m²/g, respectively