111 research outputs found
Germanates Built from Ge<sub>10</sub>(O, OH)<sub>27−28</sub> and Ge<sub>7</sub>(O, OH, F)<sub>19</sub> Secondary Building Units: From Systematic Study of Reported Compounds to Rational Design of Novel Structures
No full textDesign of novel porous compounds is one of the fastest-growing fields of materials chemistry due to the broad range of application including catalysis, adsorption, and separation. Open-framework germanates have shown large structure diversity and can form structures with extra-large pores. A systematic study of the structural features of the reported germanates is a key for the design of novel porous germanates. In this work, the topological study and classification of all known germanates that are built form Ge(10)(O, OH)(27-28) (Ge(10)) or Ge(7)(O, OH, F)(19) (Ge(7)) secondary building units, has been undertaken. We have demonstrated that the combination of topological technique and data mining provides a new insights into structural chemistry of a group of compounds. We proposed an efficient and general strategy for prediction of novel structures in germanates and other chemical systems.</p
SU-62: Synthesis and Structure Investigation of a Germanate with a Novel Three-Dimensional Net and Interconnected 10- and 14-Ring Channels
No full textA novel 3D open-framework germanate, vertical bar N(2)C(4)H(14)vertical bar(4) [Ge(20)O(41)(OH)(6)]center dot 3H(2)O (SU-62), was prepared from hydrothermal synthesis using 1,4-diaminobutane as the organic structure directing agent (SDA). The crystal structure was solved by single crystal X-ray diffraction. The framework is built from Ge(10)(O,OH)(27) (Ge(10)) secondary building units and exhibits an irregular three-dimensional channel system encircled by 10- and 14-rings. The framework of SU-62 has an underlying topology that follows a novel five-coordinated svh-5-I4(1)/amd net, while the pores follow the tsi net. The thermal behavior of SU-62 was studied by thermogravimetric (TG) analysis and in situ X-ray diffraction (XRPD). Crystallographic data: orthorhombic, space group Fdd2, unit cell parameters a = 15.297(3) angstrom, b = 53.58(1) angstrom, c = 14.422(3) angstrom, V = 11821(4) angstrom(3), Z = 8.</p
Germanates Built from Ge<sub>10</sub>(O, OH)<sub>27−28</sub> and Ge<sub>7</sub>(O, OH, F)<sub>19</sub> Secondary Building Units: From Systematic Study of Reported Compounds to Rational Design of Novel Structures
No full textDesign of novel porous compounds is one of the fastest-growing fields of materials chemistry due to the broad range of applications including catalysis, adsorption, and separation. Open-framework germanates have shown large structure diversity and can form structures with extra-large pores. A systematic study of the structural features of the reported germanates is a key for the design of novel porous germanates. In this work, the topological study and classification of all known germanates that are built from Ge10(O, OH)27−28 (Ge10) or Ge7(O, OH, F)19 (Ge7) secondary building units, has been undertaken. We have demonstrated that the combination of topological technique and data mining provides new insights into structural chemistry of a group of compounds. We proposed an efficient and general strategy for prediction of novel structures in germanates and other chemical systems
Germanates Built from Ge<sub>10</sub>(O, OH)<sub>27−28</sub> and Ge<sub>7</sub>(O, OH, F)<sub>19</sub> Secondary Building Units: From Systematic Study of Reported Compounds to Rational Design of Novel Structures
No full textDesign of novel porous compounds is one of the fastest-growing fields of materials chemistry due to the broad range of applications including catalysis, adsorption, and separation. Open-framework germanates have shown large structure diversity and can form structures with extra-large pores. A systematic study of the structural features of the reported germanates is a key for the design of novel porous germanates. In this work, the topological study and classification of all known germanates that are built from Ge10(O, OH)27−28 (Ge10) or Ge7(O, OH, F)19 (Ge7) secondary building units, has been undertaken. We have demonstrated that the combination of topological technique and data mining provides new insights into structural chemistry of a group of compounds. We proposed an efficient and general strategy for prediction of novel structures in germanates and other chemical systems
Two open-framework germanates with nickel complexes incorporated into the framework.
No full textTwo open-framework germanates, SUT-1 and SUT-2, have been synthesized under hydrothermal conditions using ethylenediamine (en, H(2)NCH(2)CH(2)NH(2)) as templates and Ni(NO(3))(2)·6H(2)O as the transition-metal source. Their frameworks are built with Ge(10) clusters and [Ni(en)(2)](2+) complexes. In both structures, Ge(10) clusters form square nets in the a-c plane, while the [Ni(en)(2)](2+) complexes bridge the square nets via Ni-O-Ge bonds to form 3D networks. They present the first examples to incorporate Ni(2+) complexes into the germanate frameworks. In SUT-2, additional linkages by Ge(2)O(7) clusters between the square nets generate a new type of topology
A series of isostructural mesoporous metal-organic frameworks obtained by ion-exchange induced single-crystal to single-crystal transformation
No full textA series of metal-organic frameworks representing a non-interpenetrated framework analogue of MOF-14 have been synthesized by using two different linkers, 4,4',4 ''-benzene-1,3,5-triyl-benzoic acid (H3BTB) and 4,4'-bipyridine (Bpy). Interestingly, the transition metal ions in the paddle-wheel metal clusters could be exchanged by other transition metal ions via a direct single-crystal to single-crystal transformation. This post-synthesis route can be used for synthesis of isomorphous metal-organic frameworks that cannot be obtained by direct synthesis.Chemistry, Inorganic & NuclearSCI(E)EI50ARTICLE143953-39554
Computational Tuning of the Paddlewheel tcb-MOF Family for Advanced Methane Sorption
No full textA series
of metal–organic frameworks (MOFs) with tcb net
topology and linkers of increasing size (combining triple bonds
and benzene rings) is computationally designed using molecular mechanics
and density functional theory. By grand canonical Monte Carlo simulations,
we identify MOFs with outstanding methane total uptakes and working
capacities, satisfying the targets of the U.S. Department of Energy
for automobile applications in cold weather regions (50 wt %, 263
cm3(STP)cm–3). For example, the 5B MOF achieves at 298 K working capacities of 52.2 wt % at
5–65 bar and 61.9 wt % at 5–80 bar. The 3B MOF exhibits at 298 K the most balanced (gravimetric versus volumetric)
total uptake and working capacity in the family of tcb-MOFs: 28.4 wt %, 160.9 cm3(STP)cm–3 at 35 bar and 23.0 wt %, 130.3 cm3(STP)cm–3 at 5–35 bar (exceeding the benchmarks of IRMOF-6, PCN-14,
Ni-MOF-74, Al-soc-MOF-1, MOF-5, MOF-205), 38.4 wt %,
218.0 cm3(STP)cm–3 at 65 bar and 33.0
wt %, 187.5 cm3(STP)cm–3 at 5–65
bar (exceeding the benchmarks of IRMOF-6, PCN-14, Ni-MOF-74, HKUST-1,
NU-111, NOTT-101a), 41.6 wt %, 235.9 cm3(STP)cm–3 at 80 bar and 36.2 wt %, 205.3 cm3(STP)cm–3 at 5–80 bar (exceeding the benchmarks of Ni-MOF-74, MOF-5,
MOF-205, HKUST-1)
Complex open-framework germanate built by 8-coordinated Ge 10 clusters
No full textA novel open-framework germanate |(C 5H 14N 2) 2(C 5H 12N 2) 0.5(H 2O) 2.5|[Ge 12.5O 26(OH) 2] with three-dimensional 10- and 11-ring channels, denoted as SU-67, has been synthesized under hydrothermal conditions using 2-methylpiperazine (MPP) as the structure-directing agent (SDA). The synthesis is intimately related to that of JLG-5, a tubular germanate built from Ge 7 clusters. The influences of synthesis parameters are discussed. A strong influence of the hydrofluoric acid quantity on the resulting cluster building units can be concluded. The framework of SU-67 is based on an elaborate topological pattern of connected Ge 10 clusters forming intersecting 10- and 11-ring channels and has a low framework density (12.4 Ge atoms per 1000 ̊ 3). We have discovered that the topology of SU-67 is a new 8-connected nce-8-I4 1/acd net. Strong hydrogen bonding among the organic SDAs, water molecules, and Ge 10 clusters resulted in helical networks in SU-67. © 2012 American Chemical Society.The project is supported by the Swedish Research Council (VR), the Swedish Governmental Agency for Innovation Systems (VINNOVA), and the Goran Gustafsson Foundation for Natural Sciences and Medical Research. H.Y. and M.V.P. were supported by postdoctoral grants from the Wenner-Gren Foundations
SU-62: Synthesis and Structure Investigation of a Germanate with a Novel Three-Dimensional Net and Interconnected 10- and 14-Ring Channels
No full textA novel 3D open-framework germanate, |N2C4H14|4 [Ge20O41(OH)6]·3H2O (SU-62), was prepared from
hydrothermal
synthesis using 1,4-diaminobutane as the organic structure directing
agent (SDA). The crystal structure was solved by single crystal X-ray
diffraction. The framework is built from Ge10(O,OH)27 (Ge10) secondary building units and exhibits
an irregular three-dimensional channel system encircled by 10- and
14-rings. The framework of SU-62 has an underlying topology that follows
a novel five-coordinated svh-5-I41/amd net, while the pores follow the tsi net. The thermal behavior of SU-62 was studied by thermogravimetric
(TG) analysis and in situ X-ray diffraction (XRPD).
Crystallographic data: orthorhombic, space group Fdd2, unit cell parameters a = 15.297(3) Å, b = 53.58(1) Å, c = 14.422(3) Å, V = 11821(4) Å3, Z = 8
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