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The crystal structure of the title compound, hexaaquanickel(II) dichloride–1,4,7,10,13,16-hexaoxacyclooctadecane–water (1/2/2), [Ni(H2O)6]Cl2·2C12H24O6·2H2O, is reported. The asymmetric unit contains half of the Ni(OH2)6moiety with a formula of C12H32ClNi0.50O10at 105 K and triclinic (P1) symmetry. The [Ni(OH2)6]2+cation has close to ideal octahedral geometry with O—Ni—O bond angles that are within 3° of idealized values. The supramolecular structure includes hydrogen bonding between the water ligands, 18-crown-6 molecules, Cl−anions, and co-crystallized water solvent. Two crown ether molecules flank the [Ni(OH2)6]2+molecule at the axial positions in a sandwich-like structure. The relatively symmetric hydrogen-bonding network is enabled by small Cl−counter-ions and likely influences the more idealized octahedral geometry of [Ni(OH2)6]2+.
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Iron Vanadates Synthesized from Hydrothermal Brines: Rb 2 FeV 6 O 16 , Cs 2 FeV 6 O 16 , and SrFe 3 V 18 O 38
- Award ID(s):
- 1808371
- PAR ID:
- 10215112
- Date Published:
- Journal Name:
- European Journal of Inorganic Chemistry
- Volume:
- 2019
- Issue:
- 42
- ISSN:
- 1434-1948
- Page Range / eLocation ID:
- 4538 to 4545
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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null (Ed.)We report the hydrothermal syntheses and crystal structures of aquabis(2,2′-bipyridine-κ 2 N , N ′)copper(II) hexafluoridosilicate tetrahydrate, [Cu(bpy) 2 (H 2 O)][SiF 6 ]·4H 2 O (bpy is 2,2′-bipyridine, C 10 H 8 N 2 ), (I), bis(2,2′-bipyridine-3κ 2 N , N ′)-di-μ-fluorido-1:3κ 2 F : F ;2:3κ 2 F : F -decafluorido-1κ 5 F ,2κ 5 F -ditantalum(V)copper(II), [Cu(bpy) 2 (TaF 6 ) 2 ], (II), tris(2,2′-bipyridine-κ 2 N , N ′)copper(II) bis[hexafluoridotantalate(V)], [Cu(bpy) 3 ][TaF 6 ] 2 , (III), and catena -poly[[diaqua(2,2′-bipyridine-κ 2 N , N ′)copper(II)]-μ-fluorido-tetrafluoridotin-μ-fluorido], [Cu(bpy)(H 2 O) 2 SnF 6 ] n , (IV). Compounds (I), (II) and (III) contain locally chiral copper coordination complexes with C 2 , D 2 , and D 3 symmetry, respectively. The extended structures of (I) and (IV) are consolidated by O—H...F and O—H...O hydrogen bonds. The structure of (III) was found to be a merohedral (racemic) twin.more » « less
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Abstract A simple optical model (OPM) method using non-monotonic (NM) potentials characterized by a repulsive core from the microscopic theory of the Pauli-led energy-density functional (EDF) has been developed to investigate the16O+16O fusion at sub-Coulomb energies relevant to the oxygen burning. The study involves the analysis of the experimental fusion cross-section (FCS) data in energy range 6.92 ≤Ecm≤ 13.83 MeV, which includes the Coulomb barrier regionEcm= 10.0–11.92 MeV. Apart from an excellent description of the existing FCS data in the studied energy range, the associated hindrance, characterized by theS-factor reaching a maximum and then gradually falling off at lower energies, so far suggested empirically for the system, is reproduced down to 4 MeV for the first time in the simple OPM. AnS-factor maximum ofS0 = 3.15 × 1025MeV.b atE0 = 7.14 MeV is observed withT ≃ 2.6 GK, which conforms to the values reported for quiescent and explosive burning. Our reaction rate, deduced from the NM potential, compares well with the Caughlan and Fowler data. Dominant partial waves implicit in the observed maximumS-factor in the studied Gamow range are also explored. Our present findings, with the success of NM potentials, suggest thatthe nucleus–nucleus potential is non-monotonic.more » « less
- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1002/ejic.201900799
