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Title: Improved synthesis and crystal structure of the flexible pillared layer porous coordination polymer: Ni(1,2-bis(4-pyridyl)ethylene)[Ni(CN)4]

This paper reports our synthesis of flexible coordination polymer, Ni(L)[Ni(CN)4], (L = 1,2-bis(4-pyridyl)ethylene (nicknamed bpene)), and its structural characterization using synchrotron single crystal X-ray diffraction. The structure of the purplish crystals has been determined to be monoclinic, space group P21/m, a = 13.5941(12) Å, b = 14.3621(12) Å, c = 14.2561(12) Å, β = 96.141(2)°, V = 2767.4(4) Å3, Z = 4, Dc = 1.46 g cm-1. Ni(bpene)[Ni(CN)4] assumes a pillared layer structure with layers defined by Ni[Ni(CN)4]n nets and bpene ligands acting as pillars. With the present crystallization technique which involves the use of concentrated ammonium hydroxide solution and dimethyl sulfoxide (DMSO), disordered free bpene ligands and solvents of crystallization (DMSO and water molecules) occupy the pores, resulting in a formula of Ni(bpene)[Ni(CN)4](1/2)bpene∙DMSO2H2O, or Ni2N7C24H25SO3. Without the inclusion of free bpene ligands and solvent molecules, the free volume is approximately 61% of the total volume; this free volume fraction is reduced to 50% with the free ligands present. Pores without the free ligands were found to have a local diameter of 5.7 Å and a main aperture of 3.5 Å. Based on the successful crystal synthesis, we also devised a new bulk synthetic technique which yielded a polycrystalline materialmore » with a significantly improved CO2 uptake as compared to the originally reported powder material. The improved synthetic technique yielded a polycrystalline material with 40% higher CO2 uptake compared to the previously reported powder material. An estimated 14.4 molecules of CO2 per unit cell was obtained.« less
 [1] ;  [2] ;  [3] ;  [4] ;  [1] ;  [1] ;  [1] ;  [3] ;  [5]
  1. National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States). Material Measurement Lab.
  2. National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States). URS Corp., South Park, PA (United States)
  3. Univ. of Chicago, IL (United States). ChemMatCARS
  4. Univ. of Maryland, College Park, MD (United States). Dept. of Chemistry and Biochemistry
  5. National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 1466-8033; CRECF4
Grant/Contract Number:
Accepted Manuscript
Journal Name:
CrystEngComm (Online)
Additional Journal Information:
Journal Name: CrystEngComm (Online); Journal Volume: 15; Journal Issue: 23; Journal ID: ISSN 1466-8033
Royal Society of Chemistry
Research Org:
Brown Univ., Providence, RI (United States). Dept. of Chemistry
Sponsoring Org:
USDOE Office of Fossil Energy (FE)
Country of Publication:
United States
36 MATERIALS SCIENCE; pillar layered solids, flexible metal organic framework, structurally dynamic, flexible porous coordination polymer, CO2 capture, spin crossover, Hofmann compound, Suzuki coupling
OSTI Identifier: