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Title: Crystalline hydrogen-bonded nanocolumns of cyclic thiourea octamers

Abstract

A bis(thiourea) containing the 1,3-dimethyl-adamantane linker and t-Bu end groups self-assembles in the solid state into crystalline columnar aggregates made of hydrogen-bonded cyclic thiourea octamers with 2 nm diameters.

Authors:
 [1];  [1];  [1]
  1. ORNL
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
932002
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: CrystEngComm; Journal Volume: 9
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 77 NANOSCIENCE AND NANOTECHNOLOGY; THIOUREA; NANOSTRUCTURES; CRYSTAL GROWTH; HYDROGEN; CHEMICAL BONDS

Citation Formats

Custelcean, Radu, Engle, Nancy L, and Bonnesen, Peter V. Crystalline hydrogen-bonded nanocolumns of cyclic thiourea octamers. United States: N. p., 2007. Web. doi:10.1039/b701570d.
Custelcean, Radu, Engle, Nancy L, & Bonnesen, Peter V. Crystalline hydrogen-bonded nanocolumns of cyclic thiourea octamers. United States. doi:10.1039/b701570d.
Custelcean, Radu, Engle, Nancy L, and Bonnesen, Peter V. Mon . "Crystalline hydrogen-bonded nanocolumns of cyclic thiourea octamers". United States. doi:10.1039/b701570d.
@article{osti_932002,
title = {Crystalline hydrogen-bonded nanocolumns of cyclic thiourea octamers},
author = {Custelcean, Radu and Engle, Nancy L and Bonnesen, Peter V},
abstractNote = {A bis(thiourea) containing the 1,3-dimethyl-adamantane linker and t-Bu end groups self-assembles in the solid state into crystalline columnar aggregates made of hydrogen-bonded cyclic thiourea octamers with 2 nm diameters.},
doi = {10.1039/b701570d},
journal = {CrystEngComm},
number = ,
volume = 9,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • No abstract prepared.
  • A stable framework has been constructed through multiple charge-assisted H-bonds between cationic coordination cages and chloride ions. The framework maintained its original structure upon desolvation, which has been established by single-crystal structure analysis. This is the first fully characterized stable porous framework based on coordination cages after desolvation, with a moderately high Brunauer–Emmett–Teller (BET) surface area of 1201 m2 g-1. This work will not only give a light to construct stable porous frameworks based on coordination cages and thus broaden their applications, but will also provide a new avenue to the assembly of other porous materials such as porous organicmore » cages and hydrogen-bonded organic frameworks (HOFs) through non covalent bonds.« less
  • The influence of the average column pressure (ACP) on the elution volume of thiourea was measured on two RPLC columns, packed with Resolve-C{sub 18} (surface coverage 2.45 {micro} mol/m{sup 2}) and Symmetry-C{sub 18} (surface coverage 3.18 {micro} mol/m{sup 2}), and it was compared to that measured under the same conditions on an underivatized silica (Resolve). Five different methanol-water mixtures (20, 40, 60, 80 and 100% methanol, v/v) were used. Once corrected for the compressibility of the mobile phase, the data show that the elution volume of thiourea increases between 3 and 7% on the C{sub 18}-bonded columns when the ACPmore » increases from 50 to 350 bar, depending on the methanol content of the eluent. No such increase is observed on the underivatized Resolve silica column. This increase is too large to be ascribed to the compressibility of the stationary phase (silica + C{sub 18} bonded chains) which accounts for less than 5% of the variation of the retention factor. It is shown that the reason for this effect is of thermodynamic origin, the difference between the partial molar volume of the solute in the stationary and the mobile phase, {Delta}V, controlling the retention volume of thiourea. While {Delta}V is nearly constant for all mobile phase compositions on Resolve silica (with {Delta}V {approx_equal} -4 mL/mol), on RPLC phases, it significantly increases with increasing methanol content, particularly above 60% methanol. It varies between - 5 mL/mol and - 17 mL/mol on Resolve-C{sub 18} and between - 9 mL/mol and - 25 mL/mol on Symmetry-C{sub 18}. The difference in surface coverage between these two RP-HPLC stationary phases increases the values of {Delta}V by about 5 mL/mol.« less
  • The influence of the average column pressure (ACP) on the elution volume of thiourea was measured on two RPLC columns, packed with Resolve-C{sub 18} (surface coverage 2.45 {micro} mol/m{sup 2}) and Symmetry-C{sub 18} (surface coverage 3.18 {micro} mol/m{sup 2}), and it was compared to that measured under the same conditions on an underivatized silica (Resolve). Five different methanol-water mixtures (20, 40, 60, 80 and 100% methanol, v/v) were used. Once corrected for the compressibility of the mobile phase, the data show that the elution volume of thiourea increases between 3 and 7% on the C{sub 18}-bonded columns when the ACPmore » increases from 50 to 350 bar, depending on the methanol content of the eluent. No such increase is observed on the underivatized Resolve silica column. This increase is too large to be ascribed to the compressibility of the stationary phase (silica + C{sub 18} bonded chains) which accounts for less than 5% of the variation of the retention factor. It is shown that the reason for this effect is of thermodynamic origin, the difference between the partial molar volume of the solute in the stationary and the mobile phase, {Delta}V, controlling the retention volume of thiourea. While {Delta}V is nearly constant for all mobile phase compositions on Resolve silica (with {approx_equal} -4 mL/mol), on RPLC phases, it significantly increases with increasing methanol content, particularly above 60% methanol. It varies between -5 mL/mol and -17 mL/mol on Resolve-C{sub 18} and between -9 mL/mol and -25 mL/mol on Symmetry-C{sub 18}. The difference in surface coverage between these two RP-HPLC stationary phases increases the values of {Delta}V by about 5 mL/mol.« less