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Volumn 26, Issue 15, 2007, Pages 3624-3626

Combining diffusion NMR and conductometric measurements to evaluate the hydrodynamic volume of ions and ion pairs

Author keywords

[No Author keywords available]

Indexed keywords

HYDRODYNAMICS; NUCLEAR MAGNETIC RESONANCE;

EID: 34547433091     PISSN: 02767333     EISSN: None     Source Type: Journal    
DOI: 10.1021/om700415f     Document Type: Article
Times cited : (29)

References (42)
  • 2
    • 34547396949 scopus 로고    scopus 로고
    • W. S. Concepts Magn. Reson. 1997, 9, 299.
    • W. S. Concepts Magn. Reson. 1997, 9, 299.
  • 23
    • 33748631532 scopus 로고    scopus 로고
    • All the PGSE NMR measurements were performed by using the standard stimulated echo pulse sequence on a Bruker AVANCE DRX 400 spectrometer, equipped with a GREAT 1/10 gradient unit and a QNP probe with a Z-gradient coil, at 296 K without spinning. Dt was determined exploiting its proportionality to the slope of the regression line obtained by plotting log(I/Io) vs G2 (Supporting Information, The proportionality constant was measured by using a sample of HDO (5, in D2O (known diffusion coefficient in the range 274-318 K, According to the Stokes-Einstein equation Dt, kT/cπηrH (where k is the Boltzman constant, T is the temperature, c is a numerical factor, and η is the fluid viscosity, cstrHst/csarHsa was obtained by measuring the Dtsa/Dtst ratio of the sample (sa) and TMSS internal standard, st, Knowing cstr
    • sa was simply derived by assuming a spherical shape of ions and ion pairs.
  • 24
    • 34547472581 scopus 로고    scopus 로고
    • Conductivity measurements were carried out at 40 Hz and 1 kHz using a digital bridge-type conductivity meter (Amel srl, model 160) with a microprobe (model 401/S111) having a cell constant of 0.203 ± 0.001 cm (measured using standard KCl solutions of known specific conductivity). The microprobe was specifically manufactured for our aims in order to fit perfectly into a typical NMR tube (diameter of 5 mm and length of 228.6 mm). It has a diameter of 3.0 mm and a length of 157 mm (Supporting Information) and allowed measurements to be carried out on 0.6 mL of solution. The temperature was held constant at 25.00 ± 0.01°C using a ThermoHaake C75P thermostat.
    • Conductivity measurements were carried out at 40 Hz and 1 kHz using a digital bridge-type conductivity meter (Amel srl, model 160) with a microprobe (model 401/S111) having a cell constant of 0.203 ± 0.001 cm (measured using standard KCl solutions of known specific conductivity). The microprobe was specifically manufactured for our aims in order to fit perfectly into a typical NMR tube (diameter of 5 mm and length of 228.6 mm). It has a diameter of 3.0 mm and a length of 157 mm (Supporting Information) and allowed measurements to be carried out on 0.6 mL of solution. The temperature was held constant at 25.00 ± 0.01°C using a ThermoHaake C75P thermostat.
  • 26
    • 34547466703 scopus 로고    scopus 로고
    • From X-ray single crystal studies, VvdW and rvdW of PF6- are found equal to 60.4 Å3 and 2.43 Å, respectively. VH0 and rH0 for other ions are as follows:6 I, 504 Å3 and 4.93 Å; BPh4, 432 Å3 and 4.69 Å; BArF, 809 Å3 and 5.78 Å. VH0+ for 2, 384 Å3) was measured in this paper by performing PGSE experiments for a diluted solution of 2BArF in CD2Cl2 Supporting Information
    • 2 (Supporting Information).
  • 27
    • 34547451147 scopus 로고    scopus 로고
    • 6
    • 6
  • 34
    • 21844453195 scopus 로고    scopus 로고
    • and references therein
    • Macchioni, A. Chem. Rev. 2005, 105, 2039, and references therein.
    • (2005) Chem. Rev , vol.105 , pp. 2039
    • Macchioni, A.1


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.