Sophisticated Analytical Instrument Facility

NUCLEAR MAGNETIC RESONANCE SPECTROMETER

         Instrument Details
Make : VARIAN, USA
Model : Mercury Plus 300MHz NMR SPECTROMETER
Specification : 5mm Autoswitchable probe with PFG (1H/ 13C/ 31P/ 19F)
  5mm Dual Broad Band probe with PFG for Multinuclear NMR (13C, 15N,
  27Al, 31P, 29Si, 77Se, 119Sn, 125Te, 199Hg, 51V, 7Li etc.)


        Nuclei with non-zero spins, when placed in a strong magnetic field precess at specific orientations with respect to the applied magnetic field. When appropriate energy is supplied in the form of radio frequency, these nuclei flip to a higher energy state. The energy absorbed during this transition is a function of nucleus type and its chemical environment in the molecule The excited nuclei are allowed to precess freely and come back to their equilibrium positions. During this process an electric signal is induced in a suitably placed RF coil. This signal which is monitored with respect to time is called free induction decay (FID). The FID, which is in time domain gives its equivalent frequency domain signal on Fourier transformation. A plot of the absorption frequency versus the intensity of the absorption constitutes the NMR spectrum.


WORKING PRINCIPLE :

                 
        




MAIN FEATURES OF THE INSTRUMENT :
          MAKE : VARIAN, USA.
          MODEL : Mercury Plus 300 NMR SPECTROMETER.
          Specification : 5mm multinuclear probes for solution studies. Multi nuclear CP-MAS probe for solids application.
         VT Accessory: Variable temperature facility is available from -80 degree to +130 degree with suitable solvent.
         The NMR Probe is switch-able between high frequency range (1H, 19F) and broad band frequency range (13C, 15N,
            27Al, 31P,29Si, 77Se, 119Sn, 125Te etc.).
         In case of solids, only broad band frequency range is available and the sample can be spun up to a maximum of 5KHz
             at the magic angle.
          High power decoupling in case of solids is limited to a power of 100 W.
          Total spectral width is limited to 100 KHz.

APPLICATIONS :


        Major application of NMR spectroscopy lies in the area of synthetic organic chemistry, inorganic chemistry, bio-organic chemistry, bio-inorganic chemistry, polymer chemistry and organometallic chemistry.One of the main advantages of FT-NMR spectroscopy is that a number of FIDs can be accumulated and Fourier transformed, enhancing S/N ratio of the spectrum. This in turn facilitates the analysis of samples with low abundant nuclei and smaller gyro-magnetic ratios, e.g.,13C, 29Si, 15N etc. Another major advantage of pulse NMR is that by suitably programming, a variety of pulse sequences can be generated and applied to obtain diverse information like relaxation times, connectivity through bond and through space etc. Thus, by using FT-NMR it is not only possible to get the information about chemical shift and spin-spin coupling but also possible to deduce the conformational structural information of a particular molecule.


NMR studies find applications in :
           Molecular conformation in solution
           Quantitative analysis of mixtures containing known compounds
           Determining the content and purity of a sample
           Through space connectivity (overhauser effect)
           Chemical dynamics (Lineshapes, relaxation phenomena)
           Solid State NMR is widely popular for the characterization of polymers, rubbers, ceramics, glasses
              and molecular sieves.


USER INSTRUCTIONS :
        1. Users are advised to provide 10-20 mg of sample depending upon its molecular weight for obtaining high resolution proton NMR spectra.
        2. The sample should be completely soluble in 0.6 cc of the given solvent.
        3. For 13C at least 30 mg of sample is necessary for obtaining spectra with reasonable signal / noise ratio. However, higher amount of sample helps in reducing data acquisition time which in turn leads to reduction of analysis charges.
        4. For MAS-NMR experiments, sample should be in the form of very fine powder (20 microns) and at least 4.0 cc of powder is required.
        5. All external users are required to submit samples accompanied by a letter containing analysis details.
        6. Users from Bombay and its surroundings may contact NMR Laboratory for advance appointments, if so desired.
        7. While requesting for analysis, information on i) type of analysis, ii) solvent and iii) spectral range should be given clearly in the letter.
        8. Users are encouraged to be present during the analysis of their samples. Users who are interested in specialised experiments are advised to contact NMR Laboratory for an appointment. All users are required to acknowledge the use of the facility when the results are published or presented in a symposium / conference. It will be highly appreciated if users send a Xerox copy of such publication/report to the NMR laboratory, SAIF, IIT, Mumbai. 400 076. 9. All samples should accompany material safety data sheets (MSDS).

REFERENCES
         1.Bovey F.A., Jelinski L., Mirau A. `Nuclear Magnetic Resonance Spectroscopy', Academic Press (1988).
         2. Gunthet H. `NMR Spectroscopy - An Introduction', John Wiley & Sons.
         3. Jeremy K.M. Sanders, Brian K. Hunter, `Modern NMR Spectroscopy-A Guide for Chemist' 2nd, edition, Oxford Uni. Press 2002.
         4. Robert M. Silverstein, Francis X. Webster, `Spectrometric Identification of Organic Compounds' 6th, Edition, John Wiley & Sons. 1998.

For NMR charges send mail to office.saif@iitb.ac.in. ( Mails regarding exact charges for NMR will be replied only if number of samples, solvent to be used & type of test (1H , 13C etc) is mentioned. )
Charges   :
             NUCLEAR MAGNETIC RESONANCE SPECTROMETER (NMR) ( Charges includes service tax)
 IndustryUniversityNational Lab/R&D's 
Proton N M R including solvent charges 2809/-562/-1236/-Per Sample
D2O Exchnage 2809/-562/-1236/-Per Sample
13C & other X nuclei & 2D N M R or Special 1D N M R experiments, solid state NMR 5056/-955/-2247/-First Hour
13C & other X nuclei & 2D N M R or Special 1D N M R experiments, solid state NMR 3596/-674/-1686/-For Subsequent hour
Di-Methyl Formamide (DMF) 1686/-1686/-1686/-Per Sample


Contact: 022-25764686 /4663                      Email Id: nmagadi@iitb.ac.in

Sophisticated Analytical Instrument Facility,
IIT-Bombay, Powai, Mumbai-400 076

Tel : 022-25767691/2     Website : http://www.rsic.iitb.ac.in
Fax : 0091-22-25723314     Email : office.saif@iitb.ac.in