Category
- Spectroscopy and Spectrometry » NMR Spectroscopy
Booking Details
Facility Management Team and Location
Facility Features, Working Principle and Specifications
This facility enables the recording and analysis of a number of conventional 1D and 2D NMR experiments for liquid organic/inorganic small molecule samples as well as 3D measurements for protonated and isotopically labelled biomolecules, below ~15 kilodaltons. These experiments are vital for identification, assignment and structural/dynamic characterization of a wide range of molecules.
NMR spectroscopy is a high resolution analytical method for structure, conformational analysis and dynamics of molecules. NMR-active nuclear spins are excited by the application of radiofrequency pulses of matching frequency. The magnetic field generated by these spins is detected by the same RF coil which is used to excite them, giving rise to the NMR signal (FID). Signal processing results in a frequency domain spectrum which is then analyzed to reveal information about the environment around the spins.
Probe Specifications:
1.Bruker 5 mm SmartProbeTM (standard room-temperature BBO probe) for multinuclear measurements of small molecules. The probe can be tuned to observe 19F or any nucleus in the range from 31P- 199Hg and 17O-109Ag excluding 171Yb-9Be. Simultaneous pulsing on 1H and 19F nuclei is possible, enabling the recording of 19F spectra with 1H decoupling. The probe is equipped with a z-gradient (5 G/A*cm), 2H locking and is capable of carrying out solvent suppression using pre-saturation or pulsed-field gradients.
2. 5mm Triple resonance (TXI) high-resolution room temperature-probe (with actively-shielded 5 G/A*cm z-gradient and 2H lock). The probe can be used for structural and dynamic analysis of doubly (13C/15N) or singly (15N) labelled biomolecules, using 1H detected measurements and 13C/15N decoupling.
Instructions for Registration, Sample Preparation, User Instructions, Precautionary Measures and Charges
An appointment will be given as per queue and will be informed by email.
New users are requested to contact the facility manager before registration.
At least 24 hours prior information should be given to the NMR lab if users want to cancel/postpone the slot.
Inorganic/organic small molecule samples which are highly soluble (minimum concentration 1 mM- 2mM) in typical NMR solvents (deuterated methanol, deuterated DMSO, deuterated acetone, deuterated chloroform or D2O etc.) can be analyzed. The molecular weight and solubility must be clearly stated when sending in samples.
Isotopically labelled samples (15N labelled or 13C/15N labelled samples) can be sent in lyophilized form or on ice in the relevant buffer. If sent in lyophilized form, please include the NMR sample buffer. Sample concentrations should be 500 μM or more for 2D experiments and 1 mM or more for 3D measurements. Currently, long experiments are possible only at room temperature, depending upon the stability and solubility of the biomolecular samples.
1. A requisition letter addressed to Faculty in Charge along with a printout of electronic fund transfer (NEFT) proof should be sent by post or submitted in person to Facility in Charge, Chemistry Department office, IIT Bombay, Powai, Mumbai-400076.
2. If you are sending samples by post please mention sample details:
a. Concentration (solution) or amount in mg (powder to be dissolved)
b. Sample name
c. deuterated (for locking) and regular solvent in which experiment should be carried out
d. Experiments to be carried out
e. If possible, experimental parameters can also be mentioned (particular scalar coupling constants etc.)
f. Temperature at which the experiment will be carried out
3. Once we receive the requisition letter and advance payment, your appointment will be scheduled as per the queue.
4. The users will be informed about their date and time of slot by e-mail.
6. NMR tube(s) and deuterated and regular solvent(s) should be included or if paid for, should be mentioned
7. We prefer that you or your representative, who knows/understands the sample/material should be present on the day of appointment.
Applications
NMR experiments:
Small molecules:
- 1D 1H with and without solvent suppression
- 1D NOESY, 1D DOSY, 1D CPMG (for T2 measurement), 1D Inversion Recovery (For T1 measurement)
- 1D 13C, 1D 19F, 1D 31P (coupled and decoupled versions), DEPT90, DEPT135
- 2D - NOESY, TOCSY, COSY, DQF-COSY, HETCOR, HSQC, HMBC
- 1D experiments on other X-nuclei (direct detection) - on request
Biomolecules:
- Standard 15N-1H HSQC, 13C-1H HSQC experiments
- 3D experiments for protein backbone and sidechain assignments (HNCO, HNCA, HN(CO)CA, HN(CA)CO, HNCACB, CBCACONH, CC(CO)NH, TOCSY-HSQC etc.)
- 3D 15N/13C edited NOESY-HSQC experiments for distance restraints
- Dynamics: Backbone (15N) R1, R2, hetNOE experiments
Variable temperature measurements:
For low temperature measurements, a liquid nitrogen exchanger is currently available. Liquid nitrogen charges will be extra. The user needs to inform at least 10 days in advance if they plan to carry out VT experiments, the details of which have to be discussed before proceeding, depending upon the current status.