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Industrial Research And Consultancy Centre

Model: EMX PLUS 10/12 (Electron-Spin Resonance Spectrometer Systemwith 10" Magnet and 12 KW Power Supply)

Digital Ultra High Resolution Hall Field Controller
Microwave Bridge: Type EMX-m40X(X-band)
Source: solid state microwave source;
Frequency range: 9,3 to 9,9 GHz
low noise: -130dBc/ 100 kHz from carrier
maximum source output : 200mW
phase sensitive detection
integrated frequency counter with 1 kHz resolution

Frequency Tuning:
tune bandwidth: 8 MHz,
suitable for standard resonator types
Automatic Frequency Control(AFC):
AFC lock range: 4 MHz
digital adjustment for modulation amplitude and gain
AFC stability: 10-8

Microwave Power Setting:
Attenuation : 60dB max
automatic phase correction over attenuation range,

Microwave Reference Arm:
Reference Arm with microwave attenuation and phase shifter,

Signal Amplifier: low noise preamplifier,
20 Hz to 600 kHz,
two 50 Ohm signal outputs

Resonator Tuning and Matching:
the system features "auto tuning" and "auto matching"
for most probeheads via iris

Q-factor Display:
the system evaluates the probehead (resonator) and
displays the loaded Q-Factor.
All parameters of the bridge are software controlled

High Sensitivity Probe (Type 2)
with optical window for CW-EPR in X-Band:

  • 10 mm sample access
  • 20 G maximum modulation amplitude
  • automatic cavity matching
  • forlossy and non-lossy samples
  • compatible with ER 4131VT and ER 4112HV
  • unloaded Q > 15.000
  • Sensitivity: Weak Pitch 1200 : 1 Absolute 2.5 x 109 spins / G

Q-Band Microwave Bridge with frequency counter
microwave source: Gunn
Operating frequency: 34 GHz
max. Power: 100 mW
operating range: 100 MHz
attenautaion precision: +/- 0.2dB
attenuation resolution: 1 dB
attenuation max.: 60 dB
Signal bandwidth: 30 Hz to 400 kHz
Integrated frequency counter with 1 kHz resolution

ER 5106QT
Cavity for room-, nitrogen, helium temperatures (X-band)

Helium Cryostat, 3.8 K to 300 K (Q-band)
with 5 mm optical window,compatible with ER 4112HV-1020 control system(including cryostat holder), used for Flexline,K- and Q-Band resonators.

ER 5106QT
Electrolytic cell assembly (X-band)
Single crystal EPR measurement One axis Goniometer




  • EPR spectrumcan be recorded for solid and in solution phase.
  • Variable temperature EPR measurement can be performed from room temperature upto 5.0 K in both X-band and Q-band.
  • In-situ generated radicals (by electrolytic reduction) can be monitored
  • Advanced level single crystal EPR measurements can be performed using the single crystal rotor.


In an EPR experiment the field of the spectrometer magnet is swept linearly to excite some of the electrons in the lower energy level to the upper energy level while the sample is exposed to fixed microwave irradiation. The free or the upaired electrons have a small magnetic field and orient themselves parallel to the larger field produced by the spectrometer's magnet. At a particular magnetic field strength the microwave irradiation will cause some of the free electrons to "flip" and orient against the spectrometer's magnetic field. This separation between the lower and the higher energy level is exactly matched by our microwave frequency. The condition where the magnetic field and the microwave frequency are "just right" to produce an EPR resonance (or absorption) is known as the resonance condition is detected by the spectrometer.




TitleAuthors NameYear, Vol. and Page No.



1Dalton TransactionStructural and magnetic properties of semiquinonate based Al(III) and Ga(III) complexesChinmoy Das, Pragya Shukla, Lorenzo Sorace and Maheswaran Shanmugam2017 46, 1439–144810.1039/c6dt04281c
2Chemistry-A European JournalRole of Halide Ions in the Nature of the Magnetic Anisotropy in Tetrahedral CoII ComplexesShefali Vaidya, Saurabh Kumar Singh, Pragya Shukla, Kamaluddin Ansari,  Gopalan Rajaraman, Maheswaran Shanmugam2017, 23, 9546–955910.1002/chem.201606031
3Inorganic Chemistry

Ruthenium-Hydride Mediated Unsymmetrical Cleavage of

Benzofuroxan to 2‑Nitroanilido with Varying Coordination Mode

Prabir Ghosh, Sanjib Panda, Soumyodip Banerjee, and Goutam Kumar Lahiri2017, 56, 10735−1074710.1021/acs.inorgchem.7b01696
4Inorganic ChemistryRu-Complex Framework toward Aerobic Oxidative Transformations of βDiketiminate and α KetodiimineSanjib Panda, Abhishek Mandal, Prabir Ghosh, and Goutam Kumar Lahiri2017, 56, 14900−1491110.1021/acs.inorgchem.7b02172
5Nature CommunicationsFerrotoroidic ground state in a heterometallic {CrIIIDyIII6} complex displaying slow magnetic relaxationKuduva R. Vignesh, Alessandro Soncini, Stuart K. Langley, Wolfgang Wernsdorfer, Keith S. Murray & Gopalan Rajaraman2017, 8, 10230.1038/s41467-017-01102-5
6European Journal of Inorganic  ChemistryMixed Donor–Acceptor-Derived N,N′-Diarylpyrazine-2,5-dicarboxamido-Bridged Diruthenium Systems: Structures, Magnetic Properties, and Electronic Forms in Multiredox StatesFarheen Fatima Khan, Abhishek Mandal, Johannes Klein,Jose Luis Priego, Reyes Jimenez-Aparicio, Biprajit Sarkar and Goutam Kumar Lahiri2017, 5497–550610.1002/ejic.201701009
7Angewandte Chemie International EditionExperimental and Computational Exploration of para-Selective Silylation with a Hydrogen-Bonded TemplateArun Maji, Srimanta Guin, Sheng Feng, Amit Dahiya, Vikas Kumar Singh, Peng Liu and Debabrata Maiti2017, 56, 14903-1490710.1002/anie.201708449
8Inorganic ChemistrySubstituted versus Naked Thiourea Ligand Containing Pseudotetrahedral Cobalt(II) Complexes: A Comparative Study on Its Magnetization Relaxation Dynamics PhenomenonShefali Vaidya, Pragya Shukla, Shalini Tripathi, Eric Rivière, Talal Mallah, Gopalan Rajaraman and Maheswaran Shanmugam

2018, 57, 3371−


9OrganometallicsMechanistic Investigation of Well-Defined Cobalt Catalyzed Formal E Selective Hydrophosphination of AlkynesJitendrasingh Rajpurohit, Pardeep Kumar, Pragya Shukla, Muralidharan Shanmugam, and Maheswaran Shanmugam2018, 37, 2297−230410.1021/acs.organomet.8b00281
10Inorganic Chemistry

Role of (1,3) {Cu-Cu} Interaction on the Magneto-Caloric Effect of Trinuclear {CuII-GdIII-CuII} Complexes: Combined DFT and

Experimental Studies

Mukesh Kumar Singh, Thayalan Rajeshkumar, Ravi Kumar, Saurabh Kumar Singh and Gopalan Rajaraman2018, 57, 1846−185810.1021/acs.inorgchem.7b02775
11Inorganic ChemistryQuestions of Noninnocence and Ease of Azo Reduction in Diruthenium Frameworks with a 1,8- Bis((E) phenyldiazenyl)naphthalene-2,7-dioxido BridgeFarheen Fatima Khan, Johannes Klein, José Luis Priego, Biprajit Sarkar, Reyes Jiménez-Aparicio, and Goutam Kumar Lahiri2018, 57, 12800−1281010.1021/acs.inorgchem.8b01996
12Chemistry-An Asian JournalSolvent-Mediated Functionalization of Benzofuroxan on Electron-Rich Ruthenium Complex PlatformPrabir Ghosh, Sanchaita Dey, Sanjib Panda, and Goutam Kumar Lahiri2018, 13, 1582–159310.1002/asia.201800308
13Inorganica Chimica ActaProbing electronic structures of redox-active ruthenium-quinonoids appended with polycyclic aromatic hydrocarbon (PAH) backboneMadhumita Chatterjee, Prabir Ghosh, Arijit Singha Hazari, Goutam Kumar Lahiri2018, 483,  343–351






Selective C–H halogenation over hydroxylation bynon-heme iron(IV)-oxoSujoy Rana, Jyoti Prasad Biswas, Asmita Sen, Martin Cl´emancey, Genevi`eve Blondin, Jean-Marc Latour, Gopalan Rajaraman and Debabrata Maiti2018, 9, 7843–785810.1039/c8sc02053a
15Journal of the Indian  Chemical  Society.Manganese-salen catalyzed oxidative benzylic chlorinationSheuli Sasmal, Sujoy Rana, Goutam Kumar Lahiri and Debabrata Maiti2018, 130:88 10.1007/s12039-018-1511-7)
  • For X-band:
    • Minimum 40-50 mg sample is needed for solid state measurement
    • For solution state measurement 1 x 10-2 M (provide the preferable solvent to dissolve your sample (avoid using highly polar solvent for measurement))
  • For Q-band:
    • Minimum 5-20 mg sample is needed for solid state measurement
    • For solution state measurement 1 x 10-3 M (provide the preferable solvent to dissolve your sample (avoid using highly polar solvent for measurement))


  • Registered user will be allotted time as per queue.
  • User should submit the samples to the EPR lab between 9:30 AM and 11:00 AM on the scheduled day.
  • Samples will be loaded in to the system on the submitted day and analysis will be carried out after 4 to 6 hours or on the next day. Data will be sent through email.


  • Internal users can register online.
  • External users need to down load registration form and submit it to lab along with the requisite demand draft. The samples should be submitted personally on the day of allotted time slot. Analysis will be performed on the next day and results will be sent through email.
  • Getting back the samples: Users desiring to get back the samples need to mark on the form. Collect them from the lab between 9:30 AM to 11:00 AM after two-three days of completion of the work (intimated through mail) and uncollected samples will be disposed off after ten days of intimation of the completion of the work and no reminders will be sent.