In the rigorous field of chemical synthesis and research, precise characterization of intermediate compounds is paramount to ensuring reaction success and product purity. 2-Bromo-5-cyanopyridine (CAS 139585-70-9) is no exception. As a leading supplier and manufacturer, we provide not only high-quality material but also an understanding of its analytical characterization. This article explores the essential spectroscopic techniques and computational methods employed to confirm the identity and purity of this versatile intermediate.

Spectroscopic Techniques for Characterization

Several spectroscopic methods are indispensable for verifying the structure and purity of 2-Bromo-5-cyanopyridine:

  • Nuclear Magnetic Resonance (NMR) Spectroscopy: Both ¹H NMR and ¹³C NMR are critical. The ¹H NMR spectrum will display distinct signals for the three protons on the pyridine ring, with characteristic chemical shifts and splitting patterns arising from proton-proton coupling. The ¹³C NMR will reveal signals for each of the six carbon atoms, including the quaternary carbons and the nitrile carbon (typically around 115-120 ppm). The presence and position of these signals, along with their integration in ¹H NMR, provide unambiguous confirmation of the compound's structure.
  • Mass Spectrometry (MS): MS is vital for determining the molecular weight and elemental composition. For 2-Bromo-5-cyanopyridine (C₆H₃BrN₂, MW ≈ 183.01), the molecular ion peak will appear as a characteristic doublet due to the natural isotopes of bromine (⁷⁹Br and ⁸¹Br, approximately 1:1 ratio). High-resolution MS (HRMS) can further confirm the exact molecular formula with high accuracy.
  • Infrared (IR) Spectroscopy: IR spectroscopy helps identify key functional groups. For 2-Bromo-5-cyanopyridine, a strong absorption band for the nitrile (-C≡N) stretch is expected around 2200-2250 cm⁻¹. Bands associated with the aromatic pyridine ring (C=C and C=N stretching) will also be present.

Computational Chemistry for Predictive Insights

Complementing experimental techniques, computational methods like Density Functional Theory (DFT) offer predictive power regarding the molecule's properties and reactivity:

  • Geometry Optimization: DFT calculations can accurately predict the optimized molecular geometry, including bond lengths and angles, providing insights into the molecule's stability and electronic distribution.
  • Frontier Molecular Orbitals (HOMO/LUMO): The energies of the Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO), and their energy gap, are crucial indicators of a molecule’s chemical reactivity and electronic properties. These calculations help predict how 2-Bromo-5-cyanopyridine will behave in various chemical reactions.
  • Spectroscopic Predictions: DFT can also predict NMR chemical shifts and IR vibrational frequencies, which can be compared with experimental data to validate structural assignments and confirm the identity of the synthesized compound.

Ensuring Quality from Our Supply Chain

As a leading manufacturer in China, we understand the importance of these analytical methods. Our commitment to providing high-purity 2-Bromo-5-cyanopyridine (99% min) is backed by rigorous quality control, often employing these very techniques. When you choose to buy from us, you are assured of a material that has been thoroughly characterized, ready to perform reliably in your synthesis. For your needs in organic synthesis intermediates, we are your trusted source.