Iodobenzene-d5
[CAS# 7379-67-1]

Identification

• Classification: Chemical reagent >> Deuterated reagent
• Name: Iodobenzene-d5
• Synonyms: 1,2,3,4,5-pentadeuterio-6-iodobenzene
• Molecular Formula: C₆D₅I
• Molecular Weight: 209.04
• CAS Registry Number: 7379-67-1
• EC Number: 664-252-9
• SMILES: [2H]C1=C(C(=C(C(=C1[2H])[2H])I)[2H])[2H]

Properties

• Density: 1.8±0.1 g/cm³, Calc.^*, 1.868 g/mL
• Index of Refraction: 1.620, Calc.^*, 1.6161
• Melting Point: -29 °C
• Boiling Point: 188.3±0.0 °C (760 mmHg), Calc.^*, 92-94 °C (45 mmHg)
• Flash Point: 74.4±0.0 °C, Calc.^*, 74 °C

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS05;GHS07 Danger
• Risk Statements: H302-H318
• Safety Statements: P264-P264+P265-P270-P280-P301+P317-P305+P354+P338-P317-P330-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Serious eye damage	Eye Dam.	1	H318
Acute toxicity	Acute Tox.	4	H302

Discovery and Applications

Iodobenzene-d5 is a deuterated derivative of iodobenzene, where five hydrogen atoms in the benzene ring are replaced by deuterium, a stable isotope of hydrogen. The discovery of iodobenzene-d5 is closely tied to the need for deuterated compounds in advanced spectroscopic techniques, particularly in nuclear magnetic resonance (NMR) spectroscopy. Deuterium's unique properties provide significant advantages in both chemical analysis and reaction mechanism studies, which led to the development and synthesis of compounds like iodobenzene-d5.

The synthesis of iodobenzene-d5 typically involves the deuteration of benzene derivatives through isotopic exchange reactions, followed by halogenation to introduce the iodine group. In a common process, deuterated benzene (benzene-d6) is reacted with iodine and a catalyst, resulting in the formation of iodobenzene-d5. The presence of deuterium atoms instead of hydrogen reduces the compound's interaction with proton-sensitive instruments, making it an excellent solvent and reference compound for spectroscopic analyses.

The primary application of iodobenzene-d5 is in NMR spectroscopy. Deuterated compounds are crucial in NMR because deuterium does not produce signals in the proton NMR spectrum. This property allows scientists to minimize background signals, improving the clarity of spectra when analyzing other organic molecules. Iodobenzene-d5 is particularly useful as a deuterated solvent in studies of halogen-containing compounds, where the iodine atom can influence the chemical environment and help in understanding halogen-based interactions and reaction mechanisms.

In addition to NMR, iodobenzene-d5 is valuable in mass spectrometry, especially as an internal standard in isotope dilution analysis. Deuterated compounds like iodobenzene-d5 have nearly identical chemical behavior as their non-deuterated analogs but possess a distinct mass shift due to the presence of deuterium. This mass shift enables accurate quantification of target compounds and enhances the reliability of mass spectrometric measurements in pharmaceutical, environmental, and biochemical applications.

Iodobenzene-d5 is also employed in reaction mechanism studies, particularly in kinetic isotope effect research. By substituting hydrogen with deuterium in the benzene ring, researchers can observe the changes in reaction rates and gain insights into bond dissociation energies and transition states. The use of iodobenzene-d5 in such studies has contributed to a better understanding of the effects of halogens and isotopic substitution on chemical reactivity.

Moreover, iodobenzene-d5 finds use in synthetic chemistry, where it acts as a building block for the preparation of more complex deuterated molecules. Deuterated iodobenzene serves as a precursor in cross-coupling reactions, such as the Suzuki and Heck reactions, allowing chemists to introduce deuterium into aromatic systems with precision. This capability is essential for producing deuterium-labeled compounds used in pharmacokinetics, drug metabolism studies, and isotope tracing experiments.

The discovery and application of iodobenzene-d5 highlight its importance in spectroscopy, synthetic chemistry, and reaction studies. Its stable deuterium incorporation provides researchers with a versatile tool for analyzing and understanding chemical systems with greater accuracy and detail.

References

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