9-Bromophenanthrene NEW

9-Bromophenanthrene is an organic compound belonging to the class of polycyclic aromatic hydrocarbons (PAHs) with a bromine substituent. Here's a breakdown of its key characteristics:

Chemical Structure:

• Core: Phenanthrene, a fused tricyclic aromatic system consisting of three benzene rings arranged in an angular fashion.

• Substituent: A bromine atom (-Br) attached specifically to carbon atom number 9 (or its equivalent position, 10) in the phenanthrene ring system. Positions 9 and 10 are chemically equivalent in unsubstituted phenanthrene.

  Molecular Formula: C₁₄H₉Br

  Physical Properties:

• Typically appears as a pale yellow to off-white crystalline solid at room temperature.

• Has a relatively high melting point (often reported around 100-110 °C).

• Insoluble in water, soluble in common organic solvents like dichloromethane, chloroform, toluene, and diethyl ether.

  Synthesis: The most common route is direct electrophilic aromatic bromination of phenanthrene:

• Phenanthrene is highly reactive towards electrophilic substitution at positions 9 and 10.

• Treatment with bromine (Br₂) in an inert solvent (e.g., carbon disulfide, carbon tetrachloride, dichloromethane), often at low temperatures or without additional catalysts, primarily yields 9-Bromophenanthrene.

• Using stronger catalysts (like FeBr₃) or excess bromine can lead to di- or polybromination.

• Alternative methods like using N-Bromosuccinimide (NBS) can also be employed.

  Key Chemical Property: The Bromine Atom.

• The C-Br bond is relatively weak and polarizable.

• This makes bromine an excellent leaving group in various reactions.

• It allows the compound to act as an electrophile in transition metal-catalyzed cross-coupling reactions (e.g., Suzuki, Stille, Negishi, Heck reactions).

  Primary Applications:

• Organic reaction mechanisms (especially electrophilic substitution and cross-coupling).

• Photophysical properties of PAHs and their derivatives.

• Materials science (e.g., as a precursor for organic semiconductors or liquid crystals).

• Substituted phenanthrenes (alkyl, aryl, alkenyl, alkynyl) via coupling reactions.

• Phenanthrenes with functional groups (amines, alcohols, carbonyls) via functional group interconversion.

• Larger polycyclic aromatic systems or more complex molecular architectures.

• Crucial Synthetic Intermediate: This is its most significant use. The bromine atom can be easily replaced or transformed, making 9-bromophenanthrene a versatile building block for synthesizing a wide variety of more complex phenanthrene derivatives. Examples include:

• Research: Used in studies of:

  Safety Considerations:

• Like many PAHs, it is suspected of being carcinogenic and mutagenic. Handle with extreme caution.

• Brominated aromatic compounds can be irritants (skin, eyes, respiratory system).

• Requires careful handling in a fume hood using appropriate personal protective equipment (gloves, lab coat, safety glasses).

• Avoid inhalation, ingestion, and skin contact.

In summary, 9-Bromophenanthrene is a pale yellow crystalline solid primarily valued as a highly useful synthetic intermediate in organic chemistry due to the reactivity of its bromine atom, enabling the construction of diverse phenanthrene-based molecules for research and materials science. Its potential toxicity necessitates careful handling.