The structure of it can be further decomposed into the following aspects:

Main structure:
Bromobiphenyl is composed of two benzene rings, each containing six carbon atoms and five hydrogen atoms. These two benzene rings are connected by a conjugated bond, resulting in a planar structure of the entire molecule.

Bromine substituents:
On a benzene ring of bromobiphenyl, the position of a hydrogen atom is replaced by a bromine atom. This bromine atom causes the molecule to exhibit partial polarity while also endowing the compound with specific chemical properties.

Conjugate structure:
The two benzene rings in bromobiphenyl are connected by conjugated bonds to form an extended conjugated system. This conjugated system enables molecules to have good electronic conductivity and stability, and affects their behavior in chemical reactions.

Space configuration:
Due to the fact that bromobiphenyl is a planar molecule, there is no chiral center or chiral isomer present. It can rotate freely without affecting the chemical properties of the molecules.

Molecular properties:
Bromobiphenyl has a high melting and boiling point and exists in a solid or liquid state. It is easily soluble in organic solvents, but almost insoluble in water. Its physical and chemical properties make it widely used in fields such as preservatives.

1) Nitrification reaction

Dissolve biphenyl in an organic solvent, add a mixture of nitric acid and sulfuric acid dropwise, and react at 55-60 ° C. After the reaction is completed, extract with water, collect the organic phase, and obtain the nitration product; Among them, the molar ratio of biphenyl to nitric acid is 1:1 to 1 6. Among them, 1:1. 2 is the optimal ratio; The organic solvent does not react with sulfuric acid or nitric acid and is not miscible with water;

2) Reduction reaction

Under stirring conditions, add iron powder and catalyst to the water to obtain a mixture of iron powder; Add nitration products dropwise to the mixture of iron powder for reaction; The optimal reaction is at 60 ° C; After the reaction is completed, alkalization is carried out to obtain the reduced product. Among them, the molar ratio of the nitration product to iron powder is 1:1 to 10, with 1:4 being the optimal ratio; The catalyst assists in the catalytic reduction of iron powder;

3) Bromination reaction

Add liquid bromine to the reduction product under stirring conditions and react at room temperature; After the reaction is completed, extract with water to obtain brominated products. Among them, the molar ratio of the reduction product to liquid bromine is 1: 1-4, where I: 1 26 is the optimal ratio;

4) Deamination reaction

Add brominated products to water, then add concentrated hydrochloric acid to the reaction system, and dissolve the generated brominated product hydrochloride under stirring conditions. Cool to o ° C to obtain a mixture of brominated products and salts; Add sodium nitrite to the brominated product hydrochloride mixture for reaction at a temperature not exceeding 5 ° C; After the reaction is completed, add sodium hypophosphate to it and stir until the reaction is complete; Finally, extract with ethyl acetate to obtain product;

Among them, the molar ratio of the brominated product, sodium nitrite, and sodium hypophosphate is 1:1 to 1 5: 5-15, of which 1: 1 2: 10 0 is the optimal reaction condition. Here, the brominated products first react with concentrated hydrochloric acid to generate hydrochloride and dissolve in water, ensuring that the reaction is homogeneous and can proceed smoothly.

Following breakthroughs in the synthetic technology of parent biphenyl in the mid-to-late 19th century, chemists across the globe launched research into substituted biphenyl derivatives.

Between 1890 and 1910, the first laboratory-scale preparation of 3-bromobiphenyl was accomplished via the Gomberg-Bachmann diazo coupling reaction, marking the earliest discovery origin of this monomer.

Early researchers prepared crude products through low-temperature diazotization of m-bromoaniline to form arenediazonium salts, followed by aromatic ring coupling with benzene.

Restricted by poor reaction selectivity, the resulting mixture contained ortho-, meta- and para-bromobiphenyl isomers. The meta-substituted monomer could only be isolated in trace amounts by vacuum distillation, limiting its application exclusively to organic reaction mechanism research with no feasibility for large-scale production.

After the 1950s, the booming development of liquid crystal and fine chemical industries brought the product into focus as a crucial coupling intermediate.

Chemists optimized a four-step synthetic route consisting of nitration, reduction, bromination and deamination, substantially raising the yield of meta-oriented product.

In the wake of the 1973 polybrominated biphenyl contamination incident in Michigan, USA, this monomer was listed under regulatory control alongside brominated flame retardant congeners, spurring extensive trace-level source-tracing research in environmental science.

The industrialization of Suzuki-Miyaura coupling in the 1980s enabled high-purity regioselective synthesis via palladium-catalyzed cross-coupling between m-bromoiodobenzene and phenylboronic acid, completing the full evolution of the product from laboratory discovery to commercial mass production.

Samples are ultrasonically extracted with toluene and purified by silica gel column chromatography using a high-temperature capillary column. The oven temperature is programmed to ramp gradiently from an initial 110 °C up to 340 °C.

Quantification is performed in SIM mode with an EI ionization source set at 70 eV. High-resolution mass spectrometry (resolution ≥5000) is adopted for ultra-trace analysis of soil and sediment samples, achieving a method detection limit at ng/kg level. This serves as the legally specified test approach for electronic plastic and environmental specimens.

A competitive immunoassay system is constructed based on polydopamine-Prussian blue modified carbon electrodes with signal amplification via enzyme-labeled carbon nanomaterials.

The assay delivers a linear detection range from 1 pM to 2 nM and a limit of detection of 0.5 pM, ideal for high-throughput preliminary screening of surface water to eliminate long turnaround times associated with off-site testing using bulky analytical instruments.

The three analytical techniques complement one another, covering full testing requirements ranging from conventional bulk content quality control down to ultra-trace environmental monitoring.