Background: Polybrominated diphenyl ethers (PBDEs) are dangerous for the environment
and human health because of their persistent organic pollutant (POP) characteristics, which have attracted
extensive research attention. Raman spectroscopy is a simple highly sensitive detection operation.
This study was performed to obtain environmentally friendly non-POP PBDE derivatives with
simple detection-based molecular design and provide theoretical support for establishing enhanced
Raman spectroscopic detection techniques.
Methods: A three-dimensional quantitative structure-activity relationship (3DQSAR) pharmacophore
model of characteristic PBDE Raman spectral was established using 20 and 10 PBDEs as training and
test sets, respectively. Full-factor experimental design was used to modify representative commercial
PBDEs, and their flame retardancy and POP characteristics were evaluated.
Results: The pharmacophore model (Hypo1) exhibited good predictive ability with the largest correlation
coefficient (R2) of 0.88, the smallest root mean square (RMS) value of 0.231, and total cost of
81.488 with a configuration value of 12.56 (˂17).74 monosubstituted and disubstituted PBDE derivatives
were obtained based on the Hypo 1 pharmacophore model and full-factor experimental design auxiliary.
Twenty PBDE derivatives were screened, and their flame-retardant capabilities were enhanced and
their migration and bio-concentration were reduced (log(KOW) <5), with unchanged toxicity and high
biodegradability. The Raman spectral intensities increased up to 380%. In addition, interference analysis
of the Raman peaks by group frequency indicated that the 20 PBDE derivatives were easily detected
with no interference in gaseous environments.
Conclusion: Nine pharmacophore models were constructed in this study; Hypo 1 was the most accurate.
Twenty PBDE derivatives showed Raman spectral intensities increased up to 380%; these were
classified as new non-POP environmentally friendly flame retardants with low toxicity, low migration,
good biodegradability, and low bio-concentrations. 2D QSAR analysis showed that the most positive
Milliken charge and lowest occupied orbital energy were the main contributors to the PBDE Raman
spectral intensities. Raman peak analysis revealed no interference between the derivatives in gaseous