Recently I am researching about POLYBROMINATED DIPHENYL ETHERS; DIBENZO-PARA-DIOXINS; DECABROMODIPHENYL ETHER; THERMAL-DECOMPOSITION; PHOTODEGRADATION MECHANISM; PHOTOCHEMICAL DEGRADATION; QUANTUM YIELDS; PBDES; TETRABROMOBISPHENOL; PRODUCTS, Saw an article supported by the Australian Research Council (ARC)Australian Research Council; Murdoch University, Australia. Published in ACADEMIC PRESS INC ELSEVIER SCIENCE in SAN DIEGO ,Authors: Saeed, A; Altarawneh, M; Siddique, K; Conesa, JA; Ortuno, N; Dlugogorski, BZ. The CAS is 92-86-4. Through research, I have a further understanding and discovery of 4,4′-Dibromobiphenyl. COA of Formula: C12H8Br2
This study investigates the geometric and electronic properties of selected BFRs in their ground (S-0) and first singlet excited (S-1) states deploying methods of the density functional theory (DFT) and the time-dependent density functional theory (TDDFT). We estimate the effect of the S-0 -> S-1 transition on the elongations of the C-Br bond, identify the frontier molecular orbitals involved in the excitation process and compute partial atomic charges for the most photoreactive bromine atoms. The bromine atom attached to an who position in HBB (with regard to C-C bond; 2,2′,4,4′,6,6′-hexabromobiphenyl), TBBA (with respect to the hydroxyl group; 2,2′,6,6′-tetrabromobisphenol A), HBDE and BTBPE (in reference to C-O linkage; 2,2′,4,4′,6,6′-hexabromodiphenylether and 1,2-bis(2,4,6-tribromophenoxy)ethane, respectively) bears the highest positive atomic charge. This suggests that, these positions undergo reductive debromination reactions to produce lower brominated molecules. Debromination reactions ensue primarily in the aromatic compounds substituted with the highest number of bromine atoms owing to the largest stretching of the C-Br bond in the first excited state. The analysis of the frontier molecular orbitals indicates that, excitations of BFRs proceed via pi ->pi*, or pi ->sigma* or n ->sigma* electronic transitions. The orbital analysis reveals that, the HOMO-LUMO energy gap (EH-L) for all investigated brominesubstituted aromatic molecules falls lower (1.85-4.91 eV) than for their non-brominated analogues (3.39-8.07 eV), in both aqueous and gaseous media. The excitation energies correlate with the EH-L values. The excitation energies and EH-L values display a linear negative correlation with the number of bromine atoms attached to the molecule. Spectral analysis of the gaseous-phase systems reveals that, the highly brominated aromatics endure lower excitation energies and exhibit red shifts of their absorption bands in comparison to their lower brominated congeners. We attained a satisfactory agreement between the experimentally measured absorption peak (lambda(max)) and the theoretically predicted oscillator strength (lambda(max)) for the UV-Vis spectra. This study further confirms that, halogenated aromatics only absorb light in the UV spectral region and that effective photodegradation of these pollutants requires the presence of photocatalysts.
Welcome to talk about 92-86-4, If you have any questions, you can contact Saeed, A; Altarawneh, M; Siddique, K; Conesa, JA; Ortuno, N; Dlugogorski, BZ or send Email.. COA of Formula: C12H8Br2
Reference:
Benzoxazole – Wikipedia,
,Benzoxazole | C7H5NO – PubChem