39568-99-5

Usage

InChI:InChI=1/C8H4Br6/c9-1-3-5(11)7(13)4(2-10)8(14)6(3)12/h1-2H2

Upstream product

• 23488-38-2 2,3,5,6-tetrabromo-p-xylene 

Downstream Products

• 148216-74-4 2,3,5,6-tetrabromo-p-phenylenedimethylenedioxydibenzaldehyde 
• 187834-87-3 1,4-bis-(thiomethyl-)-2,3,5,6-tetrabromo benzene 
• 866122-82-9 [2,3,5,6-tetrabromo-4-(diethoxy-phosphorylmethyl)-benzyl]-phosphonic acid diethyl ester 
• 1224235-10-2 α,α'-bis-(dibutoxyphosphinyl)tetrabromo p-xylene 
• 1224235-09-9 α,α'-bis-(dibutoxyphosphinyl)tetrabromo m-xylene 

Relevant academic research and scientific papers

Synthesis and characterization of water-soluble phenylene-vinylene-based singlet oxygen sensitizers for two-photon excitation

The synthesis and characterization of water-soluble singlet oxygen sensitizers with a phenylene-vinylene motif is presented. The principal motivation for this study was to better understand specific features of a water-soluble molecule that influence the photosensitized production of singlet oxygen upon nonlinear, two-photon excitation of that molecule. To achieve water solubility, sensitizers were synthesized with ionic as well as nonionic substituents. In the ionic approach, salts of N-methylated pyridine, benzothiazole, and 1-methyl-piperazine moieties were used, as were aryl-substituted sulfonic acid moieties. In the nonionic approach, aryl-substituted triethylene glycol moieties were used. Selected photophysical properties of the compounds synthesized were determined, including singlet oxygen quantum yields. Of the molecules examined, the most efficient singlet oxygen sensitizers had triethylene glycol units as the functional group that imparted water solubility. Molecules containing the ionic moieties did not make singlet oxygen in appreciable yield nor did they efficiently fluoresce. Rather, for these latter molecules, rapid charge-transfer-mediated nonradiative processes appear to dominate excited state deactivation.

Flash vacuum pyrolysis over magnesium. Part 1 - Pyrolysis of benzylic, other aryl/alkyl and aliphatic halides

Flash vacuum pyrolysis over a bed of freshly sublimed magnesium on glass wool results in efficient coupling of benzyl halides to give the corresponding bibenzyls. Where an ortho halogen substituent is present further dehalogenation gives some dihydroanthracene and anthracene. Efficient coupling is also observed for halomethylnaphthalenes and halodiphenylmethanes while chlorotriphenylmethane gives 4,4′-bis(diphenylmethyl)biphenyl. By using α,α′-dihalo-o-xylenes, benzocyclobutenes are obtained in good yield, while the isomeric α,α′-dihalo-p-xylenes give a range of high thermal stability polymers by polymerisation of the initially formed p-xylylenes. Other haloalkylbenzenes undergo largely dehydrohalogenation where this is possible, in some cases resulting in cyclisation. Deoxygenation is also observed with haloalkyl phenyl ketones to give phenylalkynes as well as other products. With simple alkyl halides there is efficient elimination of HCl or HBr to give alkenes. For aliphatic dihalides this also occurs to give dienes but there is also cyclisation to give cycloalkanes and dehalogenation with hydrogen atom transfer to give alkenes in some cases. For 5-bromopent-1-ene the products are those expected from a radical pathway but for 6-bromohex-1-ene they are clearly not. For 2,2-dichloropropane and 1,1-dichloropropane elimination of HCl occurs but for 1,1-dichlorobutane, -pentane and -hexane partial hydrolysis followed by elimination of HCl gives E, E-, E,Z- and Z,Z- isomers of the dialk-1-enyl ethers and fully assigned 13C NMR data are presented for these. With 6-chlorohex-1-yne and 7-chlorohept-1-yne there is cyclisation to give methylenecycloalkanes and -cycloalkynes. The behaviour of 1,2-dibromocyclohexane and 1,2-dichlorocyclooctane under these conditions is also examined. Various pieces of evidence are presented that suggest that these processes do not involve generation of free gas-phase radicals but rather surface-adsorbed organometallic species.

Effect of Porphyrin Ring Distortion on the Spectral and Electrochemical Properties of Short-chain Basket-handle Porphyrins

The effect of porphyrin ring distortion on the spectral and electrochemical properties of short-chain basket-handle porphyrins has been investigated.The covalent attachment of opposite phenyl rings of meso-5,10,15,20-tetraphenylporphyrin (H2tpp) by short bridging groups of varying nature and length induces distortion in the porphyrine ring.Optical absorption studies indicate large bathochromic shifts (502-1139 cm-1) for both Q and Soret bands and the magnitude of these shifts are linearly correlated with the degree of distortion.The potential values for the porphyrin ring oxidation and reduction were shifted to less-positive (180-260 mV) and to more-negative (280-390 mV) values respectively relative to planar H2tpp.The magnitude of the shifts in the optical absorption bands and redox potentials are independent of the nature of the bridging chain.The origin of these shifts are traced to structural effects caused due to the introduction of a short bridging group rather than to the electronic effect of the bridging group.Introduction of Cu2+ into the porphyrin core does not affect the degree of distortion and ESR studies indicate no significant change in the electronic structure of Cu2+ ion relative to .

Polyhalobenzylic disulfooxonium compounds

Polyhalobenzylic disulfooxonium compounds are produced by the reaction of aromatic methyl, halomethyl or hydroxymethyl substituents with sulfur trioxide. The disulfooxonium salts are readily converted to alcohols by hydrolysis to provide monomers for the production of fire resistant polymers and additives for polymers. Likewise, the disulfooxonium compounds of this invention present chemical intermediates for a wide range of useful products such as halogenated pesticides.