1.4-Dibromonaphthalene

Chemical Name 1,4-dibromonaphthalene CAS Registry No 83-53-4 Molecular Formula C10H6Br2 Molecular Weight 285.963 Melting Point (°C) ... 

Banning,43 who synthesized 1,4-naphthalene oligomer using a Grignard coupling reaction with 1,4-dibromonaphthalene as the starting material. The IR spectra of PNT-N prepared in this work all have this absorption at 699 cm-1. Films collected from different VDP reactions always exhibit this specific absorption, between 696-699 cm-1. 

The higher boiling solid by-product contains, among other substances, 1, 4-dibromonaphthalene melting at 79-80°. This can be isolated by repeated recrystallization from carbon tetrachloride, but so many crystallizations are necessary that the final yield is low. 

The nickel-catalyzed cross-coupling of 2-methyl-1-naphthylmagnesium bromide 32a has been extended to the asymmetric synthesis of ternaphthalenes (Scheme 2-21) [41]. The reaction with 1,5- and 1,4-dibromonaphthalenes in the presence of the same catalyst, nickel/(S)-(R)-9, produces the corresponding optically active ternaphthalenes with 99% ee (35) and 95% ee (36), respectively, together with a small amount of meso compounds. 

The triplet excimer phosphorescence from liquid solutions of naphthalene and di-2-naphthylalkenes in isooctane previously reported has not been confirmed and the emission probably arose from impurities like biacetyl . Exciton trapping has been studied in doped 1,4-dibromonaphthalene . ENOOR applied to the study of triplet traps of phenanthrene-TCNB in naphthalene-TCNB , and triplet 1- and 2-naphthylphenylcarbenes produced by photolysis of diazo compounds . Conformers of triplet states of 2-naphthaldehyde at 300K , T and T2 states from dual... 

The heavy-atom elfeci can be utilized for measuring phosphorescence in solution. In Figure 5.15 the luminescence spectrum of 1,4-dibromonaphthalene... 

Figure 5.15. Luminescence spectrum of 1,4-dibromonaphthalene in acetonitrile with and without purging with N, (by permission from Turro et al., 1978).

It is reported that 1,4-dibromonaphthalene can be formed selectively and in 90% yield by irradiation of naphthalene and 1-bromonaphthalene with stoichiometric amounts of bromine and with the minimum amount of CH2CI2 as solvent at —30 to — SO C. In contrast, l,2,3,4,5-pentabromo-l,2,3,4-tetrahyd-ronaphthalenes result from irradiation of 1-bromonaphthalene in CCI4 at — 30°C, whereas at 77°C only 1,5-dibromonaphthalene is formed and in 80% yield. Two of the more unusual examples of the photoinduced introduction of groups into aromatic rings which have been described within the year are the formation of 1-cyanopyrene in a yield of up to 73% from irradiation at the interface of a solution of pyrene and 1,4-dicyanobenzene in propylene carbonate and an aqueous solution of NaCN in a polymer microchannel chip, and the addition of a variety of groups e.g. NH2, OMe, CN, and CO2H) to coronene by irradiation of arene-ice mixtures at low temperature and pressure." The latter work provides the first experimental evidence that such functionalized arenes, which are detected in primitive meteorites and interplanetary dust particles, may have arisen, at least in part, from photochemistry in ice. 

Photobrominations of naphthalenes have given some interesting results. It is reported that 1,4-dibromonaphthalene can be formed selectively and in 90%... 

The number of solid state energy transfer studies is smaller than in previous years. Energy diffusion in binary solid solutions of 1,4-dibromonaphthalene and 1-brorao-4-chloronaphthalene is one... 

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