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Halogenated indocyanines: Synthesis, conformational behavior, and light absorption
Author(s) -
Grahn Walter,
Johannes HansHermann,
Rheinheimer Joachim,
Knieriem Burkhard,
Würthwein ErnstUlrich
Publication year - 1995
Publication title -
liebigs annalen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0947-3440
DOI - 10.1002/jlac.1995199506142
Subject(s) - chemistry , halogen , absorption (acoustics) , photochemistry , absorption spectroscopy , spectroscopy , organic chemistry , alkyl , physics , quantum mechanics , acoustics
The reactions of the indocyanine 1a and its corresponding 1,3‐diaminoallene 2a with N ‐halodiorganosulfonimides 3 or molecular halogen result in the formation of the four chain‐halogenated monomethine cyanines 5a‐d . With an excess of the halogenating agent not only the chain but also the end groups are halogenated affording the monomethines 6 and 7. The preferred conformations, UV/Vis absorptions, and electron densities of the cyanines were calculated by AM1 and PPP methods and experimentally investigated using NMR (DNMR, NOE) as well as UV/Vis spectroscopy.