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Phosphorus derivatives of anthracene and their dimers
Author(s) -
Wesemann Jodi,
Jones Peter G.,
Schomburg Dietmar,
Heuer Lutz,
Schmutzler Reinhard
Publication year - 1992
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19921251005
Subject(s) - chemistry , conformational isomerism , dimer , steric effects , crystallography , anthracene , molecule , bond length , dichloromethane , toluene , stereochemistry , molecular geometry , crystal structure , photochemistry , organic chemistry , solvent
The syntheses of the (9‐anthracenyl)phosphanes 2 to 7 and of the metal carbonyl complexes 8 and 9 are described. Both 1 and 4 undergo [4 + 4] cycloaddition when irradiated, forming the dimers 10 and 11 . Only one of the six possible rotamers for 10 is formed. For 11 one additional rotational isomer is observed. The relationship between the [4 + 4] dimerization and steric effects of the PR 2 group is discussed. The compounds 6, 8 and 11 were characterized by X‐ray diffraction. The structure of 6 was rendered imprecise by the presence of disordered toluene, but the influence of the bulky anthracenyl groups was clear, with wide CPC angles of 110.4°. The molecule displays imposed threefold symmetry. The two independent molecules of complex 8 , which crystallizes as a dichloromethane hemisolvate, are closely similar to each other; the WP bond lengths are 254.3 and 253.4 pm. The WC bonds trans to phosphorus are 4 pm shorter than those cis . The phosphane dimer 11 crystallizes with imposed centrosymmetry. The H atom positions, which could be tentatively identified from difference syntheses, indicate a different rotamer than was formed for the analogous fluorophosphane dimer 10 .