Molecular structure and crystal packing of 6-(p-dimethylaminophenyl)fulvene

Abstract

The single-crystal structure of 6-(p-dimethylaminophenyl)fulvene (DMAPF), ClaHlsN, Mr = 197.28, F(000) = 848, at 123 K has been determined and refined from Mo Ka (A = 0.7107 ,~) X-ray data collected up to sin0/a = 0. (13) A 3. The structure was refined using 6459 unique reflections to a final wR of 5.89% with anisotropic temperature factors on non-H atoms, isotropic temperature factors on H atoms, and populations of radial electron density distributions on every atom as variables in the refinement. All reflections were treated as observed. In both molecules of the asymmetric unit the dihedral angle between the benzenoid and fulvene rings is approximately 15 °, whereas pyramidalization at the N atom is 2.5 times greater in one molecule than in the other. The crystal structure is composed of layers parallel to the ab plane with molecules aligned in the c direction. The molecules of each layer pack with their cross-sections forming a herringbone pattern. Comparison of geometric and electronic features of crystalline DMAPF with those derived by molecular orbital calculations indicate enhanced polarization due to the crystal field.

Synthesis of bis(azafulvene)s by dehydration of hydroxymethylpyrrole derivatives

“…The bond alternation in the azafulvene structure is seen by the single bond character for the C a -C b bonds (1.481 and 1.469 A ˚for 6a; 1.456 and 1.447 A ˚for 9) and the double bond character for the C b -C b bond (1.349 A ˚for 6a; 1.331 A ˚for 9) of the pyrrole ring, which is in contrast to the structure of normal pyrrole (1.357 A ˚for the C a -C b bond; 1.423 A ˚for the C b -C b bond). 11 The distance of the exo double bond (1.351 A ˚for 6a and 1.350 A ˚for 9) is very similar to that reported for dimethylfulvene Me 2 C=C(CH=CH) 2 (1.344 A ˚) and phenylfulvene PhCH=C(CH=CH) 2 (1.362 A ˚) (Table2) 12,…”

Natural bond orbital approach to the transmission of substituent effect through the fulvene and benzene ring systems

“…linear regression between 2p occupations for two atoms in a ring may indicate which of them is stronger influenced by a substituent. In the case of fulvene, most studies and interpretations of the substituent effects on structural and other properties are related to the exocyclic substitution [16][17][18][19][20][21]. Most aromatic indices exhibit strong variability and intercorrelate for 6-substituted derivatives of fulvene [21] which is not the case for monosubstituted benzene derivatives [11,22].…”

Structural Effects of C6Substitution in 6-(4-(Dimethylamino)phenyl)fulvenes

“…The study of fulvene and substituted fulvenes encompasses many areas of chemistry, including structure, , NMR and electronic spectroscopy, reactivity, materials research, and the study of fundamental concepts such as polarity 8 and aromaticity . Fulvene has been studied in the gas phase by microwave spectroscopy and found to have alternating single and double bonds and to be only weakly polar (μ = 0.42 D) 3g.…”

“…Fulvene has been studied in the gas phase by microwave spectroscopy and found to have alternating single and double bonds and to be only weakly polar (μ = 0.42 D) 3g. Substituted fulvenes have been shown to maintain this basic structural element, although structural perturbations suggestive of an increased importance of an “aromatic” five-membered ring have been observed. 3e,f In addition, substitution greatly increases the polarity of fulvene,8b a response indicative of a highly polarizable moiety …”