<i>N</i>′-(2-Chlorobenzylidene)-4-hydroxybenzohydrazide

Hao, Yu-Mei

doi:10.1107/s1600536809030797

Cited by 6 publications

(2 citation statements)

References 10 publications

(14 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…where the slope of the extinction curve C ranges from 4.37 to 5.12 (Calzetti (2001); Seibert et al (2005);Cortese et al (2006); Hao (2009). The differences arise from differences in the bandpasses of the original datasets and in the galaxy populations.…”

Section: Dust Extinction and Reddeningmentioning

confidence: 99%

On the nature of star formation at large galactic radii

Goddard¹,

Kennicutt²,

Ryan-Weber³

2010

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We have compared far‐ultraviolet (FUV), near‐ultraviolet (NUV) and Hα measurements for star‐forming regions in 21 galaxies, in order to characterize the properties of their discs at radii beyond the main optical radius (R25). In our representative sample of extended and non‐extended ultraviolet (UV) discs, we find that half of the extended UV discs also exhibit extended Hα emission. We find that extended UV discs fall into two categories: those with a sharp truncation in the Hα disc close to the optical edge (R25), and those with extended emission in Hα as well as in the UV. Although most galaxies with strong Hα truncations near R25 show a significant corresponding falloff in UV emission (a factor of 10–100), the transition tends to be much smoother than in Hα, and significant UV emission often extends well beyond this radius, confirming earlier results by Thilker et al. and others. After correcting for dust attenuation the median fraction of total FUV emission from regions outside of R25 is 1.7 per cent, but it can be as high as 35 per cent in the most extreme cases. The corresponding fractions of Hα emission are approximately half as large on average. This difference reflects both a slightly lower ratio of Hα to UV emission in the H ii regions in the outer discs and a lower fraction of star clusters showing H ii regions. Most H ii regions in the extended disc have fluxes consistent with small numbers of ionizing O‐type stars, and this poor sampling of the upper initial mass function (IMF) in small clusters can probably account for the differences in the emission properties, consistent with earlier conclusions by Zaritsky & Christlein, without needing to invoke a significant change in the stellar IMF itself. Consistent Hα/FUV ratios and brightest H ii region to total Hα fluxes in the inner and extended discs across our whole galaxy sample demonstrate no evidence for a change in the cluster luminosity function or the IMF in the low gas density outer disc.

show abstract

Section: Dust Extinction and Reddeningmentioning

confidence: 99%

On the nature of star formation at large galactic radii

Goddard¹,

Kennicutt²,

Ryan-Weber³

2010

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

show abstract

“…Acentric non-polar structures ( P 2 1 2 1 2 1 space group) are shown by 8 , 9 , and 14 (blue entries in Table ). Ortho isomers preferentially crystallize in P 2 1 2 1 2 1 and meta isomers in Pna 2 1 . , The highest SHG activity is shown by 7 and, as a general trend, the activity of polar structures is higher than that of acentric non-polar ones. One exception within polar structures is represented by 16 and 17 , which exhibit a lower activity, comparable with P 2 1 2 1 2 1 ortho isomers 9 and 14 .…”

Section: Resultsmentioning

confidence: 86%

Winning Strategy toward Acentric Crystals: Transverse Dipole Moment Molecules

Parisi

Borbone

Carella

et al. 2023

Crystal Growth & Design

View full text Add to dashboard Cite

Imines obtained by condensation of 4-hydroxybenzohydrazide with carbonyl compounds are a rare example of non-chiral compounds showing a remarkable tendency to crystallize in acentric and polar space groups, as we underlined in a previous study of imines obtained by condensation with aliphatic ketones. Here, we present an extensive study of imines obtained by condensation with aromatic aldehydes and demonstrate that over a representative set of 60 crystal structures, the overall occurrence of acentric phases in this class of compounds is 47%. This figure is remarkably higher than the overall 22% frequency of acentric structures in the Cambridge Structural Database and pinpoints a successful strategy toward the synthesis of acentric crystals. In the crystal structures of the acentric imines, complex chains of H-bonded molecules are generally present, with formation of 2D H-bonded networks, similar to other classes of compounds described in the literature with a propensity to form acentric crystals. Another reason for the high success in achieving acentric and polar structures in this class of compounds can be related to the presence of strong transverse bond dipole moments. This feature allows a polar packing of the long molecular axes while keeping the bond dipole moments antiparallel.

show abstract

N′-[(2-Hydroxy-1-naphthyl)methylidene]-2-nitrobenzohydrazide

Hao

2010

Acta Cryst E

Self Cite

View full text Add to dashboard Cite

In the title Schiff base compound, C18H13N3O4, prepared by the reaction of 2-hydroxy-1-naphthaldehyde with 2-nitrobenzohydrazide, the dihedral angle between the benzene ring and naphthyl ring system is 23.0 (2)°. There is an intramolecular O—H⋯N hydrogen bond involving the naphthalene hydroxy substituent and a hydrazide N atom. In the crystal structure, symmetry-related molecules are linked through intermolecular N—H⋯O hydrogen bonds, forming chains propagating in [101].

show abstract

N′-(2-Chlorobenzylidene)-4-hydroxybenzohydrazide

Cited by 6 publications

References 10 publications

On the nature of star formation at large galactic radii

On the nature of star formation at large galactic radii

Winning Strategy toward Acentric Crystals: Transverse Dipole Moment Molecules

N′-[(2-Hydroxy-1-naphthyl)methylidene]-2-nitrobenzohydrazide

Contact Info

Product

Resources

About