Synthesis and spectral characterization of new homologous 1,3,5-triaryl-2-pyrazolines: Influence of alkyloxy chain length on fluorescence.

Twelve new homologous 1,3,5-triaryl-2-pyrazolines (1c-12c) have been synthesized and characterized on the basis of their spectral (IR, (1)H and (13)C NMR and MS) data and microanalysis. The influence of alkyloxy chain length on absorption and fluorescence properties of 1c-12c was studied by UV-Vis and emission spectroscopy. For all the compounds, fluorescence was observed in the blue region of the visible spectrum.

Synthesis and spectral characterization of new 1,3,5-triaryl-2-pyrazolines highlighting effect of alkyloxy chain length on fluorescence.

A series of new 1,3,5-triaryl-2-pyrazolines (1b-12b) having one to twelve carbon alkyloxy side chains were synthesized and characterized on the basis of their spectral (IR, (1)H &(13)C NMR and GC-MS) and microanalytical data. The UV-Vis and emission spectroscopy was used to study the effect of alkyloxy chain length on absorption and fluorescence properties of 1b-12b. All the compounds showed fluorescence in the blue region of the visible spectrum.

Synthesis, spectral characterization, self-assembly and biological studies of N-acyl-2-pyrazolines bearing long alkoxy side chains.

A series of new pyrazoline derivatives (1b-4c) bearing N-acyl arms and nine to twelve carbon long alkoxy side chains was synthesized and characterized on the basis of spectroscopic data and microanalysis. The nature of self-assembly to understand the interplay of alkoxy chain crystallization and various supramolecular interactions was investigated using single crystal X-ray diffraction studies. Interesting self-assembled supramolecular structures of 1b and 4c were observed in the crystal lattice owing to various CH⋯O, H⋯H, CH⋯π, lonepair⋯π and π⋯π interactions.

1-[5-(4-Meth-oxy-phen-yl)-3-phenyl-4,5-dihydro-1H-pyrazol-1-yl]ethanone.

The title mol-ecule, C(18)H(18)N(2)O(2), is V-shaped with the pyrazoline moiety being inclined to the adjacent phenyl ring by an angle of 6.49 (9)°, while the 4-meth-oxy-substituted ring is inclined to the pyrazoline ring by 82.99 (9)°.

1-{5-[4-(Hex-yloxy)phen-yl]-3-phenyl-4,5-dihydro-1H-pyrazol-1-yl}ethanone.

The crystal structure of the title compound, C(23)H(28)N(2)O(2), is composed of discrete mol-ecules with bond lengths and angles quite typical for pyrazoline derivatives of this class. The plane containing the pyrazoline unit is nearly planar with the mean plane of the phenyl ring at the 3-position, making a dihedral angle of 1.96 (3)°.

(E)-4-Nitro-benzaldehyde oxime.

In the title compound, C(7)H(6)N(2)O(3), the planes containing the CNO and ONO atoms subtend dihedral angles of 5.47 (5) and 8.31 (5)°, respectively, with the benzene ring.