A single-crystal neutron diffraction refinement of benzamide at 15 and 123 K

Panicker²,

Madhavan³

et al. 2009

FT-IR and FT-Raman spectra of 4-chloro-2-(4-bromophenylcarbamoyl)phenyl acetate were recorded and analyzed. The vibrational wavenumbers and corresponding vibrational assignments were examined theoretically using the Gaussian03 set of quantum chemistry codes. The red shift of the NH stretching wavenumber in the infrared (IR) spectrum from the computed wavenumber indicates the weakening of the NH bond resulting in proton transfer to the neighbouring oxygen atom. The simultaneous IR and Raman activations of the C O stretching mode give the charge transfer interaction through a π -conjugated path. Optimized geometrical parameters of the title compound are in agreement with similar reported structures. From the optimized structure, it is clear that the hydrogen bonding decreases the double bond character of C O bond and increases the double bond character of the C-N bonds. The first hyperpolarizability, predicted infrared intensities and Raman activities are reported. The calculated first hyperpolarizability is comparable with the reported values of similar derivativesand is an attractive object for future studies of non-linear optics. The assignments of the normal modes are done by potential energy distribution (PED) calculations.

Section: Geometrical Parameters and First Hyperpolarizabilitysupporting

confidence: 73%

Section: Geometrical Parameters and First Hyperpolarizabilitymentioning

confidence: 88%

FT‐IR, FT‐Raman and DFT calculations of the salicylanilide derivate 4‐chloro‐2‐(4‐bromophenylcarbamoyl)phenyl acetate

Panicker²,

Madhavan³

et al. 2009

“…[26 -30] The crystal structures of benzamide were determined by X-ray and neutron diffraction. [31,32] The hydrogen-bonding interactions between 382 C. Y. Panicker et al thioacetamide and several N,N-disubstituted benzamides have been studied using near-infrared absorption spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

FT‐IR, FT‐Raman, SERS spectra and computational calculations of 4‐ethyl‐N‐(2′‐hydroxy‐5′‐nitrophenyl)benzamide

Panicker¹,

Ushakumari³

et al. 2009

Fourier transform infrared (FT-IR) and FT-Raman spectra of 4-ethyl-N-(2 -hydroxy-5 -nitrophenyl)benzamide were recorded and analyzed. A surface-enhanced Raman scattering (SERS) spectrum was recorded in silver colloid. The vibrational wavenumbers and corresponding vibrational assignments were examined theoretically using the Gaussian03 set of quantum chemistry codes. The red shift of the NH stretching wavenumber in the infrared spectrum from the computational wavenumber indicates the weakening of the NH bond resulting in proton transfer to the neighboring oxygen atom. The simultaneous IR and Raman activation of the C O stretching mode gives the charge transfer interaction through a π -conjugated path. The presence of methyl modes in the SERS spectrum indicates the nearness of the methyl group to the metal surface, which affects the orientation and metal molecule interaction. The first hyperpolarizability and predicted infrared intensities are reported. The calculated first hyperpolarizability is comparable with the reported values of similar derivatives and is an attractive subject for future studies of nonlinear optics. Optimized geometrical parameters of the title compound are in agreement with reported structures.

“…Kurt [70] reported the CCl = 1.757Á, C 1 -C 6 = 1.391Á, C 5 -C 6 = 1.391Á, C 1 -C 6 -C 5 = 121.2 • , and C 1 -C 6 -Cl 10 = 119.4 • while the experimental values [88] For the acetate group, Ibrahim and Koglin [25] reported C 26 [25] The strong steric repulsion between the phenyl ring II and the amide group is confirmed by the nonplanarity of the benzamide, where the amide group is turned by 44.7 • (C 3 -C 4 -C 11 -O 12 ) with respect to the benzene ring. [85] Siddiqui et al [89] reported N 13 -C 11 = 1.3314-1.3384 Å, [89] Nonlinear optics deals with the interaction of applied electromagnetic fields in various materials to generate new electromagnetic fields, altered in wavenumber, phase, or other physical properties. [90] Organic molecules able to manipulate photonic signals efficiently are of importance in technologies such as optical communication, optical computing, and dynamic image processing.…”

Section: Phenyl Ring Vibrationsmentioning

confidence: 99%

FT‐IR, FT‐Raman, and computational calculations of 4‐chloro‐2‐(3‐chlorophenyl carbamoyl)phenyl acetate

Panicker¹,

Madhavan³

et al. 2009

FT-IR and FT-Raman spectra of 4-chloro-2-(3-chlorophenylcarbamoyl) phenyl acetate were studied. Vibrational wavenumbers and corresponding vibrational assignments were examined theoretically using the Gaussian03 set of quantum chemistry codes and the normal modes are assigned by potential energy distribution (PED) calculations. Simultaneous IR and Raman activation of the C O stretching mode shows the charge transfer interaction through a π-conjugated path. Optimized geometrical parameters of the title compound are in agreement with the reported values. Analysis of the phenyl ring modes shows that C-C stretching mode is equally active as strong bands in both IR and Raman, which can be interpreted as the evidence of intramolecular charge transfer via conjugated ring path and is responsible for hyperpolarizability enhancement leading to nonlinear optical activity. The red-shift of the NH-stretching wavenumber in the infrared spectrum from the computed wavenumber indicates the weakening of the NH bond resulting in proton transfer to the neighboring oxygen atom. Copyright