Natural Bond Orbital(NBO),Natural Population Analysis and Mulliken Analysis of Atomic Charges of 4-Amino-3-Phenylbutanoic Acid

The Molecular Structure of 4-Amino-3-phenylbutanoic acid conformers have been studied in the gas phase. Natural Bond Orbital Analysis (NBO) and Mulliken analysis of atomic charges of 4-Amino-3-phenylbutanoic acid have been performed by DFT level of theory using B3LYP/6-311++G(d,p) basis set. The atomic charges, electronic exchange interaction and charge delocalization of the molecule have been performed by Natural Bond Orbital(NBO) analysis and Natural Population Analysis(NPA) have been constructed at B3LYP/6-311++G(d,p) level.     

Natural Bond Orbitals(NBO),Natural Population Analysis,Mulliken Analysis of Atomic Charges of 2-[(2,3-Dimethylphenyl)Amino]Benzoic Acid

The spectroscopic properties of the FT-IR and FT-Raman spectra of the 2-[(2,3-dimethylphenyl)amino]benzoic acid (DMPABA) compound have been recorded in the region 4 000～400 cm-1. The molecular structure, vibrational wavenumbers were calculated using DFT (B3LYP) method with 6-31G(d,p) and 6-311++G(d,p) basis sets. The Geometrical structure, vibrational frequencies, corresponding vibrational assignments of 2-[(2,3-dimethylphenyl)amino]benzoic acid (DMPABA) have been investigated experimentally and theoretically using Gaussian03 software package. The detailed Molecular orbital calculation such as Natural Bond Orbitals (NBO), Natural Population Analysis (NPA) and Mulliken analysis of atomic charges is also calculated.     

Natural Bond Orbitals (NBO),Natural Population Analysis,Mulliken Analysis of Atomic Charges of L-Alaninium Oxalate

The Fourier Transform Infrared and Raman spectra of the L-Alaninium oxalate (LAO) have been recorded and analyzed. The fundamental vibrational wave numbers intensities of vibrational bands and optimized geometrical parameters of the compound were evaluated using DFT (B3LYP) method with 6-31+G(d,p) basis set. Natural Bond Orbital (NBO) and Natural Population Analysis (NPA) analysis for the LAO compound was carried out. Mulliken population analyses on atomic charges were also calculated.     

Conformational Analysis of (S)-4,5,6,7-Tetrahydro-5-Methylimidazo [4,5,1-jk][1,4]-Benzodiazepin-2(1H)-one (R78362)

The solution and solid state conformation of (S)-4,5,6,7-tetrahydro-5-methylimidazo [4,5,1-jk][1,4]-benzodiazepin-2(1H)-one (R78362) have been investigated by low temperature NMR and x-ray diffraction studies. The ¹H NMR spectrum of R78362 shows no evidence of the presence of multiple conformers in the temperature range 340K - 177K. Molecular mechanisms and semiempirical molecular orbital calculations suggest that the nitrogen and ring inversion barriers of R78362 are small and thus a time-averaged ¹H NMR spectrum is probably occurring at 298K. The x-ray diffraction data indicated that there were two independent molecules in the asymmetric unit of the crystal. The two molecules had similar conformations with the benzoimidazole ring being planar and the diazepine ring in a “half-chair” conformation.