The electronic absorption spectra, ground-state geometries and electronic structures of symmetric and asymmetric squaraine dyes (SQD1-SQD4) were investigated using density functional theory (DFT) and time-dependent (TD-DFT) density functional theory at the B3LYP/6-311++G** level. The calculated ground-state geometries reveal pronounced conjugation in these dyes. Long-range corrected time depend...

Detailed density functional theory (DFT) calculations on the structure and harmonic frequencies of model all-trans and all-cis polyenes were undertaken. For the first time, we report on the convergence of selected B3LYP/6-311++G** and BLYP/6-311++G** calculated structural parameters resulting from a systematic increase in polyene size (chains containing 2 to 14 C = C units). The limiting values...

The synthesis and characterization of different ether and ester derivatives of 8-hydroxyquinoline have been made. UV-visible and fluorescence spectra of these compounds have revealed spectral dependence on both solvent and O-substituent. The fluorescence intensity of ether derivatives revealed higher intensity for 8-octyloxyquinoline compared with 8-methoxyquinoline, whereas those of ester deri...

The crystal structure of four lutidinium chloranilates, (CH3)2C6H3NH + C6HO4Cl2 , was determined by single crystal X-ray diffraction at room temperature. 2,4-lutidinium chloranilate (I): triclinic, P1̄ (#2), Z = 2, a = 11.401(2), b = 11.639(2), c = 5.1588(8) Å, = 91.899(15) , = 90.104(14) , and = 83.355(16) , 2,5-lutidinium chloranilate (II): monoclinic, P21/c (#14), Z = 4, a = 7.709(2), b = 11....

Ab initio calculations at the B3LYP/aug-cc-pVDZ, B3PW91/aug-ccpVDZ, MP2/aug-cc-pVDZ, B3LYP/6-311 G(2d,2p), B3PW91/6-311 G(2d,2p), and MP2/6-311 G(2d,2p) levels are performed for the IR spectra of isolated water and methanol molecules and hydrogen-bonded water–methanol, methanol–water, and methanol–methanol complexes. Frequency shifts and changes in intensities are obtained for the proton donor ...

The quantum-chemical calculations on the conformational properties of 2-flouro-2-oxo- 1,3,2-dioxaphosphorinane (1), 2-choloro-2-oxo-1,3,2-dioxaphosphorinane (2) and 2-bromo- 2-oxo-1,3,2-dioxaphosphorinane (3) have been investigated by means of ab initio molecular orbital (HF/6-311+G**) and hybrid density functional theory (B3LYP/6-311+G**) based methods and Natural Bond Orbital (NBO) interpreta...

Structural properties, energies behavior and NBO analysis was performed for1-5 prototrophic shift endinelboran where substitutions like H, CH3 and CF3 that were placed on Benzene were investigated by usingDFT-B3LYP/6-311+G** level of theory. The Results show that, -BH2 shift doesn’t take place and a kind of[1,3] shift for borotrophic occured. In prototrophic shift, however, [1,5] transition eas...

Using the Gaussian 2003 software and MP2 /6 – 311+ G method for the C2H4 : O2, CO:Cl2 andCO2:CO2 pairs and MP2/6-311++G** method for the CO2:H2O pair and B3lyp/6-31G methodfor the O2:O2 pair the optimized interaction energies between two considered pair molecules ofstudied gases(C2H4:O2, CO:Cl2, CO2:H2O, O2:O2 and CO2:CO2 pairs) as a function of thedistances between the centers of two considere...

N-Cyclohexyl-2,4,4-trimethyl-2,3,4,5-tetrahydro-1H-benzo[b][1,5]diazepine-2-carboxamide (5) was synthesized using an efficient, highly recyclable and eco-friendly catalyst heteropolyacid/triethoxysilyl)propyl]isonicotinamide (HPA/TPI-Fe3O4 nanoparticles) in one-pot. The compound 5 was characterized by FT-IR,1H NMR, 13C NMR, mass spectra, and elemental analysis. The theoretical calculations on 5...