Crystal Structure,Conformation and Vibrational Analysis of a Mannich Base: 2-[(phenylamino) methyl]-isoindole-1,3-dione

Abstract  

The crystal structure of 2-[(phenylamino) methyl]-isoindole-1,3-dione, C₁₅H₁₂N₂O₂, crystallizes in the triclinic space group Pī with cell parameters of a = 7.1176 (2) ?, b = 8.5533 (3) ?, c = 10.9163 (4) ?, α = 95.937 (2)°, β = 102.975 (2)°, γ = 108.474 (2)°, V = 603.18 (4) ?³ and Z = 2. This indole derivative is a Mannich base in which a methyl group bridges the molecules of phthalimide and aniline molecules. The dihedral angle between the phthalimide and aniline is 75.47 (3)°. The molecules of the title compound forms a centrosymmetric hydrogen-bonded dimer through a pair of N–H···O hydrogen bonds. C–H···π and an extensive π···π interactions, in addition, stabilize the molecular structure. The compound presented here is V-shaped, the angle at the methyl bridge [N–C–N] being 115.04 (12)°. Present study reports the conformation and hydrogen bonding interactions which play an important role in biological functions. Vibration analysis complement the structure analysed.     

Spectral characteristics of 2-amino-3-benzyloxy pyridine: Effects of solvents,pH, and β-cyclodextrin

Spectral characteristics of 2-amino-3-benzyloxypyridine (2ABP) has been studied in solvents of different polarity, pH, and β-cyclodextrin (β-CD) and compared with 2-amino pyridine (2AP). The inclusion complex of both amino pyridine (AP) molecules with β-CD are analysed by UV-visible, fluorimetry, FTIR, ¹H NMR, SEM and AM1 methods. The solvent studies shows no significant shift observed in absorption maxima between both AP molecules, but in the excited state a slight red shift is noticed in 2ABP than in 2AP which indicates that the addition of benzyloxy group in 2AP does not effectively increase the resonance interaction in 2ABP. The regular red shift observed in acidic pH solutions suggests intramolecular proton transfer (IPT) interaction in both molecules. β-CD studies shows that in pH ∼7, 2ABP forms 1: 2 inclusion complex from 1: 1 inclusion complex and 1: 1 inclusion complex is formed in pH ∼ 1. In pH ∼ 7, a red shift observed in 2ABP with lower β-CD concentration suggests aromatic ring encapsulated in the β-CD cavity and blue shift noticed at higher β-CD concentrations indicates pyridine ring encapsulated in the β-CD cavity.     

Neptunium estimation in the spent fuel dissolver solution by inductively coupled plasma-atomic emission spectroscopy

This paper deals with the optimization of experimental conditions for the estimation of Np in spent fuel dissolver solution using 2-thenoyltrifluoroacetone (HTTA) as extractant. The quantitative extraction of Np from the dissolver solution employing 0.5 M HTTA/xylene was followed by its estimation by Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) after stripping it from the organic phase with 8 M HNO₃. The reliability of the method was checked by standard addition technique. The method is precise and accurate yielding Np analytical recovery of 99 ± 1%.     

Unusual spectral shifts on fast violet-B and benzanilide: Effect of solvents, pH and β-cyclodextin

The absorption and fluorescence spectra of fast violet-B (FVB) and benzanilide (BA) have been analysed in different solvents, pH and β-cyclodextrin. The inclusion complex of FVB with β-CD is investigated by UV–visible, fluorimetry, AM 1, FTIR and SEM. The absorption maximum of FVB (anilino substitution) is red shifted than that of BA, but the benzoyl substitution hardly changed the ground state structure of BA. Compared to BA, the emission maxima of FVB largely blue shifted in cyclohexane and aprotic solvents, but red shifted in protic solvents and the longer wavelength maxima in FVB is due to the intramolecular charge transfer (TICT). In BA, the normal emission originates from a locally excited state and the longer wavelength band due to intramolecular proton transfer in non-polar/aprotic solvents and in protic solvents it is due to TICT state. β-CD studies reveal that, FVB forms 1:2 complex from 1:1 complex and BA forms 1:2 complex with β-CD.     

Thermodynamical universality of the Lovelock black holes

The necessary and sufficient condition for the thermodynamical universality of the static spherically symmetric Lovelock black hole is that it is the Nth order pure Lovelock Λ-vacuum solution. By universality we mean the thermodynamical parameters: temperature and entropy always bear the same relation to the horizon radius for d = 2N + 1, 2N + 2 dimensions for all N which is the degree of the Lovelock polynomial. For instance, the entropy always goes in terms of the horizon radius as r _h and r _h ², respectively for the odd and even dimensions. Not only that the universality uniquely identifies the pure Lovelock black hole with Λ, it is the characterizing property of this class of black holes.