Conformation and NH stretching of 1,1-dihalogenoheptan-1-amines [CH₃(CH₂)₅CX₂NH₂; X=F, Cl or Br]: halogen and solvent effects

Conformational, vibrational and electronic properties of CH3(CH2)3CX2NH2 (X = H, F, Cl or Br): Halogen and solvent effects

The effects of varying halogen and solvent, in terms of vibrational and electronic properties, on the different conformers of 1-pentanamine [ CH 3( CH 2)4 NH 2] and 1,1-dihalogeno-pentan-1-amines [ CH 3( CH 2)3 CX 2 NH 2; X = F , Cl or Br ] were investigated by employing the density functional theory (DFT) and time-dependent density functional theory (TD-DFT) methods. The B3LYP functional was used with the 6-31++G(d,p) basis set. Computations were focused on the 10 conformational isomers of the compounds in the gas phase and both in non-polar (benzene) and polar (methanol) solvents. The present work explores the effects of the halogen and the medium on the conformational preference, and geometrical parameter, dipole moment, NH 2 vibrational frequency, UV spectrum, highest occupied and lowest unoccupied molecular orbitals (HOMO–LUMO) orbital and DOS diagram of the conformers. The atypical characteristics of fluorine and bromine affecting the electrical bandgap, chemical hardness, electronegativity, PDOS or OPDOS plots and the absorption band are observed correspondingly. The findings of this work can be useful to those systems involving changes in the conformations analogous to the compounds studied.

Surface-enhanced Raman scattering behaviour of 4-mercaptophenyl boronic acid on assembled silver nanoparticles

SERS properties of 4-mercaptophenylboronic acid (4-MPBA) on AgNPs were studied systematically; a self-condensation reaction of 4-MPBA, competitor of the binding of glucose, was found to preferentially happen at higher pH values.