Formation of hydrogen-bonded chains through inter- and intra-molecular hydrogen bonds by a strong base of guanidine-like character and 2,2′-biphenols

Non linear optical analyses of hexamine: phenol cocrystals based on hydrogen bonding: a comparative study

Fourier-Transform Infrared (FT-IR) spectroscopy supported by Raman spectroscopy has been employed to explain the conventional and unconventional hydrogen bonding present in the 4,4'thiodiphenol: hexamine and 4,4'sulfonyldiphenol: hexamine cocrystals. The possible internal and external vibrational modes are predicted through factor group analysis. Influence of intra molecular charge transfer (ICT) interaction caused by the strong ionic ground state hydrogen bonding between charged species, giving rise to a non centro symmetric structure which is a criterion for second harmonic generation (SHG) efficiency has been discussed. Intense low wave number hydrogen bond vibrations in Raman which arise due to electron-phonon coupling are analyzed. Optical quality of adducts is identified through UV-Vis analysis. The second harmonic generation efficiency of both adducts is determined by Kurtz-Perry method.

Reaction of some strong N-bases with chloropentafluorobenzene in the presence of water molecules

Products of reactions between chloropentafluorobenzene and strong N-bases (DBN, DBU, TBD, and MTBD) in polar aprotic solvents and in the presence of water were isolated and identified by analytical and spectroscopic methods. The products of these dehydrohalogenation reactions are apropriate lactams, and if the TBD N-base is used, a condensation occurs with formation of benzimidazole derivative. All the products are not formed directly in the nucleophilic substitution by N-bases but after the hydrolyses of the N-bases with formation of amines known as hard nucleophiles.