Formation of hydrogen-bonded chains through inter- and intra-molecular hydrogen bonds by 5,5′-dinitro-2,2′-biphenol with a strong base of guanidine-like character and triethylamine

Abstract

The complexes of 5,5′-dinitro-2,2′-biphenol (DNBPh) with 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD) and triethylamine (TEA) were studied by FTIR and 1H NMR spectroscopy. In chloroform and in acetonitrile a proton transfer from DNBPh to N-bases (MTBD, TEA) occurs. In chloroform solution the protonated N-base molecules are hydrogen-bonded to the deprotonated DNBPh molecules whereas in acetonitrile the complexes dissociate and hence protonated N-base molecules and hydrogen-bonded chains formed between DNBPh and 5,5′-dinitro-2,2′-biphenolate are present. The intra- as well as inter-molecular hydrogen bonds within the chains show large proton polarizability.