%0 Journal Article
%T Structure Characterization of [N-Phenylamino(2-boronphenyl)-R-methyl]phosphonic Acid by Vibrational Spectroscopy and Density Functional Theory Calculations
%A Natalia Piergies
%A Edyta Proniewicz
%J Journal of Spectroscopy
%D 2014
%R 10.1155/2014/247237
%X We present the first Fourier-transform infrared absorption (FT-IR) and Fourier-transform Raman (FT-Raman) analysis of vibrational structure of [N-phenylamino(2-boronphenyl)-R-methyl]phosphonic acid ([PhN-(2-PhB(OH)2)-R-Me]PO3H2). Assignments of experimental wavenumbers are based on performed theoretical calculations using density functional theory (DFT). Theoretical calculations show that the most stable structure of the investigated molecule is dimer in cis-trans conformation created by a pair of intermolecular hydrogen bonds between the boron hydroxyl groups of two monomers. 1. Introduction In recent years aminophosphonic acids gain the attention and interest of the researchers because of their diverse and interesting biological activities [1每4]. These compounds are defined as amino acid derivatives, in which the carboxylic acid group [每C(=O)OH] is replaced by the phosphonic acid moiety [每P(=O)(OH)2] [5]. Such modification inhibits the activity of certain enzymes by effective competition for the active site of the enzyme and by forming strong electrostatic binding [6]. Thus, the aminophosphonic acids found application as enzyme inhibitors [6每8] and medical [9, 10] and herbicidal agents [5]. 汐-Amino boronic acids also demonstrate high potential in medical chemistry [11, 12], especially as anticancer therapy agents [13], antibiotics [14], and enzymes inhibitors [15]. This is due to the boronic acid moiety ability to create hydrogen bonds and stable covalent bonds in the enzyme active side [12, 16]. The unique properties of the phosphonic and boronic acid groups cause that the amino acids analogues containing these functional groups become very attractive molecular systems. Therefore, we present the first vibrational characteristic of [N-phenylamino(2-boronphenyl)-R-methyl]phosphonic acid ([PhN-(2-PhB(OH)2)-R-Me]PO3H2) (see Figure 1 for molecular structure) considered as potential protease and kinase inhibitor. We used Fourier-transform Raman spectroscopy to investigate the vibrations and structure of the abovementioned compound. Because the absorption infrared method gives complementary information to the Raman method, supports the Raman analysis, and helps to solve ambiguities during this analysis, the absorption infrared spectra are also examined. Both these methods are commonly employed in both experimental investigations [17每20] and theoretical calculations [21每23] to analyze and compare structures for a large number of conformers of the investigated compounds. Interpreting the Raman and absorption infrared spectra involves explaining spectral
%U http://www.hindawi.com/journals/jspec/2014/247237/