Conformational Analysis of 2-Chloro- N-[2-((Diphenylphosphoryl)Methyl)Phenyl]-Acetamide and 2-Chloro-N-[2-((Diphenylthiophosphoryl)Methyl)Phenyl]Acetamide

Copyright © 2015 Taylor & Francis Group, LLC. The polarities of 2-chloro-N-(2-((diphenylphosphoryl)methyl)phenyl)acetamide and 2-chloro-N-(2-((diphenylthiophosphoryl)methyl)phenyl)acetamide were determined, and conformational analysis of these was carried out by the method of dipole moments and quantum chemical calculations. The formation of intramolecular hydrogen bond P=O⋯HN or P=S⋯HN in these acetamides is possible

Synthesis, polarity, and structure of 2-chloro-N-[2-(methylsulfanyl)phenyl]- and 2-(diphenylthiophosphoryl)-N-[2-(methylsulfanyl)phenyl]acetamides

© 2015 Pleiades Publishing, Ltd. Conformations of 2-chloro-N-[2-(methylsulfanyl)phenyl]- and 2-(diphenylthiophosphoryl)-N-[2-(methylsulfanyl)phenyl]acetamides have been studied by the dipole moment method and quantum chemical calculations. 2-(Diphenylthiophosphoryl)-N-[2-(methylsulfanyl)phenyl]acetamide has been found to exist as an equilibrium mixture of two conformers with synclinal and anticlinal orientations of the {C-{s{p^3}}} - {C-{s{p^2}}} and P=S bonds. 2-Chloro-N-[2-(methylsulfanyl)phenyl]acetamide is represented by one preferred conformer

Polarity and structure of P(X)-modified (X = O, S) arylcarbamoylmethylphosphine oxides and sulfides

© 2016, Pleiades Publishing, Ltd.As shown by the dipole moment method and quantum chemical calculations, (arylcarbamoylmethyl) diphenylphosphine oxides and sulfides exist as equilibrium mixtures of several rotational isomers stabilized by H · · · X intramolecular hydrogen bonds (X = O, S). The most energetically favorable rotamer and its fraction have been determined for each compound

Conformational analysis of 2-aminophenyl-, 2-aminobenzyl-, and 2-nitrobenzyl(diphenyl)phosphine oxides

The polarity and conformations of 2-aminophenyl-, 2-aminobenzyl-, and 2-nitrobenzyl(diphenyl)-phosphine oxides were studied by the dipole moment method, IR spectroscopy, and quantum chemical calculations. 2-Aminophenyl- and 2-aminobenzyl(diphenyl)phosphine oxides were found to exist preferentially as conformers with intramolecular hydrogen bond. 2-Nitrobenzyl(diphenyl)phosphine oxide is likely to be represented by equilibrium mixture of three conformers in which the phosphoryl and nitro groups are oriented syn or anti with respect to the PCsp3 Csp2 fragment. © 2014 Pleiades Publishing, Ltd

3-Aryl(hetaryl)-3-hydroxy-2-phosphorus-substituted acrylonitriles. Synthesis and experimental and theoretical conformational analysis

Under conditions of the phase transfer catalysis, acylation of (thio)phosphorylacetonitriles by (het)aroyl chlorides affords the Z-enol forms of C-acylation products in high yields. Their configurations were studied by IR spectroscopy, dipole moment measurements, and ab initio quantum-chemical calculations [B3LYP/6-31G(d)]. The C=C double bond and the phosphoryl or thiophosphoryl group have an s-cis arrangement. The possibility of strong intramolecular hydrogen bonding in these conformers is the governing factor responsible for the three-dimensional structures of the compounds under investigation. Derivatives of nicotinic acid existing in the individual form as zwitterions are the only exceptions

Integrated Operational Taxonomic Units (IOTUs) in Echolocating Bats: A Bridge between Molecular and Traditional Taxonomy

Background: Nowadays, molecular techniques are widespread tools for the identification of biological entities. However, until very few years ago, their application to taxonomy provoked intense debates between traditional and molecular taxonomists. To prevent every kind of disagreement, it is essential to standardize taxonomic definitions. Along these lines, we introduced the concept of Integrated Operational Taxonomic Unit (IOTU). IOTUs come from the concept of Operational Taxonomic Unit (OTU) and paralleled the Molecular Operational Taxonomic Unit (MOTU). The latter is largely used as a standard in many molecular-based works (even if not always explicitly formalized). However, while MOTUs are assigned solely on molecular variation criteria, IOTUs are identified from patterns of molecular variation that are supported by at least one more taxonomic characteristic. Methodology/Principal Findings: We tested the use of IOTUs on the widest DNA barcoding dataset of Italian echolocating bats species ever assembled (i.e. 31 species, 209 samples). We identified 31 molecular entities, 26 of which corresponded to the morphologically assigned species, two MOTUs and three IOTUs. Interestingly, we found three IOTUs in Myotis nattereri, one of which is a newly described lineage found only in central and southern Italy. In addition, we found a level of molecular variability within four vespertilionid species deserving further analyses. According to our scheme two of them (i.e. M. bechsteinii and Plecotus auritus) should be ranked as unconfirmed candidate species (UCS). Conclusions/Significance: From a systematic point of view, IOTUs are more informative than the general concept of OTUs and the more recent MOTUs. According to information content, IOTUs are closer to species, although it is important to underline that IOTUs are not species. Overall, the use of a more precise panel of taxonomic entities increases the clarity in the systematic field and has the potential to fill the gaps between modern and traditional taxonomy

Conformational analysis of n-alkyl-n-[2-(Diphenylphosphoryl) ethyl]amides of diphenylphosphorylacetic acid: Dipole moments, ir spectroscopy, dft study

Experimental and theoretical conformational analysis of N-methyl-N-[2-(diphenylphosphoryl) ethyl]diphenylphosphorylacetamide, N-butyl-N-[2-(diphenylphosphoryl)ethyl]diphenylphosphoryl-acetamide, and N-octyl-N-[2-(diphenylphosphoryl)ethyl]diphenylphosphorylacetamide was carried out by the methods of dipole moments, IR spectroscopy, and Density Functional Theory (DFT) B3PW91/6-311++G(df,p) calculations. In solution, these N,N-dialkyl substituted bisphosphorylated acetamides exist as a conformational equilibrium of several forms divided into two groups—with Z-or E-configuration of the carbonyl group and alkyl substituent, and syn or anti arrangement of the phosphoryl-containing fragments relative to the amide plane. The substituents at the phosphorus atoms have eclipsed cis-or staggered gauche-orientation relative to the P=O groups, and cis orientation of the substituents is due to the presence of intramolecular H-contacts P=O…H−Cphenyl or p,π conjugation between the phosphoryl group and the phenyl ring. Preferred conformers of acetamides molecules are additionally stabilized by various intramolecular hydrogen contacts with the participation of oxygen atoms of the P=O or C=O groups and hydrogen atoms of the methylene and ethylene bridges, alkyl substituents, and phenyl rings. However, steric factors, such as a flat amide fragment, the bulky phenyl groups, and the configuration of alkyl bridges, make a significant contribution to the realization of preferred conformers

Synthesis, polarity, and structure of 2-chloro-N-[2-(methylsulfanyl)phenyl]- and 2-(diphenylthiophosphoryl)-N-[2-(methylsulfanyl)phenyl]acetamides

© 2015 Pleiades Publishing, Ltd. Conformations of 2-chloro-N-[2-(methylsulfanyl)phenyl]- and 2-(diphenylthiophosphoryl)-N-[2-(methylsulfanyl)phenyl]acetamides have been studied by the dipole moment method and quantum chemical calculations. 2-(Diphenylthiophosphoryl)-N-[2-(methylsulfanyl)phenyl]acetamide has been found to exist as an equilibrium mixture of two conformers with synclinal and anticlinal orientations of the {C-{s{p^3}}} - {C-{s{p^2}}} and P=S bonds. 2-Chloro-N-[2-(methylsulfanyl)phenyl]acetamide is represented by one preferred conformer