Crystal Structure of and ab initio Calculations on [(C6H5)(CH3)CH-NH]- P(O)(p-OC6H4CH3)2, Syntheses and Spectroscopic Characterization of N-Benzyl Phosphoramidic Acid (4-Methylphenyl)ester Derivatives

2005 ◽  
Vol 60 (1) ◽  
pp. 67-74 ◽  
Author(s):  
Khodayar Gholivand ◽  
Zahra Shariatinia ◽  
Mehrdad Pourayoubi

Some new N-benzyl phosphoramidic acid (4-methylphenyl)ester derivatives were synthesized and characterized by 1H, 13C, 31P NMR and IR spectroscopy and elemental analysis. The structure of [(C6H5)(CH3)CH-NH]P(O)(p-OC6H4CH3)2 (2) was investigated. This compound exists in polymeric zigzag chains in the crystalline lattice produced by hydrogen bonding built from two alternating independent molecules. NMR data indicate two diastereotopic p-cresol groups as confirmed by Xray crystallography. Ab initio calculations were performed on the geometry of compound 2 at the UHF/6-311G** and B3LYP/6-311G** levels. The optimized structure of each independent molecule contains two different p-cresol groups, in agreement with the experimental results.

ChemistryOpen ◽  
2014 ◽  
Vol 4 (2) ◽  
pp. 161-168 ◽  
Author(s):  
Enzo Cadoni ◽  
Giulio Ferino ◽  
Patrizia Pitzanti ◽  
Francesco Secci ◽  
Claudia Fattuoni ◽  
...  

Author(s):  
Ajaykumar V. Ardhapure ◽  
Yogesh S. Sanghvi ◽  
Yulia Borozdina ◽  
Anant Ramakant Kapdi ◽  
Carola Schulzke

In the asymmetric unit, equalling the unit cell (triclinic,P1,Z= 1), two molecules of the title compound, 8-(4-methylphenyl)-D-2′-deoxyadenosine, C17H19N5O3, are present, with distinct conformations of the two sugar moieties, together with one solvent water molecule. All three ribose O atoms are involved in hydrogen bonding and the crystal packing is largely determined by hydrogen-bonding or hydrogen–heteroatom interactions (O—H...O, O—H...N, N—H...O, C—H...O and C—H...N) with one independent molecule directly linked to four neighbouring molecules and the other molecule directly linked to six neighbouring molecules. The two independent molecules of the asymmetric unit display three weak intramolecular C—H-to-heteroatom contacts, two of which are very similar despite the different conformations of the deoxyribosyl moieties. The aromatic ring systems of both molecules are in proximity to each other and somehow aligned, though not coplanar. The absolute structures of the two molecules were assumed with reference to the reactant 8-bromo-D-2′-deoxyadenosine as they could not be determined crystallographically.


2004 ◽  
Vol 59 (3) ◽  
pp. 291-297 ◽  
Author(s):  
Andreas Sofetis ◽  
Giannis S. Papaefstathiou ◽  
Aris Terzis ◽  
Catherine P. Raptopoulou ◽  
Theodoros F. Zafiropoulos

The reaction of Ga2(SO4)3·18H2O and excess 2,2′:6′,2″-terpyridine (terpy) in MeOH / H2O leads to [Ga(OH)(SO4)(terpy)(H2O)]·H2O (1·H2O] in good yield. The structure of the complex has been determined by single-crystal X-ray crystallography. The GaIII atom in 1·H2O is 6-coordinate and ligation is provided by one terdentate terpy molecule, one monodentate sulfate, one terminal hydroxide and one terminal H2O molecule; the coodination polyhedron about the metal is described as a distorted octahedron. There is an extensive hydrogen-bonding network in the crystal structure which generates corrugated layers parallel to bc. The new complex was characterized by IR and 1H NMR spectroscopy. The spectroscopic data are discussed in terms of the nature of bonding


Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2778
Author(s):  
Joseph R. Lane ◽  
Graham C. Saunders

The crystal structure of 4-(2,3,5,6-tetrafluoropyridyl)diphenylphosphine oxide (1) contains two independent molecules in the asymmetric unit. Although the molecules are virtually identical in all other aspects, the P=O bond distances differ by ca. 0.02 Å. In contrast, although tris(pentafluorophenyl)phosphine oxide (2) has a similar crystal structure, the P=O bond distances of the two independent molecules are identical. To investigate the reason for the difference, a density functional theory study was undertaken. Both structures comprise chains of molecules. The attraction between molecules of 1, which comprises lone pair–π, weak hydrogen bonding and C–H∙∙∙arene interactions, has energies of 70 and 71 kJ mol−1. The attraction between molecules of 2 comprises two lone pair–π interactions, and has energies of 99 and 100 kJ mol−1. There is weak hydrogen bonding between molecules of adjacent chains involving the oxygen atom of 1. For one molecule, this interaction is with a symmetry independent molecule, whereas for the other, it also occurs with a symmetry related molecule. This provides a reason for the difference in P=O distance. This interaction is not possible for 2, and so there is no difference between the P=O distances of 2.


2016 ◽  
Vol 3 (7) ◽  
pp. 1133-1141 ◽  
Author(s):  
Marta Feroci ◽  
Isabella Chiarotto ◽  
Francesca D'Anna ◽  
Fabrizio Gala ◽  
Renato Noto ◽  
...  

2017 ◽  
Vol 147 (18) ◽  
pp. 184301 ◽  
Author(s):  
Sergey V. Ryazantsev ◽  
Daniil A. Tyurin ◽  
Vladimir I. Feldman ◽  
Leonid Khriachtchev

1995 ◽  
Vol 117 (50) ◽  
pp. 12489-12497 ◽  
Author(s):  
Timothy L. Stemmler ◽  
Terence M. Barnhart ◽  
James E. Penner-Hahn ◽  
Charles E. Tucker ◽  
Paul Knochel ◽  
...  

2006 ◽  
Vol 62 (4) ◽  
pp. o1319-o1320 ◽  
Author(s):  
Min-Hui Cao ◽  
Sheng-Zhen Xu ◽  
Yang-Gen Hu

The title compound, C15H16N2O2S, contains a five-membered thiophene ring fused to a benzene ring and a substituted pyrimidinone ring. All three rings in each of the independent molecules of the asymmetric unit lie in approximately the same plane. The crystal structure is stabilized by intermolecular C—H...O hydrogen bonding and π–π stacking interactions.


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