Hirshfeld surface analysis of new phosphoramidates

Abstract

Hirshfeld surfaces and two-dimensional fingerprint plots are used to visualize and analyze intermolecular interactions in six new phosphoramidate structures, [2,6-F2-C6H3C(O)NH]P(O)[X]2 {X = N(C2H5)2 (1), [X]2 = NHCH2C(CH3)2CH2NH and with one CH3OH solvated molecule (2)}, [C6H5O]2P(O)Y [Y = NC4H8O (3), NHC6H4(3-Br) (4)] and [Z]2P(O)OP(O)[Z]2 [Z = N(CH3)(CH2C6H5) (5), NHC6H4(4-CH3) (6)]. Study of the short intermolecular contacts in structures (1)-(6) by Hirshfeld surfaces demonstrate that the O atom of P=O is a better H-atom acceptor than the O atom of C=O for (1) and (2), and also relative to the O atom of the C6H5O group for (3) and (4), and relative to the bridge O atom of the P(O)OP(O) segment for (5) and (6). The results confirm that the crystal packing is related to the kind of substituent linked to the P atom. Compounds (1), (2), (4) and (6), with characteristic N-H···O hydrogen bonds, show a pair of intense spikes (including the intermolecular H···O contacts) in the fingerprint plots, summarizing the major features of each structure in the related two-dimensional plot. For (3) and (5), without any N-H unit, the two short spikes are observed for (3) but are absent for (5). The upper d(e) and d(i) values (distances to the Hirshfeld surfaces for the nearest atoms outside and inside) in the fingerprint plots are more compact in (3) than in (4), and in (5) than in (6), reflecting the more efficient packing in (3) and (5). The tertiary N atoms of (3) and (5) do not take part in any intermolecular contacts involving H atoms. Moreover, structures (3)-(6) show greater contribution from C···H contacts relative to O···H contacts. Finally, Hirshfeld surfaces and fingerprint plots are employed for a comparison of the two independent molecules in the asymmetric unit of (1) and also, for a comparison of (6), in the orthorhombic crystal system, with the previously reported monoclinic polymorph (Pourayoubi, Fadaei et al., 2012).

Structural, theoretic and spectroscopic analysis of 2-methyl-5-nitroaniline salts with various inorganic acids

“…Such weak interactions used to be analysed on the Hirshfeld surface of a particular molecule. Since the surface is always different for various crystal structures, it is a handy tool for finding subtle differences in intermolecular interactions (Tarahhomi et al, 2013;Seth et al, 2011). In the case of H2Me5NA + , it appears that the NO 2 group plays a special role in the formation of the complex hydrogen-bonding network because this group is located at the opposite site of the H2Me5NA + cation towards than the NH 3 + and CH 3 groups.…”

Phosphine Oxides as Spectroscopic Halogen Bond Descriptors: IR and NMR Correlations with Interatomic Distances and Complexation Energy

“…For example, in [52,53], the crystal adducts of various phosphine oxides (Ph 2 (Me)P=O, Ph 3 PO) with strong halogen donors such as pentafluoroiodoebenzene C 6 F 5 I and 1,4-diaryl-5-iodotriazole are described. Finally, for a series of crystals containing molecules with P=O groups, the presence of short X···O contacts (X = Cl, Br, I), which can be interpreted as halogen bonds, has been established with the help of X-ray analysis and quantum-chemical calculations [54][55][56][57][58][59][60][61]. Many other examples of XBs with phosphine oxides and related compounds can be found in CCDC data, which allowed us to perform an extensive database search and analyze the distributions of geometric parameters, as described in Section 4.…”

C˭O···π Interaction: A Rare Noncovalent Binding in RC(O)NHP(O)[NR1R2]2 Phosphoric Triamide Structures

“…3 The focus of our work is study of phosphoramides structures and the CSD analysis of different structural features of phosphoramides such as noncovalent interactions, especially hydrogen bonds. [4][5][6][7] In this work, we present the analysis of lone pair…π (C═O…π and P═O…π) interactions …”