Switching between halogen- and hydrogen-bonding in stoichiometric variations of a cocrystal of a phosphine oxide

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.

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Optimization of a phosphine oxide disulfoxide array for multipoint hydrogen bonding to ammonium ions

Journal of the American Chemical Society ◽

10.1021/ja00070a055 ◽

1993 ◽

Vol 115 (17) ◽

pp. 7900-7901 ◽

Cited By ~ 17

Author(s):

Paul B. Savage ◽

Steven K. Holmgren ◽

Samuel H. Gellman

Keyword(s):

Hydrogen Bonding ◽

Phosphine Oxide ◽

Ammonium Ions

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Crystal structure of the tetrahydrofuran disolvate of a 94:6 solid solution of [N2,N6-bis(di-tert-butylphosphanyl)pyridine-2,6-diamine]dibromidomanganese(II) and its monophosphine oxide analogue

Acta Crystallographica Section E Crystallographic Communications ◽

10.1107/s2056989017011276 ◽

2017 ◽

Vol 73 (9) ◽

pp. 1308-1311 ◽

Cited By ~ 1

Author(s):

Markus Rotter ◽

Matthias Mastalir ◽

Mathias Glatz ◽

Berthold Stöger ◽

Karl Kirchner

Keyword(s):

Crystal Structure ◽

Solid Solution ◽

Hydrogen Bonding ◽

Phosphine Oxide

The MnBr2complex ofN2,N6-bis(di-tert-butylphosphanyl)pyridine-2,6-diamine (1·MnBr2) co-crystallizes with 5.69% of the monophosphine oxide analogue (1O·MnBr2) and two tetrahydrofuran (THF) molecules, namely [N2,N6-bis(di-tert-butylphosphanyl)pyridine-2,6-diamine]dibromidomanganese(II)–[bis(di-tert-butylphosphanyl)({6-[(di-tert-butylphosphanyl)amino]pyridin-2-yl}amino)phosphine oxide]dibromidomanganese(II)–tetrahydrofuran (0.94/0.06/2), [MnBr2(C21H41N3P2)]0.94[MnBr2(C21H41N3OP2)]0.06·2C4H8O. The1·MnBr2and1O·MnBr2complexes are occupationally disordered about general positions. Both complexes feature square-pyramidal coordination of the MnIIatoms. They are connected by weak N—H...Br hydrogen bonding into chains extending along [001]. The THF molecules are located between the layers formed by these chains. One THF molecule is involved in hydrogen bonding to an amine H atom.

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