A new Z %26apos; = (2+0.5+0.5) amidophosphoester structure: Hirshfeld surface analysis of symmetry-independent molecules

作者：Keikha Mojtaba; Pourayoubi Mehrdad; Tarahhomi Atekeh; van der Lee Arie

来源：Zeitschrift fur Kristallographie-Crystalline Materials, 2017, 232(6): 453-462.

DOI：10.1515/zkri-2016-2032

• amidophosphoester
• asymmetric unit
• finger-print plot
• Hirshfeld surface analysis
• hydrogen bond

Tetraethyl 1,3-phenylenebis(phosphoramidate) was synthesized and characterized by H-1, C-13, P-31 NMR, IR and mass spectroscopies. The asymmetric unit is composed of two half-molecules, each residing on a twofold axis, and two complete molecules, thus leading to a Z' = (2 + 0.5 + 0.5) = 3 structure. The most plausible explanation for the occurrence of multiple independent molecules is a frustration between relatively strong hydrogen bond interactions and weaker CH center dot center dot center dot pi interactions. In each of the molecules, the P atoms are in a similar distorted tetrahedral environment. The N atoms bonded to P atoms have mainly sp(2) character tending towards a planar environment. In the crystal structure, the phosphoryl O atoms are involved in classical N-H center dot center dot center dot O=P and weaker C-H center dot center dot center dot O = P hydrogen bonds as (N-H)(C-H)center dot center dot center dot O= P, acting as a double hydrogen-bond acceptor. These hydrogen bonds along with other C-H center dot center dot center dot O hydrogen bonds and C-H center dot center dot center dot p-interactions create a 3D crystalline network. Hirshfeld surfaces and two-dimensional (2D) fingerprint plots are calculated for analyzing intermolecular interactions in each of the independent molecules of the title compound. For all four independent molecules, the contribution of H center dot center dot center dot H contacts to the total interactions is decisive, being larger than 60% for each molecule. The O center dot center dot center dot H/H center dot center dot center dot O contacts are the characteristic intermolecular contacts in the corresponding molecules. Furthermore, the C center dot center dot center dot H/H center dot center dot center dot C, including the C-H center dot center dot center dot pi interactions, and N center dot center dot center dot H/H center dot center dot center dot N contacts cover other intermolecular contacts in the crystal lattice.

• 出版日期2017-6