Phosphorus···Iodine Halogen Bonding in Cocrystals of Bis(diphenylphosphino)ethane (dppe) and p-Diiodotetrafluorobenzene (p-F₄DIB)

Abstract

Three new cocrystals of bis­(diphenylphosphino)­ethane (dppe) and p-diiodotetrafluorobenzene (p-F4DIB) were studied using single-crystal X-ray crystallography. Two polymorphs containing a 1:1 dppe:p-F4DIB ratio were obtained, each displaying strong P···I halogen bonding along steplike chains. Additionally, a cocrystal with a 1:3 dppe:p-F4DIB ratio was studied. This cocrystal displays a similar main steplike chain to the 1:1 cocrystals, with pendant p-F4DIB molecules along the chain. In all three of the cocrystals, face-to-face and face-to-edge interactions involving both the phenyl rings and the perfluorobenzene rings contribute to the packing of the halogen bonded chains. Computational studies, including Hirshfeld surface analysis and ab initio calculations, were conducted to further elucidate the varying factors contributing to the packing of the cocrystals and the resulting structural stability.

Solid-state multinuclear magnetic resonance and X-ray crystallographic investigation of the phosphorus...iodine halogen bond in a bis(dicyclohexylphenylphosphine)(1,6-diiodoperfluorohexane) cocrystal

“…While X-ray crystallography allows us to directly observe the geometrical parameters of the halogen bond, solid-state NMR spectroscopy experiments allow us to confirm the structure of the powdered solid and to investigate the influence of the halogen bond on the isotropic chemical shifts. Part of the novelty of this work lies in establishing the validity of using a nonaromatic perfluorodiiodoalkane as a halogen bond donor to phosphorus, as previous sparse reports of halogen bonds to phosphorus in cocrystalline systems have involved only the now iconic perfluoroiodobenzenes (Xu et al, 2018;Lisac et al, 2019;Siegfried et al, 2020). Further, the dicyclohexylphenylphosphine molecule is used as a halogen bond acceptor for the first time.…”

“…The phosphorus-iodine halogen bonds in cocrystal (1a) may be discussed in the context of the small dataset available for other cocrystals featuring such interactions (Xu et al, 2018;Lisac et al, 2019;Siegfried et al, 2020). For example, a cocrystal of triphenylphosphine with 1,3,5-trifluoro-2,4,6-tri- iodobenzene which crystallizes in the P " 1 1 space group features only a single crystallographically distinct halogen bond characterized at 200 K by a IÁ Á ÁP distance of 3.376 (1) A ˚, a C-IÁ Á ÁP angle of 165.26 (9) and a reduced distance parameter of 0.857 (Xu et al, 2018).…”

“…The C-IÁ Á ÁP halogen bond moiety has remained somewhat elusive due in part to the reactivity of the phosphorus atom (Garabadzhiu, Kuznetsov et al, 1979;Garabadzhiu et al, 1980;Garabadzhiu, Kuznetsov, Shibaev et al, 1979), with the first engineered crystal structures featuring this moiety only being recently reported (Xu et al, 2018;Lisac et al, 2019;Siegfried et al, 2020). Understanding the C-IÁ Á ÁP interaction and its preparation can expand the repertoire of halogen bonds, which could allow crystal engineers to include phosphine molecules in new solid forms.…”

Database Investigation of Halogen Bonding and Halogen···Halogen Interactions between Porphyrins: Emergence of Robust Supramolecular Motifs and Frameworks

“…Importantly, square-shaped arrays of iodine atoms have previously been noted as a recurring motif in structures of halogenated organic and organometallic molecules. [42][43][44][45]137 Representative of a Z-shaped combination of L-nodes is the structure with the CSD code OCIXEG 120 A different example of a four-atom motif emerging from fusing L-shaped nodes is seen in the structures with CSD codes VIKREO 138 and VIKRIS 138 (Figures S45 and S46, respectively), which are tin(IV) tetraiodophenylporphyrins with isonicotinate and pyrimidine-5-carboxylate anions as axial ligands, respectively. While these structures reveal 1-D chains of two-point I•••I type II interactions, on consideration of interhalogen contacts that are only +0.06 Å longer than the sum of van der Waals radii for iodine reveals square-shaped (Sshaped) motifs that can be seen as a combination of two Lnodes, producing sql-type networks (Figure 28c).…”

Synthesis and cationic polymerization of halogen bonding vinyl ether monomers

“…Halogenbonding is the electrostatic interaction between the s-hole of a halogen atom, usually iodine, bromine, or chlorine, although in rare cases uorine has been shown to exhibit this, 4,5 and the lone pair of an electron rich atom such as oxygen, nitrogen, sulfur or even selenium or phosphorous in some cases. [6][7][8][9][10][11][12][13][14][15][16][17] Under appropriate circumstances, even metal centers such as Pd can function as halogen bond acceptors. 18 Compared to other intermolecular interactions, halogen bonding has only recently become more recognized as a reliable intermolecular interaction.…”