Effect of high pressure on the crystal structure and charge transport properties of the (2-fluoro-3-pyridyl)(4-iodophenyl)borinic 8-oxyquinolinate complex

Abstract

The crystal and molecular structure of IJ2-fluoro-3-pyridyl)IJ4-iodophenyl)borinic 8-oxyquinolinate has been determined at room temperature at pressures ranging from ambient to 4.9 GPa in approximately 1 GPa steps. The crystal structure symmetry is conserved during the compression while the a, b and c unit cell dimensions were compressed by 7.5%, 8.0% and 6.9%, respectively. The crystal cell volume decreased by 19.4%. The analysis of the compression of the crystal was supported by computational results obtained with the PASCAL code. They proved that the crystal compression proceeds almost isotropically. A combination of Hirshfeld surface analysis and PIXEL calculations indicated the formation of multiple new contacts involving fluorine⋯fluorine and iodine⋯π-density. Energies of interactions calculated for the observed motifs present in the crystal were rationalized on the basis of contacts observed for these motifs. Further analysis based on the Marcus model was performed to trace the possible changes in the charge transport properties of the crystal. The analysis showed that electron and hole transport properties are not affected in the same way by the compression. However, hydrostatic pressure did not affect which charge transport (electron or hole) is the dominant one for this material.

The halogen bond with isocyano carbon reduces isocyanide odor

“…According to the obtained XRD data (this work) and our processing of the CSD, such σ-donors as isocyanides and the IAd carbene under normal conditions form the shortest I•••C contacts (<3.1 Å) in the crystal state. The other C-based XB acceptors like carbon-involved π-systems also provide short XBs (d XB = 3.07-3.20 Å), but mostly under high external pressure (1.9 and 3.96 GPa) 33,34 . To the best of our knowledge, XBs with other types of C-based σ-donors (e.g., CO or C-ylides), acting as XB acceptors, have never been detected.…”

Tuning of the colour and chemical stability of model boranils: a strong effect of structural modifications

“…11 The optical properties of such complexes can be tuned mainly through the appropriate choice of a ligand acting as a chromophore. 17,18 There is a wide variety of available structures, but among them borinic complexes with (O,N)-chelating ligands have been extensively studied, presumably due to their relatively high (in most cases) stability. 2,[12][13][14][15][16] Moreover, we have proved that different crystal packing induced by either compression in diamond anvil cells or crystallization of different polymorphs can be used to improve charge transport properties (which is very important from the standpoint of application in light emitting devices).…”

“…1), represent their close analogues as they also possess phenolate oxygen and imine nitrogen atoms coordinated to the central B atom by means of covalent and dative bonds, respectively. 2,17,18,26 We observed that the character of aryl groups attached to the boron centre can influence the optical (quantum yield of emission) and other physicochemical (e.g., charge transport) properties. In general, the synthesis of salicylaldimine chelating ligands is simple and efficient.…”

Supramolecular architectures sustained by delocalised C–I⋯π(arene) interactions in molecular crystals and the propensity of their formation

“…as temperature, can have an impact upon the geometric parameters defining weak, intermolecular interactions. 244,245 In this context and the above notwithstanding, it is worth mentioning a room temperature, variable-pressure study 246 of previously described 19, 88…”