Self-Assembly of Fluorinated Boronic Esters and 4,4′-Bipyridine into 2:1 N→B Adducts and Inclusion of Aromatic Guest Molecules in the Solid State: Application for the Separation of o,m,p-Xylene

Abstract

A series of 2:1 fluorinated arylboronic ester adducts with 4,4′-bipyridine sustained by N→B dative bonds have been synthesized. The degree of fluorination in the arylboronic esters derived from catechol is shown to modulate the molecular conformation of the coordinated boronic ester moieties and the intermolecular interactions by means of C−H•••F and F•••F contacts that sustain the crystal lattices. The adduct derived from the catechol ester of 2,4-difluorophenylboronic acid was chosen to examine the formation of inclusion complexes with a large number of aromatic guests, affording solvates, cocrystals, and a cocrystal solvate. Six different crystal structure types with 1:1, 1:2, and 1:2:2 N→B adduct−guest ratios were observed, whose supramolecular organization is strongly influenced by the formation of sandwich-type complexes between the host and guest molecules. The host−guest interactions involve π•••π interactions with the bipyridine linkers and additional contacts with the catecholate and Baryl F substituents, indicating a large flexibility of the N→B adducts to adapt to the guest stereochemistry. The versatility of the crystallization system was employed to isolate o-xylene from an equimolar mixture of o-, m-, and p-xylene.

Boron–Nitrogen Double Tweezers Comprising Arylboronic Esters and Diamines: Self‐Assembly in Solution and Adaptability as Hosts for Aromatic Guests in the Solid State

“…In order to gain insight into the driving forces concerning the host‐guest interactions in these cocrystals, intermolecular interaction energies were computed using the tools implemented in CrystalExplorer . The interaction energies computed for various pairs of host:guest aggregates in cocrystals ( 7 ) 2 BiPy⊃BEN, ( 4 ) 2 DPE⊃ANT, ( 4 ) 2 DMBiPy⊃TTF, and ( 4 ) 2 DMBiPy⊃PYR are gathered in Table . These complexes are representative of the ensembles in these crystal structures (see Figure and SI).…”

“…Individual energy components due to electrostatics, polarization, dispersion and repulsion were not scaled. [b] 7= 2,4‐difluorophenyl‐B‐catecholate and BEN=benzene . [c] ANT=anthracene …”

“… Tweezer:guest aggregates extracted from the crystal structures of cocrystals ( 7 ) 2 BiPy⊃BEN, ( 4 ) 2 DPE⊃ANT, ( 4 ) 2 DMBiPy⊃TTF, and ( 4 ) 2 DMBiPy⊃PYR. Interaction energies were computed for each assembly as summarized in Table .…”

Synthesis of cis‐1,2‐diol‐type chiral ligands and their dioxaborinane derivatives: Application for the asymmetric transfer hydrogenation of various ketones and biological evaluation

“…[14][15][16][17] Besides, main-group elements (p-block elements) offer great potential since they allow the activation of various chemical bonds and, consequently enable chemical transformations. [29,30] In addition, boron-containing compounds have been explored as inhibitors for different biological targets and some of them were approved by FDA as the drugs to treat a variety of diseases such as multiple myeloma, cancer, etc. [31,32] Because of their biological potential as antibacterial, antioxidant and other agents, three-coordinated dioxaborinane and four-coordinated dioxaborinane complexes containing N !…”

Zwitterionic Systems Obtained by Condensation of Heteroaryl‐Boronic Acids and Rhodizonic Acid

“…[14][15][16] Other notable features of boronic acids are the coordination of Lewis basic species through the empty p z orbital of the boron atom and their ability to act as both hydrogen-bond donors and acceptors, that found applications in sensing, crystal engineering and assembly of supramolecular 2D and 3D architectures. [11,12,[17][18][19][20] The second compound of interest for this work is the sixmembered ring oxocarbon rhodizonic acid. Despite being known for almost two centuries, oxocarbon acids continue to spark the interest of researchers due to their unique chemistry.…”