Anion Recognition by Neutral Chalcogen Bonding Receptors: Experimental and Theoretical Investigations

Abstract

The utilization of neutral receptors for the molecular recognition of anions based on chalcogen bonding (ChB) is an undeveloped area of host‐guest chemistry. In this manuscript, the synthesis of two new families of sulfur, selenium, and tellurium‐based ChB binding motifs are reported. The stability of the thiophene, selenophene, and tellurophene binding motifs has enabled the determination of the association constants for ChB halide anion binding in the polar aprotic solvent THF by 1H, 77Se, and 125Te NMR experiments. Two different aromatic cores are used and one or two Ch‐binding motifs are incorporated with the purpose of encapsulating the anion, offering up to two concurrent chalcogen bonds. Theoretical calculations and NMR experiments reveal that, for S and Se receptors, hydrogen‐bonding interactions involving the acidic H atom adjacent to the chalcogen atom are energetically favored over the ChB interaction. However, for the tellurophene binding motif, the σ‐hole interaction is competitive and more favored than the hydrogen bond.

Zero-, one-, two- and three-dimensional supramolecular architectures sustained by Se…O chalcogen bonding: A crystallographic survey

“…It is stressed that the focus of the present review is upon the role of intermolecular Se … O contacts and upon the supramolecular aggregation patterns they sustain. In general terms, chalcogen interactions find very practical applications in a range of contexts beyond biology and medicine [16] , [17] , [18] , such as in molecular/anion recognition [19] , [20] , [21] , [22] , catalysts [23] , [24] and materials science [25] , [26] . With this level of activity, it is not surprising there are several authoritative reviews of chalcogen bonding [27] , [28] , [29] , [30] , including reviews of different physiochemical procedures for their detection in phases other than in crystals [31] , [32] , [33] , the primary importance of X-ray crystallographic investigations notwithstanding.…”

Versatility of the Cyano Group in Intermolecular Interactions

“…Following many decades of study of the H-bond [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ], a great deal of research has turned to closely related interactions in which the bridging proton is replaced by any of a number of larger atoms, generally drawn from the right side of the periodic table. Depending upon the specific column of the table in which these atoms lie, the noncovalent bonds are typically referred to as halogen, chalcogen, and pnicogen bonds [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. Despite the diversity of the bridging atoms, these various interactions share a number of characteristics.…”

Die Natur starker Chalkogenbindungen unter Beteiligung chalkogenhaltiger Heterocyclen

“…Der Fokus unserer Studien lag auf der Untersuchung der Natur starker Chalkogenbindungen, die vornehmlich zwischen tellurhaltigen Stickstoff‐Heterocyclen und verschiedenen Lewis‐Basen existieren [12, 15, 17, 18, 21, 30–33] . Letztere sind beispielsweise Sauerstoff‐ oder Stickstoffatome von Heterocyclen oder Amiden.…”

“…Während anfangs das grundsätzliche Konzept von Chalkogenbindungen im Fokus stand, [2–8] rückte in jüngster Zeit die Anwendung starker Chalkogenbindungen immer mehr in den Vordergrund [9–11] . So konnte gezeigt werden, dass dieser Bindungstypus auch im Crystal‐Engineering, [12–14] bei der molekularen Erkennung in Lösung [15–21] und in der Katalyse [11, 22–28, 20] verwendet werden kann. Besonders starke und vielversprechende Chalkogenbindungen findet man bei elektronenarmen Tellurverbindungen wie Isotellurazoloxiden [21, 29] oder Tellurdiazolen [18, 30, 31] .…”