Supramolecular Capsules: Strong versus Weak Chalcogen Bonding

Abstract

Resorcin[4]arene cavitands containing either 2,1,3benzotelluradiazole or 2,1,3-benzothiadiazole motifs were dimerizedt os upramolecular capsules by chalcogen bonding. Their respective behavior varied depending on the interaction strength of the chalcogen bonds with Te forming strong interactions and Sweak interactions.The tremendous strength of multiple 2Te-2N square interactions led to formation of ac halcogen-bonded dimeric capsule in all solvents,a ss hown by X-rayc rystal structures with 16 short Te···N distances ( 2.9 )a nd confirmed by native electrosprayi onization mass spectrometry (ESI-MS). With the Sc avitand, solventdependent crystallization resulted in different arrangements: either ashifted 2S-2N square-bonded capsule or an interlocked 1D polymer with an infinite p-p stackinga rray. The association constant to form the dimeric capsule in [D 8 ]THF at 283 K, solely based on weak 2S-2N square interactions,w as determined as K a = 786 m À1 .

Double Chalcogen Bonds: Crystal Engineering Stratagems via Diffraction and Multinuclear Solid‐State Magnetic Resonance Spectroscopy

“…This multifacetedw ork also establishes an understanding of the relationship between the geometry and local electronic environment of chalcogen bonds and chemical shift tensors, with the support of quantum chemicala nalysis. The combination of various experimental and computational methods employed in this study,a sw ell the insights gained, provide new directions for studyingm ore complex chalcogen bond environments involved in supramolecular self-assembly, [11] organocatalysis, [12] conducting polymers, [41] biological molecules, [42] and other systems where X-ray diffraction techniques mayp rovide an incomplete picture.…”

“…In the Se and the Te systems, the sum of Cl À lone pair and selenium p lone pair orbitals make as ignificantly positive contributiont od 11 .T he magnitude of these contributionsd ecreases as the NÀCh···Cl À distance shortens.T he chalcogen p lone pair orbitals also make ap ositive contribution to the intermediate component d 22 and the magnitude of this contribution also decreases as the NÀCh···Cl À distance shortens. The Cl À lone pairc ontributions were only observed significantly for d 11 for selenium, but wereo bserved in all of the three tellurium principal components.…”

“…[10] Among these interactions, chalcogenb onding (ChB) garners special attention duet ot he high polarizabilities of the electrophilicc halcogen atomss uch as S, Se, andT e( Figure 1). Recent reports have revealed thati ntra andi ntermolecularC hB plays ak ey role in supramolecular self-assembly, [11] organic reactivity, [12] anion recognition and transport, [13] pharmaceuticalo ral solids, [14] and structuralbiology. [15] According to the recommendation of IUPAC, the term chalcogen bondingr efers to the net attractive interaction between an electrophilic region associated with ac halcogena tom in a molecular entity and an ucleophilic region in another,o rt he same, molecular entity.…”

Supramolekulare Kapseln: starke und schwache Chalkogenbrücken im Vergleich

“…[15] Eine große Differenz in der Assoziationsstärke zwischen Te ···N-und S···N-Wechselwirkungen verursachte bemerkenswerte Unterschiede in den Festkçrperstrukturen. [15] Eine große Differenz in der Assoziationsstärke zwischen Te ···N-und S···N-Wechselwirkungen verursachte bemerkenswerte Unterschiede in den Festkçrperstrukturen.…”

“…[20] So dominiert in chlorierten Lçsungsmitteln (beispielsweise CH 2 Cl 2 ;siehe Abbildung S9a in den Hintergrundinformationen) die flache Drachen-Konformation mit äquatorial orientierten Wänden, was durch eine hochfeldverschobene Methinresonanzfrequenz von d = 4.2 ppm angedeutet wird. [15] Angewandte Chemie Zuschriften die tiefe Kavitätz us olvatisieren (z. b) Draufsicht auf 2:Die Verkapselung von zwei 2,1,3-Benzothiadiazol-Einheiten führt zu einer Aufweitungd er Kavität.…”