Pnictogen bonding with alkoxide cages: which pnictogen is best?

Abstract

Antimony cages have the best balance between strength and directionality compared to the other congeners.

Self-assembly of reversed bilayer vesicles through pnictogen bonding: water-stable supramolecular nanocontainers for organic solvents

“…The heavier pnictogen thiolate cages are more Lewis acidic as a result of increasing stereochemical inactivity of the lone pairs and the increasing polarity of the primary bonds. This is in line with ndings for the analogous alkoxide cages 36 and is in line with other experimental and computational ndings for pnictogen, chalcogen and halogen bonding in the +3, +2 and +1 oxidation states, respectively. [37][38][39][40][41][42] Computational study of the pnictogen bonding An oen suggested prerequisite for strong PnBs, following studies on halogen and chalcogen bonding, is the presence of large V max (maximum in the electrostatic potential energy surface calculated on a molecular surface at 0.001 au) 43,44 values associated with the electrophilic regions of the ESP surface.…”

“…The V max values, however, are intermediate to the analogous antimony alkoxide cage, which forms three pnictogen bonds, and the arsenic alkoxide cage, which only forms one in the solid state suggesting a diminished electrostatic contribution to the Sb/S pnictogen bonds. 36 Despite the lower V max values calculated for Sb-1 H, they are still considerably larger than those calculated for As-1 H (Fig. 5a) which further supports the use of the heavier pnictogens for stronger and more PnBs.…”

4,4′-Dipyridyl Dioxide·SbF3 Cocrystal: Pnictogen Bond Prevails over Halogen and Hydrogen Bonds in Driving Self-Assembly

“…While computational studies 9,20,23 and CSD analyses , 18 give consistent and forceful indications that PnB can work as a robust interaction to obtain co-crystals by design, very few cases have been reported where this potential has been explored. 24 In conclusion, results reported here increase the understanding of some key features of PnBs and may be useful in the design and realization of many other PnB driven recognition and self-assembly processes.…”

“…24 Experiments carried out on cocrystal 1 showed substantial changes of spectral parameters relative to pure SbF3 (Figure 4, Table 1). The quadrupolar coupling constants of 1 for 121 Sb and 123 Sb are 509.97 and 649.90 MHz, respectively, consistent with previous observations 24 that stronger and more directional PnBs at antimony are associated with smaller CQ values. It is also worth noting that the CQ values for 1 are comparable to those reported for the SbF3·urea co-crystal which has a chemical environment around the antimony atom somewhat similar to 1 as, in both adducts, the oxygen atom of two nearby electron density donor molecules engage in PnB formation.…”

“…1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 15 N, 34 35/37 Cl, 35 127 I, 36 31 P, 37 17 O, 38 and 39 Se 39 nuclei have been reported to undergo significant modifications on HaB and ChB formation.Tthe usefulness of 121/123 Sb NQR spectroscopy for probing PnBs in adducts formed by SbF3 and SbCl3 was reported. 24 Experiments carried out on cocrystal 1 showed substantial changes of spectral parameters relative to pure SbF3 (Figure 4, Table 1…”