SH···N and SH···P blue-shifting H-bonds and N···P interactions in complexes pairing HSN with amines and phosphines

Abstract

Quantum calculations at the MP2/aug-cc-pVDZ level examine complexes pairing HSN with aliphatic amines and phosphines. Complexes are cyclic and contain two attractive interactions. The first is a SH···N/P H-bond in which the S-H covalent bond contracts and shifts its stretching frequency to the blue, more so for amines than for phosphines. The second interaction is different for the amines and phosphines. The amines engage in a NH···N H-bond comparable in strength to the aforementioned SH···N interaction. In contrast, the second interaction in the phosphine complexes is a direct N···P attraction without an intervening H. This interaction is due in part to opposite partial charges on the N and P atoms, as well as covalent forces generated by charge transfer effects.

Mutual influence between anion–π and pnicogen bond interactions: The enhancement of P⋯N and P⋯O interactions by an anion–π bond

“…The pnicogen bond is a Lewis acid−Lewis base attractive interaction in which a pnicogen atom (N, P, As or Sb) act as the Lewis acid [19][20][21][22]. Politzer and Murray [23,24] associated its origin with the presence of an σ-hole in the prolongation of the R-Pn bond (where R is an electron-withdrawing group and Pn is a pnicogen atom), that interacts with an electron-rich moiety of a Lewis base (B) through an essentially electrostatic R-Pn···B interaction.…”

Pnicogen–pnicogen interactions in O2XP:PH2Y complexes (X=H, F, CN; Y=H, OH, OCH3, CH3, NH2)

“…Another possible mechanism for the formation of pnicogen bonds is the charge transfer from the lone pair of the base to the * X P  orbital of the acid. The extensive studies performed by Scheiner [11][12][13][14][15][16][17] and Alkorta's group [18][19][20][21][22][23][24][25][26][27][28] in the last few years highlight the significant role of orbital interaction as a potential source of the stability of pnicogen-bonded complexes. For a given base, the favorable mechanism depends on the nature of the pnicogen atom itself as well as the pnicogen-containing molecule.…”

An ab initio study on the concerted interaction between chalcogen and pnicogen bonds

“…Therefore, the pnicogen atoms (N, P, As and Sb) can also interact with an electron donor to form a noncovalent interaction, which is similar in nature to the halogen bond. The wellknown "pnicogen bond" usually refers to the noncovalent RPn⋯B interaction, in which the pnicogen atom (Pn) acts as a Lewis acid and B is an electron donor [41][42][43]. Pnicogen bond interactions have been studied widely, both theoretically [44][45][46] and experimentally [47].…”