عنوان
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The mutual influence of Y···N and H···H interactions in XHY···NCH···HM complexes (X = F, Cl, Br; Y = S, Se; M = Li, Na, BeH, MgH): tuning of the chalcogen bond by dihydrogen bond interaction
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عنوان مجله
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CANADIAN JOURNAL OF CHEMISTRY
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کلیدواژهها
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chalcogen bond, electrostatic potential, ab initio, cooperativity, NMR.
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چکیده
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The equilibrium structures, interaction energies, and bonding properties of ternary XHY···NCH···HM complexes are
studied by ab initio calculations, where X = F, Cl, Br, Y = S, Se, and M = Li, Na, BeH, MgH. The ab initio calculations are carried out
at the MP2/aug-cc-pVTZ level. The results indicate that all optimized Y···N and H···H binding distances in the ternary complexes
are smaller than the corresponding values in the binary systems. The calculated cooperative energies (E coop ) are between
−0.20 kcal/mol in BrHS···NCH···HBeH and −3.29 kcal/mol in FHSe···NCH···HNa. For a given Y and M, the estimated E coop values
increase as X = F > Cl > Br. In addition, the selenium-bonded complexes exibit larger E coop values than those of the sulfur-bonded
counterparts. The cooperativity between Y···N and H···H interactions is further analyzed by quantum theory of atoms in
molecules and natural bond orbital methods. Cooperative effects make an increase in the J(Y–N) and J(H–H) spin–spin coupling
constants of the ternary complexes with respect to the binary systems.
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