Boron as an Electron-Pair Donor for B⋅⋅⋅Cl Halogen Bonds

摘要: MP2/aug'-cc-pVTZ calculations were performed to investigate boron as an electron-pair donor in halogen-bonded complexes (CO)2 (HB):ClX and (N2 )2 (HB):ClX, for X=F, Cl, OH, NC, CN, CCH, CH3 , H. Equilibrium with the are found on all of potential surfaces, except (HB):ClCH3 (HB):ClF. The majority these stabilized by traditional halogen bonds, (HB):ClF, (HB):ClCl, (HB):ClOH, which chlorine-shared bonds. These have increased binding energies shorter B-Cl distances. Charge transfer stabilizes occurs from B lone pair σ* Cl-A orbital ClX, A is atom X directly bonded Cl. second reduced charge-transfer interaction Cl π* C≡O orbitals. Equation-of-motion coupled cluster singles doubles (EOM-CCSD) spin-spin coupling constants, 1x J(B-Cl), across bonds also indicative changing nature this bond. J(B-Cl) values both series positive at long distances, increase distance decreases, then decrease change begin approach covalent corresponding ions [(CO)2 (HB)-Cl]+ [(N2 . Changes 11 chemical shieldings upon complexation correlate changes charges B.