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Full-Text Articles in Physical Sciences and Mathematics
C···O And Si···O Tetrel Bonds: Substituent Effects And Transfer Of The Sif3 Group, Zhihao Niu, Qiaozhuo Wu, Qingzhong Li, Steve Scheiner
C···O And Si···O Tetrel Bonds: Substituent Effects And Transfer Of The Sif3 Group, Zhihao Niu, Qiaozhuo Wu, Qingzhong Li, Steve Scheiner
Chemistry and Biochemistry Faculty Publications
The tetrel bond (TB) between 1,2-benzisothiazol-3-one-2-TF3-1,1-dioxide (T = C, Si) and the O atom of pyridine-1-oxide (PO) and its derivatives (PO-X, X = H, NO2, CN, F, CH3, OH, OCH3, NH2, and Li) is examined by quantum chemical means. The Si···O TB is quite strong, with interaction energies approaching a maximum of nearly 70 kcal/mol, while the C···O TB is an order of magnitude weaker, with interaction energies between 2.0 and 2.6 kcal/mol. An electron-withdrawing substituent on the Lewis base weakens this TB, while an electron-donating group has the opposite …
Anion–Anion Interactions In Aerogen-Bonded Complexes. Influence Of Solvent Environment, Anna Grabarz, Mariusz Michalczyk, Wiktor Zierkiewicz, Steve Scheiner
Anion–Anion Interactions In Aerogen-Bonded Complexes. Influence Of Solvent Environment, Anna Grabarz, Mariusz Michalczyk, Wiktor Zierkiewicz, Steve Scheiner
Chemistry and Biochemistry Faculty Publications
Ab initio calculations are applied to the question as to whether a AeX5− anion (Ae = Kr, Xe) can engage in a stable complex with another anion: F−, Cl−, or CN−. The latter approaches the central Ae atom from above the molecular plane, along its C5 axis. While the electrostatic repulsion between the two anions prevents their association in the gas phase, immersion of the system in a polar medium allows dimerization to proceed. The aerogen bond is a weak one, with binding energies less than 2 kcal/mol, even in highly polar aqueous solvent. The complexes are …
Theoretical Studies Of Ir And Nmr Spectral Changes Induced By Sigma-Hole Hydrogen, Halogen, Chalcogen, Pnicogen, And Tetrel Bonds In A Model Protein Environment, Mariusz Michalczyk, Wiktor Zierkiewicz, Rafał Wysokiński, Steve Scheiner
Theoretical Studies Of Ir And Nmr Spectral Changes Induced By Sigma-Hole Hydrogen, Halogen, Chalcogen, Pnicogen, And Tetrel Bonds In A Model Protein Environment, Mariusz Michalczyk, Wiktor Zierkiewicz, Rafał Wysokiński, Steve Scheiner
Chemistry and Biochemistry Faculty Publications
Various types of σ-hole bond complexes were formed with FX, HFY, H2FZ, and H3FT (X = Cl, Br, I; Y = S, Se, Te; Z = P, As, Sb; T = Si, Ge, Sn) as Lewis acid. In order to examine their interactions with a protein, N-methylacetamide (NMA), a model of the peptide linkage was used as the base. These noncovalent bonds were compared by computational means with H-bonds formed by NMA with XH molecules (X = F, Cl, Br, I). In all cases, the A–F bond, which lies opposite the base and is responsible for …
Comparison Between Hydrogen And Halogen Bonds In Complexes Of 6-Ox-Fulvene With Pnicogen And Chalcogen Electron Donors, Mingchang Hou, Qing-Zhong Li, Steve Scheiner
Comparison Between Hydrogen And Halogen Bonds In Complexes Of 6-Ox-Fulvene With Pnicogen And Chalcogen Electron Donors, Mingchang Hou, Qing-Zhong Li, Steve Scheiner
Chemistry and Biochemistry Faculty Publications
Quantum chemical calculations are applied to complexes of 6‐OX‐fulvene (X=H, Cl, Br, I) with ZH3/H2Y (Z=N, P, As, Sb; Y=O, S, Se, Te) to study the competition between the hydrogen bond and the halogen bond. The H‐bond weakens as the base atom grows in size and the associated negative electrostatic potential on the Lewis base atom diminishes. The pattern for the halogen bonds is more complicated. In most cases, the halogen bond is stronger for the heavier halogen atom, and pnicogen electron donors are more strongly bound than chalcogen. Halogen bonds to chalcogen atoms strengthen in the order O
Effect Of Magnesium Bond On The Competition Between Hydrogen Bond And Halogen Bond And The Induction Of Proton And Halogen Transfer, Hui-Li Xu, Qing-Zhong Li, Steve Scheiner
Effect Of Magnesium Bond On The Competition Between Hydrogen Bond And Halogen Bond And The Induction Of Proton And Halogen Transfer, Hui-Li Xu, Qing-Zhong Li, Steve Scheiner
Chemistry and Biochemistry Faculty Publications
HOX (X=Cl, Br, I, and At) can engage in either a H‐bond (HB) or halogen bond (XB) with a base‐like HCN, NH3, and imidazole. Although the former is energetically preferred for X=Cl and Br, it is the XB that is more stable for At, with I showing little preference. MgY2 forms a Mg‐bond with the O atom of HOX, which grows stronger in the order X=Cl
Implications Of Monomer Deformation For Tetrel And Pnicogen Bonds, Wiktor Zierkiewicz, Mariusz Michalczyk, Steve Scheiner
Implications Of Monomer Deformation For Tetrel And Pnicogen Bonds, Wiktor Zierkiewicz, Mariusz Michalczyk, Steve Scheiner
Chemistry and Biochemistry Faculty Publications
A series of TF4 and ZF5 molecules (T = Si, Ge, Sn and Z = P, As, Sb) were allowed to engage in tetrel and pnicogen bonds, respectively, with NH3, pyrazine, and HCN. The interaction energies are quite large, approaching 50 kcal mol-1 in some cases. The formation of each complex is accompanied by substantial geometrical deformation of the Lewis acid to accommodate the approaching base. The energy associated with this monomer rearrangement is the largest for the smaller central atoms Si and P, where it exceeds 20 kcal mol-1. The total reaction …
Detailed Comparison Of The Pnicogen Bond With Chalcogen, Halogen And Hydrogen Bonds, Steve Scheiner
Detailed Comparison Of The Pnicogen Bond With Chalcogen, Halogen And Hydrogen Bonds, Steve Scheiner
Chemistry and Biochemistry Faculty Publications
The characteristics of the pnicogen bond are explored using a variety of quantum chemical techniques. In particular, this interaction is compared with its halogen and chalcogen bond cousins, as well as with the more common H-bond. In general, these bonds are all of comparable strength. More specifically, they are strengthened by the presence of an electronegative substituent on the electron-acceptor atom, and each gains strength as one moves down the appropriate column of the periodic table, for example, from N to P to As. These noncovalent bonds owe their stability to a mixture in nearly equal parts of electrostatic attraction …