The unexpected roles of σ and π orbitals in electron donor and acceptor group effects on the 13C NMR chemical shifts in substituted benzenes† †Electronic supplementary information (ESI) available: Experimental 13C NMR chemical shifts, individual components of the 13C NMR shielding tensor, lists and graphics of NLMO contributions, and tables of NLMO properties. See DOI: 10.1039/c7sc02163a Click here for additional data file.

Ab Initio Quantum Chemical Studies of 15N and 13C NMR Shielding Tensors in Serine and Complexes of Serine- nH2O: Investigation on Strength of the CαH…O Hydrogen bonding in the Amino Acid Residue.

In this paper, the hydrogen bonding (HB) effects on the NMR chemical shifts of selected atoms in serineand serine-nH2O complexes (from one to ten water molecules) have been investigated with quantummechanical calculations of the 15N and 13C tensors. Interaction with water molecules causes importantchanges in geometry and electronic structure of serine.For the compound studied, the most importan...

Near-IR absorbing donor–acceptor ligand-to-ligand charge-transfer complexes of nickel(ii)† †Electronic supplementary information (ESI) available: Complete experimental procedures, 1H, 13C and VT NMR data, complete electrochemical and solvatochromic analysis, and frontier orbital energies and atomic positions from DFT calculations. CCDC 1414822–1414824. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c5sc02703a Click here for additional data file. Click here for additional data file.

Thermodynamics, Solvents effects and 1H ,13C NMR Shielding :Theoretical studies of Adamantane

Some of the Adamantane properties were calculated in this study. Chemical shift, free energy ofsolvation, free energy of cavity formation, Henry's law constant, and other properties ofAdamantane in dry phase, three solvents and three temperatures have been calculated with Abinitio method base on density functional theory (DFT) at B3lyp/6-31g, B31yp/6-31g*, B3lyp/6-31+g* and B3lyp/6-31++g** leve...

The Conformational Effect of 6-Mono-Substituted and 6,7-Di-Substituted Derivatives of 5,6,7,8-Tetrahydrodibenzo[a,c]cyclo-octene on 13C Chemical Shift

Hartree-Fock (HF) and Density Functional Theory (DFT) methods employed to study the effect of conformational change on the 13C chemical shifts of 6-mono axial and equatorial substituted and 6,7-di axial-axial, equatorial-equatorial and axial-equatorial substitutedderivatives of 5,6,7,8-tetrahydrodibenzo[a,c]cyclo-octene. The geometry of the conformers have been optimized...

2H Isotope Effect on 13C Chemical Shifts of Nitro-Benzo-9-Crown-3

Deuterium substitution on two ortho-substituted-OCH2-fragments in Nitro-Benzo-9-Crown-3 induces low frequency shifts, positive mnDCj, in all 13C NMR resonances which is an indication of the increased shielding in this crown ether. The magnitude of these shifts vary from 15DC7=716 to 54D<...