Chemical shift requires the knowledge of both the sample and a reference magnetic shielding. In few cases as nitrogen (15N), the standard experimental reference corresponds to its liquid phase. Theoretical estimate of NMR magnetic shielding parameters of compounds in their liquid phase is then mandatory but usually replaced by an easily-get gas phase value, forbidding direct comparisons with ex...

Polycyclic aromatic hydrocarbons (PAHs) are a class of compounds consisting of more than twobenzene rings fused in a linear, angular, or clustered arrangement and do not contain hetero atomsor carry subsistent. PAHs originate from various sources. They are primarily formed byincomplete combustion of carbon-containing fuels such as wood, coal, diesel, fat, or tobacco. Thepresent study reports an...

IUPAC has published a number of recommendations regarding the reporting of nuclear magnetic resonance (NMR) data, especially chemical shifts. The most recent publication [Pure Appl. Chem. 73, 1795 (2001)] recommended that tetramethylsilane (TMS) serve as a universal reference for reporting the shifts of all nuclides, but it deferred recommendations for several aspects of this subject. This docu...

Calculations for 125Te magnetic shielding constants and chemical shifts were carried out using a quasirelativistic Hamiltonian including the spin-free relativistic, oneand two-electron spin–orbit, and relativistic magnetic interaction terms. For the tellurium-containing series Te(CH3)2, TeH2, TeF6, Te(CH3)4, and Te(CH3)2Cl2, the relativistic effects amounted to as much as 1300 ppm and were very...

The development of UV-shielding materials has attracted considerable attention in the field of coatings and sunscreen. This paper reports the UV-shielding mechanism of layered double hydroxide (LDH) materials in terms of chemical composition, structure and morphology, by using (LDH/PAA)n films (n stands for bilayer number) through alternate LBL assembly of LDH nanoparticles and poly(acrylic aci...

IUPAC has published a number of recommendations regarding the reporting of nuclear magnetic resonance (NMR) data, especially chemical shifts. The most recent publication [Pure Appl. Chem. 73, 1795 (2001)] recommended that tetramethylsilane (TMS) serve as a universal reference for reporting the shifts of all nuclides, but it deferred recommendations for several aspects of this subject. This docu...

In this research, geometrical structures of armchair single walled boron nitride nanotube (SWBNNT) and armchair single walled aluminum nitride nanotube (SWAlNNT) were optimized by Density Functional Theory (DFT) in the gas phase, both having the same length of 5 angstrom and n=9, m=9. B3LYP/6-31G* level of theory have been used to determine and compare electronic properties, n...

In this research, geometrical structures of armchair single walled boron nitride nanotube (SWBNNT) and armchair single walled aluminum nitride nanotube (SWAlNNT) were optimized by Density Functional Theory (DFT) in the gas phase, both having the same length of 5 angstrom and n=9, m=9. B3LYP/6-31G* level of theory have been used to determine and compare electronic properties, n...

During the 1960s Andrew and others examined the rapid spinning of a sample about an axis that makes an angle of 54” 44’ with the direction of the static magnetic field (I-LJ in order to remove broadening effects in the NMR spectra of solids (l-3). It was much later when Schaefer and Stejskal (4) applied this approach, magic-angle spinning (MAS), to remove broadening due to chemical shift anisot...

We have determined the hydrogen-bond geometry in liquid water from 0 to 80 degrees C by combining measurements of the proton magnetic shielding tensor with ab initio density functional calculations. The resulting moments of the distributions of hydrogen-bond length and angle are direct measures of thermal disorder in the hydrogen-bond network. These moments, and the distribution functions that ...