Republication or reproduction of this report or its storage and/or dissemination by electronic means is permitted without the need for formal IUPAC permission on condition that an acknowledgmentAbstract: A unified scale is recommended for reporting the NMR chemical shifts of all nuclei relative to the 1 H resonance of tetramethylsilane (TMS). The unified scale is designed to provide a precise ratio, Ξ, of the resonance frequency of a given nuclide to that of the primary reference, the 1 H resonance of TMS in dilute solution (volume fraction, ϕ < 1%) in chloroform. Referencing procedures are discussed, including matters of practical application of the unified scale. Special attention is paid to recommended reference samples, and values of Ξ for secondary references on the unified scale are listed, many of which are the results of new measurements.Some earlier recommendations relating to the reporting of chemical shifts are endorsed. The chemical shift, δ, is redefined to avoid previous ambiguities but to leave practical usage unchanged. Relations between the unified scale and recently published recommendations for referencing in aqueous solutions (for specific use in biochemical work) are discussed, as well as the special effects of working in the solid state with magic-angle spinning. In all, nine new recommendations relating to chemical shifts are made.Standardized nuclear spin data are also presented in tabular form for the stable (and some unstable) isotopes of all elements with nonzero quantum numbers. The information given includes quantum numbers, isotopic abundances, magnetic moments, magnetogyric ratios and receptivities, together with quadrupole moments and line-width factors where appropriate.

No abstract

ABSTRACT:A unified scale is recommended for reporting the NMR chemical shifts of all nuclei relative to the 1 H resonance of tetramethylsilane. The unified scale is designed to provide a precise ratio, ⌶, of the resonance frequency of a given nuclide to that of the primary reference, the 1 H resonance of tetramethylsilane (TMS) in dilute solution (volume fraction, Ͻ 1%) in chloroform. Referencing procedures are discussed, including matters of practical application of the unified scale. Special attention is paid to recommended reference samples and values of ⌶ for secondary references on the unified scale are listed, many of which are the results of new measurements. Some earlier recommendations relating to the reporting of chemical shifts are endorsed. The chemical shift, ␦, is redefined to avoid previous ambiguities but to leave practical usage unchanged. Relations between the unified scale and recently published recommendations for referencing in aqueous solutions (for specific use in biochemical work) are discussed, as well as the special effects of working in the solid state with magic-angle spinning. In all, nine new recommendations relating to chemical shifts are made. Standardized nuclear spin data are also presented in tabular form for the stable (and some unstable) isotopes of all elements with non-zero

No abstract

Single-crystal neutron diffraction has allowed accurate characterisation of N-H Pt and N-H CI interactions linking the two square-planar platinum(ii) units which comprise the dianion of NPr",],[PtCI,]~cis-[PtCI,(NH,Me),] 1: Pt... H 2.262(11) A, N-H ... Pt 167.1(9)"; CI... H 2.318(12) 6 , N-H CI 151.0(12)". An extensive network of C-H CI hydrogen bonding between the cation and anion species is also revealed, and provides valuable information on what is one of the least well characterised types of hydrogen bond. A weak C-H 9 . Pt interaction between one cation unit and the anion is also observed. In the light of this and particularly the stronger intra-anion N-H * With the exception of disordered methyl hydrogen atoms in one cation unit, for which peaks were too close to permit refinement at this data resolution, ie., H --H' x 0.33 A, CJ resolution of sine/h < 0.57 k' (&,, = 0.88 A).