The X-ray crystal structure determination of
bis[-(phenylcyanamido)bis(triphenylphosphine)copper(I)],
[{Cu(PPh3)2(C6H5NCN)}2],
(1) is reported. The complex has a centrosymmetric dimeric structure with the
phenylcyanamide ligands bridging the copper atoms in a -1,3-fashion. The
structure is compared with that of the 4-methylphenylcyanamido complex,
[{Cu(PPh3)2(4-MeC6H4NCN)}2]
(2), and the differences observed in the Cu–P bond lengths compared with
changes in the solid state 31P cross-polarization
magic-angle spinning (CPMAS) spectra of the two complexes.
Abstract. Chemical shift tensors in 13C solid-state NMR provide valuable localized information on the chemical bonding environment in organic matter, and deviations from isotropic static-limit powder line shapes sensitively encode dynamic-averaging or orientation effects. Studies in 13C natural abundance require magic-angle spinning (MAS), where the analysis must thus focus on spinning sidebands. We propose an alternative fitting procedure for spinning sidebands based upon a polynomial expansion that is more efficient than the common numerical solution of the powder average. The approach plays out its advantages in the determination of CST (chemical-shift tensor) principal values from spinning-sideband intensities and order parameters in non-isotropic samples, which is here illustrated with the example of stretched glassy polycarbonate.
Magic Angle Spinning NMR Structure Determination of Proteins from Pseudocontact Shifts