F19andP

Gold(I) and Silver(I) Complexes of Diphosphacyclobutadiene Cobaltate Sandwich Anions

“…Due to extremely short transverse relaxation times of the phosphorus nuclei (most probably due to rapid fluctuations occurring in the Zeeman states of the quadrupolar cobalt nuclei in close proximity to the 31 P nuclei), standard 2D MAS NMR spectroscopic techniques for assigning the resonances [29] were unsuccessful. Nevertheless, 31 P SPARTAN (Selective Population Anti-z and Rate of Transfer to Adjacent Nuclei) experiments, by using crossrelaxation effects between spatially close or bonded phosphorus nuclei, [30] clearly confirm the proposed peak assignments since significant spectral spin-diffusion is observed between the P atoms detected at d = 27.5 and À43.4 ppm ( Figure 5). We assign the resonance at the lowest frequency Table 2. 31 P chemical shielding anisotropy parameters of compounds 6 and 8, in the first case extracted from a slow-spinning 31 …”

Local structure of hydroxy–peroxy apatite: A combined XRD, FT-IR, Raman, SEM, and solid-state NMR study

“…Kaflak et al [22][23][24] obtained the dynamics of 1 H-31 P cross polarization in some natural bone. Yesinowski and Eckert [25][26][27][28][29][30][31][32][33][34][35][36] demonstrated the utility of 1 H, 19 F, and 31 P MAS NMR spectroscopy in studying pure HAp, HAp-containing fluoride, fluoroapatite, and other calcium phosphates. Using a series of NMR techniques, Isobe et al [37] studied the local structure of calcium phosphate nanoparticles synthesized by a wet-mechanochemical reaction.…”

Determination of the antimony substitution site in calcium fluorapatite from powder X-ray diffraction data

“…Combining the data of Fig. l(a) with recent 19F solid-state NMR observations (Moran, Yesinowski, & Berkowitz, 1991) indicates the presence of more than one antimony environment (about 75% giving the 686 cm-~ peak in the 2%Sb sample) and 'explains' the scatter in Fig. l(a).…”