High-power proton decoupling, cross-polarization, and magic-angle spinning techniques have been employed to obtain high-resolution 31 3P NMR spectra of solid tertiary phosphines, tertiary phosphine oxides, and tertiary phosphine complexes of nickel(II), palladium(II), and platinum(II). Solid-state effects can result in nonequivalence of 31P shieldings in simple di-[PtCl2(PR3)2] complexes. The magnitudes of the scalar couplings, V(195Pt,31P), in platinum(II) complexes are comparable with those obtained by high-resolution solution 31P NMR measurements, allowing the geometry of such complexes to be determined in the solid state. The ligand Ph2PCH2CH2Si(OEt}3 and its Ni(II), Pd(II), and Pt(II) complexes have been immobilized on silica gel and high-surface-area glass beads and the immobilized species studied by solid-state 31P NMR. The results show that the geometry of surface-immobilized complexes may be determined and the surface reactions may be monitored. The merits of some preparative routes to supported transition-metal catalysts have been studied and some common representations of surface reactions and surface-immobilized species shown to be misleading.

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The basis of the combined cross-polarization-magic-angle spinning (c.p.-m.a.s.) experiment, which yields high-resolution n.m.r. spectra of solid materials, is described and the general applicability of the technique, including its quantitative reliability, discussed. Solid-state n.m.r. is in many ways complementary to X-ray diffraction, as shown by its application to amorphous systems in which diffraction methods cannot be used (for example resins, coals, glasses and surface-immobilized catalysts) and also by its application to crystalline materials where X-ray structural data are available but where, for various reasons, a fuller description of the structure may be obtained by n.m.r. Examples include zeolites and chemically exchanging solid systems. The technique also provides a bridge between the solid-state structures of conformationally mobile and charged species as determined by diffraction techniques and the structures of these species in solution. Quantitative reliability of the c.p.-m.a.s. technique has been evaluated for phenolic resins and coals.

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