High-Resolution Metal NMR Spectroscopy of Organometallic Compounds [New Analytical Methods (30)]

Great advances have been made in the past decade in the field of NMR spectroscopy. Apart from the development of completely new areas of application, such as in solid-state chemistry, in materials science, in physiological chemistry, and in medicine, with the introduction of new pulse spectroscopic methods and the application of high magnetic field strengths important progress has also been made in the traditional field of high-resolution NMR spectroscopy. Thus, among other things, the observation of metal resonances has been facilitated and new areas of application have been opened up in inorganic and organometallic chemistry. In this review, recent detection methods for spin-1/2 and quadrupolar metal nuclei are presented and discussed. The use of metal-NMR spectroscopy with respect to problems of a typical chemical nature, mainly from the field of organometallics, is demonstrated for a number of selected metal nuclei (²⁵Mg, ²⁷Al, ⁴⁹Ti, ⁵⁷Fe, ⁵⁹Co, ⁶¹Ni, ⁹¹Zr, ¹⁰³Rh, and ¹⁹⁵Pt). Relations found empirically between chemical shifts and coordination number, oxidation number, and electronic configuration of a metal bound in a complex are emphasized. Furthermore, cases in which the chemical shifts of metal nuclei can be interpreted in terms of the energy difference of frontier orbitals are presented. This aspect leads to the establishment of a relationship between chemical reactivity and NMR parameters for a series of related compounds.     

The alkaloids of Delphiniumbicolor nutt.

The structures of alkaloid-$\text{A}$ and -$\text{B}$ were established via X-ray crystallography of the former as its HI salt, and its chemical conversion to the latter.     

Intermediates in the palladium-catalysed reactions of 1,3- dienes: IV. The reactions of η1,η3-octadienediyl-palladium complexes with alkynes and activated alkenes

The reactions of [Pd(PR₃)(η¹,η³-C₈H₁₂)] complexes with the dimethyl ester of acetylene dicarboxylic acid involves an unusual 1,3-addition of the alkyne to an allyl fragment to give cyclopentene-substituted η³-allylpalladium complexes. p-Benzoquinone and 5-hydroxynaphthoquinone react similarly.     

Transition metal allyls : III. The (η3-allyl)2M complexes of nickel,palladium and platinum: structural considerations

The structures of a series of (η³-allyl)₂M complexes of nickel, palladium and platinum have been investigated with the help of ¹³C NMR, ¹H NMR and Raman spectroscopy. The crystal structure of (η³-cyclooctatrienyl)₂Ni has been determined by X-ray methods; the two nickel-bonded η³-allyl groups are mutually trans.