Multinuclear NMR spectroscopy in inorganic chemistry

In this section, we introduce the applications of NMR spectroscopy to inorganic systems, not only to determine the numbers and environments of particular nuclei, but also to investigate (usually in solution) the dynamic behaviour of molecular species. A detailed description of the technique of NMR spectroscopy is beyond the scope of this book, but appropriate references are listed at the end of the chapter. In the discussion that follows, we assume that readers are already familiar with the concepts of H and NMR spectroscopies, including homonuclear H— H and heteronuclear C— H spin-spin coupling. A factual summary is given in Box 3.4. 

Each of the nuclei H and C has a magnetic spin quantum number I =, and when C and H nuclei are in close proximity, they can couple. However, in molecules containing a natural isotopic distribution of carbon atoms, only 1% are C nuclei. From a statistical consideration, it follows that in a H NMR spectrum of, for example, acetone, C- H coupling is not observed, although it is observed in the C NMR spectrum of the same sample. The C NMR spectrum of acetone exhibits a singlet due to the C=0 carbon atom, and a quartet due to the two equivalent methyl C nuclei. 

The 100 MHz H spectrum of butanone is shown below, and consists of a quartet, a singlet and a triplet. The coupling 

In this section, we introduce the applications of NMR spectroscopy to inorganic systems, not only to determine the numbers and environments of particular nuclei, but also to investigate (usually in solution) the dynamic 

---

Multinuclear NMR- ( C, Pt, T1), 1R-, Raman-spectroscopy. Electron Spectroscopy for Chemical Analysis (ESCA), X-ray, and Extended X-ray Absorption Fine Structure (EXAFS) studies confirm direct, short (2.60-2.64 A) Pt-Tl bonds. Figure 1. shows a typical ° T1 NMR spectrum of [(N C)5Pt-Tl( CN)] together with the structure determined by EXAFS. The spin-spin coupling pattern is consistent with 4 -h 1 - -1 equivalentligands (I = 1/2), respectively and one Pt nucleus (natural abundance 33.8%, 1=1 /2). The spectrum has been selected to illustrate the usefulness of T1 NMR spectroscopy in studies of the inorganic chemistry of thallium. The compounds are diamagnetic, and... 

Professor Norbert W. Mitzel is professor of inorganic and structural chemistry at the University of Bielefeld. After preparative work on phosphorus ylides and then volatile silicon hydrides and Si-N compounds for CVD purposes, he studied weak intramolecular Si- -N interactions, poly-Lewis acids of B, Al, Ga and In, and later also organometallic lithium and lanthanide chemistry. He was particularly involved in multinuclear NMR spectroscopy. X-ray crystallography, including in-situ crystal growth of low-melting substances, and gas electron diffraction. 

---