Phosphorus-31 NMR Spectroscopy : A Concise Introduction for the Synthetic Organic and Organometallic Chemist

Nuclear Magnetic Resonance is a powerful tool, especially for the identification of 1 13 hitherto unknown organic compounds. H- and C-NMR spectroscopy is known and applied by virtually every synthetically working Organic Chemist. Con- quently, the factors governing the differences in chemical shift values, based on chemical environment, bonding, temperature, solvent, pH, etc. , are well understood, and specialty methods developed for almost every conceivable structural challenge. Proton and carbon NMR spectroscopy is part of most bachelors degree courses, with advanced methods integrated into masters degree and other graduate courses. In view of this universal knowledge about proton and carbon NMR spectr- copy within the chemical community, it is remarkable that heteronuclear NMR is still looked upon as something of a curiosity. Admittedly, most organic compounds contain only nitrogen, oxygen, and sulfur atoms, as well as the obligatory hydrogen and carbon atoms, elements that have an unfavourable isotope distribution when it comes to NMR spectroscopy. Each of these three elements has a dominant isotope: 14 16 32 16 32 N (99. 63% natural abundance), O (99. 76%), and S (95. 02%), with O, S, and 34 14 S (4. 21%) NMR silent. N has a nuclear moment I = 1 and a sizeable quadrupolar moment that makes the NMR signals usually very broad and dif cult to analyse. "The book is intended for an audience already familiar with proton and carbon NMR and commencing research in phosphane chemistry (broadly defined)." "It is the primary aim of this book to enable the reader to identify the main factors governing the phosphorus chemical shift values in the [superscript 31]P-NMR spectrum and to make an educated guess as to where the phosphorus resonance(s) of a given target compound can be expected. It is not within the scope of this book to enable one to predict a phosphorus chemical shift precisely or even within a reasonable margin of error, with a few notable exceptions." "The further intent of this book is to assist the reader in determining important issues like bond order, [pi]-bonding contributions from substituents, the existence or non-existence of metallacycles etc., in short, to make structural assignments without the aid of X-ray crystal structure determinations and to explain structural differences in solution and the solid state where appropriate." --Résumé de l'éditeur