Premium
The Added Value of Solid‐State Pb NMR Spectroscopy to Understand the 3D Structures of Pb Amino Acid Complexes
Author(s) -
Gasque Laura,
Verhoeven Michiel A.,
Bernès Sylvain,
Barrios Fabiola,
Haasnoot Jaap G.,
Reedijk Jan
Publication year - 2008
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.200800535
Subject(s) - chemistry , deprotonation , counterion , crystallography , crystal structure , valine , single crystal , nuclear magnetic resonance spectroscopy , amino acid , ion , stereochemistry , organic chemistry , biochemistry
Single‐crystal X‐ray diffraction and solid‐state 207 Pb NMR spectroscopic experiments have been conducted on four lead amino acid complexes with nitrato or perchlorato counterions, namely neutral isoleucine ( 1 ), deprotonated leucine ( 2 ), monodeprotonated aspartic acid ( 3 ), and neutral valine ( 4 ). The crystal structures reveal that the Pb II ions are preferably coordinated by oxygen atoms and that the amine group of the amino acids is coordinated only in the case of leucine. The results of the solid‐state NMR spectroscopic experiments are compared to the 3D structures obtained from single‐crystal X‐ray data. The NMR spectroscopic experiments show one, two, one, and four lead sites for the Hile, leu – , Hasp – , and Hval complexes, respectively, in agreement with crystal structures. The application of this method towards the characterization of new Pb compounds, for which no 3D structure is known, is discussed and illustrated with an example where a mechanical mixture of two lead complexes is characterized successfully. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)