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The Distribution of Charge in Complex Compounds
Author(s) -
Chatt Joseph,
Leigh G. Jeffery
Publication year - 1978
Publication title -
angewandte chemie international edition in english
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 0570-0833
DOI - 10.1002/anie.197804001
Subject(s) - dipole , charge (physics) , formal charge , x ray photoelectron spectroscopy , transition metal , chemistry , metal , charge density , ion , moment (physics) , crystallography , molecule , nuclear magnetic resonance , physics , organic chemistry , classical mechanics , quantum mechanics , catalysis
Abstract The charges on metal atoms and ligands in complex compounds of transition metals may be calculated theoretically or measured empirically, but there is no reliable method of doing either. This review is concerned mainly with two experimental methods, dipole moment measurement and X‐ray photoelectron spectroscopy, applied to tertiary phosphate and such complexes of the heavier transition metals. It is concluded that the charge is rarely greater than ±0.3e and that some so‐called neutral or positive ligands, e.g. N 2 or NO + , may carry more negative charge in a complex than formally anionic ligands such as H − . Small ligands of high formal charge, e.g. O 2− , NR 2− , and N 3− , appear to carry no more negative charge than Cl − , but monoanionic ligands vary greatly in their capacity to contribute to the dipole moments. The ligands NO, CO, PF 3 , CH 3 − , and H − are all nearly neutral to slightly negative, whereas pyridines, tertiary phosphanes, etc. are the most strongly positively charged.