title: The color of complexes and UV-vis spectroscopy as an analytical tool of Alfred Werner's group at the University of Zurich.
abstract: Two PhD theses (Alexander Gordienko, 1912; Johannes Angerstein, 1914) and a dissertation in partial fulfillment of a PhD thesis (H. S. French, Zurich, 1914) are reviewed that deal with hitherto unpublished UV-vis spectroscopy work of coordination compounds in the group of Alfred Werner. The method of measurement of UV-vis spectra at Alfred Werner's time is described in detail. Examples of spectra of complexes are given, which were partly interpreted in terms of structure (cis ↔ trans configuration, counting number of bands for structural relationships, and shift of general spectral features by consecutive replacement of ligands). A more complete interpretation of spectra was hampered at Alfred Werner's time by the lack of a light absorption theory and a correct theory of electron excitation, and the lack of a ligand field theory for coordination compounds. The experimentally difficult data acquisitions and the difficult spectral interpretations might have been reasons why this method did not experience a breakthrough in Alfred Werner's group to play a more prominent role as an important analytical method. Nevertheless the application of UV-vis spectroscopy on coordination compounds was unique and novel, and witnesses Alfred Werner's great aptitude and keenness to always try and go beyond conventional practice.
authors.affiliation: Chemisches Institut, Universität Zürich Winterthurerstrasse 190, CH-8057 Zürich, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Fox
authors.affiliation: Chemisches Institut, Universität Zürich Winterthurerstrasse 190, CH-8057 Zürich, Switzerland. hberke@chem.uzh.ch.
authors.forename: Heinz
authors.initials: H
authors.lastname: Berke
mesh_terms: D015392:Chemistry, Inorganic / Q000266:history*; D056831:Coordination Complexes / Q000737:chemistry / Q000266:history*; D049673:History, 20th Century; D006801:Humans; D013056:Spectrophotometry, Ultraviolet / Q000266:history* / Q000379:methods; D013237:Stereoisomerism; D013557:Switzerland
chemical_list: D056831:Coordination Complexes