Schmidt, Otto

We start with some biographical notes on Erich Huckel, in the context of which we also mention the merits of Otto Schmidt, the inventor of the free-electron model. The basic assumptions behind the HMO (Huckel Molecular Orbital) model are discussed, and those aspects of this model are reviewed that make it still a powerful tool in Theoretical Chemistry. We ask whether HMO should be regarded as semiempirical or parameter-free. We present closed solutions for special classes of molecules, review the important concept of alternant hydrocarbons and point out how useful perturbation theory within the HMO model is. We then come to bond alternation and the question whether the pi or the sigma bonds are responsible for bond delocalization in benzene and related molecules. Mobius hydrocarbons and diamagnetic ring currents are other topics. We come to optimistic conclusions as to the further role of the HMO model, not as an approximation for the solution of the Schrodinger equation, but as a way towards the understanding of some aspects of the Chemical Bond. 

Fig. 2.23 Max Schmidt as Dean of the Faculty of Science presenting Professor Walter Hieber the Diploma of Doctor honoris causa. Left of Hieber is Ernst Otto Fischer who gave the laudatio at the ceremony held at Wurzburg in 1969 (photo by courtesy from the late Professor Max Schmidt)...

Fig. 2.39 Ernst Otto Fischer at the time when he received the Nobel Prize (photo by courtesy from the late Professor Max Schmidt)...

Locatelli S, Lutjohann D, Schmidt HH, Otto C, Beisiegel U, von Bergmann K (2002) Arch Neurol 59 213... 

O. Hecht, Otto Schmidt (1874-1943), Berichte der Deutschen Chemischen Gesellschaft, 76 A (1943), 121-125 Karl Saftien, Fritz Gunther, Chemische Berichte, 92 (1959), xxix-xxxv. 

The physical laboratory, complete with x-ray apparatus, electron diffraction, viscosity and osmotic measurement equipment, was under the direct guidance of Karl Wolf When Mark took over it was not the only department of the Central Research Laboratory. There was a synthetic organic laboratory under the leadership of Heinrich Hopff, the personal assistant of K.H. Meyer, and a technical station, called Technion, for the synthesis of amounts of polymer substances sufficient to permit study of their properties. The latter group was under Manfred Dunkel. The research group of Otto Schmidt studied catalytic reactions and synthetic rubber chemistry. ... 

There was a certain amount of collaboration of Mark with Otto Schmidt, who led an independent group in the Central Research Laboratory. As far as I has been able to determine, this collaboration focused on the field of synthetic rubbers, Buna-S and Buna-N, a second important topic in the laboratory of Otto Schmidt, and not catalysis. Catalytic reactions were also studied in the Ammonia Laboratory of Alwin Mittasch (mentioned below). 

Hecht, op. cit. (19), p. 123. Otto Schmidt, Systematische Untersuchungen liber die Absorption von Gasen an festen Korpern, research report dated 22 January 1927, no. 1719. CA BASF D 02.2/5. 

Letter of Flerman Mark to Otto Schmidt, Ludwigshafen, 28 November 1931. CA BASF W1 Schmidt. 

Leitz K-H, Redlingshofer B, Reg Y, Otto A, Schmidt M (2011) Metal ablation with short and ultrashort laser pulses. Phys Procedia 12 230-238... 

Leitz K-H, Koch H, Otto A, Schmidt M (2012a) Numerical simulation of process dynamics during laser beam drilling with short pulses. AppI Phys A 106(4) 885-891... 

Andreas Schmidts, Sascha Wiechmann, Christian F. Otto... 

The generation of three-to eight-membered N-heterocyclic carbenes is reviewed by Andreas Schmidt, Sascha Wiechmann and Christian F. Otto (Clausthal University of Technology) in Chapter 6. Christos Constantinides (North Carolina State University) and Panayiotis A. Koutentis (University of Cyprus) review recent developments in the synthesis and applications... 

Keim, W, Behr, A., and Schmidt, G. (1986) Grundlagen der industriellen Chemie, Otto Salle Verlag, Frankfurt. 

Mayer W 1973 Otto Theodor Schmidt. Justus Liebigs Ann Chem 1759-1776... 

Schmidt A-C, Fahlbusch B, Otto M. Size exclusion chromatography coupled to electrospray ionization mass spectrometry for analysis and quantitative characterization of arsenic interactions with peptides and proteins. J Mass Spectrom 2009 44 898-910. 

Celebration of von Laue s 80 birthday in the machine hall, 9 October 1959. Left to right, first row Otto Hahn, Lise Meitner, Max von Laue second row Elisabeth Schiemann, Magdalena von Laue, Anna Maria DAns third row Dietrich Schmidt-Ott... 

Mayer, W. Otto Theodor Schmidt. Liebigs Annalen 1973, 1759. 

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