Tetrahedron report number 205

When I was a student at university, my major field of study was Electrical Engineering. I did not specialize in chemistry in my studies at university, and my knowledge of chemistry overall was somewhat less than rich. Under those circumstances, upon entering the company, I applied myself wholeheartedly to the study of chemistry to challenge and overcome a barrier in analytical chemistry considered to be impenetrable. I am, of course, very pleased to receive the Nobel Prize and further, especially pleased that the Prize serves to acknowledge my efforts and successes in the field of analytical chemistry, a field that while rather inconspicuous among the general population is indeed very important and useful to the world. I am employed by the analytical instrument manufacturer, Shimadzu Corporation. I was assigned to a team charged with the task of designing and building a completely new mass spectrometer. The achievement of developing “a soft desorption ionization method for mass spectrometric analysis of biological macromolecules”, for which I was chosen to receive this prize, was one aspect of that project. At that period in the 1980’s, four of my colleagues, whom I will introduce shortly, in addition to myself, were each in charge of developing a part of the instrument. I was responsible for developing the sample preparation and ionization technologies. Success of the instrument would not have been assured unless the other technologies were suitably provided, even given the excellence of the ionization technology. First, I will briefly describe the progress of development of the technologies at that time, other than that of ionization.

The origin of macromolecule ionization by laser irradiation (Nobel lecture).

Cyclobutarenes and Related Compounds

Bioactive polysaccharides from plants

Publisher Summary This chapter focuses on the chemistry of excited complexes. The term exciplex (excited complex) is used to describe an electronically excited molecular complex of definite stoichiometry. Complexes falling into this broad classification include excimers (excited dimers) (electronically excited complexes formed between identical atoms or molecules), heteroexcimers (electronically excited complexes formed between two non identical atoms or molecules), and excited charge-transfer complexes (complexes produced by excitation of ground state molecular complexes for which there is conclusive evidence for association in the ground state). The formation of intermolecular complexes in fluid solution requires that after excitation of one of the partners, collision with the other partner must occur within the lifetime of the excited state. The maximum rate constant for the process is determined by the rate constant for diffusion control in the solvent employed.

The Chemistry of Excited Complexes: a Survey of Reactions

Characteristics of in-beam electron impact ionization mass spectra of several amino sugars, which give barely detectable molecular ion peaks by the use of conventional direct inlet probes, are described. The spectra of these compounds almost always exhibited the M + 1 peak and the spectral features were apparently a combination of those of the conventional electron impact spectrum and some major peaks originating from the M + 1 ions. In the case of neamine, effects of the measurement conditions such as the source temperature, ionizing voltage, the position of the sample and time factors on the intensity of the M + 1 peak were examined. When the samples were mixed with ammonium chloride, the M + 1 peaks in the in-beam spectra were completely suppressed, while with aqueous ammonia, the abundance of the M + 1 peaks in creased by several times.

In‐beam electron impact mass spectrometry of amino sugars

Photochemical reaction of dicyanoanthracene with acetonitrile in the presence of an aliphatic amine. A novel photochemical amination

The [2+2]cycloaddition vs substitution in photochemical reactions of methoxybenzene-acrylonitrile systems

In Beam EI spectra of amino acids are described. To obtain IBEI spectra a, sample was loaded on an end of the quartz tip of a modified direct inlet probe and inserted until the electron beam was interrupted. Except cystine and arginine IBEI spectra of amino acids so far studied always exhibited clearly M+1peaks. Relative intensities of M and M+1 peaks in IBEI and conventional EI spectra are listed in Table1. The complete spectrum was apparently a combination of a conventional EI spectrum and the M+1peak. This technique is quite useful for detection of M+1peaks of thermally unstable compounds such as creatine or glutamic acid of which conventional E1 spectrum scarcely exhibits the M or M+1peak. The spectral features are somewhat similar to those obtained from closed source instruments. In the case of phenylalanine, effects of measuring conditions such as source temper ature, ionization voltage, sample position and time factor on the ratio of[M+1]/[M]were examined. When a sample was mixed with ammonium chloride, the M+1peak in the IBEI spectrum was completely suppressed, which must be useful for identification of the M+1peak.

In Beam EI Spectra of Amino Acids

Benzene, phenanthrene, or anthracene react upon irradiation with 1,2,4,5-tetracyanobenzene in methanol to give the corresponding 1:1:1 addition-elimination products.

Shuzo Yamada

Papers

In‐beam electron impact mass spectrometry of amino sugars

Photochemical reaction of dicyanoanthracene with acetonitrile in the presence of an aliphatic amine. A novel photochemical amination

The [2+2]cycloaddition vs substitution in photochemical reactions of methoxybenzene-acrylonitrile systems

In Beam EI Spectra of Amino Acids

Photo-induced 1:1:1 reactions of 1,2,4,5-tetracyanobenzene–aromatic compounds–methanol systems