Highlights of 45 years of research: A personal account

Abstract

a b s t r a c tThis part of my biosketch, which I prepared on invitation by the Editors, made me realize again how entangled my interest for doing research and teaching and management have been over the years. Working together with my students and colleagues has always been a strong motivation and pleasure for me and I hope that this sketch of our research reflects our common enthusiasm for what we achieved.In hindsight, trying to overlook almost 45 years of research, various main themes can be discerned that marked my fundamental research in the subsequent periods at TNO Utrecht (1968e1977), University of Amsterdam (1977e1986) and University of Utrecht (1986e2007). Overarching has been my preference and fascination for working with nitrogen based ligands (culminating in the design and use of the NCNpincer ligand platform, vide infra), the study of synthetic routes for organometallics (most importantly trans-and cyclo-metallation routes), the use of NMR for the study of the stereochemistry of organometallics (cf. the early use of 107,109 Ag NMR for detecting and following the formation of coordination compounds with helical structures), chemistry involving organometallic radicals (cf. organozinc and aluminum a-diimine chemistry, development of b-lactam synthesis routes), self-assembly of organometallics to discrete aggregated species (cf. organo-Cu, -Li and cuprate chemistry), the development of palladium complexes and homogeneous metal catalysts with simple amine ligands, the synthesis of, and catalysis with, dendrimers decorated with organometallic catalysts, mimicking the active center of metallo-enzymes as well as the synthesis of organometal-lipase hybrids for catalysis.Being educated in an "eco"-system of contract research, in concert with fundamental research, the results of the above outlined items were not only published in journals with peer review (>850) but also in the patent literature (>40). Most important were the results reported in over 85 PhD theses that I had the privilege to supervise as PI. The references refer to key-papers describing this body of work. The respective reference numbers are given at the heading of each paragraph. The full list of publications in peer reviewed Journals can be found in http://www.gerardvankoten.nl and www.uu.nl/staff/GvanKoten.© 2017 The Author. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). GeneralAs indicated above, nitrogen ligands fascinated me throughout my research career, right from the very beginning. Whereas in my early days ligands with phosphorous donor atoms were the dominating "privileged" ligands in inorganic and organometallic chemistry; they have remained so up until now. However, my interest for nitrogen-containing ligands was fortified for a number of reasons; i, Nitrogen is one of the smallest donor atoms. This results in short N-metal bond distances thus affecting/interfering with its (N)R-substituents (also because of the short N-C bonds, viz. N-cone angle c...

Metal–Ligand Cooperation as Key in Formation of Dearomatized NiII–H Pincer Complexes and in Their Reactivity toward CO and CO2

“…Late-transition-metal complexes of electron-donating and bulky “pincer” ligands have found important applications in synthesis, bond activation, and catalysis. − The lutidine-based pincer ligands (Scheme ) are highly electron donating ligands with a relatively low trans influence of the pyridinic nitrogen and benzylic “arms” amenable to deprotonation.…”

Which is the Stronger Nucleophile, Platinum or Nitrogen in Rollover Cycloplatinated(II) Complexes?

“…It should be noted that such phenomenon in which the Pt group as a substituent affects the character of a nucleophilic center has been reported. 36,37 As can be seen in Table 1, the energy (or free energy) barriers for N-methylation of 1b and 1c in chloroform are 9.3 and 9.2 (or 21.1 and 18.9) kcalmol −1 , respectively. The differences are very small and this shows that the inductive and mesomeric influences exerted by Pt on the free N centers in 1b and 1c are essentially the same.…”

Halogen Bonding Involving I2 and d8 Transition-Metal Pincer Complexes

“…The two nitrogens increase electron density around metal center, contributing to the stability of Pt−η −I 2 interaction. The possible reasons for this stability are the presence of σ-donating amine ligands, the plane of the aryl ring which coincides with the coordination plane, and steric constrains [39][40][41]. This opens new pathways for investigating the variation of atoms involved in pincer complexes.…”