Band 38, Heft 2

This discussion article summarizes all protonation and stability constants data found in the literature for nonprotein l -norleucine amino acid and its metal complexes. The results of approximately 18 published articles discussing the protonation and complexation equilibria of l -norleucine using different techniques and software were presented to comprehend the data on the grounds of modern aspects of l -norleucine complex chemistry.

This review includes 16 examples of distortion isomers of heterotetranuclear platinum clusters. The clusters are of the compositions: Pt 3 Sn, Pt 2 M 2 (M=Au, Ag, W, Mo), and PtM 3 (M=Os, Ru, Re). The four metal atoms are found in a distorted tetrahedral core (most common), planar-rhombohedral, spiked-triangular, and eight-membered ring skeleton. There are three pairs (Pt 2 W 2 , Pt 2 Au 2 , and Pt 2 Ag 2 ) of clusters and all remainder clusters contain two crystallographically independent molecules within the same crystal. All are classical examples of distortion isomerism. Their structures are analyzed and discussed.

Selenium is a biocompatible element and participates in several biochemical reactions occurring in the human body. Its biocompatibility and minimal toxicity has attracted researchers to develop selenium-based drugs. Hence, recent developments on biomedical applications of selenium-based compounds have been discussed. A structure activity relationship has also been interpreted.