Low-Coordinate Monomeric Zinc Hydride Complexes with Encapsulating Dipyrromethene Ligands and Reactivity with B(C6F5)3

The dipyrromethene (DPM) ligand is the key to isolation of monomeric Zn hydride complexes with tricoordinate zinc centers. A range of ^RDPM ligands with various substituents in the pole position (1,9-positions) were prepared: R = tBu, adamantyl (Ad), mesityl (Mes), 2,6-diisopropylphenyl (DIPP), 2,4,6-triphenylphenyl (Mes*), or 9-anthracenyl (Anth). Reaction of the ligands with Et₂Zn gave a series of (^RDPM)ZnEt complexes, which were converted with I₂ to the corresponding (^RDPM)ZnI compounds. The latter reacted by salt metathesis with KN(iPr)HBH₃ to the series of Zn hydride complexes (^RDPM)ZnH. For ligands with the larger Mes* and Anth substituents, (^RDPM)ZnEt was converted to (^RDPM)ZnOSiPh₃, which after reaction with PhSiH₃ gave the hydrides. While Zn hydride complexes with R = tBu or Ad are dimeric, all complexes with aryl-substituents are monomeric. The aryl groups span a cavity around the metal, blocking dimerization and causing a high-field shift of the ¹H NMR signals due to the ASIS effect. Attempted abstraction of the hydride with B(C₆F₅)₃ led to cleavage of the B-C₆F₅ bond.     

Stable Layer Systems with Diffusion Barrier Arrangements in Thin Film Technology

The physical and chemical interaction processes in thin film arrangements are followed by different ageing phenomena which influence the stability of their physical parameters. These determine the reliability of the electronic components existing of thin films. On the base of own experimental investigations on tantalum and its oxides, beryllium oxide and tantalum-rhenium alloys technological aspects and the application of new materials for lowering the ageing intensity are considered.     

ChemInform Abstract: Redetermination of Na3TaF8.

The crystal structure of Na₃TaF₈ is redetermined at 153 K and well determined bond distances and angles are provided.