Properties and Reactions of Substituted 1,2‐Thiazetidine 1,1‐Dioxides: Functionalization and Reactions at C(4) of the β‐Sultam

The introduction of functional groups at the 4‐position of the β‐sultam ring was realized by the synthesis of mono‐ and disubstituted derivatives by reactions of N‐silylated β‐sultams with electrophiles in the presence of BuLi or LDA. As electrophiles, ketones, chlorosilanes, a β‐sultam, CO₂, chloroformiate, halogen, azodicarboxylate, phenyltriazoledione, tosyl azide, 1,3,5‐triazine, propyl nitrate, and phenyl isocyanate were used. Furthermore, a number of derivatives of these substitution products were synthesized. All products were characterized by standard spectroscopic methods, and conformations were studied, supported by calculation.     

Homoleptische Zinkamide: Der Übergang zu monomeren Molekülen

Homoleptic Zinc Amides: Transition to Monomeric Molecules Zinc chloride reacts with the lithium salts of the bulky secondary amines HN(i-Bu)₂ and HN(t-Bu)₂ to form the corresponding homoleptic zinc compounds {Zn[N(i-Bu)₂]₂}₂ ( 1 ) and Zn[N(t-Bu)₂]₂ ( 2 ). The NMR spectroscopic and mass spectrometric results as well as the molecular weight determinations and X-ray diffraction data are consistent with a dimeric structure of 1 and a monomeric structure of 2 in the gas phase, in solution and in the solid state.     

Thermophilic fermentation of hydrolysates

Lignocellulosic biomass has great potential as a cheap feedstock in biological processes to produce biofuels or chemicals; however, dilute acid pretreatment at high temperatures produces undesirable compounds. Toxicity tests were done with inhibitors in standard media, to predict the growth-limiting effects on thermophilic strains. The 22 inhibitors included furfural, levulinic acid, acetic acid, and cinnamaldehyde. Neutralizing reagents and additional treatment steps have been tested.     

Experiments on the analysis of thick, non-conductive metallic oxide layers on sheet using HF-SNMS

First experiments are described for depth profile analytical characterization of non-conducting enamel layers using secondary neutral particle mass spectrometry (SNMS) with HF sputtering technology. The homogeneous distribution of the oxidic components in the enamel layer are examined. The considerable layer thicknesses (> 80 μm) mean that the direct application of HF-SNMS for assessing interface and adhesion mechanisms is not practical at present. To prepare the interface layer from the steel side, the use of different preparation techniques is shown to abrade the sample with simple metallographic techniques down to a residual steel thickness of approx. 1–5 μm.     

Stereoselective syntheses of substituted methyl (Z,E,E)-deca-2,7.9-trienoates and substituted methyl (Z,E,E)-undeca-2,8,10-trienoates

Lindlar hydrogenation of substituted methyl ($\text{E}$,$\text{E}$)-deca-7,9-dien-2-ynoates and substituted methyl ($\text{E}$,$\text{E}$)-undeca-8,10-dien-2-ynoates affords selectively the corresponding ($\text{Z}$,$\text{E}$,$\text{E}$)-trienes.     

Photoelektronenspektroskopische untersuchung von tris(trimethylelement(IV)aminen, -phosphinen, -arsinen und -stibinen

The PE spectra of [(CH₃)₃Sn]₃N, [(CH₃)₃E]₃P (E = C, Si, Sn), [(CH₃)₃Si]₃As and [(CH₃)₃E]₃Sb (E = C, S, Ge, Sn) are analyzed. The constant level of the ionization potentials of the n-hybrid orbitals of N, P, As, and Sb, together with changes in the hybridization and interactions with ligand MO's is discussed by qualitative MO investigations.