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Si, "A1, and 'H MAS NMR studies of partially carbonated mature ordinary portland cement (OPC) and tricalcium silicate (C,S) pastes have been carried out. The water-to-solid ratios ( w / s ) have been varied between 0 and 1 at hydration temperatures of 23" and 90°C. Various Q" units with n = 0, 1, 2, 3, and 4, and a Q3 (1Al) group have been identified using ''Si NMR. Cross-polarization experiments, in addition, have made it possible to assign the OH groups. Two types of fourfold-and one type of sixfold-coordinated aluminum have been distinguished using 27Al NMR. In C3S pastes for w / s > 0.7, progressive carbonation leads to a nearly perfect three-dimensional network consisting of Q3 and Q4 only. In contrast, in OPC pastes only about 40% of the highly polymerized silicate units are formed, partially copolymerized with ,410, tetrahedra.

N‐p‐Tosyl‐α‐aminosäuren bilden mit Formaldehyd über eine intermediäre N‐Hydroxymethyl‐Verbindung (II) Oxazolidon‐Derivate (III) Diese setzen sich mit Aminen und Aminosäureestern unter Abspaltung von Formaldehyd in fast quantitativer Ausbeute zu Peptidderivaten um. Bei der Aufarbeitung werden die Estergruppen verseift. Nach Abspaltung der p‐Tosylreste erhält man peptide bzw. andere Aminosäure‐amid‐Derivate.