Four new acyclic diaminocarbenes (ADACs), viz. [(cyclo‐CnH2n−1)2N]2C (n=5–7) and iPr2N‐C‐N(cyclo‐C6H11)2, were synthesised by reacting the corresponding formamidinium hexafluorophosphates with NaN(SiMe3)2. Their nucleophilicities and electrophilicities were respectively judged from the 1JCH values determined for the N2CH unit of the corresponding formamidinium cations and from the 77Se NMR chemical shifts of the selenourea derivatives obtained from the reaction of elemental selenium with the corresponding ADACs. An ambiphilic profile essentially identical to that of the “Alder carbene” (iPr2N)2C was found in each case. Similar to the latter carbene, the new ADACs undergo a well‐defined thermal decomposition by β‐fragmentation, affording an alkene and a formamidine. The stabilities of [(cyclo‐CnH2n−1)2N]2C depend strongly on the value of n, following the order 6>5>7, with the latter congener being too unstable for isolation. [(cyclo‐C6H11)2N]2C shows no thermal decomposition at room temperature in solution and is thus significantly more stable than (iPr2N)2C. The stability of iPr2N‐C‐N(cyclo‐C6H11)2 is intermediate between that of (iPr2N)2C and [(cyclo‐C6H11)2N]2C, its β‐fragmentation selectively affording propene and iPrN=CH‐N(cyclo‐C6H11)2. [(cyclo‐CnH2n−1)2N]2C (n=5–7) react readily with CO under mild conditions, selectively affording trisubstituted spirocyclic β‐lactam derivatives with an antimicrobial activity spectrum similar to that of penicillin G.

In nanoimprint lithography (NIL), a pattern is created by mechanical deformation of an imprint resist via embossing with a stamp, where the adhesion behavior during the filling of the imprint stamp and its subsequent detachment may impose some practical challenges. Here we explored thermal and reverse NIL patterning of polyvinylferrocene and vinylferrocene-methyl methacrylate copolymers to prepare complex non-spherical objects and patterns. While neat polyvinylferrocene was found to be unsuitable for NIL, freshly-prepared vinylferrocene-methyl methacrylate copolymers, for which identity and purity were established, have been structured into 3D-micro/nano-patterns using NIL. The cross-, square-, and circle-shaped columnar structures form a 3 × 3 mm arrangement with periodicity of 3 µm, 1 µm, 542 nm, and 506 nm. According to our findings, vinylferrocene-methyl methacrylate copolymers can be imprinted without further additives in NIL processes, which opens the way for redox-responsive 3D-nano/micro-objects and patterns via NIL to be explored in the future.

Acyclic diaminocarbenes (ADACs) are ambiphilic, which makes them suitable for the activation of fundamentally important small molecules. For example, most of them react with CO under mild conditions. Unfortunately, such high reactivity is accompanied by limited thermal stability, leading to their decomposition at room temperature or below. The new ADAC [(cyclo‐C6H11)2N]2C is stable in solution up to approximately 40 °C. Nevertheless, it reacts readily with CO. The carbonylation affords a β‐lactam derivative with useful antibiotic properties. More information can be found in the Full Paper by U. Siemeling et al. on page 1488.