Aggregate formation of organometallic compounds can be straightforwardly observed and interpreted through DOSY molecular weight (MW) estimation. Recently, the power‐law approach and preparation of external calibration curves (ECCs) has propelled the applicability of this DOSY MW estimation. However, effective prediction of MWs of molecules containing heavier elements (e. g. halogenated compounds) has not been sufficiently accounted for. Hence, we introduce specialized ECCs for various halogenated molecules. In an innovative attempt we propose a correction factor for standard ECCs that scales with molecular features to extend considerably the range of molecules that can be investigated by ECC‐DOSY.

A novel sterically demanding bis(4‐benzhydryl‐benzoxazol‐2‐yl)methane ligand 6 (4−BzhH2BoxCH2) was gained in a straightforward six‐step synthesis. Starting from this ligand monomeric [M(4‐BzhH2BoxCH)] (M=Na (7), K (81)) and dimeric [{M(4‐BzhH2BoxCH)}2] (M=K (82), Rb (9), Cs (10)) alkali metal complexes were synthesised by deprotonation. Abstraction of the potassium ion of 8 by reaction with 18‐crown‐6 resulted in the solvent separated ion pair [{(THF)2K@(18‐crown‐6)}{bis(4‐benzhydryl‐benzoxazol‐2‐yl)methanide}] (11), including the energetically favoured monoanionic (E,E)‐(4‐BzhH2BoxCH) ligand. Further reaction of 4−BzhH2BoxCH2 with three equivalents KH and two equivalents 18‐crown‐6 yielded polymeric [{(THF)2K@(18‐crown‐6)}{K@(18‐crown‐6)K(4‐BzhBoxCH)}]n (n→∞) (12) containing a trianionic ligand. The neutral ligand and herein reported alkali complexes were characterised by single X‐ray analyses identifying the latter as a promising precursor for low‐valent main group complexes.

From the sodium sodate precursor [(Na­(thf)6]­[Na­{(4-Me-NCOC6H3)2CH}2] (1) three isostructural dinuclear lanthanide complexes [(μ-Cl)­LnIII{(4-MeNCOC6H3)2CH}2]2 with Ln = Gd (2), Dy (3), and Er (4) based on the N,N′-chelating monoanionic bis­(4-methylbenzoxazol-2-yl)­methanide ligand (titled “Mebox”) were synthesized and characterized by X-ray diffraction and magnetic measurements. The sodium precursor 1 was analyzed via X-ray diffraction and diffusion-ordered NMR spectroscopy experiments (DOSY-NMR) in order to investigate its aggregation in solution and the solid state. The sodium analog [(thf)3Na­(NCOC6H4)2CH] (1′) based on the bis­(benzoxazol-2-yl)-methanide ligand (titled “box”) was prepared and analyzed for comparison reasons. From the lanthanide derivatives 2–4, the DyIII complex 3 displays slow relaxation of magnetization at zero field, with a relaxation barrier of U = 315.7 cm–1. The coupling strength between the two lanthanide centers was estimated with the GdIII equivalent 2, giving a weak antiferromagnetic coupling of J = −0.035 cm–1.

A convenient new method was added to the toolbox of the ligand design of N-heterocyclic silylenes and their transition-metal complexes. Herein we report on six novel compounds of two novel classes of copper­(I) complexes based on the benzamidinate silylene (Cl)­Si­(PhC­(NtBu)2). By taming the high reactivity of the free electron pair of the Si­(II) atom via a preset metalation with a desired metal precursor (in this case copper­(I) halides) we can easily introduce novel pyridyl-based groups in the subsequent functionalization of the chloro group and undergo coordination of the metal atom at the same time. The resulting pseudocubane-like tetramer [XCu­(I) ← (Cl)­Si­(PhC­(NtBu)2)]4 2a–2c and the trinuclear dimer [(XCu­(I))3­(PyNMes)­Si­(PhC­(NtBu)2)] 3a–3c (with X = Cl (2a/3a), Br (2b/3b), I (2c/3c)) were fully characterized via X-ray diffraction analysis, NMR spectroscopy, mass spectrometry, and elemental analysis. Moreover, we took a look into the catalytic potential of the Cu­(I) complexes 2b and 3b by testing them under the conditions of the renowned copper­(I)-catalyzed alkyne–azide cycloaddition and observed an increased activity of the functionalized species.

Anionic coordination polymerizations proceed via highly reactive intermediates, whose in situ analysis has remained difficult. Here, we show that electrosprayionization mass spectrometry is a promising method to obtain detailed information on the polymerization process. Focusing on polymerization reactions of 1,3dienes initiated by CoCl 2 /RLi (R = Me, nBu, tBu, Ph), we directly observe the growing polymer chains and characterize the active anionic cobalt centers by gasphase fragmentation experiments. On the basis of these results, we suggest a plausible mechanism for the polymerization reaction. Moreover, the ESI mass spectra permit the determination of molecular weight distributions, which are in good agreement with those derived from NMR-spectroscopic as well as MALDI mass-spectrometric measurements, and afford a wealth of kinetic data.