Macrocyclic Cyclo[n]malonates – Synthetic Aspects and Observation of Columnar Arrangements by X‐ray Crystallography

Abstract

A variety of achiral and chiral macrocyclic oligomalonates were synthesised in a one-step procedure through condensation of malonyl dichloride with α,ω-diols. We have investigated the applicability of this method by varying the length and type of the spacers in the diol. Product distribution analysis revealed that the preferential formation of monomeric, dimeric, or trimeric macrocyclic malonates can be controlled by choosing diols with specific spacers connecting the hydroxy groups. Of special interest are the macrocyclic bismalonates, as they show pronounced crystallisability and arrange into columnar motifs in the solid state. They feature distinctive

Synthesis and Magnetic Properties of a Nitrogen‐Containing Fullerene Dimer

“…Spectral simulation was performed by using the EASYSPIN software package. [15][16] Compound 1 [19] was prepared according to methods reported previously in the literature.…”

“…Monoadduct 2: C 60 (626 mg, 0.88 mmol) was dissolved in anhydrous, degassed toluene (400 mL) under nitrogen with exclusion of light; cyclo [2]malonate 1 [19] (400 mg, 0.88 mmol) and I 2 (88.2 mg, 0.35 mmol) were added subsequently. P 1 -tBu (221 μL, 0.88 mmol) in anhydrous, degassed toluene (50 mL) was added dropwise to the stirred solution at room temp.…”

“…After evaporation of the solvent and precipitation from CHCl 3 by addition of pentane, the monoadduct 2 was isolated as a red-brownish solid (170 mg, 0.14 mmol, 41 % yield based on iodine). 1 [19] (99 mg, 0.22 mmol) and I 2 (120 mg, 0.47 mmol) were added subsequently. P 1 -tBu (274 μL, 1.08 mmol) in anhydrous, degassed toluene (50 mL) was added dropwise to the stirred solution at room temp.…”

Tether‐Directed Regioselective Synthesis of an Equatorialface Bisadduct of Azafullerene Using Cyclo‐[2]‐octylmalonate

“…The reduced symmetry of C 59 N bisadducts compared to that of the C 60 analogues complicates their 13 C NMR identification, even making it impossible. Although the tether‐directed remote functionalization concept utilizing cyclo ‐malonate tethers is well established for C 60 , the regioselective synthesis and characterization of bisadducts of C 59 N has hitherto remained unexplored. As a consequence, UV/Vis spectroscopy cannot be used as a tool for the primary characterization of a bisadduct by comparing the spectra in the region 400–800 nm, which serves as a fingerprint for the addition pattern of C 60 bisadducts …”

Efficient Synthesis of C2v‐Symmetrical Pentakisadducts of C60 as Versatile Building Blocks for Fullerene Architectures that Involve a Mixed Octahedral Addition Pattern

“…The protected bolaamphiphilic bisfullerene 4 was recently be prepared from cyclo [2]malonate 5 [23] by a sequential monoadduct/hexakisadduct synthesis. [18] However, the yield of this divergent reaction route was rather low, and purification with preparative HPLC was necessary after each hexakisadduct synthesis.…”