Spin transitions are a spectacular example of molecular switching that can provoke extreme electronic and structural reorganizations in coordination compounds. A new 3D cyanoheterometallic framework, [Fe(pz){Au(CN) 2 } 2 ], has been synthesized in which a highly cooperative spin crossover has been observed at 367 and 349 K in heating and cooling modes, respectively. Mössbauer spectroscopy revealed a complete transi- [a]

A series of GABA analogs and related mono‐ and bifunctional building blocks based on the monofluorinated 1,3‐disubstituted cyclobutane scaffold was designed and synthesized. The synthetic approaches included desilylative deoxyfluorination of TMS‐protected cyanohydrin and iodofluorination of methylenecyclobutane carboxylate as the key steps. Both approaches were highly efficient for the multigram synthesis of γ‐ and δ‐amino acids, monoprotected diamines, amino alcohols, and hydroxy acids. The first method was diastereoselective (dr 3:1) but it failed to produce the target products as pure, separable diastereomers. On the contrary, the second approach lacked diastereoselectivity but provided pure cis and trans isomers of the corresponding fluorocyclobutanes by separation of diastereomers; the products were obtained on up to 100 g scale in a single run. Moreover, the method was applied for the preparation of 3‐azabicyclo[3.1.1]heptane derivatives. X‐ray diffraction studies showed that the synthesized building blocks are appropriate analogs of GABA with either somewhat larger or smaller size as compared to the parent amino acid.

Thermally induced spin transition at 370 K has been observed in a Hofmann-clathrate-like metal–organic framework.

Between the tosyl­ate anions and the octa­hedral complex cations consisting of FeII, four aqua and two N-bound 2-chloro­pyrazine ligands, weak O—H⋯O as well as π–π inter­actions play important roles in the mol­ecular self-assembly, resulting in the formation of a three-dimensional structure.