Supramolecular associationviaSb...S and C—H...S interactions in dimerictris(N,N-dimethyldithiocarbamato-S,S′)antimony(III): an approach to overcome the concept of steric bulk on such interactions

Abstract

Tris(N,N-dimethyldithiocarbamato-S,S')antimony(III) has been isolated as a dimer in acetonitrile. Single-crystal X-ray analysis shows that the molecule possesses both Sb···S and C-H···S interactions, which results in a supramolecular association in the absence of hydrogen-bonding functionality on the R group. The co-existence in the title compound of such interactions is a unique character of known dimeric antimony(III) alkyl and/or aryl dithiocarbamate complexes. The literature reveals that the species where the alkyl and/or aryl dithiocarbamates carry the following groups: R = methyl (chloroform solvated), ethyl, n-propyl, pyrrolidine, morpholine, piperidine, azepane, benzyl, methylphenyl, are not capable of forming significant hydrogen-bonding interactions. However, either Sb···S or C-H···S intermolecular interactions dominate between two centrosymmetrically related molecules leading to a supramolecular aggregation. In the species where the R group carries hydrogen-bonding functionality, i.e. 2-hydroxylethyl, the C-H···S interactions are subverted by O-H···O hydrogen bonding. In addition, the title compound does not have steric hindrance or any hydrogen-bonding group but is stabilized with the co-existence of Sb···S and C-H···S interactions. Analysis of the secondary interactions of a series of analogues previously reported reveals that steric bulk is unnecessary for the mitigation of Sb···S interactions and for the establishment of C-H···S secondary bonding.

Supermolecules as a quality markers of herbal medicinal products

“…The term supermolecule was introduced in the mid-1930s, and the concept of supramolecular chemistry was first proposed in 1987 by the French scientist J. M. Lehn, a Nobel laureate in chemistry. Supramolecular chemistry is the chemistry of molecular aggregates based on non-covalent interactions between molecules; in other words, intermolecular interactions form the core of supramolecular chemistry 68 , 69 . At present, these aggregates can be divided into two categories: supermolecules formed by the self-assembly of two small molecules and supermolecules composed of small molecules and inorganic complexes [ 70 ].…”

Fracture Mode Transition in Nb–1Si Alloys Triggered by Annealing Heat Treatment

“…According to Chan et al, [18,38] the design of a ductile solid-solution alloy is achieved by obtaining a high value for the ratio g s /U P-N , where g s (surface energy) is a measure of resistance to cleavage fracture, and U P-N (Peierls-Nabarro barrier energy) can be viewed as the maximum resistance of the discrete lattice to dislocation motion. According to Chan et al, [18,38] the design of a ductile solid-solution alloy is achieved by obtaining a high value for the ratio g s /U P-N , where g s (surface energy) is a measure of resistance to cleavage fracture, and U P-N (Peierls-Nabarro barrier energy) can be viewed as the maximum resistance of the discrete lattice to dislocation motion.…”