Stabilization of Near Identical Hydrogen Bonded Octameric Water Clusters in Crystal Structures of Three Distinct Non-Charged Polyamide Macrocyclic Host Molecules

Kajetan Dąbrowa, Magdalena Ceborska, Janusz Jurczak
2021 Molecules  
In this paper, we present a comparative analysis of the solid state structures of three well-resolved hydrates of macrocyclic host molecules 1a, 1b, and 2 containing an intrannular amide-aryl substituent (lariat arm) connected to a fixed 26-membered ring in a normal (-NHCOAr, hosts 1a and 1b) or reverse manner (-CONHAr, host 2). Despite different chemical structures, these hosts crystallize as isostructural tetrahydrates in the same P-1 space group. Moreover, their crystals exhibit identical
more » ... rogen bond motifs resulting in a stabilization of an almost identical unusual octameric water cluster built from the cyclic tetramer core and four water molecules, attached sequentially in an "up-and-down" manner. Further analysis reveals that, among the series, the structure of host 2 provides the most suitable environment for the accommodation of this type of water cluster.
doi:10.3390/molecules26092787 pmid:34065060 fatcat:p5siqlrtonhl3mhrsvnkatk6a4