Searching the Cambridge Structural Database for solvatedvsunsolvated pairs

Abstract

The more than 365,000 organic and organometallic small-molecule crystal structures in the Cambridge Structural Database (CSD) are a good source of data for understanding the crystal structures of solvates. It is trivial with the existing search software [1] to find all CSD entries containing a particular solvent, say water, and a survey of the 50 most common solvents in the CSD has been published [2]. It might be interesting, however, to know if any of these solvates also exist in an unsolvated form; given a crystal structure of di-isopropylammonium chloride hydrate in the CSD, for example, one could wonder if a crystal structure of di-isopropylammonium chloride itself is present in the database.A computer program was written that for a given solvent molecule finds all pairs of solvated versus unsolvated CSD entries; a list of solvate structures for which no unsolvated form exists in the CSD is also generated. These lists enable us to examine if properties such as the number of hydrogen-bond donors / acceptors or the molecular flexibility influence solvate formation. Results for hydrates will be presented.[1] Bruno, I.J.; Cole, J.C.; Edgington, P.R.; Kessler, M.; Macrae, C.F.;McCabe, P.; Pearson, J.; Taylor, R

Preferred Geometries and Energies of Sulfur–Sulfur Interactions in Crystal Structures

“…The statistical study is based on the crystal structures archived in the Cambridge Structural Database (CSD, version 5.36). [39][40][41][42][43] A CSD search was performed using the ConQuest 1.17 program 44 to extract all structures containing a cysteine residues and satisfying given geometric criteria. As a fragment for CSD search we used cysteine thiol residue which is bonded to any atom or group (X-CH 2 SH).…”