Wydział Chemii

Katarzyna Ślepokura

Anna Piątkowska

Tadeusz Lis

2002

Zeitschrift für Kristallographie

217

614-621

10.1524/zkri.217.11.614.20779

Naukowa

Angielski

Artykuł

All crystals of the title compounds, with gen-eral formula M2þ(C2H4O5P)2(H2O)2, (MAP), are isomor-phous and crystallize in the space groupP
11withZ¼2.The two crystallographically independent M2þcations aresituated on a center of symmetry and are octahedrally co-ordinated by two phosphonate monoanions and two watermolecules. In the case of Cu2þcation, Jahn-Teller effectcauses strong extension of two Cu –– O bonds. The mono-anions coordinate the metal ions by one carboxylic andone phosphonate oxygen atom, which is facilitated bytheir specific overall conformation. In each monoanion,one of the phosphonate O atoms is nearly antiperiplanarapto the carboxylic C atom, and the remaining phospho-nate O atoms are nearlygauche(þscandsc) with re-spect to the mentioned C atom. The carboxylic O atomsare in positions close toþscandacin relation to thephosphonate P atom. The complex molecules form wellseparated layers in all MAP compounds. The phosphonateand carboxylic groups act as donors in medium strong andweak intermolecular O ––H...O hydrogen bonding and, asacceptors, in C ––H...O hydrogen interactions in all struc-tures. Additionally both crystallographically independentwater molecules are donors of weak hydrogen bonding tophosphonate oxygen atoms from adjacent complex mole-cules.

https://doi.org/10.1524/zkri.217.11.614.20779