METAL-BETAINE INTERACTIONS .12. CRYSTAL-STRUCTURES OF CATENA-DIAQUA(PYRIDINE BETAINE)(SULFATO)COPPER(II) AND DIAQUADICHLORO(PYRIDINE BETAINE)COPPER(II) MONOHYDRATE

Two copper(II) complexes of pyridine betaine (C5H5N+CH2COO-; pyBET) were prepared and characterized by X-ray crystallography. In [Cu(pyBET)(H2O)2(SO4)]n (1), each Cu(II) atom is in a distorted square-pyramidal environment surrounded by a carboxylato oxygen atom [1.944(5) angstrom], two oxygen atoms [1.921(5) basal, 2.268(5) apical Al from different sulfato groups, and two aqua ligands [1.944(4) angstrom]. The primary coordination sphere is extended into a zigzag chain through sulfato bridging linkages, and hydrogen bonding involving the aqua ligands generates a three-dimensional network. [Cu(pyBET)(H2O)2Cl2].H2O (2) features a discrete metal complex with its distorted square-pyramidal coordination sites occupied by a carboxylato oxygen atom [2.000(2) angstrom], two aqua ligands [1.968(3) angstrom], and two chloro ligands [2.266(1), 2.469(1) angstrom] of which one is apical. The lattice water molecules form hydrogen bonds with the aqua and chloro ligands to yield a layer structure.