THE SYNTHESES AND CRYSTAL-STRUCTURES OF CS-2[CO-2(NTA)(2)(MU-OH)(2)]CENTER-DOT-4H(2)O AND (C10H10N3)(2)[COCL4]

The crystal structure of Cs-2[Co-2(nta)(2)(mu-OH)(2)].4H(2)O (nta = ni trilotriacetate) has been determined from three-dimensional X-ray diff raction data. Two hydroxo groups act as bridging groups between the tw o Co metal centres, The Co-OH bond distances are 1.899(5) and 1.897(5) Angstrom, respectively and the Co-OH-Co bond angles 98.2(2)degrees. T he nta ligand acts as a tetradentate ligand and bonds with a nitrogen as well as three oxygen atoms to the Co metal centre. The Co-N and Co- O-(av) bonds are 1.922(6) and 1.895(5) Angstrom, respectively (C10H10H 3)(2)[CoCl4] consists of discrete monoprotonated 2,2'-iminodipyridiniu m cations and CoCl42- anions. The anions assume a regular tetrahedral geometry, with the Cl-Co-Cl bond angles varying between 107.34(10) and 112.07(10)degrees. The Co-Cl bond distances are 2.270(2) and 2.282(2) Angstrom, respectively. The two pyridine rings in the cation assume a n almost planar orientation with a deviation of 7.7(6)degrees for the dihedral angle between the two ring systems. The planar orientation ca n be attributed to weak hydrogen bonding between the unprotonated nitr ogen atom of the one pyridine ring and the proton bonded to the other nitrogen atom on the adjacent ring. (C) 1997 Elsevier Science Ltd.